version: 1.1.0

src/OcrLiteJni.cpp

+#ifdef __JNI__
+
+#include "version.h"
+#include <jni.h>
+#include "OcrLite.h"
+#include "OcrResultUtils.h"
+#include "OcrUtils.h"
+
+static OcrLite *ocrLite;
+
+JNIEXPORT jint JNICALL
+JNI_OnLoad(JavaVM *vm, void *reserved) {
+    ocrLite = new OcrLite();
+    return JNI_VERSION_1_4;
+}
+
+JNIEXPORT void JNICALL
+JNI_OnUnload(JavaVM *vm, void *reserved) {
+    //printf("JNI_OnUnload\n");
+    delete ocrLite;
+}
+
+#ifdef _WIN32
+char *jstringToChar(JNIEnv *env, jstring jstr) {
+    char *rtn = NULL;
+    jclass clsstring = env->FindClass("java/lang/String");
+    jstring strencode = env->NewStringUTF("gbk");
+    jmethodID mid = env->GetMethodID(clsstring, "getBytes", "(Ljava/lang/String;)[B");
+    jbyteArray barr = (jbyteArray) env->CallObjectMethod(jstr, mid, strencode);
+    jsize alen = env->GetArrayLength(barr);
+    jbyte *ba = env->GetByteArrayElements(barr, JNI_FALSE);
+    if (alen > 0) {
+        rtn = (char *) malloc(alen + 1);
+        memcpy(rtn, ba, alen);
+        rtn[alen] = 0;
+    }
+    env->ReleaseByteArrayElements(barr, ba, 0);
+    return rtn;
+}
+#else
+
+char *jstringToChar(JNIEnv *env, jstring input) {
+    char *str = NULL;
+    jclass clsstring = env->FindClass("java/lang/String");
+    jstring strencode = env->NewStringUTF("utf-8");
+    jmethodID mid = env->GetMethodID(clsstring, "getBytes", "(Ljava/lang/String;)[B");
+    jbyteArray barr = (jbyteArray) env->CallObjectMethod(input, mid, strencode);
+    jsize alen = env->GetArrayLength(barr);
+    jbyte *ba = env->GetByteArrayElements(barr, JNI_FALSE);
+    if (alen > 0) {
+        str = (char *) malloc(alen + 1);
+        memcpy(str, ba, alen);
+        str[alen] = 0;
+    }
+    env->ReleaseByteArrayElements(barr, ba, 0);
+    return str;
+}
+
+#endif
+
+extern "C" JNIEXPORT jstring JNICALL
+Java_com_benjaminwan_ocrlibrary_OcrEngine_getVersion(JNIEnv *env, jobject thiz) {
+    jstring ver = env->NewStringUTF(VERSION);
+    return ver;
+}
+
+extern "C" JNIEXPORT jboolean JNICALL
+Java_com_benjaminwan_ocrlibrary_OcrEngine_setNumThread(JNIEnv *env, jobject thiz, jint numThread) {
+    ocrLite->setNumThread(numThread);
+    printf("numThread=%d\n", numThread);
+    return JNI_TRUE;
+}
+
+extern "C" JNIEXPORT void JNICALL
+Java_com_benjaminwan_ocrlibrary_OcrEngine_initLogger(JNIEnv *env, jobject thiz, jboolean isConsole,
+                                                     jboolean isPartImg, jboolean isResultImg) {
+    ocrLite->initLogger(isConsole,//isOutputConsole
+                        isPartImg,//isOutputPartImg
+                        isResultImg);//isOutputResultImg
+}
+
+extern "C" JNIEXPORT void JNICALL
+Java_com_benjaminwan_ocrlibrary_OcrEngine_enableResultText(JNIEnv *env, jobject thiz, jstring input) {
+    std::string imgPath = jstringToChar(env, input);
+    std::string imgDir = imgPath.substr(0, imgPath.find_last_of('/') + 1);
+    std::string imgName = imgPath.substr(imgPath.find_last_of('/') + 1);
+    ocrLite->enableResultTxt(imgDir.c_str(), imgName.c_str());
+}
+
+extern "C" JNIEXPORT jboolean JNICALL
+Java_com_benjaminwan_ocrlibrary_OcrEngine_initModels(JNIEnv *env, jobject thiz, jstring path,
+                                                     jstring det, jstring cls, jstring rec, jstring keys) {
+    std::string modelsDir = jstringToChar(env, path);
+    std::string detName = jstringToChar(env, det);
+    std::string clsName = jstringToChar(env, cls);
+    std::string recName = jstringToChar(env, rec);
+    std::string keysName = jstringToChar(env, keys);
+    std::string modelDetPath = modelsDir + "/" + detName;
+    std::string modelClsPath = modelsDir + "/" + clsName;
+    std::string modelRecPath = modelsDir + "/" + recName;
+    std::string keysPath = modelsDir + "/" + keysName;
+    printf("modelsDir=%s\ndet=%s\ncls=%s\nrec=%s\nkeys=%s\n", modelsDir.c_str(), detName.c_str(), clsName.c_str(),
+           recName.c_str(), keysName.c_str());
+    bool hasModelDetFile = isFileExists(modelDetPath);
+    if (!hasModelDetFile) {
+        fprintf(stderr, "Model det file not found: %s\n", modelDetPath.c_str());
+        return false;
+    }
+    bool hasModelClsFile = isFileExists(modelClsPath);
+    if (!hasModelClsFile) {
+        fprintf(stderr, "Model cls file not found: %s\n", modelClsPath.c_str());
+        return false;
+    }
+    bool hasModelRecFile = isFileExists(modelRecPath);
+    if (!hasModelRecFile) {
+        fprintf(stderr, "Model rec file not found: %s\n", modelRecPath.c_str());
+        return false;
+    }
+    bool hasKeysFile = isFileExists(keysPath);
+    if (!hasKeysFile) {
+        fprintf(stderr, "keys file not found: %s\n", keysPath.c_str());
+        return false;
+    }
+    ocrLite->initModels(modelDetPath, modelClsPath, modelRecPath, keysPath);
+    return true;
+}
+
+extern "C" JNIEXPORT jobject JNICALL
+Java_com_benjaminwan_ocrlibrary_OcrEngine_detect(JNIEnv *env, jobject thiz, jstring input, jint padding,
+                                                 jint maxSideLen,
+                                                 jfloat boxScoreThresh, jfloat boxThresh, jfloat unClipRatio,
+                                                 jboolean doAngle, jboolean mostAngle
+) {
+    std::string imgPath = jstringToChar(env, input);
+    bool hasTargetImgFile = isFileExists(imgPath);
+    if (!hasTargetImgFile) {
+        fprintf(stderr, "Target image not found: %s\n", imgPath.c_str());
+        OcrResult result{};
+        return OcrResultUtils(env, result).getJObject();
+    }
+    std::string imgDir = imgPath.substr(0, imgPath.find_last_of('/') + 1);
+    std::string imgName = imgPath.substr(imgPath.find_last_of('/') + 1);
+    printf("imgDir=%s, imgName=%s\n", imgDir.c_str(), imgName.c_str());
+    OcrResult result = ocrLite->detect(imgDir.c_str(), imgName.c_str(), padding, maxSideLen,
+                                       boxScoreThresh, boxThresh, unClipRatio, doAngle, mostAngle);
+    return OcrResultUtils(env, result).getJObject();
+}
+#endif
\ No newline at end of file

src/OcrResultUtils.cpp

+#ifdef __JNI__
+#include <OcrUtils.h>
+#include "OcrResultUtils.h"
+
+OcrResultUtils::OcrResultUtils(JNIEnv *env, OcrResult &ocrResult) {
+    jniEnv = env;
+
+    jclass jOcrResultClass = env->FindClass("com/benjaminwan/ocrlibrary/OcrResult");
+
+    if (jOcrResultClass == NULL) {
+        printf("OcrResult class is null\n");
+    }
+
+    jmethodID jOcrResultConstructor = env->GetMethodID(jOcrResultClass, "<init>",
+                                                       "(DLjava/util/ArrayList;DLjava/lang/String;)V");
+
+    jobject textBlocks = getTextBlocks(ocrResult.textBlocks);
+    jdouble dbNetTime = (jdouble) ocrResult.dbNetTime;
+    jdouble detectTime = (jdouble) ocrResult.detectTime;
+    jstring jStrRest = jniEnv->NewStringUTF(ocrResult.strRes.c_str());
+
+    jOcrResult = env->NewObject(jOcrResultClass, jOcrResultConstructor, dbNetTime,
+                                textBlocks, detectTime, jStrRest);
+}
+
+OcrResultUtils::~OcrResultUtils() {
+    jniEnv = NULL;
+}
+
+jobject OcrResultUtils::getJObject() {
+    return jOcrResult;
+}
+
+jclass OcrResultUtils::newJListClass() {
+    jclass clazz = jniEnv->FindClass("java/util/ArrayList");
+    if (clazz == NULL) {
+        printf("ArrayList class is null\n");
+        return NULL;
+    }
+    return clazz;
+}
+
+jmethodID OcrResultUtils::getListConstructor(jclass clazz) {
+    jmethodID constructor = jniEnv->GetMethodID(clazz, "<init>", "()V");
+    return constructor;
+}
+
+jobject OcrResultUtils::newJPoint(cv::Point &point) {
+    jclass clazz = jniEnv->FindClass("com/benjaminwan/ocrlibrary/Point");
+    if (clazz == NULL) {
+        printf("Point class is null\n");
+        return NULL;
+    }
+    jmethodID constructor = jniEnv->GetMethodID(clazz, "<init>", "(II)V");
+    jobject obj = jniEnv->NewObject(clazz, constructor, point.x, point.y);
+    return obj;
+}
+
+jobject OcrResultUtils::newJBoxPoint(std::vector<cv::Point> &boxPoint) {
+    jclass jListClass = newJListClass();
+    jmethodID jListConstructor = getListConstructor(jListClass);
+    jobject jList = jniEnv->NewObject(jListClass, jListConstructor);
+    jmethodID jListAdd = jniEnv->GetMethodID(jListClass, "add", "(Ljava/lang/Object;)Z");
+
+    for (auto point : boxPoint) {
+        jobject jPoint = newJPoint(point);
+        jniEnv->CallBooleanMethod(jList, jListAdd, jPoint);
+    }
+    return jList;
+}
+
+jobject OcrResultUtils::getTextBlock(TextBlock &textBlock) {
+    jobject jBoxPint = newJBoxPoint(textBlock.boxPoint);
+    jfloat jBoxScore = (jfloat) textBlock.boxScore;
+    jfloat jAngleScore = (jfloat) textBlock.angleScore;
+    jdouble jAngleTime = (jdouble) textBlock.angleTime;
+    jstring jText = jniEnv->NewStringUTF(textBlock.text.c_str());
+    jobject jCharScores = newJScoreArray(textBlock.charScores);
+    jdouble jCrnnTime = (jdouble) textBlock.crnnTime;
+    jdouble jBlockTime = (jdouble) textBlock.blockTime;
+    jclass clazz = jniEnv->FindClass("com/benjaminwan/ocrlibrary/TextBlock");
+    if (clazz == NULL) {
+        printf("TextBlock class is null\n");
+        return NULL;
+    }
+    jmethodID constructor = jniEnv->GetMethodID(clazz, "<init>",
+                                                "(Ljava/util/ArrayList;FIFDLjava/lang/String;[FDD)V");
+    jobject obj = jniEnv->NewObject(clazz, constructor, jBoxPint, jBoxScore, textBlock.angleIndex,
+                                    jAngleScore, jAngleTime, jText, jCharScores, jCrnnTime,
+                                    jBlockTime);
+    return obj;
+}
+
+jobject OcrResultUtils::getTextBlocks(std::vector<TextBlock> &textBlocks) {
+    jclass jListClass = newJListClass();
+    jmethodID jListConstructor = getListConstructor(jListClass);
+    jobject jList = jniEnv->NewObject(jListClass, jListConstructor);
+    jmethodID jListAdd = jniEnv->GetMethodID(jListClass, "add", "(Ljava/lang/Object;)Z");
+
+    for (int i = 0; i < textBlocks.size(); ++i) {
+        auto textBlock = textBlocks[i];
+        jobject jTextBlock = getTextBlock(textBlock);
+        jniEnv->CallBooleanMethod(jList, jListAdd, jTextBlock);
+    }
+    return jList;
+}
+
+jfloatArray OcrResultUtils::newJScoreArray(std::vector<float> &scores) {
+    jfloatArray jScores = jniEnv->NewFloatArray(scores.size());
+    jniEnv->SetFloatArrayRegion(jScores, 0, scores.size(), (jfloat *) scores.data());
+    return jScores;
+}
+
+#endif
\ No newline at end of file

src/OcrUtils.cpp

+#include <opencv2/imgproc.hpp>
+#include <opencv2/imgcodecs.hpp>
+#include <numeric>
+#include "OcrUtils.h"
+#include "clipper.hpp"
+
+double getCurrentTime() {
+    return (static_cast<double>(cv::getTickCount())) / cv::getTickFrequency() * 1000;//单位毫秒
+}
+
+//onnxruntime init windows
+std::wstring strToWstr(std::string str) {
+    if (str.length() == 0)
+        return L"";
+    std::wstring wstr;
+    wstr.assign(str.begin(), str.end());
+    return wstr;
+}
+
+ScaleParam getScaleParam(cv::Mat &src, const float scale) {
+    int srcWidth = src.cols;
+    int srcHeight = src.rows;
+    int dstWidth = int((float) srcWidth * scale);
+    int dstHeight = int((float) srcHeight * scale);
+    if (dstWidth % 32 != 0) {
+        dstWidth = (dstWidth / 32 - 1) * 32;
+        dstWidth = (std::max)(dstWidth, 32);
+    }
+    if (dstHeight % 32 != 0) {
+        dstHeight = (dstHeight / 32 - 1) * 32;
+        dstHeight = (std::max)(dstHeight, 32);
+    }
+    float scaleWidth = (float) dstWidth / (float) srcWidth;
+    float scaleHeight = (float) dstHeight / (float) srcHeight;
+    return {srcWidth, srcHeight, dstWidth, dstHeight, scaleWidth, scaleHeight};
+}
+
+ScaleParam getScaleParam(cv::Mat &src, const int targetSize) {
+    int srcWidth, srcHeight, dstWidth, dstHeight;
+    srcWidth = dstWidth = src.cols;
+    srcHeight = dstHeight = src.rows;
+
+    float ratio = 1.f;
+    if (srcWidth > srcHeight) {
+        ratio = float(targetSize) / float(srcWidth);
+    } else {
+        ratio = float(targetSize) / float(srcHeight);
+    }
+    dstWidth = int(float(srcWidth) * ratio);
+    dstHeight = int(float(srcHeight) * ratio);
+    if (dstWidth % 32 != 0) {
+        dstWidth = (dstWidth / 32) * 32;
+        dstWidth = (std::max)(dstWidth, 32);
+    }
+    if (dstHeight % 32 != 0) {
+        dstHeight = (dstHeight / 32) * 32;
+        dstHeight = (std::max)(dstHeight, 32);
+    }
+    float ratioWidth = (float) dstWidth / (float) srcWidth;
+    float ratioHeight = (float) dstHeight / (float) srcHeight;
+    return {srcWidth, srcHeight, dstWidth, dstHeight, ratioWidth, ratioHeight};
+}
+
+std::vector<cv::Point2f> getBox(const cv::RotatedRect &rect) {
+    cv::Point2f vertices[4];
+    rect.points(vertices);
+    //std::vector<cv::Point2f> ret(4);
+    std::vector<cv::Point2f> ret2(vertices, vertices + sizeof(vertices) / sizeof(vertices[0]));
+    //memcpy(vertices, &ret[0], ret.size() * sizeof(ret[0]));
+    return ret2;
+}
+
+int getThickness(cv::Mat &boxImg) {
+    int minSize = boxImg.cols > boxImg.rows ? boxImg.rows : boxImg.cols;
+    int thickness = minSize / 1000 + 2;
+    return thickness;
+}
+
+void drawTextBox(cv::Mat &boxImg, cv::RotatedRect &rect, int thickness) {
+    cv::Point2f vertices[4];
+    rect.points(vertices);
+    for (int i = 0; i < 4; i++)
+        cv::line(boxImg, vertices[i], vertices[(i + 1) % 4], cv::Scalar(0, 0, 255), thickness);
+    //cv::polylines(srcmat, textpoint, true, cv::Scalar(0, 255, 0), 2);
+}
+
+void drawTextBox(cv::Mat &boxImg, const std::vector<cv::Point> &box, int thickness) {
+    auto color = cv::Scalar(0, 0, 255);// B(0) G(0) R(255)
+    cv::line(boxImg, box[0], box[1], color, thickness);
+    cv::line(boxImg, box[1], box[2], color, thickness);
+    cv::line(boxImg, box[2], box[3], color, thickness);
+    cv::line(boxImg, box[3], box[0], color, thickness);
+}
+
+void drawTextBoxes(cv::Mat &boxImg, std::vector<TextBox> &textBoxes, int thickness) {
+    for (int i = 0; i < textBoxes.size(); ++i) {
+        drawTextBox(boxImg, textBoxes[i].boxPoint, thickness);
+    }
+}
+
+cv::Mat matRotateClockWise180(cv::Mat src) {
+    flip(src, src, 0);
+    flip(src, src, 1);
+    return src;
+}
+
+cv::Mat matRotateClockWise90(cv::Mat src) {
+    transpose(src, src);
+    flip(src, src, 1);
+    return src;
+}
+
+cv::Mat getRotateCropImage(const cv::Mat &src, std::vector<cv::Point> box) {
+    cv::Mat image;
+    src.copyTo(image);
+    std::vector<cv::Point> points = box;
+
+    int collectX[4] = {box[0].x, box[1].x, box[2].x, box[3].x};
+    int collectY[4] = {box[0].y, box[1].y, box[2].y, box[3].y};
+    int left = int(*std::min_element(collectX, collectX + 4));
+    int right = int(*std::max_element(collectX, collectX + 4));
+    int top = int(*std::min_element(collectY, collectY + 4));
+    int bottom = int(*std::max_element(collectY, collectY + 4));
+
+    cv::Mat imgCrop;
+    image(cv::Rect(left, top, right - left, bottom - top)).copyTo(imgCrop);
+
+    for (int i = 0; i < points.size(); i++) {
+        points[i].x -= left;
+        points[i].y -= top;
+    }
+
+    int imgCropWidth = int(sqrt(pow(points[0].x - points[1].x, 2) +
+                                pow(points[0].y - points[1].y, 2)));
+    int imgCropHeight = int(sqrt(pow(points[0].x - points[3].x, 2) +
+                                 pow(points[0].y - points[3].y, 2)));
+
+    cv::Point2f ptsDst[4];
+    ptsDst[0] = cv::Point2f(0., 0.);
+    ptsDst[1] = cv::Point2f(imgCropWidth, 0.);
+    ptsDst[2] = cv::Point2f(imgCropWidth, imgCropHeight);
+    ptsDst[3] = cv::Point2f(0.f, imgCropHeight);
+
+    cv::Point2f ptsSrc[4];
+    ptsSrc[0] = cv::Point2f(points[0].x, points[0].y);
+    ptsSrc[1] = cv::Point2f(points[1].x, points[1].y);
+    ptsSrc[2] = cv::Point2f(points[2].x, points[2].y);
+    ptsSrc[3] = cv::Point2f(points[3].x, points[3].y);
+
+    cv::Mat M = cv::getPerspectiveTransform(ptsSrc, ptsDst);
+
+    cv::Mat partImg;
+    cv::warpPerspective(imgCrop, partImg, M,
+                        cv::Size(imgCropWidth, imgCropHeight),
+                        cv::BORDER_REPLICATE);
+
+    if (float(partImg.rows) >= float(partImg.cols) * 1.5) {
+        cv::Mat srcCopy = cv::Mat(partImg.rows, partImg.cols, partImg.depth());
+        cv::transpose(partImg, srcCopy);
+        cv::flip(srcCopy, srcCopy, 0);
+        return srcCopy;
+    } else {
+        return partImg;
+    }
+}
+
+cv::Mat adjustTargetImg(cv::Mat &src, int dstWidth, int dstHeight) {
+    cv::Mat srcResize;
+    float scale = (float) dstHeight / (float) src.rows;
+    int angleWidth = int((float) src.cols * scale);
+    cv::resize(src, srcResize, cv::Size(angleWidth, dstHeight));
+    cv::Mat srcFit = cv::Mat(dstHeight, dstWidth, CV_8UC3, cv::Scalar(255, 255, 255));
+    if (angleWidth < dstWidth) {
+        cv::Rect rect(0, 0, srcResize.cols, srcResize.rows);
+        srcResize.copyTo(srcFit(rect));
+    } else {
+        cv::Rect rect(0, 0, dstWidth, dstHeight);
+        srcResize(rect).copyTo(srcFit);
+    }
+    return srcFit;
+}
+
+bool cvPointCompare(const cv::Point &a, const cv::Point &b) {
+    return a.x < b.x;
+}
+
+std::vector<cv::Point2f> getMinBoxes(const cv::RotatedRect &boxRect, float &maxSideLen) {
+    maxSideLen = std::max(boxRect.size.width, boxRect.size.height);
+    std::vector<cv::Point2f> boxPoint = getBox(boxRect);
+    std::sort(boxPoint.begin(), boxPoint.end(), cvPointCompare);
+    int index1, index2, index3, index4;
+    if (boxPoint[1].y > boxPoint[0].y) {
+        index1 = 0;
+        index4 = 1;
+    } else {
+        index1 = 1;
+        index4 = 0;
+    }
+    if (boxPoint[3].y > boxPoint[2].y) {
+        index2 = 2;
+        index3 = 3;
+    } else {
+        index2 = 3;
+        index3 = 2;
+    }
+    std::vector<cv::Point2f> minBox(4);
+    minBox[0] = boxPoint[index1];
+    minBox[1] = boxPoint[index2];
+    minBox[2] = boxPoint[index3];
+    minBox[3] = boxPoint[index4];
+    return minBox;
+}
+
+float boxScoreFast(const std::vector<cv::Point2f> &boxes, const cv::Mat &pred) {
+    int width = pred.cols;
+    int height = pred.rows;
+
+    float arrayX[4] = {boxes[0].x, boxes[1].x, boxes[2].x, boxes[3].x};
+    float arrayY[4] = {boxes[0].y, boxes[1].y, boxes[2].y, boxes[3].y};
+
+    int minX = clamp(int(std::floor(*(std::min_element(arrayX, arrayX + 4)))), 0, width - 1);
+    int maxX = clamp(int(std::ceil(*(std::max_element(arrayX, arrayX + 4)))), 0, width - 1);
+    int minY = clamp(int(std::floor(*(std::min_element(arrayY, arrayY + 4)))), 0, height - 1);
+    int maxY = clamp(int(std::ceil(*(std::max_element(arrayY, arrayY + 4)))), 0, height - 1);
+
+    cv::Mat mask = cv::Mat::zeros(maxY - minY + 1, maxX - minX + 1, CV_8UC1);
+
+    cv::Point box[4];
+    box[0] = cv::Point(int(boxes[0].x) - minX, int(boxes[0].y) - minY);
+    box[1] = cv::Point(int(boxes[1].x) - minX, int(boxes[1].y) - minY);
+    box[2] = cv::Point(int(boxes[2].x) - minX, int(boxes[2].y) - minY);
+    box[3] = cv::Point(int(boxes[3].x) - minX, int(boxes[3].y) - minY);
+    const cv::Point *pts[1] = {box};
+    int npts[] = {4};
+    cv::fillPoly(mask, pts, npts, 1, cv::Scalar(1));
+
+    cv::Mat croppedImg;
+    pred(cv::Rect(minX, minY, maxX - minX + 1, maxY - minY + 1))
+            .copyTo(croppedImg);
+
+    auto score = cv::mean(croppedImg, mask)[0];
+    return score;
+}
+
+float getContourArea(const std::vector<cv::Point2f> &box, float unClipRatio) {
+    int size = box.size();
+    float area = 0.0f;
+    float dist = 0.0f;
+    for (int i = 0; i < size; i++) {
+        area += box[i].x * box[(i + 1) % size].y -
+                box[i].y * box[(i + 1) % size].x;
+        dist += sqrtf((box[i].x - box[(i + 1) % size].x) *
+                      (box[i].x - box[(i + 1) % size].x) +
+                      (box[i].y - box[(i + 1) % size].y) *
+                      (box[i].y - box[(i + 1) % size].y));
+    }
+    area = fabs(float(area / 2.0));
+
+    return area * unClipRatio / dist;
+}
+
+cv::RotatedRect unClip(std::vector<cv::Point2f> box, float unClipRatio) {
+    float distance = getContourArea(box, unClipRatio);
+
+    ClipperLib::ClipperOffset offset;
+    ClipperLib::Path p;
+    p << ClipperLib::IntPoint(int(box[0].x), int(box[0].y))
+      << ClipperLib::IntPoint(int(box[1].x), int(box[1].y))
+      << ClipperLib::IntPoint(int(box[2].x), int(box[2].y))
+      << ClipperLib::IntPoint(int(box[3].x), int(box[3].y));
+    offset.AddPath(p, ClipperLib::jtRound, ClipperLib::etClosedPolygon);
+
+    ClipperLib::Paths soln;
+    offset.Execute(soln, distance);
+    std::vector<cv::Point2f> points;
+
+    for (int j = 0; j < soln.size(); j++) {
+        for (int i = 0; i < soln[soln.size() - 1].size(); i++) {
+            points.emplace_back(soln[j][i].X, soln[j][i].Y);
+        }
+    }
+    cv::RotatedRect res;
+    if (points.empty()) {
+        res = cv::RotatedRect(cv::Point2f(0, 0), cv::Size2f(1, 1), 0);
+    } else {
+        res = cv::minAreaRect(points);
+    }
+    return res;
+}
+
+std::vector<float> substractMeanNormalize(cv::Mat &src, const float *meanVals, const float *normVals) {
+    auto inputTensorSize = src.cols * src.rows * src.channels();
+    std::vector<float> inputTensorValues(inputTensorSize);
+    size_t numChannels = src.channels();
+    size_t imageSize = src.cols * src.rows;
+
+    for (size_t pid = 0; pid < imageSize; pid++) {
+        for (size_t ch = 0; ch < numChannels; ++ch) {
+            float data = (float) (src.data[pid * numChannels + ch] * normVals[ch] - meanVals[ch] * normVals[ch]);
+            inputTensorValues[ch * imageSize + pid] = data;
+        }
+    }
+    return inputTensorValues;
+}
+
+std::vector<int> getAngleIndexes(std::vector<Angle> &angles) {
+    std::vector<int> angleIndexes;
+    angleIndexes.reserve(angles.size());
+    for (int i = 0; i < angles.size(); ++i) {
+        angleIndexes.push_back(angles[i].index);
+    }
+    return angleIndexes;
+}
+
+std::vector<char *> getInputNames(Ort::Session *session) {
+    Ort::AllocatorWithDefaultOptions allocator;
+    size_t numInputNodes = session->GetInputCount();
+    std::vector<char *> inputNodeNames(numInputNodes);
+    //std::vector<int64_t> inputNodeDims;
+
+    //printf("Number of inputs = %zu\n", numInputNodes);
+
+    for (int i = 0; i < numInputNodes; i++) {
+        // print input node names
+        char *inputName = session->GetInputName(i, allocator);
+        //printf("InputName[%d]=%s\n", i, inputName);
+        inputNodeNames[i] = inputName;
+
+        // print input node types
+        //Ort::TypeInfo typeInfo = session->GetInputTypeInfo(i);
+        //auto tensorInfo = typeInfo.GetTensorTypeAndShapeInfo();
+
+        //ONNXTensorElementDataType type = tensorInfo.GetElementType();
+        //printf("Input[%d] type=%d\n", i, type);
+
+        // print input shapes/dims
+        //inputNodeDims = tensorInfo.GetShape();
+        //printf("Input[%d] num_dims=%zu\n", i, inputNodeDims.size());
+        /*for (int j = 0; j < inputNodeDims.size(); j++)
+            printf("Input[%d] dim%d=%jd\n", i, j, inputNodeDims[j]);*/
+    }
+    return inputNodeNames;
+}
+
+std::vector<char *> getOutputNames(Ort::Session *session) {
+    Ort::AllocatorWithDefaultOptions allocator;
+    size_t numOutputNodes = session->GetOutputCount();
+    std::vector<char *> outputNodeNames(numOutputNodes);
+    //std::vector<int64_t> outputNodeDims;
+
+    //printf("Number of outputs = %zu\n", numOutputNodes);
+
+    for (int i = 0; i < numOutputNodes; i++) {
+        // print input node names
+        char *outputName = session->GetOutputName(i, allocator);
+        //printf("OutputName[%d]=%s\n", i, outputName);
+        outputNodeNames[i] = outputName;
+
+        // print input node types
+        //Ort::TypeInfo type_info = session->GetOutputTypeInfo(i);
+        //auto tensorInfo = type_info.GetTensorTypeAndShapeInfo();
+
+        //ONNXTensorElementDataType type = tensorInfo.GetElementType();
+        //printf("Output %d : type=%d\n", i, type);
+
+        // print input shapes/dims
+        //outputNodeDims = tensorInfo.GetShape();
+        //printf("Output %d : num_dims=%zu\n", i, outputNodeDims.size());
+        /*for (int j = 0; j < outputNodeDims.size(); j++)
+            printf("Output %d : dim %d=%jd\n", i, j, outputNodeDims[j]);*/
+    }
+    return outputNodeNames;
+}
+
+void saveImg(cv::Mat &img, const char *imgPath) {
+    cv::imwrite(imgPath, img);
+}
+
+std::string getSrcImgFilePath(const char *path, const char *imgName) {
+    std::string filePath;
+    filePath.append(path).append(imgName);
+    return filePath;
+}
+
+std::string getResultTxtFilePath(const char *path, const char *imgName) {
+    std::string filePath;
+    filePath.append(path).append(imgName).append("-result.txt");
+    return filePath;
+}
+
+std::string getResultImgFilePath(const char *path, const char *imgName) {
+    std::string filePath;
+    filePath.append(path).append(imgName).append("-result.jpg");
+    return filePath;
+}
+
+std::string getDebugImgFilePath(const char *path, const char *imgName, int i, const char *tag) {
+    std::string filePath;
+    filePath.append(path).append(imgName).append(tag).append(std::to_string(i)).append(".jpg");
+    return filePath;
+}
\ No newline at end of file

src/clipper.cpp

+/*******************************************************************************
+*                                                                              *
+* Author    :  Angus Johnson                                                   *
+* Version   :  6.4.2                                                           *
+* Date      :  27 February 2017                                                *
+* Website   :  http://www.angusj.com                                           *
+* Copyright :  Angus Johnson 2010-2017                                         *
+*                                                                              *
+* License:                                                                     *
+* Use, modification & distribution is subject to Boost Software License Ver 1. *
+* http://www.boost.org/LICENSE_1_0.txt                                         *
+*                                                                              *
+* Attributions:                                                                *
+* The code in this library is an extension of Bala Vatti's clipping algorithm: *
+* "A generic solution to polygon clipping"                                     *
+* Communications of the ACM, Vol 35, Issue 7 (July 1992) pp 56-63.             *
+* http://portal.acm.org/citation.cfm?id=129906                                 *
+*                                                                              *
+* Computer graphics and geometric modeling: implementation and algorithms      *
+* By Max K. Agoston                                                            *
+* Springer; 1 edition (January 4, 2005)                                        *
+* http://books.google.com/books?q=vatti+clipping+agoston                       *
+*                                                                              *
+* See also:                                                                    *
+* "Polygon Offsetting by Computing Winding Numbers"                            *
+* Paper no. DETC2005-85513 pp. 565-575                                         *
+* ASME 2005 International Design Engineering Technical Conferences             *
+* and Computers and Information in Engineering Conference (IDETC/CIE2005)      *
+* September 24-28, 2005 , Long Beach, California, USA                          *
+* http://www.me.berkeley.edu/~mcmains/pubs/DAC05OffsetPolygon.pdf              *
+*                                                                              *
+*******************************************************************************/
+
+/*******************************************************************************
+*                                                                              *
+* This is a translation of the Delphi Clipper library and the naming style     *
+* used has retained a Delphi flavour.                                          *
+*                                                                              *
+*******************************************************************************/
+
+#include "clipper.hpp"
+#include <cmath>
+#include <vector>
+#include <algorithm>
+#include <stdexcept>
+#include <cstring>
+#include <cstdlib>
+#include <ostream>
+#include <functional>
+
+namespace ClipperLib {
+
+    static double const pi = 3.141592653589793238;
+    static double const two_pi = pi *2;
+    static double const def_arc_tolerance = 0.25;
+
+    enum Direction { dRightToLeft, dLeftToRight };
+
+    static int const Unassigned = -1;  //edge not currently 'owning' a solution
+    static int const Skip = -2;        //edge that would otherwise close a path
+
+#define HORIZONTAL (-1.0E+40)
+#define TOLERANCE (1.0e-20)
+#define NEAR_ZERO(val) (((val) > -TOLERANCE) && ((val) < TOLERANCE))
+
+    struct TEdge {
+        IntPoint Bot;
+        IntPoint Curr; //current (updated for every new scanbeam)
+        IntPoint Top;
+        double Dx;
+        PolyType PolyTyp;
+        EdgeSide Side; //side only refers to current side of solution poly
+        int WindDelta; //1 or -1 depending on winding direction
+        int WindCnt;
+        int WindCnt2; //winding count of the opposite polytype
+        int OutIdx;
+        TEdge *Next;
+        TEdge *Prev;
+        TEdge *NextInLML;
+        TEdge *NextInAEL;
+        TEdge *PrevInAEL;
+        TEdge *NextInSEL;
+        TEdge *PrevInSEL;
+    };
+
+    struct IntersectNode {
+        TEdge          *Edge1;
+        TEdge          *Edge2;
+        IntPoint        Pt;
+    };
+
+    struct LocalMinimum {
+        cInt          Y;
+        TEdge        *LeftBound;
+        TEdge        *RightBound;
+    };
+
+    struct OutPt;
+
+//OutRec: contains a path in the clipping solution. Edges in the AEL will
+//carry a pointer to an OutRec when they are part of the clipping solution.
+    struct OutRec {
+        int       Idx;
+        bool      IsHole;
+        bool      IsOpen;
+        OutRec   *FirstLeft;  //see comments in clipper.pas
+        PolyNode *PolyNd;
+        OutPt    *Pts;
+        OutPt    *BottomPt;
+    };
+
+    struct OutPt {
+        int       Idx;
+        IntPoint  Pt;
+        OutPt    *Next;
+        OutPt    *Prev;
+    };
+
+    struct Join {
+        OutPt    *OutPt1;
+        OutPt    *OutPt2;
+        IntPoint  OffPt;
+    };
+
+    struct LocMinSorter
+    {
+        inline bool operator()(const LocalMinimum& locMin1, const LocalMinimum& locMin2)
+        {
+            return locMin2.Y < locMin1.Y;
+        }
+    };
+
+//------------------------------------------------------------------------------
+//------------------------------------------------------------------------------
+
+    inline cInt Round(double val)
+    {
+        if ((val < 0)) return static_cast<cInt>(val - 0.5);
+        else return static_cast<cInt>(val + 0.5);
+    }
+//------------------------------------------------------------------------------
+
+    inline cInt Abs(cInt val)
+    {
+        return val < 0 ? -val : val;
+    }
+
+//------------------------------------------------------------------------------
+// PolyTree methods ...
+//------------------------------------------------------------------------------
+
+    void PolyTree::Clear()
+    {
+        for (PolyNodes::size_type i = 0; i < AllNodes.size(); ++i)
+            delete AllNodes[i];
+        AllNodes.resize(0);
+        Childs.resize(0);
+    }
+//------------------------------------------------------------------------------
+
+    PolyNode* PolyTree::GetFirst() const
+    {
+        if (!Childs.empty())
+            return Childs[0];
+        else
+            return 0;
+    }
+//------------------------------------------------------------------------------
+
+    int PolyTree::Total() const
+    {
+        int result = (int)AllNodes.size();
+        //with negative offsets, ignore the hidden outer polygon ...
+        if (result > 0 && Childs[0] != AllNodes[0]) result--;
+        return result;
+    }
+
+//------------------------------------------------------------------------------
+// PolyNode methods ...
+//------------------------------------------------------------------------------
+
+    PolyNode::PolyNode(): Parent(0), Index(0), m_IsOpen(false)
+    {
+    }
+//------------------------------------------------------------------------------
+
+    int PolyNode::ChildCount() const
+    {
+        return (int)Childs.size();
+    }
+//------------------------------------------------------------------------------
+
+    void PolyNode::AddChild(PolyNode& child)
+    {
+        unsigned cnt = (unsigned)Childs.size();
+        Childs.push_back(&child);
+        child.Parent = this;
+        child.Index = cnt;
+    }
+//------------------------------------------------------------------------------
+
+    PolyNode* PolyNode::GetNext() const
+    {
+        if (!Childs.empty())
+            return Childs[0];
+        else
+            return GetNextSiblingUp();
+    }
+//------------------------------------------------------------------------------
+
+    PolyNode* PolyNode::GetNextSiblingUp() const
+    {
+        if (!Parent) //protects against PolyTree.GetNextSiblingUp()
+            return 0;
+        else if (Index == Parent->Childs.size() - 1)
+            return Parent->GetNextSiblingUp();
+        else
+            return Parent->Childs[Index + 1];
+    }
+//------------------------------------------------------------------------------
+
+    bool PolyNode::IsHole() const
+    {
+        bool result = true;
+        PolyNode* node = Parent;
+        while (node)
+        {
+            result = !result;
+            node = node->Parent;
+        }
+        return result;
+    }
+//------------------------------------------------------------------------------
+
+    bool PolyNode::IsOpen() const
+    {
+        return m_IsOpen;
+    }
+//------------------------------------------------------------------------------
+
+#ifndef use_int32
+
+//------------------------------------------------------------------------------
+// Int128 class (enables safe math on signed 64bit integers)
+// eg Int128 val1((long64)9223372036854775807); //ie 2^63 -1
+//    Int128 val2((long64)9223372036854775807);
+//    Int128 val3 = val1 * val2;
+//    val3.AsString => "85070591730234615847396907784232501249" (8.5e+37)
+//------------------------------------------------------------------------------
+
+    class Int128
+    {
+    public:
+        ulong64 lo;
+        long64 hi;
+
+        Int128(long64 _lo = 0)
+        {
+            lo = (ulong64)_lo;
+            if (_lo < 0)  hi = -1; else hi = 0;
+        }
+
+
+        Int128(const Int128 &val): lo(val.lo), hi(val.hi){}
+
+        Int128(const long64& _hi, const ulong64& _lo): lo(_lo), hi(_hi){}
+
+        Int128& operator = (const long64 &val)
+        {
+            lo = (ulong64)val;
+            if (val < 0) hi = -1; else hi = 0;
+            return *this;
+        }
+
+        bool operator == (const Int128 &val) const
+        {return (hi == val.hi && lo == val.lo);}
+
+        bool operator != (const Int128 &val) const
+        { return !(*this == val);}
+
+        bool operator > (const Int128 &val) const
+        {
+            if (hi != val.hi)
+                return hi > val.hi;
+            else
+                return lo > val.lo;
+        }
+
+        bool operator < (const Int128 &val) const
+        {
+            if (hi != val.hi)
+                return hi < val.hi;
+            else
+                return lo < val.lo;
+        }
+
+        bool operator >= (const Int128 &val) const
+        { return !(*this < val);}
+
+        bool operator <= (const Int128 &val) const
+        { return !(*this > val);}
+
+        Int128& operator += (const Int128 &rhs)
+        {
+            hi += rhs.hi;
+            lo += rhs.lo;
+            if (lo < rhs.lo) hi++;
+            return *this;
+        }
+
+        Int128 operator + (const Int128 &rhs) const
+        {
+            Int128 result(*this);
+            result+= rhs;
+            return result;
+        }
+
+        Int128& operator -= (const Int128 &rhs)
+        {
+            *this += -rhs;
+            return *this;
+        }
+
+        Int128 operator - (const Int128 &rhs) const
+        {
+            Int128 result(*this);
+            result -= rhs;
+            return result;
+        }
+
+        Int128 operator-() const //unary negation
+        {
+            if (lo == 0)
+                return Int128(-hi, 0);
+            else
+                return Int128(~hi, ~lo + 1);
+        }
+
+        operator double() const
+        {
+            const double shift64 = 18446744073709551616.0; //2^64
+            if (hi < 0)
+            {
+                if (lo == 0) return (double)hi * shift64;
+                else return -(double)(~lo + ~hi * shift64);
+            }
+            else
+                return (double)(lo + hi * shift64);
+        }
+
+    };
+//------------------------------------------------------------------------------
+
+    Int128 Int128Mul (long64 lhs, long64 rhs)
+    {
+        bool negate = (lhs < 0) != (rhs < 0);
+
+        if (lhs < 0) lhs = -lhs;
+        ulong64 int1Hi = ulong64(lhs) >> 32;
+        ulong64 int1Lo = ulong64(lhs & 0xFFFFFFFF);
+
+        if (rhs < 0) rhs = -rhs;
+        ulong64 int2Hi = ulong64(rhs) >> 32;
+        ulong64 int2Lo = ulong64(rhs & 0xFFFFFFFF);
+
+        //nb: see comments in clipper.pas
+        ulong64 a = int1Hi * int2Hi;
+        ulong64 b = int1Lo * int2Lo;
+        ulong64 c = int1Hi * int2Lo + int1Lo * int2Hi;
+
+        Int128 tmp;
+        tmp.hi = long64(a + (c >> 32));
+        tmp.lo = long64(c << 32);
+        tmp.lo += long64(b);
+        if (tmp.lo < b) tmp.hi++;
+        if (negate) tmp = -tmp;
+        return tmp;
+    };
+#endif
+
+//------------------------------------------------------------------------------
+// Miscellaneous global functions
+//------------------------------------------------------------------------------
+
+    bool Orientation(const Path &poly)
+    {
+        return Area(poly) >= 0;
+    }
+//------------------------------------------------------------------------------
+
+    double Area(const Path &poly)
+    {
+        int size = (int)poly.size();
+        if (size < 3) return 0;
+
+        double a = 0;
+        for (int i = 0, j = size -1; i < size; ++i)
+        {
+            a += ((double)poly[j].X + poly[i].X) * ((double)poly[j].Y - poly[i].Y);
+            j = i;
+        }
+        return -a * 0.5;
+    }
+//------------------------------------------------------------------------------
+
+    double Area(const OutPt *op)
+    {
+        const OutPt *startOp = op;
+        if (!op) return 0;
+        double a = 0;
+        do {
+            a +=  (double)(op->Prev->Pt.X + op->Pt.X) * (double)(op->Prev->Pt.Y - op->Pt.Y);
+            op = op->Next;
+        } while (op != startOp);
+        return a * 0.5;
+    }
+//------------------------------------------------------------------------------
+
+    double Area(const OutRec &outRec)
+    {
+        return Area(outRec.Pts);
+    }
+//------------------------------------------------------------------------------
+
+    bool PointIsVertex(const IntPoint &Pt, OutPt *pp)
+    {
+        OutPt *pp2 = pp;
+        do
+        {
+            if (pp2->Pt == Pt) return true;
+            pp2 = pp2->Next;
+        }
+        while (pp2 != pp);
+        return false;
+    }
+//------------------------------------------------------------------------------
+
+//See "The Point in Polygon Problem for Arbitrary Polygons" by Hormann & Agathos
+//http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.88.5498&rep=rep1&type=pdf
+    int PointInPolygon(const IntPoint &pt, const Path &path)
+    {
+        //returns 0 if false, +1 if true, -1 if pt ON polygon boundary
+        int result = 0;
+        size_t cnt = path.size();
+        if (cnt < 3) return 0;
+        IntPoint ip = path[0];
+        for(size_t i = 1; i <= cnt; ++i)
+        {
+            IntPoint ipNext = (i == cnt ? path[0] : path[i]);
+            if (ipNext.Y == pt.Y)
+            {
+                if ((ipNext.X == pt.X) || (ip.Y == pt.Y &&
+                                           ((ipNext.X > pt.X) == (ip.X < pt.X)))) return -1;
+            }
+            if ((ip.Y < pt.Y) != (ipNext.Y < pt.Y))
+            {
+                if (ip.X >= pt.X)
+                {
+                    if (ipNext.X > pt.X) result = 1 - result;
+                    else
+                    {
+                        double d = (double)(ip.X - pt.X) * (ipNext.Y - pt.Y) -
+                                   (double)(ipNext.X - pt.X) * (ip.Y - pt.Y);
+                        if (!d) return -1;
+                        if ((d > 0) == (ipNext.Y > ip.Y)) result = 1 - result;
+                    }
+                } else
+                {
+                    if (ipNext.X > pt.X)
+                    {
+                        double d = (double)(ip.X - pt.X) * (ipNext.Y - pt.Y) -
+                                   (double)(ipNext.X - pt.X) * (ip.Y - pt.Y);
+                        if (!d) return -1;
+                        if ((d > 0) == (ipNext.Y > ip.Y)) result = 1 - result;
+                    }
+                }
+            }
+            ip = ipNext;
+        }
+        return result;
+    }
+//------------------------------------------------------------------------------
+
+    int PointInPolygon (const IntPoint &pt, OutPt *op)
+    {
+        //returns 0 if false, +1 if true, -1 if pt ON polygon boundary
+        int result = 0;
+        OutPt* startOp = op;
+        for(;;)
+        {
+            if (op->Next->Pt.Y == pt.Y)
+            {
+                if ((op->Next->Pt.X == pt.X) || (op->Pt.Y == pt.Y &&
+                                                 ((op->Next->Pt.X > pt.X) == (op->Pt.X < pt.X)))) return -1;
+            }
+            if ((op->Pt.Y < pt.Y) != (op->Next->Pt.Y < pt.Y))
+            {
+                if (op->Pt.X >= pt.X)
+                {
+                    if (op->Next->Pt.X > pt.X) result = 1 - result;
+                    else
+                    {
+                        double d = (double)(op->Pt.X - pt.X) * (op->Next->Pt.Y - pt.Y) -
+                                   (double)(op->Next->Pt.X - pt.X) * (op->Pt.Y - pt.Y);
+                        if (!d) return -1;
+                        if ((d > 0) == (op->Next->Pt.Y > op->Pt.Y)) result = 1 - result;
+                    }
+                } else
+                {
+                    if (op->Next->Pt.X > pt.X)
+                    {
+                        double d = (double)(op->Pt.X - pt.X) * (op->Next->Pt.Y - pt.Y) -
+                                   (double)(op->Next->Pt.X - pt.X) * (op->Pt.Y - pt.Y);
+                        if (!d) return -1;
+                        if ((d > 0) == (op->Next->Pt.Y > op->Pt.Y)) result = 1 - result;
+                    }
+                }
+            }
+            op = op->Next;
+            if (startOp == op) break;
+        }
+        return result;
+    }
+//------------------------------------------------------------------------------
+
+    bool Poly2ContainsPoly1(OutPt *OutPt1, OutPt *OutPt2)
+    {
+        OutPt* op = OutPt1;
+        do
+        {
+            //nb: PointInPolygon returns 0 if false, +1 if true, -1 if pt on polygon
+            int res = PointInPolygon(op->Pt, OutPt2);
+            if (res >= 0) return res > 0;
+            op = op->Next;
+        }
+        while (op != OutPt1);
+        return true;
+    }
+//----------------------------------------------------------------------
+
+    bool SlopesEqual(const TEdge &e1, const TEdge &e2, bool UseFullInt64Range)
+    {
+#ifndef use_int32
+        if (UseFullInt64Range)
+            return Int128Mul(e1.Top.Y - e1.Bot.Y, e2.Top.X - e2.Bot.X) ==
+                   Int128Mul(e1.Top.X - e1.Bot.X, e2.Top.Y - e2.Bot.Y);
+        else
+#endif
+            return (e1.Top.Y - e1.Bot.Y) * (e2.Top.X - e2.Bot.X) ==
+                   (e1.Top.X - e1.Bot.X) * (e2.Top.Y - e2.Bot.Y);
+    }
+//------------------------------------------------------------------------------
+
+    bool SlopesEqual(const IntPoint pt1, const IntPoint pt2,
+                     const IntPoint pt3, bool UseFullInt64Range)
+    {
+#ifndef use_int32
+        if (UseFullInt64Range)
+            return Int128Mul(pt1.Y-pt2.Y, pt2.X-pt3.X) == Int128Mul(pt1.X-pt2.X, pt2.Y-pt3.Y);
+        else
+#endif
+            return (pt1.Y-pt2.Y)*(pt2.X-pt3.X) == (pt1.X-pt2.X)*(pt2.Y-pt3.Y);
+    }
+//------------------------------------------------------------------------------
+
+    bool SlopesEqual(const IntPoint pt1, const IntPoint pt2,
+                     const IntPoint pt3, const IntPoint pt4, bool UseFullInt64Range)
+    {
+#ifndef use_int32
+        if (UseFullInt64Range)
+            return Int128Mul(pt1.Y-pt2.Y, pt3.X-pt4.X) == Int128Mul(pt1.X-pt2.X, pt3.Y-pt4.Y);
+        else
+#endif
+            return (pt1.Y-pt2.Y)*(pt3.X-pt4.X) == (pt1.X-pt2.X)*(pt3.Y-pt4.Y);
+    }
+//------------------------------------------------------------------------------
+
+    inline bool IsHorizontal(TEdge &e)
+    {
+        return e.Dx == HORIZONTAL;
+    }
+//------------------------------------------------------------------------------
+
+    inline double GetDx(const IntPoint pt1, const IntPoint pt2)
+    {
+        return (pt1.Y == pt2.Y) ?
+               HORIZONTAL : (double)(pt2.X - pt1.X) / (pt2.Y - pt1.Y);
+    }
+//---------------------------------------------------------------------------
+
+    inline void SetDx(TEdge &e)
+    {
+        cInt dy  = (e.Top.Y - e.Bot.Y);
+        if (dy == 0) e.Dx = HORIZONTAL;
+        else e.Dx = (double)(e.Top.X - e.Bot.X) / dy;
+    }
+//---------------------------------------------------------------------------
+
+    inline void SwapSides(TEdge &Edge1, TEdge &Edge2)
+    {
+        EdgeSide Side =  Edge1.Side;
+        Edge1.Side = Edge2.Side;
+        Edge2.Side = Side;
+    }
+//------------------------------------------------------------------------------
+
+    inline void SwapPolyIndexes(TEdge &Edge1, TEdge &Edge2)
+    {
+        int OutIdx =  Edge1.OutIdx;
+        Edge1.OutIdx = Edge2.OutIdx;
+        Edge2.OutIdx = OutIdx;
+    }
+//------------------------------------------------------------------------------
+
+    inline cInt TopX(TEdge &edge, const cInt currentY)
+    {
+        return ( currentY == edge.Top.Y ) ?
+               edge.Top.X : edge.Bot.X + Round(edge.Dx *(currentY - edge.Bot.Y));
+    }
+//------------------------------------------------------------------------------
+
+    void IntersectPoint(TEdge &Edge1, TEdge &Edge2, IntPoint &ip)
+    {
+#ifdef use_xyz
+        ip.Z = 0;
+#endif
+
+        double b1, b2;
+        if (Edge1.Dx == Edge2.Dx)
+        {
+            ip.Y = Edge1.Curr.Y;
+            ip.X = TopX(Edge1, ip.Y);
+            return;
+        }
+        else if (Edge1.Dx == 0)
+        {
+            ip.X = Edge1.Bot.X;
+            if (IsHorizontal(Edge2))
+                ip.Y = Edge2.Bot.Y;
+            else
+            {
+                b2 = Edge2.Bot.Y - (Edge2.Bot.X / Edge2.Dx);
+                ip.Y = Round(ip.X / Edge2.Dx + b2);
+            }
+        }
+        else if (Edge2.Dx == 0)
+        {
+            ip.X = Edge2.Bot.X;
+            if (IsHorizontal(Edge1))
+                ip.Y = Edge1.Bot.Y;
+            else
+            {
+                b1 = Edge1.Bot.Y - (Edge1.Bot.X / Edge1.Dx);
+                ip.Y = Round(ip.X / Edge1.Dx + b1);
+            }
+        }
+        else
+        {
+            b1 = Edge1.Bot.X - Edge1.Bot.Y * Edge1.Dx;
+            b2 = Edge2.Bot.X - Edge2.Bot.Y * Edge2.Dx;
+            double q = (b2-b1) / (Edge1.Dx - Edge2.Dx);
+            ip.Y = Round(q);
+            if (std::fabs(Edge1.Dx) < std::fabs(Edge2.Dx))
+                ip.X = Round(Edge1.Dx * q + b1);
+            else
+                ip.X = Round(Edge2.Dx * q + b2);
+        }
+
+        if (ip.Y < Edge1.Top.Y || ip.Y < Edge2.Top.Y)
+        {
+            if (Edge1.Top.Y > Edge2.Top.Y)
+                ip.Y = Edge1.Top.Y;
+            else
+                ip.Y = Edge2.Top.Y;
+            if (std::fabs(Edge1.Dx) < std::fabs(Edge2.Dx))
+                ip.X = TopX(Edge1, ip.Y);
+            else
+                ip.X = TopX(Edge2, ip.Y);
+        }
+        //finally, don't allow 'ip' to be BELOW curr.Y (ie bottom of scanbeam) ...
+        if (ip.Y > Edge1.Curr.Y)
+        {
+            ip.Y = Edge1.Curr.Y;
+            //use the more vertical edge to derive X ...
+            if (std::fabs(Edge1.Dx) > std::fabs(Edge2.Dx))
+                ip.X = TopX(Edge2, ip.Y); else
+                ip.X = TopX(Edge1, ip.Y);
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void ReversePolyPtLinks(OutPt *pp)
+    {
+        if (!pp) return;
+        OutPt *pp1, *pp2;
+        pp1 = pp;
+        do {
+            pp2 = pp1->Next;
+            pp1->Next = pp1->Prev;
+            pp1->Prev = pp2;
+            pp1 = pp2;
+        } while( pp1 != pp );
+    }
+//------------------------------------------------------------------------------
+
+    void DisposeOutPts(OutPt*& pp)
+    {
+        if (pp == 0) return;
+        pp->Prev->Next = 0;
+        while( pp )
+        {
+            OutPt *tmpPp = pp;
+            pp = pp->Next;
+            delete tmpPp;
+        }
+    }
+//------------------------------------------------------------------------------
+
+    inline void InitEdge(TEdge* e, TEdge* eNext, TEdge* ePrev, const IntPoint& Pt)
+    {
+        std::memset(e, 0, sizeof(TEdge));
+        e->Next = eNext;
+        e->Prev = ePrev;
+        e->Curr = Pt;
+        e->OutIdx = Unassigned;
+    }
+//------------------------------------------------------------------------------
+
+    void InitEdge2(TEdge& e, PolyType Pt)
+    {
+        if (e.Curr.Y >= e.Next->Curr.Y)
+        {
+            e.Bot = e.Curr;
+            e.Top = e.Next->Curr;
+        } else
+        {
+            e.Top = e.Curr;
+            e.Bot = e.Next->Curr;
+        }
+        SetDx(e);
+        e.PolyTyp = Pt;
+    }
+//------------------------------------------------------------------------------
+
+    TEdge* RemoveEdge(TEdge* e)
+    {
+        //removes e from double_linked_list (but without removing from memory)
+        e->Prev->Next = e->Next;
+        e->Next->Prev = e->Prev;
+        TEdge* result = e->Next;
+        e->Prev = 0; //flag as removed (see ClipperBase.Clear)
+        return result;
+    }
+//------------------------------------------------------------------------------
+
+    inline void ReverseHorizontal(TEdge &e)
+    {
+        //swap horizontal edges' Top and Bottom x's so they follow the natural
+        //progression of the bounds - ie so their xbots will align with the
+        //adjoining lower edge. [Helpful in the ProcessHorizontal() method.]
+        std::swap(e.Top.X, e.Bot.X);
+#ifdef use_xyz
+        std::swap(e.Top.Z, e.Bot.Z);
+#endif
+    }
+//------------------------------------------------------------------------------
+
+    void SwapPoints(IntPoint &pt1, IntPoint &pt2)
+    {
+        IntPoint tmp = pt1;
+        pt1 = pt2;
+        pt2 = tmp;
+    }
+//------------------------------------------------------------------------------
+
+    bool GetOverlapSegment(IntPoint pt1a, IntPoint pt1b, IntPoint pt2a,
+                           IntPoint pt2b, IntPoint &pt1, IntPoint &pt2)
+    {
+        //precondition: segments are Collinear.
+        if (Abs(pt1a.X - pt1b.X) > Abs(pt1a.Y - pt1b.Y))
+        {
+            if (pt1a.X > pt1b.X) SwapPoints(pt1a, pt1b);
+            if (pt2a.X > pt2b.X) SwapPoints(pt2a, pt2b);
+            if (pt1a.X > pt2a.X) pt1 = pt1a; else pt1 = pt2a;
+            if (pt1b.X < pt2b.X) pt2 = pt1b; else pt2 = pt2b;
+            return pt1.X < pt2.X;
+        } else
+        {
+            if (pt1a.Y < pt1b.Y) SwapPoints(pt1a, pt1b);
+            if (pt2a.Y < pt2b.Y) SwapPoints(pt2a, pt2b);
+            if (pt1a.Y < pt2a.Y) pt1 = pt1a; else pt1 = pt2a;
+            if (pt1b.Y > pt2b.Y) pt2 = pt1b; else pt2 = pt2b;
+            return pt1.Y > pt2.Y;
+        }
+    }
+//------------------------------------------------------------------------------
+
+    bool FirstIsBottomPt(const OutPt* btmPt1, const OutPt* btmPt2)
+    {
+        OutPt *p = btmPt1->Prev;
+        while ((p->Pt == btmPt1->Pt) && (p != btmPt1)) p = p->Prev;
+        double dx1p = std::fabs(GetDx(btmPt1->Pt, p->Pt));
+        p = btmPt1->Next;
+        while ((p->Pt == btmPt1->Pt) && (p != btmPt1)) p = p->Next;
+        double dx1n = std::fabs(GetDx(btmPt1->Pt, p->Pt));
+
+        p = btmPt2->Prev;
+        while ((p->Pt == btmPt2->Pt) && (p != btmPt2)) p = p->Prev;
+        double dx2p = std::fabs(GetDx(btmPt2->Pt, p->Pt));
+        p = btmPt2->Next;
+        while ((p->Pt == btmPt2->Pt) && (p != btmPt2)) p = p->Next;
+        double dx2n = std::fabs(GetDx(btmPt2->Pt, p->Pt));
+
+        if (std::max(dx1p, dx1n) == std::max(dx2p, dx2n) &&
+            std::min(dx1p, dx1n) == std::min(dx2p, dx2n))
+            return Area(btmPt1) > 0; //if otherwise identical use orientation
+        else
+            return (dx1p >= dx2p && dx1p >= dx2n) || (dx1n >= dx2p && dx1n >= dx2n);
+    }
+//------------------------------------------------------------------------------
+
+    OutPt* GetBottomPt(OutPt *pp)
+    {
+        OutPt* dups = 0;
+        OutPt* p = pp->Next;
+        while (p != pp)
+        {
+            if (p->Pt.Y > pp->Pt.Y)
+            {
+                pp = p;
+                dups = 0;
+            }
+            else if (p->Pt.Y == pp->Pt.Y && p->Pt.X <= pp->Pt.X)
+            {
+                if (p->Pt.X < pp->Pt.X)
+                {
+                    dups = 0;
+                    pp = p;
+                } else
+                {
+                    if (p->Next != pp && p->Prev != pp) dups = p;
+                }
+            }
+            p = p->Next;
+        }
+        if (dups)
+        {
+            //there appears to be at least 2 vertices at BottomPt so ...
+            while (dups != p)
+            {
+                if (!FirstIsBottomPt(p, dups)) pp = dups;
+                dups = dups->Next;
+                while (dups->Pt != pp->Pt) dups = dups->Next;
+            }
+        }
+        return pp;
+    }
+//------------------------------------------------------------------------------
+
+    bool Pt2IsBetweenPt1AndPt3(const IntPoint pt1,
+                               const IntPoint pt2, const IntPoint pt3)
+    {
+        if ((pt1 == pt3) || (pt1 == pt2) || (pt3 == pt2))
+            return false;
+        else if (pt1.X != pt3.X)
+            return (pt2.X > pt1.X) == (pt2.X < pt3.X);
+        else
+            return (pt2.Y > pt1.Y) == (pt2.Y < pt3.Y);
+    }
+//------------------------------------------------------------------------------
+
+    bool HorzSegmentsOverlap(cInt seg1a, cInt seg1b, cInt seg2a, cInt seg2b)
+    {
+        if (seg1a > seg1b) std::swap(seg1a, seg1b);
+        if (seg2a > seg2b) std::swap(seg2a, seg2b);
+        return (seg1a < seg2b) && (seg2a < seg1b);
+    }
+
+//------------------------------------------------------------------------------
+// ClipperBase class methods ...
+//------------------------------------------------------------------------------
+
+    ClipperBase::ClipperBase() //constructor
+    {
+        m_CurrentLM = m_MinimaList.begin(); //begin() == end() here
+        m_UseFullRange = false;
+    }
+//------------------------------------------------------------------------------
+
+    ClipperBase::~ClipperBase() //destructor
+    {
+        Clear();
+    }
+//------------------------------------------------------------------------------
+
+    void RangeTest(const IntPoint& Pt, bool& useFullRange)
+    {
+        if (useFullRange)
+        {
+            if (Pt.X > hiRange || Pt.Y > hiRange || -Pt.X > hiRange || -Pt.Y > hiRange)
+                throw clipperException("Coordinate outside allowed range");
+        }
+        else if (Pt.X > loRange|| Pt.Y > loRange || -Pt.X > loRange || -Pt.Y > loRange)
+        {
+            useFullRange = true;
+            RangeTest(Pt, useFullRange);
+        }
+    }
+//------------------------------------------------------------------------------
+
+    TEdge* FindNextLocMin(TEdge* E)
+    {
+        for (;;)
+        {
+            while (E->Bot != E->Prev->Bot || E->Curr == E->Top) E = E->Next;
+            if (!IsHorizontal(*E) && !IsHorizontal(*E->Prev)) break;
+            while (IsHorizontal(*E->Prev)) E = E->Prev;
+            TEdge* E2 = E;
+            while (IsHorizontal(*E)) E = E->Next;
+            if (E->Top.Y == E->Prev->Bot.Y) continue; //ie just an intermediate horz.
+            if (E2->Prev->Bot.X < E->Bot.X) E = E2;
+            break;
+        }
+        return E;
+    }
+//------------------------------------------------------------------------------
+
+    TEdge* ClipperBase::ProcessBound(TEdge* E, bool NextIsForward)
+    {
+        TEdge *Result = E;
+        TEdge *Horz = 0;
+
+        if (E->OutIdx == Skip)
+        {
+            //if edges still remain in the current bound beyond the skip edge then
+            //create another LocMin and call ProcessBound once more
+            if (NextIsForward)
+            {
+                while (E->Top.Y == E->Next->Bot.Y) E = E->Next;
+                //don't include top horizontals when parsing a bound a second time,
+                //they will be contained in the opposite bound ...
+                while (E != Result && IsHorizontal(*E)) E = E->Prev;
+            }
+            else
+            {
+                while (E->Top.Y == E->Prev->Bot.Y) E = E->Prev;
+                while (E != Result && IsHorizontal(*E)) E = E->Next;
+            }
+
+            if (E == Result)
+            {
+                if (NextIsForward) Result = E->Next;
+                else Result = E->Prev;
+            }
+            else
+            {
+                //there are more edges in the bound beyond result starting with E
+                if (NextIsForward)
+                    E = Result->Next;
+                else
+                    E = Result->Prev;
+                MinimaList::value_type locMin;
+                locMin.Y = E->Bot.Y;
+                locMin.LeftBound = 0;
+                locMin.RightBound = E;
+                E->WindDelta = 0;
+                Result = ProcessBound(E, NextIsForward);
+                m_MinimaList.push_back(locMin);
+            }
+            return Result;
+        }
+
+        TEdge *EStart;
+
+        if (IsHorizontal(*E))
+        {
+            //We need to be careful with open paths because this may not be a
+            //true local minima (ie E may be following a skip edge).
+            //Also, consecutive horz. edges may start heading left before going right.
+            if (NextIsForward)
+                EStart = E->Prev;
+            else
+                EStart = E->Next;
+            if (IsHorizontal(*EStart)) //ie an adjoining horizontal skip edge
+            {
+                if (EStart->Bot.X != E->Bot.X && EStart->Top.X != E->Bot.X)
+                    ReverseHorizontal(*E);
+            }
+            else if (EStart->Bot.X != E->Bot.X)
+                ReverseHorizontal(*E);
+        }
+
+        EStart = E;
+        if (NextIsForward)
+        {
+            while (Result->Top.Y == Result->Next->Bot.Y && Result->Next->OutIdx != Skip)
+                Result = Result->Next;
+            if (IsHorizontal(*Result) && Result->Next->OutIdx != Skip)
+            {
+                //nb: at the top of a bound, horizontals are added to the bound
+                //only when the preceding edge attaches to the horizontal's left vertex
+                //unless a Skip edge is encountered when that becomes the top divide
+                Horz = Result;
+                while (IsHorizontal(*Horz->Prev)) Horz = Horz->Prev;
+                if (Horz->Prev->Top.X > Result->Next->Top.X) Result = Horz->Prev;
+            }
+            while (E != Result)
+            {
+                E->NextInLML = E->Next;
+                if (IsHorizontal(*E) && E != EStart &&
+                    E->Bot.X != E->Prev->Top.X) ReverseHorizontal(*E);
+                E = E->Next;
+            }
+            if (IsHorizontal(*E) && E != EStart && E->Bot.X != E->Prev->Top.X)
+                ReverseHorizontal(*E);
+            Result = Result->Next; //move to the edge just beyond current bound
+        } else
+        {
+            while (Result->Top.Y == Result->Prev->Bot.Y && Result->Prev->OutIdx != Skip)
+                Result = Result->Prev;
+            if (IsHorizontal(*Result) && Result->Prev->OutIdx != Skip)
+            {
+                Horz = Result;
+                while (IsHorizontal(*Horz->Next)) Horz = Horz->Next;
+                if (Horz->Next->Top.X == Result->Prev->Top.X ||
+                    Horz->Next->Top.X > Result->Prev->Top.X) Result = Horz->Next;
+            }
+
+            while (E != Result)
+            {
+                E->NextInLML = E->Prev;
+                if (IsHorizontal(*E) && E != EStart && E->Bot.X != E->Next->Top.X)
+                    ReverseHorizontal(*E);
+                E = E->Prev;
+            }
+            if (IsHorizontal(*E) && E != EStart && E->Bot.X != E->Next->Top.X)
+                ReverseHorizontal(*E);
+            Result = Result->Prev; //move to the edge just beyond current bound
+        }
+
+        return Result;
+    }
+//------------------------------------------------------------------------------
+
+    bool ClipperBase::AddPath(const Path &pg, PolyType PolyTyp, bool Closed)
+    {
+#ifdef use_lines
+        if (!Closed && PolyTyp == ptClip)
+            throw clipperException("AddPath: Open paths must be subject.");
+#else
+        if (!Closed)
+    throw clipperException("AddPath: Open paths have been disabled.");
+#endif
+
+        int highI = (int)pg.size() -1;
+        if (Closed) while (highI > 0 && (pg[highI] == pg[0])) --highI;
+        while (highI > 0 && (pg[highI] == pg[highI -1])) --highI;
+        if ((Closed && highI < 2) || (!Closed && highI < 1)) return false;
+
+        //create a new edge array ...
+        TEdge *edges = new TEdge [highI +1];
+
+        bool IsFlat = true;
+        //1. Basic (first) edge initialization ...
+        try
+        {
+            edges[1].Curr = pg[1];
+            RangeTest(pg[0], m_UseFullRange);
+            RangeTest(pg[highI], m_UseFullRange);
+            InitEdge(&edges[0], &edges[1], &edges[highI], pg[0]);
+            InitEdge(&edges[highI], &edges[0], &edges[highI-1], pg[highI]);
+            for (int i = highI - 1; i >= 1; --i)
+            {
+                RangeTest(pg[i], m_UseFullRange);
+                InitEdge(&edges[i], &edges[i+1], &edges[i-1], pg[i]);
+            }
+        }
+        catch(...)
+        {
+            delete [] edges;
+            throw; //range test fails
+        }
+        TEdge *eStart = &edges[0];
+
+        //2. Remove duplicate vertices, and (when closed) collinear edges ...
+        TEdge *E = eStart, *eLoopStop = eStart;
+        for (;;)
+        {
+            //nb: allows matching start and end points when not Closed ...
+            if (E->Curr == E->Next->Curr && (Closed || E->Next != eStart))
+            {
+                if (E == E->Next) break;
+                if (E == eStart) eStart = E->Next;
+                E = RemoveEdge(E);
+                eLoopStop = E;
+                continue;
+            }
+            if (E->Prev == E->Next)
+                break; //only two vertices
+            else if (Closed &&
+                     SlopesEqual(E->Prev->Curr, E->Curr, E->Next->Curr, m_UseFullRange) &&
+                     (!m_PreserveCollinear ||
+                      !Pt2IsBetweenPt1AndPt3(E->Prev->Curr, E->Curr, E->Next->Curr)))
+            {
+                //Collinear edges are allowed for open paths but in closed paths
+                //the default is to merge adjacent collinear edges into a single edge.
+                //However, if the PreserveCollinear property is enabled, only overlapping
+                //collinear edges (ie spikes) will be removed from closed paths.
+                if (E == eStart) eStart = E->Next;
+                E = RemoveEdge(E);
+                E = E->Prev;
+                eLoopStop = E;
+                continue;
+            }
+            E = E->Next;
+            if ((E == eLoopStop) || (!Closed && E->Next == eStart)) break;
+        }
+
+        if ((!Closed && (E == E->Next)) || (Closed && (E->Prev == E->Next)))
+        {
+            delete [] edges;
+            return false;
+        }
+
+        if (!Closed)
+        {
+            m_HasOpenPaths = true;
+            eStart->Prev->OutIdx = Skip;
+        }
+
+        //3. Do second stage of edge initialization ...
+        E = eStart;
+        do
+        {
+            InitEdge2(*E, PolyTyp);
+            E = E->Next;
+            if (IsFlat && E->Curr.Y != eStart->Curr.Y) IsFlat = false;
+        }
+        while (E != eStart);
+
+        //4. Finally, add edge bounds to LocalMinima list ...
+
+        //Totally flat paths must be handled differently when adding them
+        //to LocalMinima list to avoid endless loops etc ...
+        if (IsFlat)
+        {
+            if (Closed)
+            {
+                delete [] edges;
+                return false;
+            }
+            E->Prev->OutIdx = Skip;
+            MinimaList::value_type locMin;
+            locMin.Y = E->Bot.Y;
+            locMin.LeftBound = 0;
+            locMin.RightBound = E;
+            locMin.RightBound->Side = esRight;
+            locMin.RightBound->WindDelta = 0;
+            for (;;)
+            {
+                if (E->Bot.X != E->Prev->Top.X) ReverseHorizontal(*E);
+                if (E->Next->OutIdx == Skip) break;
+                E->NextInLML = E->Next;
+                E = E->Next;
+            }
+            m_MinimaList.push_back(locMin);
+            m_edges.push_back(edges);
+            return true;
+        }
+
+        m_edges.push_back(edges);
+        bool leftBoundIsForward;
+        TEdge* EMin = 0;
+
+        //workaround to avoid an endless loop in the while loop below when
+        //open paths have matching start and end points ...
+        if (E->Prev->Bot == E->Prev->Top) E = E->Next;
+
+        for (;;)
+        {
+            E = FindNextLocMin(E);
+            if (E == EMin) break;
+            else if (!EMin) EMin = E;
+
+            //E and E.Prev now share a local minima (left aligned if horizontal).
+            //Compare their slopes to find which starts which bound ...
+            MinimaList::value_type locMin;
+            locMin.Y = E->Bot.Y;
+            if (E->Dx < E->Prev->Dx)
+            {
+                locMin.LeftBound = E->Prev;
+                locMin.RightBound = E;
+                leftBoundIsForward = false; //Q.nextInLML = Q.prev
+            } else
+            {
+                locMin.LeftBound = E;
+                locMin.RightBound = E->Prev;
+                leftBoundIsForward = true; //Q.nextInLML = Q.next
+            }
+
+            if (!Closed) locMin.LeftBound->WindDelta = 0;
+            else if (locMin.LeftBound->Next == locMin.RightBound)
+                locMin.LeftBound->WindDelta = -1;
+            else locMin.LeftBound->WindDelta = 1;
+            locMin.RightBound->WindDelta = -locMin.LeftBound->WindDelta;
+
+            E = ProcessBound(locMin.LeftBound, leftBoundIsForward);
+            if (E->OutIdx == Skip) E = ProcessBound(E, leftBoundIsForward);
+
+            TEdge* E2 = ProcessBound(locMin.RightBound, !leftBoundIsForward);
+            if (E2->OutIdx == Skip) E2 = ProcessBound(E2, !leftBoundIsForward);
+
+            if (locMin.LeftBound->OutIdx == Skip)
+                locMin.LeftBound = 0;
+            else if (locMin.RightBound->OutIdx == Skip)
+                locMin.RightBound = 0;
+            m_MinimaList.push_back(locMin);
+            if (!leftBoundIsForward) E = E2;
+        }
+        return true;
+    }
+//------------------------------------------------------------------------------
+
+    bool ClipperBase::AddPaths(const Paths &ppg, PolyType PolyTyp, bool Closed)
+    {
+        bool result = false;
+        for (Paths::size_type i = 0; i < ppg.size(); ++i)
+            if (AddPath(ppg[i], PolyTyp, Closed)) result = true;
+        return result;
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperBase::Clear()
+    {
+        DisposeLocalMinimaList();
+        for (EdgeList::size_type i = 0; i < m_edges.size(); ++i)
+        {
+            TEdge* edges = m_edges[i];
+            delete [] edges;
+        }
+        m_edges.clear();
+        m_UseFullRange = false;
+        m_HasOpenPaths = false;
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperBase::Reset()
+    {
+        m_CurrentLM = m_MinimaList.begin();
+        if (m_CurrentLM == m_MinimaList.end()) return; //ie nothing to process
+        std::sort(m_MinimaList.begin(), m_MinimaList.end(), LocMinSorter());
+
+        m_Scanbeam = ScanbeamList(); //clears/resets priority_queue
+        //reset all edges ...
+        for (MinimaList::iterator lm = m_MinimaList.begin(); lm != m_MinimaList.end(); ++lm)
+        {
+            InsertScanbeam(lm->Y);
+            TEdge* e = lm->LeftBound;
+            if (e)
+            {
+                e->Curr = e->Bot;
+                e->Side = esLeft;
+                e->OutIdx = Unassigned;
+            }
+
+            e = lm->RightBound;
+            if (e)
+            {
+                e->Curr = e->Bot;
+                e->Side = esRight;
+                e->OutIdx = Unassigned;
+            }
+        }
+        m_ActiveEdges = 0;
+        m_CurrentLM = m_MinimaList.begin();
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperBase::DisposeLocalMinimaList()
+    {
+        m_MinimaList.clear();
+        m_CurrentLM = m_MinimaList.begin();
+    }
+//------------------------------------------------------------------------------
+
+    bool ClipperBase::PopLocalMinima(cInt Y, const LocalMinimum *&locMin)
+    {
+        if (m_CurrentLM == m_MinimaList.end() || (*m_CurrentLM).Y != Y) return false;
+        locMin = &(*m_CurrentLM);
+        ++m_CurrentLM;
+        return true;
+    }
+//------------------------------------------------------------------------------
+
+    IntRect ClipperBase::GetBounds()
+    {
+        IntRect result;
+        MinimaList::iterator lm = m_MinimaList.begin();
+        if (lm == m_MinimaList.end())
+        {
+            result.left = result.top = result.right = result.bottom = 0;
+            return result;
+        }
+        result.left = lm->LeftBound->Bot.X;
+        result.top = lm->LeftBound->Bot.Y;
+        result.right = lm->LeftBound->Bot.X;
+        result.bottom = lm->LeftBound->Bot.Y;
+        while (lm != m_MinimaList.end())
+        {
+            //todo - needs fixing for open paths
+            result.bottom = std::max(result.bottom, lm->LeftBound->Bot.Y);
+            TEdge* e = lm->LeftBound;
+            for (;;) {
+                TEdge* bottomE = e;
+                while (e->NextInLML)
+                {
+                    if (e->Bot.X < result.left) result.left = e->Bot.X;
+                    if (e->Bot.X > result.right) result.right = e->Bot.X;
+                    e = e->NextInLML;
+                }
+                result.left = std::min(result.left, e->Bot.X);
+                result.right = std::max(result.right, e->Bot.X);
+                result.left = std::min(result.left, e->Top.X);
+                result.right = std::max(result.right, e->Top.X);
+                result.top = std::min(result.top, e->Top.Y);
+                if (bottomE == lm->LeftBound) e = lm->RightBound;
+                else break;
+            }
+            ++lm;
+        }
+        return result;
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperBase::InsertScanbeam(const cInt Y)
+    {
+        m_Scanbeam.push(Y);
+    }
+//------------------------------------------------------------------------------
+
+    bool ClipperBase::PopScanbeam(cInt &Y)
+    {
+        if (m_Scanbeam.empty()) return false;
+        Y = m_Scanbeam.top();
+        m_Scanbeam.pop();
+        while (!m_Scanbeam.empty() && Y == m_Scanbeam.top()) { m_Scanbeam.pop(); } // Pop duplicates.
+        return true;
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperBase::DisposeAllOutRecs(){
+        for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+            DisposeOutRec(i);
+        m_PolyOuts.clear();
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperBase::DisposeOutRec(PolyOutList::size_type index)
+    {
+        OutRec *outRec = m_PolyOuts[index];
+        if (outRec->Pts) DisposeOutPts(outRec->Pts);
+        delete outRec;
+        m_PolyOuts[index] = 0;
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperBase::DeleteFromAEL(TEdge *e)
+    {
+        TEdge* AelPrev = e->PrevInAEL;
+        TEdge* AelNext = e->NextInAEL;
+        if (!AelPrev &&  !AelNext && (e != m_ActiveEdges)) return; //already deleted
+        if (AelPrev) AelPrev->NextInAEL = AelNext;
+        else m_ActiveEdges = AelNext;
+        if (AelNext) AelNext->PrevInAEL = AelPrev;
+        e->NextInAEL = 0;
+        e->PrevInAEL = 0;
+    }
+//------------------------------------------------------------------------------
+
+    OutRec* ClipperBase::CreateOutRec()
+    {
+        OutRec* result = new OutRec;
+        result->IsHole = false;
+        result->IsOpen = false;
+        result->FirstLeft = 0;
+        result->Pts = 0;
+        result->BottomPt = 0;
+        result->PolyNd = 0;
+        m_PolyOuts.push_back(result);
+        result->Idx = (int)m_PolyOuts.size() - 1;
+        return result;
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperBase::SwapPositionsInAEL(TEdge *Edge1, TEdge *Edge2)
+    {
+        //check that one or other edge hasn't already been removed from AEL ...
+        if (Edge1->NextInAEL == Edge1->PrevInAEL ||
+            Edge2->NextInAEL == Edge2->PrevInAEL) return;
+
+        if (Edge1->NextInAEL == Edge2)
+        {
+            TEdge* Next = Edge2->NextInAEL;
+            if (Next) Next->PrevInAEL = Edge1;
+            TEdge* Prev = Edge1->PrevInAEL;
+            if (Prev) Prev->NextInAEL = Edge2;
+            Edge2->PrevInAEL = Prev;
+            Edge2->NextInAEL = Edge1;
+            Edge1->PrevInAEL = Edge2;
+            Edge1->NextInAEL = Next;
+        }
+        else if (Edge2->NextInAEL == Edge1)
+        {
+            TEdge* Next = Edge1->NextInAEL;
+            if (Next) Next->PrevInAEL = Edge2;
+            TEdge* Prev = Edge2->PrevInAEL;
+            if (Prev) Prev->NextInAEL = Edge1;
+            Edge1->PrevInAEL = Prev;
+            Edge1->NextInAEL = Edge2;
+            Edge2->PrevInAEL = Edge1;
+            Edge2->NextInAEL = Next;
+        }
+        else
+        {
+            TEdge* Next = Edge1->NextInAEL;
+            TEdge* Prev = Edge1->PrevInAEL;
+            Edge1->NextInAEL = Edge2->NextInAEL;
+            if (Edge1->NextInAEL) Edge1->NextInAEL->PrevInAEL = Edge1;
+            Edge1->PrevInAEL = Edge2->PrevInAEL;
+            if (Edge1->PrevInAEL) Edge1->PrevInAEL->NextInAEL = Edge1;
+            Edge2->NextInAEL = Next;
+            if (Edge2->NextInAEL) Edge2->NextInAEL->PrevInAEL = Edge2;
+            Edge2->PrevInAEL = Prev;
+            if (Edge2->PrevInAEL) Edge2->PrevInAEL->NextInAEL = Edge2;
+        }
+
+        if (!Edge1->PrevInAEL) m_ActiveEdges = Edge1;
+        else if (!Edge2->PrevInAEL) m_ActiveEdges = Edge2;
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperBase::UpdateEdgeIntoAEL(TEdge *&e)
+    {
+        if (!e->NextInLML)
+            throw clipperException("UpdateEdgeIntoAEL: invalid call");
+
+        e->NextInLML->OutIdx = e->OutIdx;
+        TEdge* AelPrev = e->PrevInAEL;
+        TEdge* AelNext = e->NextInAEL;
+        if (AelPrev) AelPrev->NextInAEL = e->NextInLML;
+        else m_ActiveEdges = e->NextInLML;
+        if (AelNext) AelNext->PrevInAEL = e->NextInLML;
+        e->NextInLML->Side = e->Side;
+        e->NextInLML->WindDelta = e->WindDelta;
+        e->NextInLML->WindCnt = e->WindCnt;
+        e->NextInLML->WindCnt2 = e->WindCnt2;
+        e = e->NextInLML;
+        e->Curr = e->Bot;
+        e->PrevInAEL = AelPrev;
+        e->NextInAEL = AelNext;
+        if (!IsHorizontal(*e)) InsertScanbeam(e->Top.Y);
+    }
+//------------------------------------------------------------------------------
+
+    bool ClipperBase::LocalMinimaPending()
+    {
+        return (m_CurrentLM != m_MinimaList.end());
+    }
+
+//------------------------------------------------------------------------------
+// TClipper methods ...
+//------------------------------------------------------------------------------
+
+    Clipper::Clipper(int initOptions) : ClipperBase() //constructor
+    {
+        m_ExecuteLocked = false;
+        m_UseFullRange = false;
+        m_ReverseOutput = ((initOptions & ioReverseSolution) != 0);
+        m_StrictSimple = ((initOptions & ioStrictlySimple) != 0);
+        m_PreserveCollinear = ((initOptions & ioPreserveCollinear) != 0);
+        m_HasOpenPaths = false;
+#ifdef use_xyz
+        m_ZFill = 0;
+#endif
+    }
+//------------------------------------------------------------------------------
+
+#ifdef use_xyz
+    void Clipper::ZFillFunction(ZFillCallback zFillFunc)
+{
+  m_ZFill = zFillFunc;
+}
+//------------------------------------------------------------------------------
+#endif
+
+    bool Clipper::Execute(ClipType clipType, Paths &solution, PolyFillType fillType)
+    {
+        return Execute(clipType, solution, fillType, fillType);
+    }
+//------------------------------------------------------------------------------
+
+    bool Clipper::Execute(ClipType clipType, PolyTree &polytree, PolyFillType fillType)
+    {
+        return Execute(clipType, polytree, fillType, fillType);
+    }
+//------------------------------------------------------------------------------
+
+    bool Clipper::Execute(ClipType clipType, Paths &solution,
+                          PolyFillType subjFillType, PolyFillType clipFillType)
+    {
+        if( m_ExecuteLocked ) return false;
+        if (m_HasOpenPaths)
+            throw clipperException("Error: PolyTree struct is needed for open path clipping.");
+        m_ExecuteLocked = true;
+        solution.resize(0);
+        m_SubjFillType = subjFillType;
+        m_ClipFillType = clipFillType;
+        m_ClipType = clipType;
+        m_UsingPolyTree = false;
+        bool succeeded = ExecuteInternal();
+        if (succeeded) BuildResult(solution);
+        DisposeAllOutRecs();
+        m_ExecuteLocked = false;
+        return succeeded;
+    }
+//------------------------------------------------------------------------------
+
+    bool Clipper::Execute(ClipType clipType, PolyTree& polytree,
+                          PolyFillType subjFillType, PolyFillType clipFillType)
+    {
+        if( m_ExecuteLocked ) return false;
+        m_ExecuteLocked = true;
+        m_SubjFillType = subjFillType;
+        m_ClipFillType = clipFillType;
+        m_ClipType = clipType;
+        m_UsingPolyTree = true;
+        bool succeeded = ExecuteInternal();
+        if (succeeded) BuildResult2(polytree);
+        DisposeAllOutRecs();
+        m_ExecuteLocked = false;
+        return succeeded;
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::FixHoleLinkage(OutRec &outrec)
+    {
+        //skip OutRecs that (a) contain outermost polygons or
+        //(b) already have the correct owner/child linkage ...
+        if (!outrec.FirstLeft ||
+            (outrec.IsHole != outrec.FirstLeft->IsHole &&
+             outrec.FirstLeft->Pts)) return;
+
+        OutRec* orfl = outrec.FirstLeft;
+        while (orfl && ((orfl->IsHole == outrec.IsHole) || !orfl->Pts))
+            orfl = orfl->FirstLeft;
+        outrec.FirstLeft = orfl;
+    }
+//------------------------------------------------------------------------------
+
+    bool Clipper::ExecuteInternal()
+    {
+        bool succeeded = true;
+        try {
+            Reset();
+            m_Maxima = MaximaList();
+            m_SortedEdges = 0;
+
+            succeeded = true;
+            cInt botY, topY;
+            if (!PopScanbeam(botY)) return false;
+            InsertLocalMinimaIntoAEL(botY);
+            while (PopScanbeam(topY) || LocalMinimaPending())
+            {
+                ProcessHorizontals();
+                ClearGhostJoins();
+                if (!ProcessIntersections(topY))
+                {
+                    succeeded = false;
+                    break;
+                }
+                ProcessEdgesAtTopOfScanbeam(topY);
+                botY = topY;
+                InsertLocalMinimaIntoAEL(botY);
+            }
+        }
+        catch(...)
+        {
+            succeeded = false;
+        }
+
+        if (succeeded)
+        {
+            //fix orientations ...
+            for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+            {
+                OutRec *outRec = m_PolyOuts[i];
+                if (!outRec->Pts || outRec->IsOpen) continue;
+                if ((outRec->IsHole ^ m_ReverseOutput) == (Area(*outRec) > 0))
+                    ReversePolyPtLinks(outRec->Pts);
+            }
+
+            if (!m_Joins.empty()) JoinCommonEdges();
+
+            //unfortunately FixupOutPolygon() must be done after JoinCommonEdges()
+            for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+            {
+                OutRec *outRec = m_PolyOuts[i];
+                if (!outRec->Pts) continue;
+                if (outRec->IsOpen)
+                    FixupOutPolyline(*outRec);
+                else
+                    FixupOutPolygon(*outRec);
+            }
+
+            if (m_StrictSimple) DoSimplePolygons();
+        }
+
+        ClearJoins();
+        ClearGhostJoins();
+        return succeeded;
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::SetWindingCount(TEdge &edge)
+    {
+        TEdge *e = edge.PrevInAEL;
+        //find the edge of the same polytype that immediately preceeds 'edge' in AEL
+        while (e  && ((e->PolyTyp != edge.PolyTyp) || (e->WindDelta == 0))) e = e->PrevInAEL;
+        if (!e)
+        {
+            if (edge.WindDelta == 0)
+            {
+                PolyFillType pft = (edge.PolyTyp == ptSubject ? m_SubjFillType : m_ClipFillType);
+                edge.WindCnt = (pft == pftNegative ? -1 : 1);
+            }
+            else
+                edge.WindCnt = edge.WindDelta;
+            edge.WindCnt2 = 0;
+            e = m_ActiveEdges; //ie get ready to calc WindCnt2
+        }
+        else if (edge.WindDelta == 0 && m_ClipType != ctUnion)
+        {
+            edge.WindCnt = 1;
+            edge.WindCnt2 = e->WindCnt2;
+            e = e->NextInAEL; //ie get ready to calc WindCnt2
+        }
+        else if (IsEvenOddFillType(edge))
+        {
+            //EvenOdd filling ...
+            if (edge.WindDelta == 0)
+            {
+                //are we inside a subj polygon ...
+                bool Inside = true;
+                TEdge *e2 = e->PrevInAEL;
+                while (e2)
+                {
+                    if (e2->PolyTyp == e->PolyTyp && e2->WindDelta != 0)
+                        Inside = !Inside;
+                    e2 = e2->PrevInAEL;
+                }
+                edge.WindCnt = (Inside ? 0 : 1);
+            }
+            else
+            {
+                edge.WindCnt = edge.WindDelta;
+            }
+            edge.WindCnt2 = e->WindCnt2;
+            e = e->NextInAEL; //ie get ready to calc WindCnt2
+        }
+        else
+        {
+            //nonZero, Positive or Negative filling ...
+            if (e->WindCnt * e->WindDelta < 0)
+            {
+                //prev edge is 'decreasing' WindCount (WC) toward zero
+                //so we're outside the previous polygon ...
+                if (Abs(e->WindCnt) > 1)
+                {
+                    //outside prev poly but still inside another.
+                    //when reversing direction of prev poly use the same WC
+                    if (e->WindDelta * edge.WindDelta < 0) edge.WindCnt = e->WindCnt;
+                        //otherwise continue to 'decrease' WC ...
+                    else edge.WindCnt = e->WindCnt + edge.WindDelta;
+                }
+                else
+                    //now outside all polys of same polytype so set own WC ...
+                    edge.WindCnt = (edge.WindDelta == 0 ? 1 : edge.WindDelta);
+            } else
+            {
+                //prev edge is 'increasing' WindCount (WC) away from zero
+                //so we're inside the previous polygon ...
+                if (edge.WindDelta == 0)
+                    edge.WindCnt = (e->WindCnt < 0 ? e->WindCnt - 1 : e->WindCnt + 1);
+                    //if wind direction is reversing prev then use same WC
+                else if (e->WindDelta * edge.WindDelta < 0) edge.WindCnt = e->WindCnt;
+                    //otherwise add to WC ...
+                else edge.WindCnt = e->WindCnt + edge.WindDelta;
+            }
+            edge.WindCnt2 = e->WindCnt2;
+            e = e->NextInAEL; //ie get ready to calc WindCnt2
+        }
+
+        //update WindCnt2 ...
+        if (IsEvenOddAltFillType(edge))
+        {
+            //EvenOdd filling ...
+            while (e != &edge)
+            {
+                if (e->WindDelta != 0)
+                    edge.WindCnt2 = (edge.WindCnt2 == 0 ? 1 : 0);
+                e = e->NextInAEL;
+            }
+        } else
+        {
+            //nonZero, Positive or Negative filling ...
+            while ( e != &edge )
+            {
+                edge.WindCnt2 += e->WindDelta;
+                e = e->NextInAEL;
+            }
+        }
+    }
+//------------------------------------------------------------------------------
+
+    bool Clipper::IsEvenOddFillType(const TEdge& edge) const
+    {
+        if (edge.PolyTyp == ptSubject)
+            return m_SubjFillType == pftEvenOdd; else
+            return m_ClipFillType == pftEvenOdd;
+    }
+//------------------------------------------------------------------------------
+
+    bool Clipper::IsEvenOddAltFillType(const TEdge& edge) const
+    {
+        if (edge.PolyTyp == ptSubject)
+            return m_ClipFillType == pftEvenOdd; else
+            return m_SubjFillType == pftEvenOdd;
+    }
+//------------------------------------------------------------------------------
+
+    bool Clipper::IsContributing(const TEdge& edge) const
+    {
+        PolyFillType pft, pft2;
+        if (edge.PolyTyp == ptSubject)
+        {
+            pft = m_SubjFillType;
+            pft2 = m_ClipFillType;
+        } else
+        {
+            pft = m_ClipFillType;
+            pft2 = m_SubjFillType;
+        }
+
+        switch(pft)
+        {
+            case pftEvenOdd:
+                //return false if a subj line has been flagged as inside a subj polygon
+                if (edge.WindDelta == 0 && edge.WindCnt != 1) return false;
+                break;
+            case pftNonZero:
+                if (Abs(edge.WindCnt) != 1) return false;
+                break;
+            case pftPositive:
+                if (edge.WindCnt != 1) return false;
+                break;
+            default: //pftNegative
+                if (edge.WindCnt != -1) return false;
+        }
+
+        switch(m_ClipType)
+        {
+            case ctIntersection:
+                switch(pft2)
+                {
+                    case pftEvenOdd:
+                    case pftNonZero:
+                        return (edge.WindCnt2 != 0);
+                    case pftPositive:
+                        return (edge.WindCnt2 > 0);
+                    default:
+                        return (edge.WindCnt2 < 0);
+                }
+                break;
+            case ctUnion:
+                switch(pft2)
+                {
+                    case pftEvenOdd:
+                    case pftNonZero:
+                        return (edge.WindCnt2 == 0);
+                    case pftPositive:
+                        return (edge.WindCnt2 <= 0);
+                    default:
+                        return (edge.WindCnt2 >= 0);
+                }
+                break;
+            case ctDifference:
+                if (edge.PolyTyp == ptSubject)
+                    switch(pft2)
+                    {
+                        case pftEvenOdd:
+                        case pftNonZero:
+                            return (edge.WindCnt2 == 0);
+                        case pftPositive:
+                            return (edge.WindCnt2 <= 0);
+                        default:
+                            return (edge.WindCnt2 >= 0);
+                    }
+                else
+                    switch(pft2)
+                    {
+                        case pftEvenOdd:
+                        case pftNonZero:
+                            return (edge.WindCnt2 != 0);
+                        case pftPositive:
+                            return (edge.WindCnt2 > 0);
+                        default:
+                            return (edge.WindCnt2 < 0);
+                    }
+                break;
+            case ctXor:
+                if (edge.WindDelta == 0) //XOr always contributing unless open
+                    switch(pft2)
+                    {
+                        case pftEvenOdd:
+                        case pftNonZero:
+                            return (edge.WindCnt2 == 0);
+                        case pftPositive:
+                            return (edge.WindCnt2 <= 0);
+                        default:
+                            return (edge.WindCnt2 >= 0);
+                    }
+                else
+                    return true;
+                break;
+            default:
+                return true;
+        }
+    }
+//------------------------------------------------------------------------------
+
+    OutPt* Clipper::AddLocalMinPoly(TEdge *e1, TEdge *e2, const IntPoint &Pt)
+    {
+        OutPt* result;
+        TEdge *e, *prevE;
+        if (IsHorizontal(*e2) || ( e1->Dx > e2->Dx ))
+        {
+            result = AddOutPt(e1, Pt);
+            e2->OutIdx = e1->OutIdx;
+            e1->Side = esLeft;
+            e2->Side = esRight;
+            e = e1;
+            if (e->PrevInAEL == e2)
+                prevE = e2->PrevInAEL;
+            else
+                prevE = e->PrevInAEL;
+        } else
+        {
+            result = AddOutPt(e2, Pt);
+            e1->OutIdx = e2->OutIdx;
+            e1->Side = esRight;
+            e2->Side = esLeft;
+            e = e2;
+            if (e->PrevInAEL == e1)
+                prevE = e1->PrevInAEL;
+            else
+                prevE = e->PrevInAEL;
+        }
+
+        if (prevE && prevE->OutIdx >= 0 && prevE->Top.Y < Pt.Y && e->Top.Y < Pt.Y)
+        {
+            cInt xPrev = TopX(*prevE, Pt.Y);
+            cInt xE = TopX(*e, Pt.Y);
+            if (xPrev == xE && (e->WindDelta != 0) && (prevE->WindDelta != 0) &&
+                SlopesEqual(IntPoint(xPrev, Pt.Y), prevE->Top, IntPoint(xE, Pt.Y), e->Top, m_UseFullRange))
+            {
+                OutPt* outPt = AddOutPt(prevE, Pt);
+                AddJoin(result, outPt, e->Top);
+            }
+        }
+        return result;
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::AddLocalMaxPoly(TEdge *e1, TEdge *e2, const IntPoint &Pt)
+    {
+        AddOutPt( e1, Pt );
+        if (e2->WindDelta == 0) AddOutPt(e2, Pt);
+        if( e1->OutIdx == e2->OutIdx )
+        {
+            e1->OutIdx = Unassigned;
+            e2->OutIdx = Unassigned;
+        }
+        else if (e1->OutIdx < e2->OutIdx)
+            AppendPolygon(e1, e2);
+        else
+            AppendPolygon(e2, e1);
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::AddEdgeToSEL(TEdge *edge)
+    {
+        //SEL pointers in PEdge are reused to build a list of horizontal edges.
+        //However, we don't need to worry about order with horizontal edge processing.
+        if( !m_SortedEdges )
+        {
+            m_SortedEdges = edge;
+            edge->PrevInSEL = 0;
+            edge->NextInSEL = 0;
+        }
+        else
+        {
+            edge->NextInSEL = m_SortedEdges;
+            edge->PrevInSEL = 0;
+            m_SortedEdges->PrevInSEL = edge;
+            m_SortedEdges = edge;
+        }
+    }
+//------------------------------------------------------------------------------
+
+    bool Clipper::PopEdgeFromSEL(TEdge *&edge)
+    {
+        if (!m_SortedEdges) return false;
+        edge = m_SortedEdges;
+        DeleteFromSEL(m_SortedEdges);
+        return true;
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::CopyAELToSEL()
+    {
+        TEdge* e = m_ActiveEdges;
+        m_SortedEdges = e;
+        while ( e )
+        {
+            e->PrevInSEL = e->PrevInAEL;
+            e->NextInSEL = e->NextInAEL;
+            e = e->NextInAEL;
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::AddJoin(OutPt *op1, OutPt *op2, const IntPoint OffPt)
+    {
+        Join* j = new Join;
+        j->OutPt1 = op1;
+        j->OutPt2 = op2;
+        j->OffPt = OffPt;
+        m_Joins.push_back(j);
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::ClearJoins()
+    {
+        for (JoinList::size_type i = 0; i < m_Joins.size(); i++)
+            delete m_Joins[i];
+        m_Joins.resize(0);
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::ClearGhostJoins()
+    {
+        for (JoinList::size_type i = 0; i < m_GhostJoins.size(); i++)
+            delete m_GhostJoins[i];
+        m_GhostJoins.resize(0);
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::AddGhostJoin(OutPt *op, const IntPoint OffPt)
+    {
+        Join* j = new Join;
+        j->OutPt1 = op;
+        j->OutPt2 = 0;
+        j->OffPt = OffPt;
+        m_GhostJoins.push_back(j);
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::InsertLocalMinimaIntoAEL(const cInt botY)
+    {
+        const LocalMinimum *lm;
+        while (PopLocalMinima(botY, lm))
+        {
+            TEdge* lb = lm->LeftBound;
+            TEdge* rb = lm->RightBound;
+
+            OutPt *Op1 = 0;
+            if (!lb)
+            {
+                //nb: don't insert LB into either AEL or SEL
+                InsertEdgeIntoAEL(rb, 0);
+                SetWindingCount(*rb);
+                if (IsContributing(*rb))
+                    Op1 = AddOutPt(rb, rb->Bot);
+            }
+            else if (!rb)
+            {
+                InsertEdgeIntoAEL(lb, 0);
+                SetWindingCount(*lb);
+                if (IsContributing(*lb))
+                    Op1 = AddOutPt(lb, lb->Bot);
+                InsertScanbeam(lb->Top.Y);
+            }
+            else
+            {
+                InsertEdgeIntoAEL(lb, 0);
+                InsertEdgeIntoAEL(rb, lb);
+                SetWindingCount( *lb );
+                rb->WindCnt = lb->WindCnt;
+                rb->WindCnt2 = lb->WindCnt2;
+                if (IsContributing(*lb))
+                    Op1 = AddLocalMinPoly(lb, rb, lb->Bot);
+                InsertScanbeam(lb->Top.Y);
+            }
+
+            if (rb)
+            {
+                if (IsHorizontal(*rb))
+                {
+                    AddEdgeToSEL(rb);
+                    if (rb->NextInLML)
+                        InsertScanbeam(rb->NextInLML->Top.Y);
+                }
+                else InsertScanbeam( rb->Top.Y );
+            }
+
+            if (!lb || !rb) continue;
+
+            //if any output polygons share an edge, they'll need joining later ...
+            if (Op1 && IsHorizontal(*rb) &&
+                m_GhostJoins.size() > 0 && (rb->WindDelta != 0))
+            {
+                for (JoinList::size_type i = 0; i < m_GhostJoins.size(); ++i)
+                {
+                    Join* jr = m_GhostJoins[i];
+                    //if the horizontal Rb and a 'ghost' horizontal overlap, then convert
+                    //the 'ghost' join to a real join ready for later ...
+                    if (HorzSegmentsOverlap(jr->OutPt1->Pt.X, jr->OffPt.X, rb->Bot.X, rb->Top.X))
+                        AddJoin(jr->OutPt1, Op1, jr->OffPt);
+                }
+            }
+
+            if (lb->OutIdx >= 0 && lb->PrevInAEL &&
+                lb->PrevInAEL->Curr.X == lb->Bot.X &&
+                lb->PrevInAEL->OutIdx >= 0 &&
+                SlopesEqual(lb->PrevInAEL->Bot, lb->PrevInAEL->Top, lb->Curr, lb->Top, m_UseFullRange) &&
+                (lb->WindDelta != 0) && (lb->PrevInAEL->WindDelta != 0))
+            {
+                OutPt *Op2 = AddOutPt(lb->PrevInAEL, lb->Bot);
+                AddJoin(Op1, Op2, lb->Top);
+            }
+
+            if(lb->NextInAEL != rb)
+            {
+
+                if (rb->OutIdx >= 0 && rb->PrevInAEL->OutIdx >= 0 &&
+                    SlopesEqual(rb->PrevInAEL->Curr, rb->PrevInAEL->Top, rb->Curr, rb->Top, m_UseFullRange) &&
+                    (rb->WindDelta != 0) && (rb->PrevInAEL->WindDelta != 0))
+                {
+                    OutPt *Op2 = AddOutPt(rb->PrevInAEL, rb->Bot);
+                    AddJoin(Op1, Op2, rb->Top);
+                }
+
+                TEdge* e = lb->NextInAEL;
+                if (e)
+                {
+                    while( e != rb )
+                    {
+                        //nb: For calculating winding counts etc, IntersectEdges() assumes
+                        //that param1 will be to the Right of param2 ABOVE the intersection ...
+                        IntersectEdges(rb , e , lb->Curr); //order important here
+                        e = e->NextInAEL;
+                    }
+                }
+            }
+
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::DeleteFromSEL(TEdge *e)
+    {
+        TEdge* SelPrev = e->PrevInSEL;
+        TEdge* SelNext = e->NextInSEL;
+        if( !SelPrev &&  !SelNext && (e != m_SortedEdges) ) return; //already deleted
+        if( SelPrev ) SelPrev->NextInSEL = SelNext;
+        else m_SortedEdges = SelNext;
+        if( SelNext ) SelNext->PrevInSEL = SelPrev;
+        e->NextInSEL = 0;
+        e->PrevInSEL = 0;
+    }
+//------------------------------------------------------------------------------
+
+#ifdef use_xyz
+    void Clipper::SetZ(IntPoint& pt, TEdge& e1, TEdge& e2)
+{
+  if (pt.Z != 0 || !m_ZFill) return;
+  else if (pt == e1.Bot) pt.Z = e1.Bot.Z;
+  else if (pt == e1.Top) pt.Z = e1.Top.Z;
+  else if (pt == e2.Bot) pt.Z = e2.Bot.Z;
+  else if (pt == e2.Top) pt.Z = e2.Top.Z;
+  else (*m_ZFill)(e1.Bot, e1.Top, e2.Bot, e2.Top, pt);
+}
+//------------------------------------------------------------------------------
+#endif
+
+    void Clipper::IntersectEdges(TEdge *e1, TEdge *e2, IntPoint &Pt)
+    {
+        bool e1Contributing = ( e1->OutIdx >= 0 );
+        bool e2Contributing = ( e2->OutIdx >= 0 );
+
+#ifdef use_xyz
+        SetZ(Pt, *e1, *e2);
+#endif
+
+#ifdef use_lines
+        //if either edge is on an OPEN path ...
+        if (e1->WindDelta == 0 || e2->WindDelta == 0)
+        {
+            //ignore subject-subject open path intersections UNLESS they
+            //are both open paths, AND they are both 'contributing maximas' ...
+            if (e1->WindDelta == 0 && e2->WindDelta == 0) return;
+
+                //if intersecting a subj line with a subj poly ...
+            else if (e1->PolyTyp == e2->PolyTyp &&
+                     e1->WindDelta != e2->WindDelta && m_ClipType == ctUnion)
+            {
+                if (e1->WindDelta == 0)
+                {
+                    if (e2Contributing)
+                    {
+                        AddOutPt(e1, Pt);
+                        if (e1Contributing) e1->OutIdx = Unassigned;
+                    }
+                }
+                else
+                {
+                    if (e1Contributing)
+                    {
+                        AddOutPt(e2, Pt);
+                        if (e2Contributing) e2->OutIdx = Unassigned;
+                    }
+                }
+            }
+            else if (e1->PolyTyp != e2->PolyTyp)
+            {
+                //toggle subj open path OutIdx on/off when Abs(clip.WndCnt) == 1 ...
+                if ((e1->WindDelta == 0) && abs(e2->WindCnt) == 1 &&
+                    (m_ClipType != ctUnion || e2->WindCnt2 == 0))
+                {
+                    AddOutPt(e1, Pt);
+                    if (e1Contributing) e1->OutIdx = Unassigned;
+                }
+                else if ((e2->WindDelta == 0) && (abs(e1->WindCnt) == 1) &&
+                         (m_ClipType != ctUnion || e1->WindCnt2 == 0))
+                {
+                    AddOutPt(e2, Pt);
+                    if (e2Contributing) e2->OutIdx = Unassigned;
+                }
+            }
+            return;
+        }
+#endif
+
+        //update winding counts...
+        //assumes that e1 will be to the Right of e2 ABOVE the intersection
+        if ( e1->PolyTyp == e2->PolyTyp )
+        {
+            if ( IsEvenOddFillType( *e1) )
+            {
+                int oldE1WindCnt = e1->WindCnt;
+                e1->WindCnt = e2->WindCnt;
+                e2->WindCnt = oldE1WindCnt;
+            } else
+            {
+                if (e1->WindCnt + e2->WindDelta == 0 ) e1->WindCnt = -e1->WindCnt;
+                else e1->WindCnt += e2->WindDelta;
+                if ( e2->WindCnt - e1->WindDelta == 0 ) e2->WindCnt = -e2->WindCnt;
+                else e2->WindCnt -= e1->WindDelta;
+            }
+        } else
+        {
+            if (!IsEvenOddFillType(*e2)) e1->WindCnt2 += e2->WindDelta;
+            else e1->WindCnt2 = ( e1->WindCnt2 == 0 ) ? 1 : 0;
+            if (!IsEvenOddFillType(*e1)) e2->WindCnt2 -= e1->WindDelta;
+            else e2->WindCnt2 = ( e2->WindCnt2 == 0 ) ? 1 : 0;
+        }
+
+        PolyFillType e1FillType, e2FillType, e1FillType2, e2FillType2;
+        if (e1->PolyTyp == ptSubject)
+        {
+            e1FillType = m_SubjFillType;
+            e1FillType2 = m_ClipFillType;
+        } else
+        {
+            e1FillType = m_ClipFillType;
+            e1FillType2 = m_SubjFillType;
+        }
+        if (e2->PolyTyp == ptSubject)
+        {
+            e2FillType = m_SubjFillType;
+            e2FillType2 = m_ClipFillType;
+        } else
+        {
+            e2FillType = m_ClipFillType;
+            e2FillType2 = m_SubjFillType;
+        }
+
+        cInt e1Wc, e2Wc;
+        switch (e1FillType)
+        {
+            case pftPositive: e1Wc = e1->WindCnt; break;
+            case pftNegative: e1Wc = -e1->WindCnt; break;
+            default: e1Wc = Abs(e1->WindCnt);
+        }
+        switch(e2FillType)
+        {
+            case pftPositive: e2Wc = e2->WindCnt; break;
+            case pftNegative: e2Wc = -e2->WindCnt; break;
+            default: e2Wc = Abs(e2->WindCnt);
+        }
+
+        if ( e1Contributing && e2Contributing )
+        {
+            if ((e1Wc != 0 && e1Wc != 1) || (e2Wc != 0 && e2Wc != 1) ||
+                (e1->PolyTyp != e2->PolyTyp && m_ClipType != ctXor) )
+            {
+                AddLocalMaxPoly(e1, e2, Pt);
+            }
+            else
+            {
+                AddOutPt(e1, Pt);
+                AddOutPt(e2, Pt);
+                SwapSides( *e1 , *e2 );
+                SwapPolyIndexes( *e1 , *e2 );
+            }
+        }
+        else if ( e1Contributing )
+        {
+            if (e2Wc == 0 || e2Wc == 1)
+            {
+                AddOutPt(e1, Pt);
+                SwapSides(*e1, *e2);
+                SwapPolyIndexes(*e1, *e2);
+            }
+        }
+        else if ( e2Contributing )
+        {
+            if (e1Wc == 0 || e1Wc == 1)
+            {
+                AddOutPt(e2, Pt);
+                SwapSides(*e1, *e2);
+                SwapPolyIndexes(*e1, *e2);
+            }
+        }
+        else if ( (e1Wc == 0 || e1Wc == 1) && (e2Wc == 0 || e2Wc == 1))
+        {
+            //neither edge is currently contributing ...
+
+            cInt e1Wc2, e2Wc2;
+            switch (e1FillType2)
+            {
+                case pftPositive: e1Wc2 = e1->WindCnt2; break;
+                case pftNegative : e1Wc2 = -e1->WindCnt2; break;
+                default: e1Wc2 = Abs(e1->WindCnt2);
+            }
+            switch (e2FillType2)
+            {
+                case pftPositive: e2Wc2 = e2->WindCnt2; break;
+                case pftNegative: e2Wc2 = -e2->WindCnt2; break;
+                default: e2Wc2 = Abs(e2->WindCnt2);
+            }
+
+            if (e1->PolyTyp != e2->PolyTyp)
+            {
+                AddLocalMinPoly(e1, e2, Pt);
+            }
+            else if (e1Wc == 1 && e2Wc == 1)
+                switch( m_ClipType ) {
+                    case ctIntersection:
+                        if (e1Wc2 > 0 && e2Wc2 > 0)
+                            AddLocalMinPoly(e1, e2, Pt);
+                        break;
+                    case ctUnion:
+                        if ( e1Wc2 <= 0 && e2Wc2 <= 0 )
+                            AddLocalMinPoly(e1, e2, Pt);
+                        break;
+                    case ctDifference:
+                        if (((e1->PolyTyp == ptClip) && (e1Wc2 > 0) && (e2Wc2 > 0)) ||
+                            ((e1->PolyTyp == ptSubject) && (e1Wc2 <= 0) && (e2Wc2 <= 0)))
+                            AddLocalMinPoly(e1, e2, Pt);
+                        break;
+                    case ctXor:
+                        AddLocalMinPoly(e1, e2, Pt);
+                }
+            else
+                SwapSides( *e1, *e2 );
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::SetHoleState(TEdge *e, OutRec *outrec)
+    {
+        TEdge *e2 = e->PrevInAEL;
+        TEdge *eTmp = 0;
+        while (e2)
+        {
+            if (e2->OutIdx >= 0 && e2->WindDelta != 0)
+            {
+                if (!eTmp) eTmp = e2;
+                else if (eTmp->OutIdx == e2->OutIdx) eTmp = 0;
+            }
+            e2 = e2->PrevInAEL;
+        }
+        if (!eTmp)
+        {
+            outrec->FirstLeft = 0;
+            outrec->IsHole = false;
+        }
+        else
+        {
+            outrec->FirstLeft = m_PolyOuts[eTmp->OutIdx];
+            outrec->IsHole = !outrec->FirstLeft->IsHole;
+        }
+    }
+//------------------------------------------------------------------------------
+
+    OutRec* GetLowermostRec(OutRec *outRec1, OutRec *outRec2)
+    {
+        //work out which polygon fragment has the correct hole state ...
+        if (!outRec1->BottomPt)
+            outRec1->BottomPt = GetBottomPt(outRec1->Pts);
+        if (!outRec2->BottomPt)
+            outRec2->BottomPt = GetBottomPt(outRec2->Pts);
+        OutPt *OutPt1 = outRec1->BottomPt;
+        OutPt *OutPt2 = outRec2->BottomPt;
+        if (OutPt1->Pt.Y > OutPt2->Pt.Y) return outRec1;
+        else if (OutPt1->Pt.Y < OutPt2->Pt.Y) return outRec2;
+        else if (OutPt1->Pt.X < OutPt2->Pt.X) return outRec1;
+        else if (OutPt1->Pt.X > OutPt2->Pt.X) return outRec2;
+        else if (OutPt1->Next == OutPt1) return outRec2;
+        else if (OutPt2->Next == OutPt2) return outRec1;
+        else if (FirstIsBottomPt(OutPt1, OutPt2)) return outRec1;
+        else return outRec2;
+    }
+//------------------------------------------------------------------------------
+
+    bool OutRec1RightOfOutRec2(OutRec* outRec1, OutRec* outRec2)
+    {
+        do
+        {
+            outRec1 = outRec1->FirstLeft;
+            if (outRec1 == outRec2) return true;
+        } while (outRec1);
+        return false;
+    }
+//------------------------------------------------------------------------------
+
+    OutRec* Clipper::GetOutRec(int Idx)
+    {
+        OutRec* outrec = m_PolyOuts[Idx];
+        while (outrec != m_PolyOuts[outrec->Idx])
+            outrec = m_PolyOuts[outrec->Idx];
+        return outrec;
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::AppendPolygon(TEdge *e1, TEdge *e2)
+    {
+        //get the start and ends of both output polygons ...
+        OutRec *outRec1 = m_PolyOuts[e1->OutIdx];
+        OutRec *outRec2 = m_PolyOuts[e2->OutIdx];
+
+        OutRec *holeStateRec;
+        if (OutRec1RightOfOutRec2(outRec1, outRec2))
+            holeStateRec = outRec2;
+        else if (OutRec1RightOfOutRec2(outRec2, outRec1))
+            holeStateRec = outRec1;
+        else
+            holeStateRec = GetLowermostRec(outRec1, outRec2);
+
+        //get the start and ends of both output polygons and
+        //join e2 poly onto e1 poly and delete pointers to e2 ...
+
+        OutPt* p1_lft = outRec1->Pts;
+        OutPt* p1_rt = p1_lft->Prev;
+        OutPt* p2_lft = outRec2->Pts;
+        OutPt* p2_rt = p2_lft->Prev;
+
+        //join e2 poly onto e1 poly and delete pointers to e2 ...
+        if(  e1->Side == esLeft )
+        {
+            if(  e2->Side == esLeft )
+            {
+                //z y x a b c
+                ReversePolyPtLinks(p2_lft);
+                p2_lft->Next = p1_lft;
+                p1_lft->Prev = p2_lft;
+                p1_rt->Next = p2_rt;
+                p2_rt->Prev = p1_rt;
+                outRec1->Pts = p2_rt;
+            } else
+            {
+                //x y z a b c
+                p2_rt->Next = p1_lft;
+                p1_lft->Prev = p2_rt;
+                p2_lft->Prev = p1_rt;
+                p1_rt->Next = p2_lft;
+                outRec1->Pts = p2_lft;
+            }
+        } else
+        {
+            if(  e2->Side == esRight )
+            {
+                //a b c z y x
+                ReversePolyPtLinks(p2_lft);
+                p1_rt->Next = p2_rt;
+                p2_rt->Prev = p1_rt;
+                p2_lft->Next = p1_lft;
+                p1_lft->Prev = p2_lft;
+            } else
+            {
+                //a b c x y z
+                p1_rt->Next = p2_lft;
+                p2_lft->Prev = p1_rt;
+                p1_lft->Prev = p2_rt;
+                p2_rt->Next = p1_lft;
+            }
+        }
+
+        outRec1->BottomPt = 0;
+        if (holeStateRec == outRec2)
+        {
+            if (outRec2->FirstLeft != outRec1)
+                outRec1->FirstLeft = outRec2->FirstLeft;
+            outRec1->IsHole = outRec2->IsHole;
+        }
+        outRec2->Pts = 0;
+        outRec2->BottomPt = 0;
+        outRec2->FirstLeft = outRec1;
+
+        int OKIdx = e1->OutIdx;
+        int ObsoleteIdx = e2->OutIdx;
+
+        e1->OutIdx = Unassigned; //nb: safe because we only get here via AddLocalMaxPoly
+        e2->OutIdx = Unassigned;
+
+        TEdge* e = m_ActiveEdges;
+        while( e )
+        {
+            if( e->OutIdx == ObsoleteIdx )
+            {
+                e->OutIdx = OKIdx;
+                e->Side = e1->Side;
+                break;
+            }
+            e = e->NextInAEL;
+        }
+
+        outRec2->Idx = outRec1->Idx;
+    }
+//------------------------------------------------------------------------------
+
+    OutPt* Clipper::AddOutPt(TEdge *e, const IntPoint &pt)
+    {
+        if(  e->OutIdx < 0 )
+        {
+            OutRec *outRec = CreateOutRec();
+            outRec->IsOpen = (e->WindDelta == 0);
+            OutPt* newOp = new OutPt;
+            outRec->Pts = newOp;
+            newOp->Idx = outRec->Idx;
+            newOp->Pt = pt;
+            newOp->Next = newOp;
+            newOp->Prev = newOp;
+            if (!outRec->IsOpen)
+                SetHoleState(e, outRec);
+            e->OutIdx = outRec->Idx;
+            return newOp;
+        } else
+        {
+            OutRec *outRec = m_PolyOuts[e->OutIdx];
+            //OutRec.Pts is the 'Left-most' point & OutRec.Pts.Prev is the 'Right-most'
+            OutPt* op = outRec->Pts;
+
+            bool ToFront = (e->Side == esLeft);
+            if (ToFront && (pt == op->Pt)) return op;
+            else if (!ToFront && (pt == op->Prev->Pt)) return op->Prev;
+
+            OutPt* newOp = new OutPt;
+            newOp->Idx = outRec->Idx;
+            newOp->Pt = pt;
+            newOp->Next = op;
+            newOp->Prev = op->Prev;
+            newOp->Prev->Next = newOp;
+            op->Prev = newOp;
+            if (ToFront) outRec->Pts = newOp;
+            return newOp;
+        }
+    }
+//------------------------------------------------------------------------------
+
+    OutPt* Clipper::GetLastOutPt(TEdge *e)
+    {
+        OutRec *outRec = m_PolyOuts[e->OutIdx];
+        if (e->Side == esLeft)
+            return outRec->Pts;
+        else
+            return outRec->Pts->Prev;
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::ProcessHorizontals()
+    {
+        TEdge* horzEdge;
+        while (PopEdgeFromSEL(horzEdge))
+            ProcessHorizontal(horzEdge);
+    }
+//------------------------------------------------------------------------------
+
+    inline bool IsMinima(TEdge *e)
+    {
+        return e  && (e->Prev->NextInLML != e) && (e->Next->NextInLML != e);
+    }
+//------------------------------------------------------------------------------
+
+    inline bool IsMaxima(TEdge *e, const cInt Y)
+    {
+        return e && e->Top.Y == Y && !e->NextInLML;
+    }
+//------------------------------------------------------------------------------
+
+    inline bool IsIntermediate(TEdge *e, const cInt Y)
+    {
+        return e->Top.Y == Y && e->NextInLML;
+    }
+//------------------------------------------------------------------------------
+
+    TEdge *GetMaximaPair(TEdge *e)
+    {
+        if ((e->Next->Top == e->Top) && !e->Next->NextInLML)
+            return e->Next;
+        else if ((e->Prev->Top == e->Top) && !e->Prev->NextInLML)
+            return e->Prev;
+        else return 0;
+    }
+//------------------------------------------------------------------------------
+
+    TEdge *GetMaximaPairEx(TEdge *e)
+    {
+        //as GetMaximaPair() but returns 0 if MaxPair isn't in AEL (unless it's horizontal)
+        TEdge* result = GetMaximaPair(e);
+        if (result && (result->OutIdx == Skip ||
+                       (result->NextInAEL == result->PrevInAEL && !IsHorizontal(*result)))) return 0;
+        return result;
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::SwapPositionsInSEL(TEdge *Edge1, TEdge *Edge2)
+    {
+        if(  !( Edge1->NextInSEL ) &&  !( Edge1->PrevInSEL ) ) return;
+        if(  !( Edge2->NextInSEL ) &&  !( Edge2->PrevInSEL ) ) return;
+
+        if(  Edge1->NextInSEL == Edge2 )
+        {
+            TEdge* Next = Edge2->NextInSEL;
+            if( Next ) Next->PrevInSEL = Edge1;
+            TEdge* Prev = Edge1->PrevInSEL;
+            if( Prev ) Prev->NextInSEL = Edge2;
+            Edge2->PrevInSEL = Prev;
+            Edge2->NextInSEL = Edge1;
+            Edge1->PrevInSEL = Edge2;
+            Edge1->NextInSEL = Next;
+        }
+        else if(  Edge2->NextInSEL == Edge1 )
+        {
+            TEdge* Next = Edge1->NextInSEL;
+            if( Next ) Next->PrevInSEL = Edge2;
+            TEdge* Prev = Edge2->PrevInSEL;
+            if( Prev ) Prev->NextInSEL = Edge1;
+            Edge1->PrevInSEL = Prev;
+            Edge1->NextInSEL = Edge2;
+            Edge2->PrevInSEL = Edge1;
+            Edge2->NextInSEL = Next;
+        }
+        else
+        {
+            TEdge* Next = Edge1->NextInSEL;
+            TEdge* Prev = Edge1->PrevInSEL;
+            Edge1->NextInSEL = Edge2->NextInSEL;
+            if( Edge1->NextInSEL ) Edge1->NextInSEL->PrevInSEL = Edge1;
+            Edge1->PrevInSEL = Edge2->PrevInSEL;
+            if( Edge1->PrevInSEL ) Edge1->PrevInSEL->NextInSEL = Edge1;
+            Edge2->NextInSEL = Next;
+            if( Edge2->NextInSEL ) Edge2->NextInSEL->PrevInSEL = Edge2;
+            Edge2->PrevInSEL = Prev;
+            if( Edge2->PrevInSEL ) Edge2->PrevInSEL->NextInSEL = Edge2;
+        }
+
+        if( !Edge1->PrevInSEL ) m_SortedEdges = Edge1;
+        else if( !Edge2->PrevInSEL ) m_SortedEdges = Edge2;
+    }
+//------------------------------------------------------------------------------
+
+    TEdge* GetNextInAEL(TEdge *e, Direction dir)
+    {
+        return dir == dLeftToRight ? e->NextInAEL : e->PrevInAEL;
+    }
+//------------------------------------------------------------------------------
+
+    void GetHorzDirection(TEdge& HorzEdge, Direction& Dir, cInt& Left, cInt& Right)
+    {
+        if (HorzEdge.Bot.X < HorzEdge.Top.X)
+        {
+            Left = HorzEdge.Bot.X;
+            Right = HorzEdge.Top.X;
+            Dir = dLeftToRight;
+        } else
+        {
+            Left = HorzEdge.Top.X;
+            Right = HorzEdge.Bot.X;
+            Dir = dRightToLeft;
+        }
+    }
+//------------------------------------------------------------------------
+
+/*******************************************************************************
+* Notes: Horizontal edges (HEs) at scanline intersections (ie at the Top or    *
+* Bottom of a scanbeam) are processed as if layered. The order in which HEs    *
+* are processed doesn't matter. HEs intersect with other HE Bot.Xs only [#]    *
+* (or they could intersect with Top.Xs only, ie EITHER Bot.Xs OR Top.Xs),      *
+* and with other non-horizontal edges [*]. Once these intersections are        *
+* processed, intermediate HEs then 'promote' the Edge above (NextInLML) into   *
+* the AEL. These 'promoted' edges may in turn intersect [%] with other HEs.    *
+*******************************************************************************/
+
+    void Clipper::ProcessHorizontal(TEdge *horzEdge)
+    {
+        Direction dir;
+        cInt horzLeft, horzRight;
+        bool IsOpen = (horzEdge->WindDelta == 0);
+
+        GetHorzDirection(*horzEdge, dir, horzLeft, horzRight);
+
+        TEdge* eLastHorz = horzEdge, *eMaxPair = 0;
+        while (eLastHorz->NextInLML && IsHorizontal(*eLastHorz->NextInLML))
+            eLastHorz = eLastHorz->NextInLML;
+        if (!eLastHorz->NextInLML)
+            eMaxPair = GetMaximaPair(eLastHorz);
+
+        MaximaList::const_iterator maxIt;
+        MaximaList::const_reverse_iterator maxRit;
+        if (m_Maxima.size() > 0)
+        {
+            //get the first maxima in range (X) ...
+            if (dir == dLeftToRight)
+            {
+                maxIt = m_Maxima.begin();
+                while (maxIt != m_Maxima.end() && *maxIt <= horzEdge->Bot.X) maxIt++;
+                if (maxIt != m_Maxima.end() && *maxIt >= eLastHorz->Top.X)
+                    maxIt = m_Maxima.end();
+            }
+            else
+            {
+                maxRit = m_Maxima.rbegin();
+                while (maxRit != m_Maxima.rend() && *maxRit > horzEdge->Bot.X) maxRit++;
+                if (maxRit != m_Maxima.rend() && *maxRit <= eLastHorz->Top.X)
+                    maxRit = m_Maxima.rend();
+            }
+        }
+
+        OutPt* op1 = 0;
+
+        for (;;) //loop through consec. horizontal edges
+        {
+
+            bool IsLastHorz = (horzEdge == eLastHorz);
+            TEdge* e = GetNextInAEL(horzEdge, dir);
+            while(e)
+            {
+
+                //this code block inserts extra coords into horizontal edges (in output
+                //polygons) whereever maxima touch these horizontal edges. This helps
+                //'simplifying' polygons (ie if the Simplify property is set).
+                if (m_Maxima.size() > 0)
+                {
+                    if (dir == dLeftToRight)
+                    {
+                        while (maxIt != m_Maxima.end() && *maxIt < e->Curr.X)
+                        {
+                            if (horzEdge->OutIdx >= 0 && !IsOpen)
+                                AddOutPt(horzEdge, IntPoint(*maxIt, horzEdge->Bot.Y));
+                            maxIt++;
+                        }
+                    }
+                    else
+                    {
+                        while (maxRit != m_Maxima.rend() && *maxRit > e->Curr.X)
+                        {
+                            if (horzEdge->OutIdx >= 0 && !IsOpen)
+                                AddOutPt(horzEdge, IntPoint(*maxRit, horzEdge->Bot.Y));
+                            maxRit++;
+                        }
+                    }
+                };
+
+                if ((dir == dLeftToRight && e->Curr.X > horzRight) ||
+                    (dir == dRightToLeft && e->Curr.X < horzLeft)) break;
+
+                //Also break if we've got to the end of an intermediate horizontal edge ...
+                //nb: Smaller Dx's are to the right of larger Dx's ABOVE the horizontal.
+                if (e->Curr.X == horzEdge->Top.X && horzEdge->NextInLML &&
+                    e->Dx < horzEdge->NextInLML->Dx) break;
+
+                if (horzEdge->OutIdx >= 0 && !IsOpen)  //note: may be done multiple times
+                {
+#ifdef use_xyz
+                    if (dir == dLeftToRight) SetZ(e->Curr, *horzEdge, *e);
+			else SetZ(e->Curr, *e, *horzEdge);
+#endif
+                    op1 = AddOutPt(horzEdge, e->Curr);
+                    TEdge* eNextHorz = m_SortedEdges;
+                    while (eNextHorz)
+                    {
+                        if (eNextHorz->OutIdx >= 0 &&
+                            HorzSegmentsOverlap(horzEdge->Bot.X,
+                                                horzEdge->Top.X, eNextHorz->Bot.X, eNextHorz->Top.X))
+                        {
+                            OutPt* op2 = GetLastOutPt(eNextHorz);
+                            AddJoin(op2, op1, eNextHorz->Top);
+                        }
+                        eNextHorz = eNextHorz->NextInSEL;
+                    }
+                    AddGhostJoin(op1, horzEdge->Bot);
+                }
+
+                //OK, so far we're still in range of the horizontal Edge  but make sure
+                //we're at the last of consec. horizontals when matching with eMaxPair
+                if(e == eMaxPair && IsLastHorz)
+                {
+                    if (horzEdge->OutIdx >= 0)
+                        AddLocalMaxPoly(horzEdge, eMaxPair, horzEdge->Top);
+                    DeleteFromAEL(horzEdge);
+                    DeleteFromAEL(eMaxPair);
+                    return;
+                }
+
+                if(dir == dLeftToRight)
+                {
+                    IntPoint Pt = IntPoint(e->Curr.X, horzEdge->Curr.Y);
+                    IntersectEdges(horzEdge, e, Pt);
+                }
+                else
+                {
+                    IntPoint Pt = IntPoint(e->Curr.X, horzEdge->Curr.Y);
+                    IntersectEdges( e, horzEdge, Pt);
+                }
+                TEdge* eNext = GetNextInAEL(e, dir);
+                SwapPositionsInAEL( horzEdge, e );
+                e = eNext;
+            } //end while(e)
+
+            //Break out of loop if HorzEdge.NextInLML is not also horizontal ...
+            if (!horzEdge->NextInLML || !IsHorizontal(*horzEdge->NextInLML)) break;
+
+            UpdateEdgeIntoAEL(horzEdge);
+            if (horzEdge->OutIdx >= 0) AddOutPt(horzEdge, horzEdge->Bot);
+            GetHorzDirection(*horzEdge, dir, horzLeft, horzRight);
+
+        } //end for (;;)
+
+        if (horzEdge->OutIdx >= 0 && !op1)
+        {
+            op1 = GetLastOutPt(horzEdge);
+            TEdge* eNextHorz = m_SortedEdges;
+            while (eNextHorz)
+            {
+                if (eNextHorz->OutIdx >= 0 &&
+                    HorzSegmentsOverlap(horzEdge->Bot.X,
+                                        horzEdge->Top.X, eNextHorz->Bot.X, eNextHorz->Top.X))
+                {
+                    OutPt* op2 = GetLastOutPt(eNextHorz);
+                    AddJoin(op2, op1, eNextHorz->Top);
+                }
+                eNextHorz = eNextHorz->NextInSEL;
+            }
+            AddGhostJoin(op1, horzEdge->Top);
+        }
+
+        if (horzEdge->NextInLML)
+        {
+            if(horzEdge->OutIdx >= 0)
+            {
+                op1 = AddOutPt( horzEdge, horzEdge->Top);
+                UpdateEdgeIntoAEL(horzEdge);
+                if (horzEdge->WindDelta == 0) return;
+                //nb: HorzEdge is no longer horizontal here
+                TEdge* ePrev = horzEdge->PrevInAEL;
+                TEdge* eNext = horzEdge->NextInAEL;
+                if (ePrev && ePrev->Curr.X == horzEdge->Bot.X &&
+                    ePrev->Curr.Y == horzEdge->Bot.Y && ePrev->WindDelta != 0 &&
+                    (ePrev->OutIdx >= 0 && ePrev->Curr.Y > ePrev->Top.Y &&
+                     SlopesEqual(*horzEdge, *ePrev, m_UseFullRange)))
+                {
+                    OutPt* op2 = AddOutPt(ePrev, horzEdge->Bot);
+                    AddJoin(op1, op2, horzEdge->Top);
+                }
+                else if (eNext && eNext->Curr.X == horzEdge->Bot.X &&
+                         eNext->Curr.Y == horzEdge->Bot.Y && eNext->WindDelta != 0 &&
+                         eNext->OutIdx >= 0 && eNext->Curr.Y > eNext->Top.Y &&
+                         SlopesEqual(*horzEdge, *eNext, m_UseFullRange))
+                {
+                    OutPt* op2 = AddOutPt(eNext, horzEdge->Bot);
+                    AddJoin(op1, op2, horzEdge->Top);
+                }
+            }
+            else
+                UpdateEdgeIntoAEL(horzEdge);
+        }
+        else
+        {
+            if (horzEdge->OutIdx >= 0) AddOutPt(horzEdge, horzEdge->Top);
+            DeleteFromAEL(horzEdge);
+        }
+    }
+//------------------------------------------------------------------------------
+
+    bool Clipper::ProcessIntersections(const cInt topY)
+    {
+        if( !m_ActiveEdges ) return true;
+        try {
+            BuildIntersectList(topY);
+            size_t IlSize = m_IntersectList.size();
+            if (IlSize == 0) return true;
+            if (IlSize == 1 || FixupIntersectionOrder()) ProcessIntersectList();
+            else return false;
+        }
+        catch(...)
+        {
+            m_SortedEdges = 0;
+            DisposeIntersectNodes();
+            throw clipperException("ProcessIntersections error");
+        }
+        m_SortedEdges = 0;
+        return true;
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::DisposeIntersectNodes()
+    {
+        for (size_t i = 0; i < m_IntersectList.size(); ++i )
+            delete m_IntersectList[i];
+        m_IntersectList.clear();
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::BuildIntersectList(const cInt topY)
+    {
+        if ( !m_ActiveEdges ) return;
+
+        //prepare for sorting ...
+        TEdge* e = m_ActiveEdges;
+        m_SortedEdges = e;
+        while( e )
+        {
+            e->PrevInSEL = e->PrevInAEL;
+            e->NextInSEL = e->NextInAEL;
+            e->Curr.X = TopX( *e, topY );
+            e = e->NextInAEL;
+        }
+
+        //bubblesort ...
+        bool isModified;
+        do
+        {
+            isModified = false;
+            e = m_SortedEdges;
+            while( e->NextInSEL )
+            {
+                TEdge *eNext = e->NextInSEL;
+                IntPoint Pt;
+                if(e->Curr.X > eNext->Curr.X)
+                {
+                    IntersectPoint(*e, *eNext, Pt);
+                    if (Pt.Y < topY) Pt = IntPoint(TopX(*e, topY), topY);
+                    IntersectNode * newNode = new IntersectNode;
+                    newNode->Edge1 = e;
+                    newNode->Edge2 = eNext;
+                    newNode->Pt = Pt;
+                    m_IntersectList.push_back(newNode);
+
+                    SwapPositionsInSEL(e, eNext);
+                    isModified = true;
+                }
+                else
+                    e = eNext;
+            }
+            if( e->PrevInSEL ) e->PrevInSEL->NextInSEL = 0;
+            else break;
+        }
+        while ( isModified );
+        m_SortedEdges = 0; //important
+    }
+//------------------------------------------------------------------------------
+
+
+    void Clipper::ProcessIntersectList()
+    {
+        for (size_t i = 0; i < m_IntersectList.size(); ++i)
+        {
+            IntersectNode* iNode = m_IntersectList[i];
+            {
+                IntersectEdges( iNode->Edge1, iNode->Edge2, iNode->Pt);
+                SwapPositionsInAEL( iNode->Edge1 , iNode->Edge2 );
+            }
+            delete iNode;
+        }
+        m_IntersectList.clear();
+    }
+//------------------------------------------------------------------------------
+
+    bool IntersectListSort(IntersectNode* node1, IntersectNode* node2)
+    {
+        return node2->Pt.Y < node1->Pt.Y;
+    }
+//------------------------------------------------------------------------------
+
+    inline bool EdgesAdjacent(const IntersectNode &inode)
+    {
+        return (inode.Edge1->NextInSEL == inode.Edge2) ||
+               (inode.Edge1->PrevInSEL == inode.Edge2);
+    }
+//------------------------------------------------------------------------------
+
+    bool Clipper::FixupIntersectionOrder()
+    {
+        //pre-condition: intersections are sorted Bottom-most first.
+        //Now it's crucial that intersections are made only between adjacent edges,
+        //so to ensure this the order of intersections may need adjusting ...
+        CopyAELToSEL();
+        std::sort(m_IntersectList.begin(), m_IntersectList.end(), IntersectListSort);
+        size_t cnt = m_IntersectList.size();
+        for (size_t i = 0; i < cnt; ++i)
+        {
+            if (!EdgesAdjacent(*m_IntersectList[i]))
+            {
+                size_t j = i + 1;
+                while (j < cnt && !EdgesAdjacent(*m_IntersectList[j])) j++;
+                if (j == cnt)  return false;
+                std::swap(m_IntersectList[i], m_IntersectList[j]);
+            }
+            SwapPositionsInSEL(m_IntersectList[i]->Edge1, m_IntersectList[i]->Edge2);
+        }
+        return true;
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::DoMaxima(TEdge *e)
+    {
+        TEdge* eMaxPair = GetMaximaPairEx(e);
+        if (!eMaxPair)
+        {
+            if (e->OutIdx >= 0)
+                AddOutPt(e, e->Top);
+            DeleteFromAEL(e);
+            return;
+        }
+
+        TEdge* eNext = e->NextInAEL;
+        while(eNext && eNext != eMaxPair)
+        {
+            IntersectEdges(e, eNext, e->Top);
+            SwapPositionsInAEL(e, eNext);
+            eNext = e->NextInAEL;
+        }
+
+        if(e->OutIdx == Unassigned && eMaxPair->OutIdx == Unassigned)
+        {
+            DeleteFromAEL(e);
+            DeleteFromAEL(eMaxPair);
+        }
+        else if( e->OutIdx >= 0 && eMaxPair->OutIdx >= 0 )
+        {
+            if (e->OutIdx >= 0) AddLocalMaxPoly(e, eMaxPair, e->Top);
+            DeleteFromAEL(e);
+            DeleteFromAEL(eMaxPair);
+        }
+#ifdef use_lines
+        else if (e->WindDelta == 0)
+        {
+            if (e->OutIdx >= 0)
+            {
+                AddOutPt(e, e->Top);
+                e->OutIdx = Unassigned;
+            }
+            DeleteFromAEL(e);
+
+            if (eMaxPair->OutIdx >= 0)
+            {
+                AddOutPt(eMaxPair, e->Top);
+                eMaxPair->OutIdx = Unassigned;
+            }
+            DeleteFromAEL(eMaxPair);
+        }
+#endif
+        else throw clipperException("DoMaxima error");
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::ProcessEdgesAtTopOfScanbeam(const cInt topY)
+    {
+        TEdge* e = m_ActiveEdges;
+        while( e )
+        {
+            //1. process maxima, treating them as if they're 'bent' horizontal edges,
+            //   but exclude maxima with horizontal edges. nb: e can't be a horizontal.
+            bool IsMaximaEdge = IsMaxima(e, topY);
+
+            if(IsMaximaEdge)
+            {
+                TEdge* eMaxPair = GetMaximaPairEx(e);
+                IsMaximaEdge = (!eMaxPair || !IsHorizontal(*eMaxPair));
+            }
+
+            if(IsMaximaEdge)
+            {
+                if (m_StrictSimple) m_Maxima.push_back(e->Top.X);
+                TEdge* ePrev = e->PrevInAEL;
+                DoMaxima(e);
+                if( !ePrev ) e = m_ActiveEdges;
+                else e = ePrev->NextInAEL;
+            }
+            else
+            {
+                //2. promote horizontal edges, otherwise update Curr.X and Curr.Y ...
+                if (IsIntermediate(e, topY) && IsHorizontal(*e->NextInLML))
+                {
+                    UpdateEdgeIntoAEL(e);
+                    if (e->OutIdx >= 0)
+                        AddOutPt(e, e->Bot);
+                    AddEdgeToSEL(e);
+                }
+                else
+                {
+                    e->Curr.X = TopX( *e, topY );
+                    e->Curr.Y = topY;
+#ifdef use_xyz
+                    e->Curr.Z = topY == e->Top.Y ? e->Top.Z : (topY == e->Bot.Y ? e->Bot.Z : 0);
+#endif
+                }
+
+                //When StrictlySimple and 'e' is being touched by another edge, then
+                //make sure both edges have a vertex here ...
+                if (m_StrictSimple)
+                {
+                    TEdge* ePrev = e->PrevInAEL;
+                    if ((e->OutIdx >= 0) && (e->WindDelta != 0) && ePrev && (ePrev->OutIdx >= 0) &&
+                        (ePrev->Curr.X == e->Curr.X) && (ePrev->WindDelta != 0))
+                    {
+                        IntPoint pt = e->Curr;
+#ifdef use_xyz
+                        SetZ(pt, *ePrev, *e);
+#endif
+                        OutPt* op = AddOutPt(ePrev, pt);
+                        OutPt* op2 = AddOutPt(e, pt);
+                        AddJoin(op, op2, pt); //StrictlySimple (type-3) join
+                    }
+                }
+
+                e = e->NextInAEL;
+            }
+        }
+
+        //3. Process horizontals at the Top of the scanbeam ...
+        m_Maxima.sort();
+        ProcessHorizontals();
+        m_Maxima.clear();
+
+        //4. Promote intermediate vertices ...
+        e = m_ActiveEdges;
+        while(e)
+        {
+            if(IsIntermediate(e, topY))
+            {
+                OutPt* op = 0;
+                if( e->OutIdx >= 0 )
+                    op = AddOutPt(e, e->Top);
+                UpdateEdgeIntoAEL(e);
+
+                //if output polygons share an edge, they'll need joining later ...
+                TEdge* ePrev = e->PrevInAEL;
+                TEdge* eNext = e->NextInAEL;
+                if (ePrev && ePrev->Curr.X == e->Bot.X &&
+                    ePrev->Curr.Y == e->Bot.Y && op &&
+                    ePrev->OutIdx >= 0 && ePrev->Curr.Y > ePrev->Top.Y &&
+                    SlopesEqual(e->Curr, e->Top, ePrev->Curr, ePrev->Top, m_UseFullRange) &&
+                    (e->WindDelta != 0) && (ePrev->WindDelta != 0))
+                {
+                    OutPt* op2 = AddOutPt(ePrev, e->Bot);
+                    AddJoin(op, op2, e->Top);
+                }
+                else if (eNext && eNext->Curr.X == e->Bot.X &&
+                         eNext->Curr.Y == e->Bot.Y && op &&
+                         eNext->OutIdx >= 0 && eNext->Curr.Y > eNext->Top.Y &&
+                         SlopesEqual(e->Curr, e->Top, eNext->Curr, eNext->Top, m_UseFullRange) &&
+                         (e->WindDelta != 0) && (eNext->WindDelta != 0))
+                {
+                    OutPt* op2 = AddOutPt(eNext, e->Bot);
+                    AddJoin(op, op2, e->Top);
+                }
+            }
+            e = e->NextInAEL;
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::FixupOutPolyline(OutRec &outrec)
+    {
+        OutPt *pp = outrec.Pts;
+        OutPt *lastPP = pp->Prev;
+        while (pp != lastPP)
+        {
+            pp = pp->Next;
+            if (pp->Pt == pp->Prev->Pt)
+            {
+                if (pp == lastPP) lastPP = pp->Prev;
+                OutPt *tmpPP = pp->Prev;
+                tmpPP->Next = pp->Next;
+                pp->Next->Prev = tmpPP;
+                delete pp;
+                pp = tmpPP;
+            }
+        }
+
+        if (pp == pp->Prev)
+        {
+            DisposeOutPts(pp);
+            outrec.Pts = 0;
+            return;
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::FixupOutPolygon(OutRec &outrec)
+    {
+        //FixupOutPolygon() - removes duplicate points and simplifies consecutive
+        //parallel edges by removing the middle vertex.
+        OutPt *lastOK = 0;
+        outrec.BottomPt = 0;
+        OutPt *pp = outrec.Pts;
+        bool preserveCol = m_PreserveCollinear || m_StrictSimple;
+
+        for (;;)
+        {
+            if (pp->Prev == pp || pp->Prev == pp->Next)
+            {
+                DisposeOutPts(pp);
+                outrec.Pts = 0;
+                return;
+            }
+
+            //test for duplicate points and collinear edges ...
+            if ((pp->Pt == pp->Next->Pt) || (pp->Pt == pp->Prev->Pt) ||
+                (SlopesEqual(pp->Prev->Pt, pp->Pt, pp->Next->Pt, m_UseFullRange) &&
+                 (!preserveCol || !Pt2IsBetweenPt1AndPt3(pp->Prev->Pt, pp->Pt, pp->Next->Pt))))
+            {
+                lastOK = 0;
+                OutPt *tmp = pp;
+                pp->Prev->Next = pp->Next;
+                pp->Next->Prev = pp->Prev;
+                pp = pp->Prev;
+                delete tmp;
+            }
+            else if (pp == lastOK) break;
+            else
+            {
+                if (!lastOK) lastOK = pp;
+                pp = pp->Next;
+            }
+        }
+        outrec.Pts = pp;
+    }
+//------------------------------------------------------------------------------
+
+    int PointCount(OutPt *Pts)
+    {
+        if (!Pts) return 0;
+        int result = 0;
+        OutPt* p = Pts;
+        do
+        {
+            result++;
+            p = p->Next;
+        }
+        while (p != Pts);
+        return result;
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::BuildResult(Paths &polys)
+    {
+        polys.reserve(m_PolyOuts.size());
+        for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+        {
+            if (!m_PolyOuts[i]->Pts) continue;
+            Path pg;
+            OutPt* p = m_PolyOuts[i]->Pts->Prev;
+            int cnt = PointCount(p);
+            if (cnt < 2) continue;
+            pg.reserve(cnt);
+            for (int i = 0; i < cnt; ++i)
+            {
+                pg.push_back(p->Pt);
+                p = p->Prev;
+            }
+            polys.push_back(pg);
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::BuildResult2(PolyTree& polytree)
+    {
+        polytree.Clear();
+        polytree.AllNodes.reserve(m_PolyOuts.size());
+        //add each output polygon/contour to polytree ...
+        for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); i++)
+        {
+            OutRec* outRec = m_PolyOuts[i];
+            int cnt = PointCount(outRec->Pts);
+            if ((outRec->IsOpen && cnt < 2) || (!outRec->IsOpen && cnt < 3)) continue;
+            FixHoleLinkage(*outRec);
+            PolyNode* pn = new PolyNode();
+            //nb: polytree takes ownership of all the PolyNodes
+            polytree.AllNodes.push_back(pn);
+            outRec->PolyNd = pn;
+            pn->Parent = 0;
+            pn->Index = 0;
+            pn->Contour.reserve(cnt);
+            OutPt *op = outRec->Pts->Prev;
+            for (int j = 0; j < cnt; j++)
+            {
+                pn->Contour.push_back(op->Pt);
+                op = op->Prev;
+            }
+        }
+
+        //fixup PolyNode links etc ...
+        polytree.Childs.reserve(m_PolyOuts.size());
+        for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); i++)
+        {
+            OutRec* outRec = m_PolyOuts[i];
+            if (!outRec->PolyNd) continue;
+            if (outRec->IsOpen)
+            {
+                outRec->PolyNd->m_IsOpen = true;
+                polytree.AddChild(*outRec->PolyNd);
+            }
+            else if (outRec->FirstLeft && outRec->FirstLeft->PolyNd)
+                outRec->FirstLeft->PolyNd->AddChild(*outRec->PolyNd);
+            else
+                polytree.AddChild(*outRec->PolyNd);
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void SwapIntersectNodes(IntersectNode &int1, IntersectNode &int2)
+    {
+        //just swap the contents (because fIntersectNodes is a single-linked-list)
+        IntersectNode inode = int1; //gets a copy of Int1
+        int1.Edge1 = int2.Edge1;
+        int1.Edge2 = int2.Edge2;
+        int1.Pt = int2.Pt;
+        int2.Edge1 = inode.Edge1;
+        int2.Edge2 = inode.Edge2;
+        int2.Pt = inode.Pt;
+    }
+//------------------------------------------------------------------------------
+
+    inline bool E2InsertsBeforeE1(TEdge &e1, TEdge &e2)
+    {
+        if (e2.Curr.X == e1.Curr.X)
+        {
+            if (e2.Top.Y > e1.Top.Y)
+                return e2.Top.X < TopX(e1, e2.Top.Y);
+            else return e1.Top.X > TopX(e2, e1.Top.Y);
+        }
+        else return e2.Curr.X < e1.Curr.X;
+    }
+//------------------------------------------------------------------------------
+
+    bool GetOverlap(const cInt a1, const cInt a2, const cInt b1, const cInt b2,
+                    cInt& Left, cInt& Right)
+    {
+        if (a1 < a2)
+        {
+            if (b1 < b2) {Left = std::max(a1,b1); Right = std::min(a2,b2);}
+            else {Left = std::max(a1,b2); Right = std::min(a2,b1);}
+        }
+        else
+        {
+            if (b1 < b2) {Left = std::max(a2,b1); Right = std::min(a1,b2);}
+            else {Left = std::max(a2,b2); Right = std::min(a1,b1);}
+        }
+        return Left < Right;
+    }
+//------------------------------------------------------------------------------
+
+    inline void UpdateOutPtIdxs(OutRec& outrec)
+    {
+        OutPt* op = outrec.Pts;
+        do
+        {
+            op->Idx = outrec.Idx;
+            op = op->Prev;
+        }
+        while(op != outrec.Pts);
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::InsertEdgeIntoAEL(TEdge *edge, TEdge* startEdge)
+    {
+        if(!m_ActiveEdges)
+        {
+            edge->PrevInAEL = 0;
+            edge->NextInAEL = 0;
+            m_ActiveEdges = edge;
+        }
+        else if(!startEdge && E2InsertsBeforeE1(*m_ActiveEdges, *edge))
+        {
+            edge->PrevInAEL = 0;
+            edge->NextInAEL = m_ActiveEdges;
+            m_ActiveEdges->PrevInAEL = edge;
+            m_ActiveEdges = edge;
+        }
+        else
+        {
+            if(!startEdge) startEdge = m_ActiveEdges;
+            while(startEdge->NextInAEL  &&
+                  !E2InsertsBeforeE1(*startEdge->NextInAEL , *edge))
+                startEdge = startEdge->NextInAEL;
+            edge->NextInAEL = startEdge->NextInAEL;
+            if(startEdge->NextInAEL) startEdge->NextInAEL->PrevInAEL = edge;
+            edge->PrevInAEL = startEdge;
+            startEdge->NextInAEL = edge;
+        }
+    }
+//----------------------------------------------------------------------
+
+    OutPt* DupOutPt(OutPt* outPt, bool InsertAfter)
+    {
+        OutPt* result = new OutPt;
+        result->Pt = outPt->Pt;
+        result->Idx = outPt->Idx;
+        if (InsertAfter)
+        {
+            result->Next = outPt->Next;
+            result->Prev = outPt;
+            outPt->Next->Prev = result;
+            outPt->Next = result;
+        }
+        else
+        {
+            result->Prev = outPt->Prev;
+            result->Next = outPt;
+            outPt->Prev->Next = result;
+            outPt->Prev = result;
+        }
+        return result;
+    }
+//------------------------------------------------------------------------------
+
+    bool JoinHorz(OutPt* op1, OutPt* op1b, OutPt* op2, OutPt* op2b,
+                  const IntPoint Pt, bool DiscardLeft)
+    {
+        Direction Dir1 = (op1->Pt.X > op1b->Pt.X ? dRightToLeft : dLeftToRight);
+        Direction Dir2 = (op2->Pt.X > op2b->Pt.X ? dRightToLeft : dLeftToRight);
+        if (Dir1 == Dir2) return false;
+
+        //When DiscardLeft, we want Op1b to be on the Left of Op1, otherwise we
+        //want Op1b to be on the Right. (And likewise with Op2 and Op2b.)
+        //So, to facilitate this while inserting Op1b and Op2b ...
+        //when DiscardLeft, make sure we're AT or RIGHT of Pt before adding Op1b,
+        //otherwise make sure we're AT or LEFT of Pt. (Likewise with Op2b.)
+        if (Dir1 == dLeftToRight)
+        {
+            while (op1->Next->Pt.X <= Pt.X &&
+                   op1->Next->Pt.X >= op1->Pt.X && op1->Next->Pt.Y == Pt.Y)
+                op1 = op1->Next;
+            if (DiscardLeft && (op1->Pt.X != Pt.X)) op1 = op1->Next;
+            op1b = DupOutPt(op1, !DiscardLeft);
+            if (op1b->Pt != Pt)
+            {
+                op1 = op1b;
+                op1->Pt = Pt;
+                op1b = DupOutPt(op1, !DiscardLeft);
+            }
+        }
+        else
+        {
+            while (op1->Next->Pt.X >= Pt.X &&
+                   op1->Next->Pt.X <= op1->Pt.X && op1->Next->Pt.Y == Pt.Y)
+                op1 = op1->Next;
+            if (!DiscardLeft && (op1->Pt.X != Pt.X)) op1 = op1->Next;
+            op1b = DupOutPt(op1, DiscardLeft);
+            if (op1b->Pt != Pt)
+            {
+                op1 = op1b;
+                op1->Pt = Pt;
+                op1b = DupOutPt(op1, DiscardLeft);
+            }
+        }
+
+        if (Dir2 == dLeftToRight)
+        {
+            while (op2->Next->Pt.X <= Pt.X &&
+                   op2->Next->Pt.X >= op2->Pt.X && op2->Next->Pt.Y == Pt.Y)
+                op2 = op2->Next;
+            if (DiscardLeft && (op2->Pt.X != Pt.X)) op2 = op2->Next;
+            op2b = DupOutPt(op2, !DiscardLeft);
+            if (op2b->Pt != Pt)
+            {
+                op2 = op2b;
+                op2->Pt = Pt;
+                op2b = DupOutPt(op2, !DiscardLeft);
+            };
+        } else
+        {
+            while (op2->Next->Pt.X >= Pt.X &&
+                   op2->Next->Pt.X <= op2->Pt.X && op2->Next->Pt.Y == Pt.Y)
+                op2 = op2->Next;
+            if (!DiscardLeft && (op2->Pt.X != Pt.X)) op2 = op2->Next;
+            op2b = DupOutPt(op2, DiscardLeft);
+            if (op2b->Pt != Pt)
+            {
+                op2 = op2b;
+                op2->Pt = Pt;
+                op2b = DupOutPt(op2, DiscardLeft);
+            };
+        };
+
+        if ((Dir1 == dLeftToRight) == DiscardLeft)
+        {
+            op1->Prev = op2;
+            op2->Next = op1;
+            op1b->Next = op2b;
+            op2b->Prev = op1b;
+        }
+        else
+        {
+            op1->Next = op2;
+            op2->Prev = op1;
+            op1b->Prev = op2b;
+            op2b->Next = op1b;
+        }
+        return true;
+    }
+//------------------------------------------------------------------------------
+
+    bool Clipper::JoinPoints(Join *j, OutRec* outRec1, OutRec* outRec2)
+    {
+        OutPt *op1 = j->OutPt1, *op1b;
+        OutPt *op2 = j->OutPt2, *op2b;
+
+        //There are 3 kinds of joins for output polygons ...
+        //1. Horizontal joins where Join.OutPt1 & Join.OutPt2 are vertices anywhere
+        //along (horizontal) collinear edges (& Join.OffPt is on the same horizontal).
+        //2. Non-horizontal joins where Join.OutPt1 & Join.OutPt2 are at the same
+        //location at the Bottom of the overlapping segment (& Join.OffPt is above).
+        //3. StrictSimple joins where edges touch but are not collinear and where
+        //Join.OutPt1, Join.OutPt2 & Join.OffPt all share the same point.
+        bool isHorizontal = (j->OutPt1->Pt.Y == j->OffPt.Y);
+
+        if (isHorizontal  && (j->OffPt == j->OutPt1->Pt) &&
+            (j->OffPt == j->OutPt2->Pt))
+        {
+            //Strictly Simple join ...
+            if (outRec1 != outRec2) return false;
+            op1b = j->OutPt1->Next;
+            while (op1b != op1 && (op1b->Pt == j->OffPt))
+                op1b = op1b->Next;
+            bool reverse1 = (op1b->Pt.Y > j->OffPt.Y);
+            op2b = j->OutPt2->Next;
+            while (op2b != op2 && (op2b->Pt == j->OffPt))
+                op2b = op2b->Next;
+            bool reverse2 = (op2b->Pt.Y > j->OffPt.Y);
+            if (reverse1 == reverse2) return false;
+            if (reverse1)
+            {
+                op1b = DupOutPt(op1, false);
+                op2b = DupOutPt(op2, true);
+                op1->Prev = op2;
+                op2->Next = op1;
+                op1b->Next = op2b;
+                op2b->Prev = op1b;
+                j->OutPt1 = op1;
+                j->OutPt2 = op1b;
+                return true;
+            } else
+            {
+                op1b = DupOutPt(op1, true);
+                op2b = DupOutPt(op2, false);
+                op1->Next = op2;
+                op2->Prev = op1;
+                op1b->Prev = op2b;
+                op2b->Next = op1b;
+                j->OutPt1 = op1;
+                j->OutPt2 = op1b;
+                return true;
+            }
+        }
+        else if (isHorizontal)
+        {
+            //treat horizontal joins differently to non-horizontal joins since with
+            //them we're not yet sure where the overlapping is. OutPt1.Pt & OutPt2.Pt
+            //may be anywhere along the horizontal edge.
+            op1b = op1;
+            while (op1->Prev->Pt.Y == op1->Pt.Y && op1->Prev != op1b && op1->Prev != op2)
+                op1 = op1->Prev;
+            while (op1b->Next->Pt.Y == op1b->Pt.Y && op1b->Next != op1 && op1b->Next != op2)
+                op1b = op1b->Next;
+            if (op1b->Next == op1 || op1b->Next == op2) return false; //a flat 'polygon'
+
+            op2b = op2;
+            while (op2->Prev->Pt.Y == op2->Pt.Y && op2->Prev != op2b && op2->Prev != op1b)
+                op2 = op2->Prev;
+            while (op2b->Next->Pt.Y == op2b->Pt.Y && op2b->Next != op2 && op2b->Next != op1)
+                op2b = op2b->Next;
+            if (op2b->Next == op2 || op2b->Next == op1) return false; //a flat 'polygon'
+
+            cInt Left, Right;
+            //Op1 --> Op1b & Op2 --> Op2b are the extremites of the horizontal edges
+            if (!GetOverlap(op1->Pt.X, op1b->Pt.X, op2->Pt.X, op2b->Pt.X, Left, Right))
+                return false;
+
+            //DiscardLeftSide: when overlapping edges are joined, a spike will created
+            //which needs to be cleaned up. However, we don't want Op1 or Op2 caught up
+            //on the discard Side as either may still be needed for other joins ...
+            IntPoint Pt;
+            bool DiscardLeftSide;
+            if (op1->Pt.X >= Left && op1->Pt.X <= Right)
+            {
+                Pt = op1->Pt; DiscardLeftSide = (op1->Pt.X > op1b->Pt.X);
+            }
+            else if (op2->Pt.X >= Left&& op2->Pt.X <= Right)
+            {
+                Pt = op2->Pt; DiscardLeftSide = (op2->Pt.X > op2b->Pt.X);
+            }
+            else if (op1b->Pt.X >= Left && op1b->Pt.X <= Right)
+            {
+                Pt = op1b->Pt; DiscardLeftSide = op1b->Pt.X > op1->Pt.X;
+            }
+            else
+            {
+                Pt = op2b->Pt; DiscardLeftSide = (op2b->Pt.X > op2->Pt.X);
+            }
+            j->OutPt1 = op1; j->OutPt2 = op2;
+            return JoinHorz(op1, op1b, op2, op2b, Pt, DiscardLeftSide);
+        } else
+        {
+            //nb: For non-horizontal joins ...
+            //    1. Jr.OutPt1.Pt.Y == Jr.OutPt2.Pt.Y
+            //    2. Jr.OutPt1.Pt > Jr.OffPt.Y
+
+            //make sure the polygons are correctly oriented ...
+            op1b = op1->Next;
+            while ((op1b->Pt == op1->Pt) && (op1b != op1)) op1b = op1b->Next;
+            bool Reverse1 = ((op1b->Pt.Y > op1->Pt.Y) ||
+                             !SlopesEqual(op1->Pt, op1b->Pt, j->OffPt, m_UseFullRange));
+            if (Reverse1)
+            {
+                op1b = op1->Prev;
+                while ((op1b->Pt == op1->Pt) && (op1b != op1)) op1b = op1b->Prev;
+                if ((op1b->Pt.Y > op1->Pt.Y) ||
+                    !SlopesEqual(op1->Pt, op1b->Pt, j->OffPt, m_UseFullRange)) return false;
+            };
+            op2b = op2->Next;
+            while ((op2b->Pt == op2->Pt) && (op2b != op2))op2b = op2b->Next;
+            bool Reverse2 = ((op2b->Pt.Y > op2->Pt.Y) ||
+                             !SlopesEqual(op2->Pt, op2b->Pt, j->OffPt, m_UseFullRange));
+            if (Reverse2)
+            {
+                op2b = op2->Prev;
+                while ((op2b->Pt == op2->Pt) && (op2b != op2)) op2b = op2b->Prev;
+                if ((op2b->Pt.Y > op2->Pt.Y) ||
+                    !SlopesEqual(op2->Pt, op2b->Pt, j->OffPt, m_UseFullRange)) return false;
+            }
+
+            if ((op1b == op1) || (op2b == op2) || (op1b == op2b) ||
+                ((outRec1 == outRec2) && (Reverse1 == Reverse2))) return false;
+
+            if (Reverse1)
+            {
+                op1b = DupOutPt(op1, false);
+                op2b = DupOutPt(op2, true);
+                op1->Prev = op2;
+                op2->Next = op1;
+                op1b->Next = op2b;
+                op2b->Prev = op1b;
+                j->OutPt1 = op1;
+                j->OutPt2 = op1b;
+                return true;
+            } else
+            {
+                op1b = DupOutPt(op1, true);
+                op2b = DupOutPt(op2, false);
+                op1->Next = op2;
+                op2->Prev = op1;
+                op1b->Prev = op2b;
+                op2b->Next = op1b;
+                j->OutPt1 = op1;
+                j->OutPt2 = op1b;
+                return true;
+            }
+        }
+    }
+//----------------------------------------------------------------------
+
+    static OutRec* ParseFirstLeft(OutRec* FirstLeft)
+    {
+        while (FirstLeft && !FirstLeft->Pts)
+            FirstLeft = FirstLeft->FirstLeft;
+        return FirstLeft;
+    }
+//------------------------------------------------------------------------------
+
+    void Clipper::FixupFirstLefts1(OutRec* OldOutRec, OutRec* NewOutRec)
+    {
+        //tests if NewOutRec contains the polygon before reassigning FirstLeft
+        for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+        {
+            OutRec* outRec = m_PolyOuts[i];
+            OutRec* firstLeft = ParseFirstLeft(outRec->FirstLeft);
+            if (outRec->Pts  && firstLeft == OldOutRec)
+            {
+                if (Poly2ContainsPoly1(outRec->Pts, NewOutRec->Pts))
+                    outRec->FirstLeft = NewOutRec;
+            }
+        }
+    }
+//----------------------------------------------------------------------
+
+    void Clipper::FixupFirstLefts2(OutRec* InnerOutRec, OutRec* OuterOutRec)
+    {
+        //A polygon has split into two such that one is now the inner of the other.
+        //It's possible that these polygons now wrap around other polygons, so check
+        //every polygon that's also contained by OuterOutRec's FirstLeft container
+        //(including 0) to see if they've become inner to the new inner polygon ...
+        OutRec* orfl = OuterOutRec->FirstLeft;
+        for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+        {
+            OutRec* outRec = m_PolyOuts[i];
+
+            if (!outRec->Pts || outRec == OuterOutRec || outRec == InnerOutRec)
+                continue;
+            OutRec* firstLeft = ParseFirstLeft(outRec->FirstLeft);
+            if (firstLeft != orfl && firstLeft != InnerOutRec && firstLeft != OuterOutRec)
+                continue;
+            if (Poly2ContainsPoly1(outRec->Pts, InnerOutRec->Pts))
+                outRec->FirstLeft = InnerOutRec;
+            else if (Poly2ContainsPoly1(outRec->Pts, OuterOutRec->Pts))
+                outRec->FirstLeft = OuterOutRec;
+            else if (outRec->FirstLeft == InnerOutRec || outRec->FirstLeft == OuterOutRec)
+                outRec->FirstLeft = orfl;
+        }
+    }
+//----------------------------------------------------------------------
+    void Clipper::FixupFirstLefts3(OutRec* OldOutRec, OutRec* NewOutRec)
+    {
+        //reassigns FirstLeft WITHOUT testing if NewOutRec contains the polygon
+        for (PolyOutList::size_type i = 0; i < m_PolyOuts.size(); ++i)
+        {
+            OutRec* outRec = m_PolyOuts[i];
+            OutRec* firstLeft = ParseFirstLeft(outRec->FirstLeft);
+            if (outRec->Pts && firstLeft == OldOutRec)
+                outRec->FirstLeft = NewOutRec;
+        }
+    }
+//----------------------------------------------------------------------
+
+    void Clipper::JoinCommonEdges()
+    {
+        for (JoinList::size_type i = 0; i < m_Joins.size(); i++)
+        {
+            Join* join = m_Joins[i];
+
+            OutRec *outRec1 = GetOutRec(join->OutPt1->Idx);
+            OutRec *outRec2 = GetOutRec(join->OutPt2->Idx);
+
+            if (!outRec1->Pts || !outRec2->Pts) continue;
+            if (outRec1->IsOpen || outRec2->IsOpen) continue;
+
+            //get the polygon fragment with the correct hole state (FirstLeft)
+            //before calling JoinPoints() ...
+            OutRec *holeStateRec;
+            if (outRec1 == outRec2) holeStateRec = outRec1;
+            else if (OutRec1RightOfOutRec2(outRec1, outRec2)) holeStateRec = outRec2;
+            else if (OutRec1RightOfOutRec2(outRec2, outRec1)) holeStateRec = outRec1;
+            else holeStateRec = GetLowermostRec(outRec1, outRec2);
+
+            if (!JoinPoints(join, outRec1, outRec2)) continue;
+
+            if (outRec1 == outRec2)
+            {
+                //instead of joining two polygons, we've just created a new one by
+                //splitting one polygon into two.
+                outRec1->Pts = join->OutPt1;
+                outRec1->BottomPt = 0;
+                outRec2 = CreateOutRec();
+                outRec2->Pts = join->OutPt2;
+
+                //update all OutRec2.Pts Idx's ...
+                UpdateOutPtIdxs(*outRec2);
+
+                if (Poly2ContainsPoly1(outRec2->Pts, outRec1->Pts))
+                {
+                    //outRec1 contains outRec2 ...
+                    outRec2->IsHole = !outRec1->IsHole;
+                    outRec2->FirstLeft = outRec1;
+
+                    if (m_UsingPolyTree) FixupFirstLefts2(outRec2, outRec1);
+
+                    if ((outRec2->IsHole ^ m_ReverseOutput) == (Area(*outRec2) > 0))
+                        ReversePolyPtLinks(outRec2->Pts);
+
+                } else if (Poly2ContainsPoly1(outRec1->Pts, outRec2->Pts))
+                {
+                    //outRec2 contains outRec1 ...
+                    outRec2->IsHole = outRec1->IsHole;
+                    outRec1->IsHole = !outRec2->IsHole;
+                    outRec2->FirstLeft = outRec1->FirstLeft;
+                    outRec1->FirstLeft = outRec2;
+
+                    if (m_UsingPolyTree) FixupFirstLefts2(outRec1, outRec2);
+
+                    if ((outRec1->IsHole ^ m_ReverseOutput) == (Area(*outRec1) > 0))
+                        ReversePolyPtLinks(outRec1->Pts);
+                }
+                else
+                {
+                    //the 2 polygons are completely separate ...
+                    outRec2->IsHole = outRec1->IsHole;
+                    outRec2->FirstLeft = outRec1->FirstLeft;
+
+                    //fixup FirstLeft pointers that may need reassigning to OutRec2
+                    if (m_UsingPolyTree) FixupFirstLefts1(outRec1, outRec2);
+                }
+
+            } else
+            {
+                //joined 2 polygons together ...
+
+                outRec2->Pts = 0;
+                outRec2->BottomPt = 0;
+                outRec2->Idx = outRec1->Idx;
+
+                outRec1->IsHole = holeStateRec->IsHole;
+                if (holeStateRec == outRec2)
+                    outRec1->FirstLeft = outRec2->FirstLeft;
+                outRec2->FirstLeft = outRec1;
+
+                if (m_UsingPolyTree) FixupFirstLefts3(outRec2, outRec1);
+            }
+        }
+    }
+
+//------------------------------------------------------------------------------
+// ClipperOffset support functions ...
+//------------------------------------------------------------------------------
+
+    DoublePoint GetUnitNormal(const IntPoint &pt1, const IntPoint &pt2)
+    {
+        if(pt2.X == pt1.X && pt2.Y == pt1.Y)
+            return DoublePoint(0, 0);
+
+        double Dx = (double)(pt2.X - pt1.X);
+        double dy = (double)(pt2.Y - pt1.Y);
+        double f = 1 *1.0/ std::sqrt( Dx*Dx + dy*dy );
+        Dx *= f;
+        dy *= f;
+        return DoublePoint(dy, -Dx);
+    }
+
+//------------------------------------------------------------------------------
+// ClipperOffset class
+//------------------------------------------------------------------------------
+
+    ClipperOffset::ClipperOffset(double miterLimit, double arcTolerance)
+    {
+        this->MiterLimit = miterLimit;
+        this->ArcTolerance = arcTolerance;
+        m_lowest.X = -1;
+    }
+//------------------------------------------------------------------------------
+
+    ClipperOffset::~ClipperOffset()
+    {
+        Clear();
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperOffset::Clear()
+    {
+        for (int i = 0; i < m_polyNodes.ChildCount(); ++i)
+            delete m_polyNodes.Childs[i];
+        m_polyNodes.Childs.clear();
+        m_lowest.X = -1;
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperOffset::AddPath(const Path& path, JoinType joinType, EndType endType)
+    {
+        int highI = (int)path.size() - 1;
+        if (highI < 0) return;
+        PolyNode* newNode = new PolyNode();
+        newNode->m_jointype = joinType;
+        newNode->m_endtype = endType;
+
+        //strip duplicate points from path and also get index to the lowest point ...
+        if (endType == etClosedLine || endType == etClosedPolygon)
+            while (highI > 0 && path[0] == path[highI]) highI--;
+        newNode->Contour.reserve(highI + 1);
+        newNode->Contour.push_back(path[0]);
+        int j = 0, k = 0;
+        for (int i = 1; i <= highI; i++)
+            if (newNode->Contour[j] != path[i])
+            {
+                j++;
+                newNode->Contour.push_back(path[i]);
+                if (path[i].Y > newNode->Contour[k].Y ||
+                    (path[i].Y == newNode->Contour[k].Y &&
+                     path[i].X < newNode->Contour[k].X)) k = j;
+            }
+        if (endType == etClosedPolygon && j < 2)
+        {
+            delete newNode;
+            return;
+        }
+        m_polyNodes.AddChild(*newNode);
+
+        //if this path's lowest pt is lower than all the others then update m_lowest
+        if (endType != etClosedPolygon) return;
+        if (m_lowest.X < 0)
+            m_lowest = IntPoint(m_polyNodes.ChildCount() - 1, k);
+        else
+        {
+            IntPoint ip = m_polyNodes.Childs[(int)m_lowest.X]->Contour[(int)m_lowest.Y];
+            if (newNode->Contour[k].Y > ip.Y ||
+                (newNode->Contour[k].Y == ip.Y &&
+                 newNode->Contour[k].X < ip.X))
+                m_lowest = IntPoint(m_polyNodes.ChildCount() - 1, k);
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperOffset::AddPaths(const Paths& paths, JoinType joinType, EndType endType)
+    {
+        for (Paths::size_type i = 0; i < paths.size(); ++i)
+            AddPath(paths[i], joinType, endType);
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperOffset::FixOrientations()
+    {
+        //fixup orientations of all closed paths if the orientation of the
+        //closed path with the lowermost vertex is wrong ...
+        if (m_lowest.X >= 0 &&
+            !Orientation(m_polyNodes.Childs[(int)m_lowest.X]->Contour))
+        {
+            for (int i = 0; i < m_polyNodes.ChildCount(); ++i)
+            {
+                PolyNode& node = *m_polyNodes.Childs[i];
+                if (node.m_endtype == etClosedPolygon ||
+                    (node.m_endtype == etClosedLine && Orientation(node.Contour)))
+                    ReversePath(node.Contour);
+            }
+        } else
+        {
+            for (int i = 0; i < m_polyNodes.ChildCount(); ++i)
+            {
+                PolyNode& node = *m_polyNodes.Childs[i];
+                if (node.m_endtype == etClosedLine && !Orientation(node.Contour))
+                    ReversePath(node.Contour);
+            }
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperOffset::Execute(Paths& solution, double delta)
+    {
+        solution.clear();
+        FixOrientations();
+        DoOffset(delta);
+
+        //now clean up 'corners' ...
+        Clipper clpr;
+        clpr.AddPaths(m_destPolys, ptSubject, true);
+        if (delta > 0)
+        {
+            clpr.Execute(ctUnion, solution, pftPositive, pftPositive);
+        }
+        else
+        {
+            IntRect r = clpr.GetBounds();
+            Path outer(4);
+            outer[0] = IntPoint(r.left - 10, r.bottom + 10);
+            outer[1] = IntPoint(r.right + 10, r.bottom + 10);
+            outer[2] = IntPoint(r.right + 10, r.top - 10);
+            outer[3] = IntPoint(r.left - 10, r.top - 10);
+
+            clpr.AddPath(outer, ptSubject, true);
+            clpr.ReverseSolution(true);
+            clpr.Execute(ctUnion, solution, pftNegative, pftNegative);
+            if (solution.size() > 0) solution.erase(solution.begin());
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperOffset::Execute(PolyTree& solution, double delta)
+    {
+        solution.Clear();
+        FixOrientations();
+        DoOffset(delta);
+
+        //now clean up 'corners' ...
+        Clipper clpr;
+        clpr.AddPaths(m_destPolys, ptSubject, true);
+        if (delta > 0)
+        {
+            clpr.Execute(ctUnion, solution, pftPositive, pftPositive);
+        }
+        else
+        {
+            IntRect r = clpr.GetBounds();
+            Path outer(4);
+            outer[0] = IntPoint(r.left - 10, r.bottom + 10);
+            outer[1] = IntPoint(r.right + 10, r.bottom + 10);
+            outer[2] = IntPoint(r.right + 10, r.top - 10);
+            outer[3] = IntPoint(r.left - 10, r.top - 10);
+
+            clpr.AddPath(outer, ptSubject, true);
+            clpr.ReverseSolution(true);
+            clpr.Execute(ctUnion, solution, pftNegative, pftNegative);
+            //remove the outer PolyNode rectangle ...
+            if (solution.ChildCount() == 1 && solution.Childs[0]->ChildCount() > 0)
+            {
+                PolyNode* outerNode = solution.Childs[0];
+                solution.Childs.reserve(outerNode->ChildCount());
+                solution.Childs[0] = outerNode->Childs[0];
+                solution.Childs[0]->Parent = outerNode->Parent;
+                for (int i = 1; i < outerNode->ChildCount(); ++i)
+                    solution.AddChild(*outerNode->Childs[i]);
+            }
+            else
+                solution.Clear();
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperOffset::DoOffset(double delta)
+    {
+        m_destPolys.clear();
+        m_delta = delta;
+
+        //if Zero offset, just copy any CLOSED polygons to m_p and return ...
+        if (NEAR_ZERO(delta))
+        {
+            m_destPolys.reserve(m_polyNodes.ChildCount());
+            for (int i = 0; i < m_polyNodes.ChildCount(); i++)
+            {
+                PolyNode& node = *m_polyNodes.Childs[i];
+                if (node.m_endtype == etClosedPolygon)
+                    m_destPolys.push_back(node.Contour);
+            }
+            return;
+        }
+
+        //see offset_triginometry3.svg in the documentation folder ...
+        if (MiterLimit > 2) m_miterLim = 2/(MiterLimit * MiterLimit);
+        else m_miterLim = 0.5;
+
+        double y;
+        if (ArcTolerance <= 0.0) y = def_arc_tolerance;
+        else if (ArcTolerance > std::fabs(delta) * def_arc_tolerance)
+            y = std::fabs(delta) * def_arc_tolerance;
+        else y = ArcTolerance;
+        //see offset_triginometry2.svg in the documentation folder ...
+        double steps = pi / std::acos(1 - y / std::fabs(delta));
+        if (steps > std::fabs(delta) * pi)
+            steps = std::fabs(delta) * pi;  //ie excessive precision check
+        m_sin = std::sin(two_pi / steps);
+        m_cos = std::cos(two_pi / steps);
+        m_StepsPerRad = steps / two_pi;
+        if (delta < 0.0) m_sin = -m_sin;
+
+        m_destPolys.reserve(m_polyNodes.ChildCount() * 2);
+        for (int i = 0; i < m_polyNodes.ChildCount(); i++)
+        {
+            PolyNode& node = *m_polyNodes.Childs[i];
+            m_srcPoly = node.Contour;
+
+            int len = (int)m_srcPoly.size();
+            if (len == 0 || (delta <= 0 && (len < 3 || node.m_endtype != etClosedPolygon)))
+                continue;
+
+            m_destPoly.clear();
+            if (len == 1)
+            {
+                if (node.m_jointype == jtRound)
+                {
+                    double X = 1.0, Y = 0.0;
+                    for (cInt j = 1; j <= steps; j++)
+                    {
+                        m_destPoly.push_back(IntPoint(
+                                Round(m_srcPoly[0].X + X * delta),
+                                Round(m_srcPoly[0].Y + Y * delta)));
+                        double X2 = X;
+                        X = X * m_cos - m_sin * Y;
+                        Y = X2 * m_sin + Y * m_cos;
+                    }
+                }
+                else
+                {
+                    double X = -1.0, Y = -1.0;
+                    for (int j = 0; j < 4; ++j)
+                    {
+                        m_destPoly.push_back(IntPoint(
+                                Round(m_srcPoly[0].X + X * delta),
+                                Round(m_srcPoly[0].Y + Y * delta)));
+                        if (X < 0) X = 1;
+                        else if (Y < 0) Y = 1;
+                        else X = -1;
+                    }
+                }
+                m_destPolys.push_back(m_destPoly);
+                continue;
+            }
+            //build m_normals ...
+            m_normals.clear();
+            m_normals.reserve(len);
+            for (int j = 0; j < len - 1; ++j)
+                m_normals.push_back(GetUnitNormal(m_srcPoly[j], m_srcPoly[j + 1]));
+            if (node.m_endtype == etClosedLine || node.m_endtype == etClosedPolygon)
+                m_normals.push_back(GetUnitNormal(m_srcPoly[len - 1], m_srcPoly[0]));
+            else
+                m_normals.push_back(DoublePoint(m_normals[len - 2]));
+
+            if (node.m_endtype == etClosedPolygon)
+            {
+                int k = len - 1;
+                for (int j = 0; j < len; ++j)
+                    OffsetPoint(j, k, node.m_jointype);
+                m_destPolys.push_back(m_destPoly);
+            }
+            else if (node.m_endtype == etClosedLine)
+            {
+                int k = len - 1;
+                for (int j = 0; j < len; ++j)
+                    OffsetPoint(j, k, node.m_jointype);
+                m_destPolys.push_back(m_destPoly);
+                m_destPoly.clear();
+                //re-build m_normals ...
+                DoublePoint n = m_normals[len -1];
+                for (int j = len - 1; j > 0; j--)
+                    m_normals[j] = DoublePoint(-m_normals[j - 1].X, -m_normals[j - 1].Y);
+                m_normals[0] = DoublePoint(-n.X, -n.Y);
+                k = 0;
+                for (int j = len - 1; j >= 0; j--)
+                    OffsetPoint(j, k, node.m_jointype);
+                m_destPolys.push_back(m_destPoly);
+            }
+            else
+            {
+                int k = 0;
+                for (int j = 1; j < len - 1; ++j)
+                    OffsetPoint(j, k, node.m_jointype);
+
+                IntPoint pt1;
+                if (node.m_endtype == etOpenButt)
+                {
+                    int j = len - 1;
+                    pt1 = IntPoint((cInt)Round(m_srcPoly[j].X + m_normals[j].X *
+                                                                delta), (cInt)Round(m_srcPoly[j].Y + m_normals[j].Y * delta));
+                    m_destPoly.push_back(pt1);
+                    pt1 = IntPoint((cInt)Round(m_srcPoly[j].X - m_normals[j].X *
+                                                                delta), (cInt)Round(m_srcPoly[j].Y - m_normals[j].Y * delta));
+                    m_destPoly.push_back(pt1);
+                }
+                else
+                {
+                    int j = len - 1;
+                    k = len - 2;
+                    m_sinA = 0;
+                    m_normals[j] = DoublePoint(-m_normals[j].X, -m_normals[j].Y);
+                    if (node.m_endtype == etOpenSquare)
+                        DoSquare(j, k);
+                    else
+                        DoRound(j, k);
+                }
+
+                //re-build m_normals ...
+                for (int j = len - 1; j > 0; j--)
+                    m_normals[j] = DoublePoint(-m_normals[j - 1].X, -m_normals[j - 1].Y);
+                m_normals[0] = DoublePoint(-m_normals[1].X, -m_normals[1].Y);
+
+                k = len - 1;
+                for (int j = k - 1; j > 0; --j) OffsetPoint(j, k, node.m_jointype);
+
+                if (node.m_endtype == etOpenButt)
+                {
+                    pt1 = IntPoint((cInt)Round(m_srcPoly[0].X - m_normals[0].X * delta),
+                                   (cInt)Round(m_srcPoly[0].Y - m_normals[0].Y * delta));
+                    m_destPoly.push_back(pt1);
+                    pt1 = IntPoint((cInt)Round(m_srcPoly[0].X + m_normals[0].X * delta),
+                                   (cInt)Round(m_srcPoly[0].Y + m_normals[0].Y * delta));
+                    m_destPoly.push_back(pt1);
+                }
+                else
+                {
+                    k = 1;
+                    m_sinA = 0;
+                    if (node.m_endtype == etOpenSquare)
+                        DoSquare(0, 1);
+                    else
+                        DoRound(0, 1);
+                }
+                m_destPolys.push_back(m_destPoly);
+            }
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperOffset::OffsetPoint(int j, int& k, JoinType jointype)
+    {
+        //cross product ...
+        m_sinA = (m_normals[k].X * m_normals[j].Y - m_normals[j].X * m_normals[k].Y);
+        if (std::fabs(m_sinA * m_delta) < 1.0)
+        {
+            //dot product ...
+            double cosA = (m_normals[k].X * m_normals[j].X + m_normals[j].Y * m_normals[k].Y );
+            if (cosA > 0) // angle => 0 degrees
+            {
+                m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + m_normals[k].X * m_delta),
+                                              Round(m_srcPoly[j].Y + m_normals[k].Y * m_delta)));
+                return;
+            }
+            //else angle => 180 degrees
+        }
+        else if (m_sinA > 1.0) m_sinA = 1.0;
+        else if (m_sinA < -1.0) m_sinA = -1.0;
+
+        if (m_sinA * m_delta < 0)
+        {
+            m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + m_normals[k].X * m_delta),
+                                          Round(m_srcPoly[j].Y + m_normals[k].Y * m_delta)));
+            m_destPoly.push_back(m_srcPoly[j]);
+            m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + m_normals[j].X * m_delta),
+                                          Round(m_srcPoly[j].Y + m_normals[j].Y * m_delta)));
+        }
+        else
+            switch (jointype)
+            {
+                case jtMiter:
+                {
+                    double r = 1 + (m_normals[j].X * m_normals[k].X +
+                                    m_normals[j].Y * m_normals[k].Y);
+                    if (r >= m_miterLim) DoMiter(j, k, r); else DoSquare(j, k);
+                    break;
+                }
+                case jtSquare: DoSquare(j, k); break;
+                case jtRound: DoRound(j, k); break;
+            }
+        k = j;
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperOffset::DoSquare(int j, int k)
+    {
+        double dx = std::tan(std::atan2(m_sinA,
+                                        m_normals[k].X * m_normals[j].X + m_normals[k].Y * m_normals[j].Y) / 4);
+        m_destPoly.push_back(IntPoint(
+                Round(m_srcPoly[j].X + m_delta * (m_normals[k].X - m_normals[k].Y * dx)),
+                Round(m_srcPoly[j].Y + m_delta * (m_normals[k].Y + m_normals[k].X * dx))));
+        m_destPoly.push_back(IntPoint(
+                Round(m_srcPoly[j].X + m_delta * (m_normals[j].X + m_normals[j].Y * dx)),
+                Round(m_srcPoly[j].Y + m_delta * (m_normals[j].Y - m_normals[j].X * dx))));
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperOffset::DoMiter(int j, int k, double r)
+    {
+        double q = m_delta / r;
+        m_destPoly.push_back(IntPoint(Round(m_srcPoly[j].X + (m_normals[k].X + m_normals[j].X) * q),
+                                      Round(m_srcPoly[j].Y + (m_normals[k].Y + m_normals[j].Y) * q)));
+    }
+//------------------------------------------------------------------------------
+
+    void ClipperOffset::DoRound(int j, int k)
+    {
+        double a = std::atan2(m_sinA,
+                              m_normals[k].X * m_normals[j].X + m_normals[k].Y * m_normals[j].Y);
+        int steps = std::max((int)Round(m_StepsPerRad * std::fabs(a)), 1);
+
+        double X = m_normals[k].X, Y = m_normals[k].Y, X2;
+        for (int i = 0; i < steps; ++i)
+        {
+            m_destPoly.push_back(IntPoint(
+                    Round(m_srcPoly[j].X + X * m_delta),
+                    Round(m_srcPoly[j].Y + Y * m_delta)));
+            X2 = X;
+            X = X * m_cos - m_sin * Y;
+            Y = X2 * m_sin + Y * m_cos;
+        }
+        m_destPoly.push_back(IntPoint(
+                Round(m_srcPoly[j].X + m_normals[j].X * m_delta),
+                Round(m_srcPoly[j].Y + m_normals[j].Y * m_delta)));
+    }
+
+//------------------------------------------------------------------------------
+// Miscellaneous public functions
+//------------------------------------------------------------------------------
+
+    void Clipper::DoSimplePolygons()
+    {
+        PolyOutList::size_type i = 0;
+        while (i < m_PolyOuts.size())
+        {
+            OutRec* outrec = m_PolyOuts[i++];
+            OutPt* op = outrec->Pts;
+            if (!op || outrec->IsOpen) continue;
+            do //for each Pt in Polygon until duplicate found do ...
+            {
+                OutPt* op2 = op->Next;
+                while (op2 != outrec->Pts)
+                {
+                    if ((op->Pt == op2->Pt) && op2->Next != op && op2->Prev != op)
+                    {
+                        //split the polygon into two ...
+                        OutPt* op3 = op->Prev;
+                        OutPt* op4 = op2->Prev;
+                        op->Prev = op4;
+                        op4->Next = op;
+                        op2->Prev = op3;
+                        op3->Next = op2;
+
+                        outrec->Pts = op;
+                        OutRec* outrec2 = CreateOutRec();
+                        outrec2->Pts = op2;
+                        UpdateOutPtIdxs(*outrec2);
+                        if (Poly2ContainsPoly1(outrec2->Pts, outrec->Pts))
+                        {
+                            //OutRec2 is contained by OutRec1 ...
+                            outrec2->IsHole = !outrec->IsHole;
+                            outrec2->FirstLeft = outrec;
+                            if (m_UsingPolyTree) FixupFirstLefts2(outrec2, outrec);
+                        }
+                        else
+                        if (Poly2ContainsPoly1(outrec->Pts, outrec2->Pts))
+                        {
+                            //OutRec1 is contained by OutRec2 ...
+                            outrec2->IsHole = outrec->IsHole;
+                            outrec->IsHole = !outrec2->IsHole;
+                            outrec2->FirstLeft = outrec->FirstLeft;
+                            outrec->FirstLeft = outrec2;
+                            if (m_UsingPolyTree) FixupFirstLefts2(outrec, outrec2);
+                        }
+                        else
+                        {
+                            //the 2 polygons are separate ...
+                            outrec2->IsHole = outrec->IsHole;
+                            outrec2->FirstLeft = outrec->FirstLeft;
+                            if (m_UsingPolyTree) FixupFirstLefts1(outrec, outrec2);
+                        }
+                        op2 = op; //ie get ready for the Next iteration
+                    }
+                    op2 = op2->Next;
+                }
+                op = op->Next;
+            }
+            while (op != outrec->Pts);
+        }
+    }
+//------------------------------------------------------------------------------
+
+    void ReversePath(Path& p)
+    {
+        std::reverse(p.begin(), p.end());
+    }
+//------------------------------------------------------------------------------
+
+    void ReversePaths(Paths& p)
+    {
+        for (Paths::size_type i = 0; i < p.size(); ++i)
+            ReversePath(p[i]);
+    }
+//------------------------------------------------------------------------------
+
+    void SimplifyPolygon(const Path &in_poly, Paths &out_polys, PolyFillType fillType)
+    {
+        Clipper c;
+        c.StrictlySimple(true);
+        c.AddPath(in_poly, ptSubject, true);
+        c.Execute(ctUnion, out_polys, fillType, fillType);
+    }
+//------------------------------------------------------------------------------
+
+    void SimplifyPolygons(const Paths &in_polys, Paths &out_polys, PolyFillType fillType)
+    {
+        Clipper c;
+        c.StrictlySimple(true);
+        c.AddPaths(in_polys, ptSubject, true);
+        c.Execute(ctUnion, out_polys, fillType, fillType);
+    }
+//------------------------------------------------------------------------------
+
+    void SimplifyPolygons(Paths &polys, PolyFillType fillType)
+    {
+        SimplifyPolygons(polys, polys, fillType);
+    }
+//------------------------------------------------------------------------------
+
+    inline double DistanceSqrd(const IntPoint& pt1, const IntPoint& pt2)
+    {
+        double Dx = ((double)pt1.X - pt2.X);
+        double dy = ((double)pt1.Y - pt2.Y);
+        return (Dx*Dx + dy*dy);
+    }
+//------------------------------------------------------------------------------
+
+    double DistanceFromLineSqrd(
+            const IntPoint& pt, const IntPoint& ln1, const IntPoint& ln2)
+    {
+        //The equation of a line in general form (Ax + By + C = 0)
+        //given 2 points (x?y? & (x?y? is ...
+        //(y?- y?x + (x?- x?y + (y?- y?x?- (x?- x?y?= 0
+        //A = (y?- y?; B = (x?- x?; C = (y?- y?x?- (x?- x?y?
+        //perpendicular distance of point (x?y? = (Ax?+ By?+ C)/Sqrt(A?+ B?
+        //see http://en.wikipedia.org/wiki/Perpendicular_distance
+        double A = double(ln1.Y - ln2.Y);
+        double B = double(ln2.X - ln1.X);
+        double C = A * ln1.X  + B * ln1.Y;
+        C = A * pt.X + B * pt.Y - C;
+        return (C * C) / (A * A + B * B);
+    }
+//---------------------------------------------------------------------------
+
+    bool SlopesNearCollinear(const IntPoint& pt1,
+                             const IntPoint& pt2, const IntPoint& pt3, double distSqrd)
+    {
+        //this function is more accurate when the point that's geometrically
+        //between the other 2 points is the one that's tested for distance.
+        //ie makes it more likely to pick up 'spikes' ...
+        if (Abs(pt1.X - pt2.X) > Abs(pt1.Y - pt2.Y))
+        {
+            if ((pt1.X > pt2.X) == (pt1.X < pt3.X))
+                return DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd;
+            else if ((pt2.X > pt1.X) == (pt2.X < pt3.X))
+                return DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd;
+            else
+                return DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd;
+        }
+        else
+        {
+            if ((pt1.Y > pt2.Y) == (pt1.Y < pt3.Y))
+                return DistanceFromLineSqrd(pt1, pt2, pt3) < distSqrd;
+            else if ((pt2.Y > pt1.Y) == (pt2.Y < pt3.Y))
+                return DistanceFromLineSqrd(pt2, pt1, pt3) < distSqrd;
+            else
+                return DistanceFromLineSqrd(pt3, pt1, pt2) < distSqrd;
+        }
+    }
+//------------------------------------------------------------------------------
+
+    bool PointsAreClose(IntPoint pt1, IntPoint pt2, double distSqrd)
+    {
+        double Dx = (double)pt1.X - pt2.X;
+        double dy = (double)pt1.Y - pt2.Y;
+        return ((Dx * Dx) + (dy * dy) <= distSqrd);
+    }
+//------------------------------------------------------------------------------
+
+    OutPt* ExcludeOp(OutPt* op)
+    {
+        OutPt* result = op->Prev;
+        result->Next = op->Next;
+        op->Next->Prev = result;
+        result->Idx = 0;
+        return result;
+    }
+//------------------------------------------------------------------------------
+
+    void CleanPolygon(const Path& in_poly, Path& out_poly, double distance)
+    {
+        //distance = proximity in units/pixels below which vertices
+        //will be stripped. Default ~= sqrt(2).
+
+        size_t size = in_poly.size();
+
+        if (size == 0)
+        {
+            out_poly.clear();
+            return;
+        }
+
+        OutPt* outPts = new OutPt[size];
+        for (size_t i = 0; i < size; ++i)
+        {
+            outPts[i].Pt = in_poly[i];
+            outPts[i].Next = &outPts[(i + 1) % size];
+            outPts[i].Next->Prev = &outPts[i];
+            outPts[i].Idx = 0;
+        }
+
+        double distSqrd = distance * distance;
+        OutPt* op = &outPts[0];
+        while (op->Idx == 0 && op->Next != op->Prev)
+        {
+            if (PointsAreClose(op->Pt, op->Prev->Pt, distSqrd))
+            {
+                op = ExcludeOp(op);
+                size--;
+            }
+            else if (PointsAreClose(op->Prev->Pt, op->Next->Pt, distSqrd))
+            {
+                ExcludeOp(op->Next);
+                op = ExcludeOp(op);
+                size -= 2;
+            }
+            else if (SlopesNearCollinear(op->Prev->Pt, op->Pt, op->Next->Pt, distSqrd))
+            {
+                op = ExcludeOp(op);
+                size--;
+            }
+            else
+            {
+                op->Idx = 1;
+                op = op->Next;
+            }
+        }
+
+        if (size < 3) size = 0;
+        out_poly.resize(size);
+        for (size_t i = 0; i < size; ++i)
+        {
+            out_poly[i] = op->Pt;
+            op = op->Next;
+        }
+        delete [] outPts;
+    }
+//------------------------------------------------------------------------------
+
+    void CleanPolygon(Path& poly, double distance)
+    {
+        CleanPolygon(poly, poly, distance);
+    }
+//------------------------------------------------------------------------------
+
+    void CleanPolygons(const Paths& in_polys, Paths& out_polys, double distance)
+    {
+        out_polys.resize(in_polys.size());
+        for (Paths::size_type i = 0; i < in_polys.size(); ++i)
+            CleanPolygon(in_polys[i], out_polys[i], distance);
+    }
+//------------------------------------------------------------------------------
+
+    void CleanPolygons(Paths& polys, double distance)
+    {
+        CleanPolygons(polys, polys, distance);
+    }
+//------------------------------------------------------------------------------
+
+    void Minkowski(const Path& poly, const Path& path,
+                   Paths& solution, bool isSum, bool isClosed)
+    {
+        int delta = (isClosed ? 1 : 0);
+        size_t polyCnt = poly.size();
+        size_t pathCnt = path.size();
+        Paths pp;
+        pp.reserve(pathCnt);
+        if (isSum)
+            for (size_t i = 0; i < pathCnt; ++i)
+            {
+                Path p;
+                p.reserve(polyCnt);
+                for (size_t j = 0; j < poly.size(); ++j)
+                    p.push_back(IntPoint(path[i].X + poly[j].X, path[i].Y + poly[j].Y));
+                pp.push_back(p);
+            }
+        else
+            for (size_t i = 0; i < pathCnt; ++i)
+            {
+                Path p;
+                p.reserve(polyCnt);
+                for (size_t j = 0; j < poly.size(); ++j)
+                    p.push_back(IntPoint(path[i].X - poly[j].X, path[i].Y - poly[j].Y));
+                pp.push_back(p);
+            }
+
+        solution.clear();
+        solution.reserve((pathCnt + delta) * (polyCnt + 1));
+        for (size_t i = 0; i < pathCnt - 1 + delta; ++i)
+            for (size_t j = 0; j < polyCnt; ++j)
+            {
+                Path quad;
+                quad.reserve(4);
+                quad.push_back(pp[i % pathCnt][j % polyCnt]);
+                quad.push_back(pp[(i + 1) % pathCnt][j % polyCnt]);
+                quad.push_back(pp[(i + 1) % pathCnt][(j + 1) % polyCnt]);
+                quad.push_back(pp[i % pathCnt][(j + 1) % polyCnt]);
+                if (!Orientation(quad)) ReversePath(quad);
+                solution.push_back(quad);
+            }
+    }
+//------------------------------------------------------------------------------
+
+    void MinkowskiSum(const Path& pattern, const Path& path, Paths& solution, bool pathIsClosed)
+    {
+        Minkowski(pattern, path, solution, true, pathIsClosed);
+        Clipper c;
+        c.AddPaths(solution, ptSubject, true);
+        c.Execute(ctUnion, solution, pftNonZero, pftNonZero);
+    }
+//------------------------------------------------------------------------------
+
+    void TranslatePath(const Path& input, Path& output, const IntPoint delta)
+    {
+        //precondition: input != output
+        output.resize(input.size());
+        for (size_t i = 0; i < input.size(); ++i)
+            output[i] = IntPoint(input[i].X + delta.X, input[i].Y + delta.Y);
+    }
+//------------------------------------------------------------------------------
+
+    void MinkowskiSum(const Path& pattern, const Paths& paths, Paths& solution, bool pathIsClosed)
+    {
+        Clipper c;
+        for (size_t i = 0; i < paths.size(); ++i)
+        {
+            Paths tmp;
+            Minkowski(pattern, paths[i], tmp, true, pathIsClosed);
+            c.AddPaths(tmp, ptSubject, true);
+            if (pathIsClosed)
+            {
+                Path tmp2;
+                TranslatePath(paths[i], tmp2, pattern[0]);
+                c.AddPath(tmp2, ptClip, true);
+            }
+        }
+        c.Execute(ctUnion, solution, pftNonZero, pftNonZero);
+    }
+//------------------------------------------------------------------------------
+
+    void MinkowskiDiff(const Path& poly1, const Path& poly2, Paths& solution)
+    {
+        Minkowski(poly1, poly2, solution, false, true);
+        Clipper c;
+        c.AddPaths(solution, ptSubject, true);
+        c.Execute(ctUnion, solution, pftNonZero, pftNonZero);
+    }
+//------------------------------------------------------------------------------
+
+    enum NodeType {ntAny, ntOpen, ntClosed};
+
+    void AddPolyNodeToPaths(const PolyNode& polynode, NodeType nodetype, Paths& paths)
+    {
+        bool match = true;
+        if (nodetype == ntClosed) match = !polynode.IsOpen();
+        else if (nodetype == ntOpen) return;
+
+        if (!polynode.Contour.empty() && match)
+            paths.push_back(polynode.Contour);
+        for (int i = 0; i < polynode.ChildCount(); ++i)
+            AddPolyNodeToPaths(*polynode.Childs[i], nodetype, paths);
+    }
+//------------------------------------------------------------------------------
+
+    void PolyTreeToPaths(const PolyTree& polytree, Paths& paths)
+    {
+        paths.resize(0);
+        paths.reserve(polytree.Total());
+        AddPolyNodeToPaths(polytree, ntAny, paths);
+    }
+//------------------------------------------------------------------------------
+
+    void ClosedPathsFromPolyTree(const PolyTree& polytree, Paths& paths)
+    {
+        paths.resize(0);
+        paths.reserve(polytree.Total());
+        AddPolyNodeToPaths(polytree, ntClosed, paths);
+    }
+//------------------------------------------------------------------------------
+
+    void OpenPathsFromPolyTree(PolyTree& polytree, Paths& paths)
+    {
+        paths.resize(0);
+        paths.reserve(polytree.Total());
+        //Open paths are top level only, so ...
+        for (int i = 0; i < polytree.ChildCount(); ++i)
+            if (polytree.Childs[i]->IsOpen())
+                paths.push_back(polytree.Childs[i]->Contour);
+    }
+//------------------------------------------------------------------------------
+
+    std::ostream& operator <<(std::ostream &s, const IntPoint &p)
+    {
+        s << "(" << p.X << "," << p.Y << ")";
+        return s;
+    }
+//------------------------------------------------------------------------------
+
+    std::ostream& operator <<(std::ostream &s, const Path &p)
+    {
+        if (p.empty()) return s;
+        Path::size_type last = p.size() -1;
+        for (Path::size_type i = 0; i < last; i++)
+            s << "(" << p[i].X << "," << p[i].Y << "), ";
+        s << "(" << p[last].X << "," << p[last].Y << ")\n";
+        return s;
+    }
+//------------------------------------------------------------------------------
+
+    std::ostream& operator <<(std::ostream &s, const Paths &p)
+    {
+        for (Paths::size_type i = 0; i < p.size(); i++)
+            s << p[i];
+        s << "\n";
+        return s;
+    }
+//------------------------------------------------------------------------------
+
+} //ClipperLib namespace

src/getopt.cpp

+/*
+ * getopt - POSIX like getopt for Windows console Application
+ *
+ * win-c - Windows Console Library
+ * Copyright (c) 2015 Koji Takami
+ * Released under the MIT license
+ * https://github.com/takamin/win-c/blob/master/LICENSE
+ */
+#ifndef  __CLIB__
+
+#include <stdio.h>
+#include <string.h>
+#include "getopt.h"
+
+char *optarg = 0;
+int optind = 1;
+int opterr = 1;
+int optopt = 0;
+
+int postpone_count = 0;
+int nextchar = 0;
+
+static void postpone(int argc, char *const argv[], int index) {
+    char **nc_argv = (char **) argv;
+    char *p = nc_argv[index];
+    int j = index;
+    for (; j < argc - 1; j++) {
+        nc_argv[j] = nc_argv[j + 1];
+    }
+    nc_argv[argc - 1] = p;
+}
+
+static int postpone_noopt(int argc, char *const argv[], int index) {
+    int i = index;
+    for (; i < argc; i++) {
+        if (*(argv[i]) == '-') {
+            postpone(argc, argv, index);
+            return 1;
+        }
+    }
+    return 0;
+}
+
+static int _getopt_(int argc, char *const argv[],
+                    const char *optstring,
+                    const struct option *longopts, int *longindex) {
+    while (1) {
+        int c;
+        const char *optptr = 0;
+        if (optind >= argc - postpone_count) {
+            c = 0;
+            optarg = 0;
+            break;
+        }
+        c = *(argv[optind] + nextchar);
+        if (c == '\0') {
+            nextchar = 0;
+            ++optind;
+            continue;
+        }
+        if (nextchar == 0) {
+            if (optstring[0] != '+' && optstring[0] != '-') {
+                while (c != '-') {
+                    /* postpone non-opt parameter */
+                    if (!postpone_noopt(argc, argv, optind)) {
+                        break; /* all args are non-opt param */
+                    }
+                    ++postpone_count;
+                    c = *argv[optind];
+                }
+            }
+            if (c != '-') {
+                if (optstring[0] == '-') {
+                    optarg = argv[optind];
+                    nextchar = 0;
+                    ++optind;
+                    return 1;
+                }
+                break;
+            } else {
+                if (strcmp(argv[optind], "--") == 0) {
+                    optind++;
+                    break;
+                }
+                ++nextchar;
+                if (longopts != 0 && *(argv[optind] + 1) == '-') {
+                    char const *spec_long = argv[optind] + 2;
+                    char const *pos_eq = strchr(spec_long, '=');
+                    int spec_len = (pos_eq == NULL ? strlen(spec_long) : pos_eq - spec_long);
+                    int index_search = 0;
+                    int index_found = -1;
+                    const struct option *optdef = 0;
+                    while (longopts->name != 0) {
+                        if (strncmp(spec_long, longopts->name, spec_len) == 0) {
+                            if (optdef != 0) {
+                                if (opterr) {
+                                    fprintf(stderr, "ambiguous option: %s\n", spec_long);
+                                }
+                                return '?';
+                            }
+                            optdef = longopts;
+                            index_found = index_search;
+                        }
+                        longopts++;
+                        index_search++;
+                    }
+                    if (optdef == 0) {
+                        if (opterr) {
+                            fprintf(stderr, "no such a option: %s\n", spec_long);
+                        }
+                        return '?';
+                    }
+                    switch (optdef->has_arg) {
+                        case no_argument:
+                            optarg = 0;
+                            if (pos_eq != 0) {
+                                if (opterr) {
+                                    fprintf(stderr, "no argument for %s\n", optdef->name);
+                                }
+                                return '?';
+                            }
+                            break;
+                        case required_argument:
+                            if (pos_eq == NULL) {
+                                ++optind;
+                                optarg = argv[optind];
+                            } else {
+                                optarg = (char *) pos_eq + 1;
+                            }
+                            break;
+                    }
+                    ++optind;
+                    nextchar = 0;
+                    if (longindex != 0) {
+                        *longindex = index_found;
+                    }
+                    if (optdef->flag != 0) {
+                        *optdef->flag = optdef->val;
+                        return 0;
+                    }
+                    return optdef->val;
+                }
+                continue;
+            }
+        }
+        optptr = strchr(optstring, c);
+        if (optptr == NULL) {
+            optopt = c;
+            if (opterr) {
+                fprintf(stderr,
+                        "%s: invalid option -- %c\n",
+                        argv[0], c);
+            }
+            ++nextchar;
+            return '?';
+        }
+        if (*(optptr + 1) != ':') {
+            nextchar++;
+            if (*(argv[optind] + nextchar) == '\0') {
+                ++optind;
+                nextchar = 0;
+            }
+            optarg = 0;
+        } else {
+            nextchar++;
+            if (*(argv[optind] + nextchar) != '\0') {
+                optarg = argv[optind] + nextchar;
+            } else {
+                ++optind;
+                if (optind < argc - postpone_count) {
+                    optarg = argv[optind];
+                } else {
+                    optopt = c;
+                    if (opterr) {
+                        fprintf(stderr,
+                                "%s: option requires an argument -- %c\n",
+                                argv[0], c);
+                    }
+                    if (optstring[0] == ':' ||
+                        (optstring[0] == '-' || optstring[0] == '+') &&
+                        optstring[1] == ':') {
+                        c = ':';
+                    } else {
+                        c = '?';
+                    }
+                }
+            }
+            ++optind;
+            nextchar = 0;
+        }
+        return c;
+    }
+
+    /* end of option analysis */
+
+    /* fix the order of non-opt params to original */
+    while ((argc - optind - postpone_count) > 0) {
+        postpone(argc, argv, optind);
+        ++postpone_count;
+    }
+
+    nextchar = 0;
+    postpone_count = 0;
+    return -1;
+}
+
+int getopt(int argc, char *const argv[],
+           const char *optstring) {
+    return _getopt_(argc, argv, optstring, 0, 0);
+}
+
+int getopt_long(int argc, char *const argv[],
+                const char *optstring,
+                const struct option *longopts, int *longindex) {
+    return _getopt_(argc, argv, optstring, longopts, longindex);
+}
+/********************************************************
+int getopt_long_only(int argc, char* const argv[],
+        const char* optstring,
+        const struct option* longopts, int* longindex)
+{
+    return -1;
+}
+********************************************************/
+
+#endif //  __CLIB__

src/main.cpp

+#ifndef __JNI__
+#ifndef __CLIB__
+#include <cstdio>
+#include "main.h"
+#include "version.h"
+#include "OcrLite.h"
+#include "OcrUtils.h"
+
+void printHelp(FILE *out, char *argv0) {
+    fprintf(out, " ------- Usage -------\n");
+    fprintf(out, "%s %s", argv0, usageMsg);
+    fprintf(out, " ------- Required Parameters -------\n");
+    fprintf(out, "%s", requiredMsg);
+    fprintf(out, " ------- Optional Parameters -------\n");
+    fprintf(out, "%s", optionalMsg);
+    fprintf(out, " ------- Other Parameters -------\n");
+    fprintf(out, "%s", otherMsg);
+    fprintf(out, " ------- Examples -------\n");
+    fprintf(out, example1Msg, argv0);
+    fprintf(out, example2Msg, argv0);
+}
+
+int main(int argc, char **argv) {
+    if (argc <= 1) {
+        printHelp(stderr, argv[0]);
+        return -1;
+    }
+    std::string modelsDir, modelDetPath, modelClsPath, modelRecPath, keysPath;
+    std::string imgPath, imgDir, imgName;
+    int numThread = 4;
+    int padding = 0;
+    int maxSideLen = 1024;
+    float boxScoreThresh = 0.5f;
+    float boxThresh = 0.3f;
+    float unClipRatio = 2.0f;
+    bool doAngle = true;
+    int flagDoAngle = 1;
+    bool mostAngle = true;
+    int flagMostAngle = 1;
+
+    int opt;
+    int optionIndex = 0;
+    while ((opt = getopt_long(argc, argv, "d:1:2:3:4:i:t:p:s:b:o:u:a:A:v:h", long_options, &optionIndex)) != -1) {
+        //printf("option(-%c)=%s\n", opt, optarg);
+        switch (opt) {
+            case 'd':
+                modelsDir = optarg;
+                printf("modelsPath=%s\n", modelsDir.c_str());
+                break;
+            case '1':
+                modelDetPath = modelsDir + "/" + optarg;
+                printf("model det path=%s\n", modelDetPath.c_str());
+                break;
+            case '2':
+                modelClsPath = modelsDir + "/" + optarg;
+                printf("model cls path=%s\n", modelClsPath.c_str());
+                break;
+            case '3':
+                modelRecPath = modelsDir + "/" + optarg;
+                printf("model rec path=%s\n", modelRecPath.c_str());
+                break;
+            case '4':
+                keysPath = modelsDir + "/" + optarg;
+                printf("keys path=%s\n", keysPath.c_str());
+                break;
+            case 'i':
+                imgPath.assign(optarg);
+                imgDir.assign(imgPath.substr(0, imgPath.find_last_of('/') + 1));
+                imgName.assign(imgPath.substr(imgPath.find_last_of('/') + 1));
+                printf("imgDir=%s, imgName=%s\n", imgDir.c_str(), imgName.c_str());
+                break;
+            case 't':
+                numThread = (int) strtol(optarg, NULL, 10);
+                //printf("numThread=%d\n", numThread);
+                break;
+            case 'p':
+                padding = (int) strtol(optarg, NULL, 10);
+                //printf("padding=%d\n", padding);
+                break;
+            case 's':
+                maxSideLen = (int) strtol(optarg, NULL, 10);
+                //printf("maxSideLen=%d\n", maxSideLen);
+                break;
+            case 'b':
+                boxScoreThresh = strtof(optarg, NULL);
+                //printf("boxScoreThresh=%f\n", boxScoreThresh);
+                break;
+            case 'o':
+                boxThresh = strtof(optarg, NULL);
+                //printf("boxThresh=%f\n", boxThresh);
+                break;
+            case 'u':
+                unClipRatio = strtof(optarg, NULL);
+                //printf("unClipRatio=%f\n", unClipRatio);
+                break;
+            case 'a':
+                flagDoAngle = (int) strtol(optarg, NULL, 10);
+                if (flagDoAngle == 0) {
+                    doAngle = false;
+                } else {
+                    doAngle = true;
+                }
+                //printf("doAngle=%d\n", doAngle);
+                break;
+            case 'A':
+                flagMostAngle = (int) strtol(optarg, NULL, 10);
+                if (flagMostAngle == 0) {
+                    mostAngle = false;
+                } else {
+                    mostAngle = true;
+                }
+                //printf("mostAngle=%d\n", mostAngle);
+                break;
+            case 'v':
+                printf("%s\n", VERSION);
+                return 0;
+            case 'h':
+                printHelp(stdout, argv[0]);
+                return 0;
+            default:
+                printf("other option %c :%s\n", opt, optarg);
+        }
+    }
+    bool hasTargetImgFile = isFileExists(imgPath);
+    if (!hasTargetImgFile) {
+        fprintf(stderr, "Target image not found: %s\n", imgPath.c_str());
+        return -1;
+    }
+    bool hasModelDetFile = isFileExists(modelDetPath);
+    if (!hasModelDetFile) {
+        fprintf(stderr, "Model det file not found: %s\n", modelDetPath.c_str());
+        return -1;
+    }
+    bool hasModelClsFile = isFileExists(modelClsPath);
+    if (!hasModelClsFile) {
+        fprintf(stderr, "Model cls file not found: %s\n", modelClsPath.c_str());
+        return -1;
+    }
+    bool hasModelRecFile = isFileExists(modelRecPath);
+    if (!hasModelRecFile) {
+        fprintf(stderr, "Model rec file not found: %s\n", modelRecPath.c_str());
+        return -1;
+    }
+    bool hasKeysFile = isFileExists(keysPath);
+    if (!hasKeysFile) {
+        fprintf(stderr, "keys file not found: %s\n", keysPath.c_str());
+        return -1;
+    }
+    OcrLite ocrLite;
+    ocrLite.setNumThread(numThread);
+    ocrLite.initLogger(
+            true,//isOutputConsole
+            false,//isOutputPartImg
+            true);//isOutputResultImg
+
+    ocrLite.enableResultTxt(imgDir.c_str(), imgName.c_str());
+    ocrLite.Logger("=====Input Params=====\n");
+    ocrLite.Logger(
+            "numThread(%d),padding(%d),maxSideLen(%d),boxScoreThresh(%f),boxThresh(%f),unClipRatio(%f),doAngle(%d),mostAngle(%d)\n",
+            numThread, padding, maxSideLen, boxScoreThresh, boxThresh, unClipRatio, doAngle, mostAngle);
+
+    ocrLite.initModels(modelDetPath, modelClsPath, modelRecPath, keysPath);
+
+    OcrResult result = ocrLite.detect(imgDir.c_str(), imgName.c_str(), padding, maxSideLen,
+                                      boxScoreThresh, boxThresh, unClipRatio, doAngle, mostAngle);
+    ocrLite.Logger("%s\n", result.strRes.c_str());
+    return 0;
+}
+
+#endif
+#endif
\ No newline at end of file

valgrind-massif.sh

+#!/bin/bash
+## script for 内存占用检查
+# ========== macOS ==========
+# https://github.com/LouisBrunner/valgrind-macos
+# brew tap LouisBrunner/valgrind
+# brew install --HEAD LouisBrunner/valgrind/valgrind
+# ========== linux ==========
+# https://www.valgrind.org/
+# apt install valgrind
+
+NUM_THREADS=1
+
+set OMP_NUM_THREADS=$NUM_THREADS
+
+TARGET_IMG=images/1.jpg
+if [ ! -f "$TARGET_IMG" ]; then
+echo "找不到待识别的目标图片：${TARGET_IMG}，请打开本文件并编辑TARGET_IMG"
+exit
+fi
+
+##### run test on MacOS or Linux
+valgrind --tool=massif --pages-as-heap=yes \
+./${EXE_PATH}/RapidOcrOnnx --models models \
+--det ch_PP-OCRv3_det_infer.onnx \
+--cls ch_ppocr_mobile_v2.0_cls_infer.onnx \
+--rec ch_PP-OCRv3_rec_infer.onnx \
+--keys ppocr_keys_v1.txt \
+--image $TARGET_IMG \
+--numThread $NUM_THREADS \
+--padding 50 \
+--maxSideLen 1024 \
+--boxScoreThresh 0.6 \
+--boxThresh 0.3 \
+--unClipRatio 2.0 \
+--doAngle 1 \
+--mostAngle 1

valgrind-memcheck.sh

+#!/bin/bash
+## script for 内存泄露检查
+# ========== macOS ==========
+# https://github.com/LouisBrunner/valgrind-macos
+# brew tap LouisBrunner/valgrind
+# brew install --HEAD LouisBrunner/valgrind/valgrind
+# ========== linux ==========
+# https://www.valgrind.org/
+# apt install valgrind
+
+NUM_THREADS=1
+
+set OMP_NUM_THREADS=$NUM_THREADS
+
+TARGET_IMG=images/1.jpg
+if [ ! -f "$TARGET_IMG" ]; then
+echo "找不到待识别的目标图片：${TARGET_IMG}，请打开本文件并编辑TARGET_IMG"
+exit
+fi
+
+sysOS=`uname -s`
+EXE_PATH=${sysOS}-BIN
+
+##### run test on MacOS or Linux
+valgrind --tool=memcheck --leak-check=full --leak-resolution=med --track-origins=yes --vgdb=no --log-file=valgrind-memcheck.txt \
+./${EXE_PATH}/RapidOcrOnnx --models models \
+--det ch_PP-OCRv3_det_infer.onnx \
+--cls ch_ppocr_mobile_v2.0_cls_infer.onnx \
+--rec ch_PP-OCRv3_rec_infer.onnx \
+--keys ppocr_keys_v1.txt \
+--image $TARGET_IMG \
+--numThread $NUM_THREADS \
+--padding 50 \
+--maxSideLen 1024 \
+--boxScoreThresh 0.5 \
+--boxThresh 0.3 \
+--unClipRatio 1.5 \
+--doAngle 1 \
+--mostAngle 1