Merge pull request #2 from PaddlePaddle/develop

mergepaddleocr

deploy/cpp_infer/include/utility.h

+// Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#pragma once
+
+#include <chrono>
+#include <iomanip>
+#include <iostream>
+#include <ostream>
+#include <stdlib.h>
+#include <vector>
+
+#include <algorithm>
+#include <cstring>
+#include <fstream>
+#include <numeric>
+
+#include "opencv2/core.hpp"
+#include "opencv2/imgcodecs.hpp"
+#include "opencv2/imgproc.hpp"
+
+namespace PaddleOCR {
+
+class Utility {
+public:
+  static std::vector<std::string> ReadDict(const std::string &path);
+
+  static void
+  VisualizeBboxes(const cv::Mat &srcimg,
+                  const std::vector<std::vector<std::vector<int>>> &boxes);
+
+  template <class ForwardIterator>
+  inline static size_t argmax(ForwardIterator first, ForwardIterator last) {
+    return std::distance(first, std::max_element(first, last));
+  }
+};
+
+} // namespace PaddleOCR
\ No newline at end of file

deploy/cpp_infer/readme.md

+# 服务器端C++预测
+
+本教程将介绍在服务器端部署PaddleOCR超轻量中文检测、识别模型的详细步骤。
+
+
+## 1. 准备环境
+
+### 运行准备
+- Linux环境，推荐使用docker。
+- Windows环境，目前支持基于`Visual Studio 2019 Community`进行编译。
+
+* 该文档主要介绍基于Linux环境的PaddleOCR C++预测流程，如果需要在Windows下基于预测库进行C++预测，具体编译方法请参考[Windows下编译教程](./docs/windows_vs2019_build.md)
+
+### 1.1 编译opencv库
+
+* 首先需要从opencv官网上下载在Linux环境下源码编译的包，以opencv3.4.7为例，下载命令如下。
+
+```
+wget https://github.com/opencv/opencv/archive/3.4.7.tar.gz
+tar -xf 3.4.7.tar.gz
+```
+
+最终可以在当前目录下看到`opencv-3.4.7/`的文件夹。
+
+* 编译opencv，设置opencv源码路径(`root_path`)以及安装路径(`install_path`)。进入opencv源码路径下，按照下面的方式进行编译。
+
+```shell
+root_path=your_opencv_root_path
+install_path=${root_path}/opencv3
+
+rm -rf build
+mkdir build
+cd build
+
+cmake .. \
+    -DCMAKE_INSTALL_PREFIX=${install_path} \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DBUILD_SHARED_LIBS=OFF \
+    -DWITH_IPP=OFF \
+    -DBUILD_IPP_IW=OFF \
+    -DWITH_LAPACK=OFF \
+    -DWITH_EIGEN=OFF \
+    -DCMAKE_INSTALL_LIBDIR=lib64 \
+    -DWITH_ZLIB=ON \
+    -DBUILD_ZLIB=ON \
+    -DWITH_JPEG=ON \
+    -DBUILD_JPEG=ON \
+    -DWITH_PNG=ON \
+    -DBUILD_PNG=ON \
+    -DWITH_TIFF=ON \
+    -DBUILD_TIFF=ON
+
+make -j
+make install
+```
+
+
+其中`root_path`为下载的opencv源码路径，`install_path`为opencv的安装路径，`make install`完成之后，会在该文件夹下生成opencv头文件和库文件，用于后面的OCR代码编译。
+
+最终在安装路径下的文件结构如下所示。
+
+```
+opencv3/
+|-- bin
+|-- include
+|-- lib
+|-- lib64
+|-- share
+```
+
+### 1.2 下载或者编译Paddle预测库
+
+* 有2种方式获取Paddle预测库，下面进行详细介绍。
+
+#### 1.2.1 预测库源码编译
+* 如果希望获取最新预测库特性，可以从Paddle github上克隆最新代码，源码编译预测库。
+* 可以参考[Paddle预测库官网](https://www.paddlepaddle.org.cn/documentation/docs/zh/advanced_guide/inference_deployment/inference/build_and_install_lib_cn.html)的说明，从github上获取Paddle代码，然后进行编译，生成最新的预测库。使用git获取代码方法如下。
+
+```shell
+git clone https://github.com/PaddlePaddle/Paddle.git
+```
+
+* 进入Paddle目录后，编译方法如下。
+
+```shell
+rm -rf build
+mkdir build
+cd build
+
+cmake  .. \
+    -DWITH_CONTRIB=OFF \
+    -DWITH_MKL=ON \
+    -DWITH_MKLDNN=ON  \
+    -DWITH_TESTING=OFF \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DWITH_INFERENCE_API_TEST=OFF \
+    -DON_INFER=ON \
+    -DWITH_PYTHON=ON
+make -j
+make inference_lib_dist
+```
+
+更多编译参数选项可以参考Paddle C++预测库官网：[https://www.paddlepaddle.org.cn/documentation/docs/zh/advanced_guide/inference_deployment/inference/build_and_install_lib_cn.html](https://www.paddlepaddle.org.cn/documentation/docs/zh/advanced_guide/inference_deployment/inference/build_and_install_lib_cn.html)。
+
+
+* 编译完成之后，可以在`build/fluid_inference_install_dir/`文件下看到生成了以下文件及文件夹。
+
+```
+build/fluid_inference_install_dir/
+|-- CMakeCache.txt
+|-- paddle
+|-- third_party
+|-- version.txt
+```
+
+其中`paddle`就是之后进行C++预测时所需的Paddle库，`version.txt`中包含当前预测库的版本信息。
+
+#### 1.2.2 直接下载安装
+
+* [Paddle预测库官网](https://www.paddlepaddle.org.cn/documentation/docs/zh/advanced_guide/inference_deployment/inference/build_and_install_lib_cn.html)上提供了不同cuda版本的Linux预测库，可以在官网查看并选择合适的预测库版本。
+
+* 下载之后使用下面的方法解压。
+
+```
+tar -xf fluid_inference.tgz
+```
+
+最终会在当前的文件夹中生成`fluid_inference/`的子文件夹。
+
+
+## 2 开始运行
+
+### 2.1 将模型导出为inference model
+
+* 可以参考[模型预测章节](../../doc/doc_ch/inference.md)，导出inference model，用于模型预测。模型导出之后，假设放在`inference`目录下，则目录结构如下。
+
+```
+inference/
+|-- det_db
+|   |--model
+|   |--params
+|-- rec_rcnn
+|   |--model
+|   |--params
+```
+
+
+### 2.2 编译PaddleOCR C++预测demo
+
+* 编译命令如下，其中Paddle C++预测库、opencv等其他依赖库的地址需要换成自己机器上的实际地址。
+
+
+```shell
+sh tools/build.sh
+```
+
+具体地，`tools/build.sh`中内容如下。
+
+```shell
+OPENCV_DIR=your_opencv_dir
+LIB_DIR=your_paddle_inference_dir
+CUDA_LIB_DIR=your_cuda_lib_dir
+CUDNN_LIB_DIR=/your_cudnn_lib_dir
+
+BUILD_DIR=build
+rm -rf ${BUILD_DIR}
+mkdir ${BUILD_DIR}
+cd ${BUILD_DIR}
+cmake .. \
+    -DPADDLE_LIB=${LIB_DIR} \
+    -DWITH_MKL=ON \
+    -DDEMO_NAME=ocr_system \
+    -DWITH_GPU=OFF \
+    -DWITH_STATIC_LIB=OFF \
+    -DUSE_TENSORRT=OFF \
+    -DOPENCV_DIR=${OPENCV_DIR} \
+    -DCUDNN_LIB=${CUDNN_LIB_DIR} \
+    -DCUDA_LIB=${CUDA_LIB_DIR} \
+
+make -j
+```
+
+`OPENCV_DIR`为opencv编译安装的地址；`LIB_DIR`为下载(`fluid_inference`文件夹)或者编译生成的Paddle预测库地址(`build/fluid_inference_install_dir`文件夹)；`CUDA_LIB_DIR`为cuda库文件地址，在docker中；为`/usr/local/cuda/lib64`；`CUDNN_LIB_DIR`为cudnn库文件地址，在docker中为`/usr/lib/x86_64-linux-gnu/`。
+
+
+* 编译完成之后，会在`build`文件夹下生成一个名为`ocr_system`的可执行文件。
+
+
+### 运行demo
+* 执行以下命令，完成对一幅图像的OCR识别与检测。
+
+```shell
+sh tools/run.sh
+```
+
+最终屏幕上会输出检测结果如下。
+
+<div align="center">
+    <img src="../imgs/cpp_infer_pred_12.png" width="600">
+</div>
+
+
+### 2.3 注意
+
+* C++预测默认未开启MKLDNN(`tools/config.txt`中的`use_mkldnn`设置为0)，如果需要使用MKLDNN进行预测加速，则需要将`use_mkldnn`修改为1，同时使用最新版本的Paddle源码编译预测库。在使用MKLDNN进行CPU预测时，如果同时预测多张图像，则会出现内存泄露的问题（不打开MKLDNN则没有该问题），目前该问题正在修复中，临时解决方案为：预测多张图片时，每隔30张图片左右对识别(`CRNNRecognizer`)和检测类(`DBDetector`)重新初始化一次。

deploy/cpp_infer/readme_en.md

+# Server-side C++ inference
+
+
+In this tutorial, we will introduce the detailed steps of deploying PaddleOCR ultra-lightweight Chinese detection and recognition models on the server side.
+
+
+## 1. Prepare the environment
+
+### Environment
+
+- Linux, docker is recommended.
+
+
+### 1.1 Compile opencv
+
+* First of all, you need to download the source code compiled package in the Linux environment from the opencv official website. Taking opencv3.4.7 as an example, the download command is as follows.
+
+```
+wget https://github.com/opencv/opencv/archive/3.4.7.tar.gz
+tar -xf 3.4.7.tar.gz
+```
+
+Finally, you can see the folder of `opencv-3.4.7/` in the current directory.
+
+* Compile opencv, the opencv source path (`root_path`) and installation path (`install_path`) should be set by yourself. Enter the opencv source code path and compile it in the following way.
+
+
+```shell
+root_path=your_opencv_root_path
+install_path=${root_path}/opencv3
+
+rm -rf build
+mkdir build
+cd build
+
+cmake .. \
+    -DCMAKE_INSTALL_PREFIX=${install_path} \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DBUILD_SHARED_LIBS=OFF \
+    -DWITH_IPP=OFF \
+    -DBUILD_IPP_IW=OFF \
+    -DWITH_LAPACK=OFF \
+    -DWITH_EIGEN=OFF \
+    -DCMAKE_INSTALL_LIBDIR=lib64 \
+    -DWITH_ZLIB=ON \
+    -DBUILD_ZLIB=ON \
+    -DWITH_JPEG=ON \
+    -DBUILD_JPEG=ON \
+    -DWITH_PNG=ON \
+    -DBUILD_PNG=ON \
+    -DWITH_TIFF=ON \
+    -DBUILD_TIFF=ON
+
+make -j
+make install
+```
+
+Among them, `root_path` is the downloaded opencv source code path, and `install_path` is the installation path of opencv. After `make install` is completed, the opencv header file and library file will be generated in this folder for later OCR source code compilation.
+
+
+
+The final file structure under the opencv installation path is as follows.
+
+```
+opencv3/
+|-- bin
+|-- include
+|-- lib
+|-- lib64
+|-- share
+```
+
+### 1.2 Compile or download or  the Paddle inference library
+
+* There are 2 ways to obtain the Paddle inference library, described in detail below.
+
+
+#### 1.2.1 Compile from the source code
+* If you want to get the latest Paddle inference library features, you can download the latest code from Paddle github repository and compile the inference library from the source code.
+* You can refer to [Paddle inference library] (https://www.paddlepaddle.org.cn/documentation/docs/en/advanced_guide/inference_deployment/inference/build_and_install_lib_en.html) to get the Paddle source code from github, and then compile To generate the latest inference library. The method of using git to access the code is as follows.
+
+
+```shell
+git clone https://github.com/PaddlePaddle/Paddle.git
+```
+
+* After entering the Paddle directory, the compilation method is as follows.
+
+```shell
+rm -rf build
+mkdir build
+cd build
+
+cmake  .. \
+    -DWITH_CONTRIB=OFF \
+    -DWITH_MKL=ON \
+    -DWITH_MKLDNN=ON  \
+    -DWITH_TESTING=OFF \
+    -DCMAKE_BUILD_TYPE=Release \
+    -DWITH_INFERENCE_API_TEST=OFF \
+    -DON_INFER=ON \
+    -DWITH_PYTHON=ON
+make -j
+make inference_lib_dist
+```
+
+For more compilation parameter options, please refer to the official website of the Paddle C++ inference library:[https://www.paddlepaddle.org.cn/documentation/docs/en/advanced_guide/inference_deployment/inference/build_and_install_lib_en.html](https://www.paddlepaddle.org.cn/documentation/docs/en/advanced_guide/inference_deployment/inference/build_and_install_lib_en.html).
+
+
+* After the compilation process, you can see the following files in the folder of `build/fluid_inference_install_dir/`.
+
+```
+build/fluid_inference_install_dir/
+|-- CMakeCache.txt
+|-- paddle
+|-- third_party
+|-- version.txt
+```
+
+Among them, `paddle` is the Paddle library required for C++ prediction later, and `version.txt` contains the version information of the current inference library.
+
+
+
+#### 1.2.2 Direct download and installation
+
+* Different cuda versions of the Linux inference library (based on GCC 4.8.2) are provided on the
+[Paddle inference library official website](https://www.paddlepaddle.org.cn/documentation/docs/en/advanced_guide/inference_deployment/inference/build_and_install_lib_en.html). You can view and select the appropriate version of the inference library on the official website.
+
+
+* After downloading, use the following method to uncompress.
+
+```
+tar -xf fluid_inference.tgz
+```
+
+Finally you can see the following files in the folder of `fluid_inference/`.
+
+
+## 2. Compile and run the demo
+
+### 2.1 Export the inference model
+
+* You can refer to [Model inference](../../doc/doc_ch/inference.md)，export the inference model. After the model is exported, assuming it is placed in the `inference` directory, the directory structure is as follows.
+
+```
+inference/
+|-- det_db
+|   |--model
+|   |--params
+|-- rec_rcnn
+|   |--model
+|   |--params
+```
+
+
+### 2.2 Compile PaddleOCR C++ inference demo
+
+
+* The compilation commands are as follows. The addresses of Paddle C++ inference library, opencv and other Dependencies need to be replaced with the actual addresses on your own machines.
+
+```shell
+sh tools/build.sh
+```
+
+具体地，`tools/build.sh`中内容如下。
+
+```shell
+OPENCV_DIR=your_opencv_dir
+LIB_DIR=your_paddle_inference_dir
+CUDA_LIB_DIR=your_cuda_lib_dir
+CUDNN_LIB_DIR=your_cudnn_lib_dir
+
+BUILD_DIR=build
+rm -rf ${BUILD_DIR}
+mkdir ${BUILD_DIR}
+cd ${BUILD_DIR}
+cmake .. \
+    -DPADDLE_LIB=${LIB_DIR} \
+    -DWITH_MKL=ON \
+    -DDEMO_NAME=ocr_system \
+    -DWITH_GPU=OFF \
+    -DWITH_STATIC_LIB=OFF \
+    -DUSE_TENSORRT=OFF \
+    -DOPENCV_DIR=${OPENCV_DIR} \
+    -DCUDNN_LIB=${CUDNN_LIB_DIR} \
+    -DCUDA_LIB=${CUDA_LIB_DIR} \
+
+make -j
+```
+
+`OPENCV_DIR` is the opencv installation path; `LIB_DIR` is the download (`fluid_inference` folder) or the generated Paddle inference library path (`build/fluid_inference_install_dir` folder); `CUDA_LIB_DIR` is the cuda library file path, in docker; it is `/usr/local/cuda/lib64`; `CUDNN_LIB_DIR` is the cudnn library file path, in docker it is `/usr/lib/x86_64-linux-gnu/`.
+
+
+* After the compilation is completed, an executable file named `ocr_system` will be generated in the `build` folder.
+
+
+### Run the demo
+* Execute the following command to complete the OCR recognition and detection of an image.
+
+```shell
+sh tools/run.sh
+```
+
+The detection results will be shown on the screen, which is as follows.
+
+<div align="center">
+    <img src="../imgs/cpp_infer_pred_12.png" width="600">
+</div>
+
+
+### 2.3 Note
+
+* `MKLDNN` is disabled by default for C++ inference (`use_mkldnn` in `tools/config.txt` is set to 0), if you need to use MKLDNN for inference acceleration, you need to modify `use_mkldnn` to 1, and use the latest version of the Paddle source code to compile the inference library. When using MKLDNN for CPU prediction, if multiple images are predicted at the same time, there will be a memory leak problem (the problem is not present if MKLDNN is disabled). The problem is currently being fixed, and the temporary solution is: when predicting multiple pictures, Re-initialize the recognition (`CRNNRecognizer`) and detection class (`DBDetector`) every 30 pictures or so.

deploy/cpp_infer/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 <algorithm>
+#include <cmath>
+#include <cstdlib>
+#include <cstring>
+#include <functional>
+#include <ostream>
+#include <stdexcept>
+#include <vector>
+
+#include "include/clipper.h"
+
+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

deploy/cpp_infer/src/config.cpp

+// Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <include/config.h>
+
+namespace PaddleOCR {
+
+std::vector<std::string> Config::split(const std::string &str,
+                                       const std::string &delim) {
+  std::vector<std::string> res;
+  if ("" == str)
+    return res;
+  char *strs = new char[str.length() + 1];
+  std::strcpy(strs, str.c_str());
+
+  char *d = new char[delim.length() + 1];
+  std::strcpy(d, delim.c_str());
+
+  char *p = std::strtok(strs, d);
+  while (p) {
+    std::string s = p;
+    res.push_back(s);
+    p = std::strtok(NULL, d);
+  }
+
+  return res;
+}
+
+std::map<std::string, std::string>
+Config::LoadConfig(const std::string &config_path) {
+  auto config = Utility::ReadDict(config_path);
+
+  std::map<std::string, std::string> dict;
+  for (int i = 0; i < config.size(); i++) {
+    // pass for empty line or comment
+    if (config[i].size() <= 1 || config[i][0] == '#') {
+      continue;
+    }
+    std::vector<std::string> res = split(config[i], " ");
+    dict[res[0]] = res[1];
+  }
+  return dict;
+}
+
+void Config::PrintConfigInfo() {
+  std::cout << "=======Paddle OCR inference config======" << std::endl;
+  for (auto iter = config_map_.begin(); iter != config_map_.end(); iter++) {
+    std::cout << iter->first << " : " << iter->second << std::endl;
+  }
+  std::cout << "=======End of Paddle OCR inference config======" << std::endl;
+}
+
+} // namespace PaddleOCR
\ No newline at end of file

deploy/cpp_infer/src/main.cpp

+// Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "opencv2/core.hpp"
+#include "opencv2/imgcodecs.hpp"
+#include "opencv2/imgproc.hpp"
+#include <chrono>
+#include <iomanip>
+#include <iostream>
+#include <ostream>
+#include <vector>
+
+#include <cstring>
+#include <fstream>
+#include <numeric>
+
+#include <include/config.h>
+#include <include/ocr_det.h>
+#include <include/ocr_rec.h>
+
+using namespace std;
+using namespace cv;
+using namespace PaddleOCR;
+
+int main(int argc, char **argv) {
+  if (argc < 3) {
+    std::cerr << "[ERROR] usage: " << argv[0]
+              << " configure_filepath image_path\n";
+    exit(1);
+  }
+
+  Config config(argv[1]);
+
+  config.PrintConfigInfo();
+
+  std::string img_path(argv[2]);
+
+  cv::Mat srcimg = cv::imread(img_path, cv::IMREAD_COLOR);
+
+  DBDetector det(config.det_model_dir, config.use_gpu, config.gpu_id,
+                 config.gpu_mem, config.cpu_math_library_num_threads,
+                 config.use_mkldnn, config.max_side_len, config.det_db_thresh,
+                 config.det_db_box_thresh, config.det_db_unclip_ratio,
+                 config.visualize);
+  CRNNRecognizer rec(config.rec_model_dir, config.use_gpu, config.gpu_id,
+                     config.gpu_mem, config.cpu_math_library_num_threads,
+                     config.use_mkldnn, config.char_list_file);
+
+  auto start = std::chrono::system_clock::now();
+  std::vector<std::vector<std::vector<int>>> boxes;
+  det.Run(srcimg, boxes);
+
+  rec.Run(boxes, srcimg);
+
+  auto end = std::chrono::system_clock::now();
+  auto duration =
+      std::chrono::duration_cast<std::chrono::microseconds>(end - start);
+  std::cout << "花费了"
+            << double(duration.count()) *
+                   std::chrono::microseconds::period::num /
+                   std::chrono::microseconds::period::den
+            << "秒" << std::endl;
+
+  return 0;
+}

deploy/cpp_infer/src/ocr_det.cpp

+// Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <include/ocr_det.h>
+
+namespace PaddleOCR {
+
+void DBDetector::LoadModel(const std::string &model_dir) {
+  AnalysisConfig config;
+  config.SetModel(model_dir + "/model", model_dir + "/params");
+
+  if (this->use_gpu_) {
+    config.EnableUseGpu(this->gpu_mem_, this->gpu_id_);
+  } else {
+    config.DisableGpu();
+    if (this->use_mkldnn_) {
+      config.EnableMKLDNN();
+    }
+    config.SetCpuMathLibraryNumThreads(this->cpu_math_library_num_threads_);
+  }
+
+  // false for zero copy tensor
+  config.SwitchUseFeedFetchOps(false);
+  // true for multiple input
+  config.SwitchSpecifyInputNames(true);
+
+  config.SwitchIrOptim(true);
+
+  config.EnableMemoryOptim();
+  config.DisableGlogInfo();
+
+  this->predictor_ = CreatePaddlePredictor(config);
+}
+
+void DBDetector::Run(cv::Mat &img,
+                     std::vector<std::vector<std::vector<int>>> &boxes) {
+  float ratio_h{};
+  float ratio_w{};
+
+  cv::Mat srcimg;
+  cv::Mat resize_img;
+  img.copyTo(srcimg);
+  this->resize_op_.Run(img, resize_img, this->max_side_len_, ratio_h, ratio_w);
+
+  this->normalize_op_.Run(&resize_img, this->mean_, this->scale_,
+                          this->is_scale_);
+
+  std::vector<float> input(1 * 3 * resize_img.rows * resize_img.cols, 0.0f);
+  this->permute_op_.Run(&resize_img, input.data());
+
+  auto input_names = this->predictor_->GetInputNames();
+  auto input_t = this->predictor_->GetInputTensor(input_names[0]);
+  input_t->Reshape({1, 3, resize_img.rows, resize_img.cols});
+  input_t->copy_from_cpu(input.data());
+
+  this->predictor_->ZeroCopyRun();
+
+  std::vector<float> out_data;
+  auto output_names = this->predictor_->GetOutputNames();
+  auto output_t = this->predictor_->GetOutputTensor(output_names[0]);
+  std::vector<int> output_shape = output_t->shape();
+  int out_num = std::accumulate(output_shape.begin(), output_shape.end(), 1,
+                                std::multiplies<int>());
+
+  out_data.resize(out_num);
+  output_t->copy_to_cpu(out_data.data());
+
+  int n2 = output_shape[2];
+  int n3 = output_shape[3];
+  int n = n2 * n3;
+
+  std::vector<float> pred(n, 0.0);
+  std::vector<unsigned char> cbuf(n, ' ');
+
+  for (int i = 0; i < n; i++) {
+    pred[i] = float(out_data[i]);
+    cbuf[i] = (unsigned char)((out_data[i]) * 255);
+  }
+
+  cv::Mat cbuf_map(n2, n3, CV_8UC1, (unsigned char *)cbuf.data());
+  cv::Mat pred_map(n2, n3, CV_32F, (float *)pred.data());
+
+  const double threshold = this->det_db_thresh_ * 255;
+  const double maxvalue = 255;
+  cv::Mat bit_map;
+  cv::threshold(cbuf_map, bit_map, threshold, maxvalue, cv::THRESH_BINARY);
+
+  boxes = post_processor_.BoxesFromBitmap(
+      pred_map, bit_map, this->det_db_box_thresh_, this->det_db_unclip_ratio_);
+
+  boxes = post_processor_.FilterTagDetRes(boxes, ratio_h, ratio_w, srcimg);
+
+  //// visualization
+  if (this->visualize_) {
+    Utility::VisualizeBboxes(srcimg, boxes);
+  }
+}
+
+} // namespace PaddleOCR

deploy/cpp_infer/src/ocr_rec.cpp

+// Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <include/ocr_rec.h>
+
+namespace PaddleOCR {
+
+void CRNNRecognizer::Run(std::vector<std::vector<std::vector<int>>> boxes,
+                         cv::Mat &img) {
+  cv::Mat srcimg;
+  img.copyTo(srcimg);
+  cv::Mat crop_img;
+  cv::Mat resize_img;
+
+  std::cout << "The predicted text is :" << std::endl;
+  int index = 0;
+  for (int i = boxes.size() - 1; i >= 0; i--) {
+    crop_img = GetRotateCropImage(srcimg, boxes[i]);
+
+    float wh_ratio = float(crop_img.cols) / float(crop_img.rows);
+
+    this->resize_op_.Run(crop_img, resize_img, wh_ratio);
+
+    this->normalize_op_.Run(&resize_img, this->mean_, this->scale_,
+                            this->is_scale_);
+
+    std::vector<float> input(1 * 3 * resize_img.rows * resize_img.cols, 0.0f);
+
+    this->permute_op_.Run(&resize_img, input.data());
+
+    auto input_names = this->predictor_->GetInputNames();
+    auto input_t = this->predictor_->GetInputTensor(input_names[0]);
+    input_t->Reshape({1, 3, resize_img.rows, resize_img.cols});
+    input_t->copy_from_cpu(input.data());
+
+    this->predictor_->ZeroCopyRun();
+
+    std::vector<int64_t> rec_idx;
+    auto output_names = this->predictor_->GetOutputNames();
+    auto output_t = this->predictor_->GetOutputTensor(output_names[0]);
+    auto rec_idx_lod = output_t->lod();
+    auto shape_out = output_t->shape();
+    int out_num = std::accumulate(shape_out.begin(), shape_out.end(), 1,
+                                  std::multiplies<int>());
+
+    rec_idx.resize(out_num);
+    output_t->copy_to_cpu(rec_idx.data());
+
+    std::vector<int> pred_idx;
+    for (int n = int(rec_idx_lod[0][0]); n < int(rec_idx_lod[0][1]); n++) {
+      pred_idx.push_back(int(rec_idx[n]));
+    }
+
+    if (pred_idx.size() < 1e-3)
+      continue;
+
+    index += 1;
+    std::cout << index << "\t";
+    for (int n = 0; n < pred_idx.size(); n++) {
+      std::cout << label_list_[pred_idx[n]];
+    }
+
+    std::vector<float> predict_batch;
+    auto output_t_1 = this->predictor_->GetOutputTensor(output_names[1]);
+
+    auto predict_lod = output_t_1->lod();
+    auto predict_shape = output_t_1->shape();
+    int out_num_1 = std::accumulate(predict_shape.begin(), predict_shape.end(),
+                                    1, std::multiplies<int>());
+
+    predict_batch.resize(out_num_1);
+    output_t_1->copy_to_cpu(predict_batch.data());
+
+    int argmax_idx;
+    int blank = predict_shape[1];
+    float score = 0.f;
+    int count = 0;
+    float max_value = 0.0f;
+
+    for (int n = predict_lod[0][0]; n < predict_lod[0][1] - 1; n++) {
+      argmax_idx =
+          int(Utility::argmax(&predict_batch[n * predict_shape[1]],
+                              &predict_batch[(n + 1) * predict_shape[1]]));
+      max_value =
+          float(*std::max_element(&predict_batch[n * predict_shape[1]],
+                                  &predict_batch[(n + 1) * predict_shape[1]]));
+      if (blank - 1 - argmax_idx > 1e-5) {
+        score += max_value;
+        count += 1;
+      }
+    }
+    score /= count;
+    std::cout << "\tscore: " << score << std::endl;
+  }
+}
+
+void CRNNRecognizer::LoadModel(const std::string &model_dir) {
+  AnalysisConfig config;
+  config.SetModel(model_dir + "/model", model_dir + "/params");
+
+  if (this->use_gpu_) {
+    config.EnableUseGpu(this->gpu_mem_, this->gpu_id_);
+  } else {
+    config.DisableGpu();
+    if (this->use_mkldnn_) {
+      config.EnableMKLDNN();
+    }
+    config.SetCpuMathLibraryNumThreads(this->cpu_math_library_num_threads_);
+  }
+
+  // false for zero copy tensor
+  config.SwitchUseFeedFetchOps(false);
+  // true for multiple input
+  config.SwitchSpecifyInputNames(true);
+
+  config.SwitchIrOptim(true);
+
+  config.EnableMemoryOptim();
+  config.DisableGlogInfo();
+
+  this->predictor_ = CreatePaddlePredictor(config);
+}
+
+cv::Mat CRNNRecognizer::GetRotateCropImage(const cv::Mat &srcimage,
+                                           std::vector<std::vector<int>> box) {
+  cv::Mat image;
+  srcimage.copyTo(image);
+  std::vector<std::vector<int>> points = box;
+
+  int x_collect[4] = {box[0][0], box[1][0], box[2][0], box[3][0]};
+  int y_collect[4] = {box[0][1], box[1][1], box[2][1], box[3][1]};
+  int left = int(*std::min_element(x_collect, x_collect + 4));
+  int right = int(*std::max_element(x_collect, x_collect + 4));
+  int top = int(*std::min_element(y_collect, y_collect + 4));
+  int bottom = int(*std::max_element(y_collect, y_collect + 4));
+
+  cv::Mat img_crop;
+  image(cv::Rect(left, top, right - left, bottom - top)).copyTo(img_crop);
+
+  for (int i = 0; i < points.size(); i++) {
+    points[i][0] -= left;
+    points[i][1] -= top;
+  }
+
+  int img_crop_width = int(sqrt(pow(points[0][0] - points[1][0], 2) +
+                                pow(points[0][1] - points[1][1], 2)));
+  int img_crop_height = int(sqrt(pow(points[0][0] - points[3][0], 2) +
+                                 pow(points[0][1] - points[3][1], 2)));
+
+  cv::Point2f pts_std[4];
+  pts_std[0] = cv::Point2f(0., 0.);
+  pts_std[1] = cv::Point2f(img_crop_width, 0.);
+  pts_std[2] = cv::Point2f(img_crop_width, img_crop_height);
+  pts_std[3] = cv::Point2f(0.f, img_crop_height);
+
+  cv::Point2f pointsf[4];
+  pointsf[0] = cv::Point2f(points[0][0], points[0][1]);
+  pointsf[1] = cv::Point2f(points[1][0], points[1][1]);
+  pointsf[2] = cv::Point2f(points[2][0], points[2][1]);
+  pointsf[3] = cv::Point2f(points[3][0], points[3][1]);
+
+  cv::Mat M = cv::getPerspectiveTransform(pointsf, pts_std);
+
+  cv::Mat dst_img;
+  cv::warpPerspective(img_crop, dst_img, M,
+                      cv::Size(img_crop_width, img_crop_height),
+                      cv::BORDER_REPLICATE);
+
+  if (float(dst_img.rows) >= float(dst_img.cols) * 1.5) {
+    cv::Mat srcCopy = cv::Mat(dst_img.rows, dst_img.cols, dst_img.depth());
+    cv::transpose(dst_img, srcCopy);
+    cv::flip(srcCopy, srcCopy, 0);
+    return srcCopy;
+  } else {
+    return dst_img;
+  }
+}
+
+} // namespace PaddleOCR

deploy/cpp_infer/src/postprocess_op.cpp

+// Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <include/postprocess_op.h>
+
+namespace PaddleOCR {
+
+void PostProcessor::GetContourArea(const std::vector<std::vector<float>> &box,
+                                   float unclip_ratio, float &distance) {
+  int pts_num = 4;
+  float area = 0.0f;
+  float dist = 0.0f;
+  for (int i = 0; i < pts_num; i++) {
+    area += box[i][0] * box[(i + 1) % pts_num][1] -
+            box[i][1] * box[(i + 1) % pts_num][0];
+    dist += sqrtf((box[i][0] - box[(i + 1) % pts_num][0]) *
+                      (box[i][0] - box[(i + 1) % pts_num][0]) +
+                  (box[i][1] - box[(i + 1) % pts_num][1]) *
+                      (box[i][1] - box[(i + 1) % pts_num][1]));
+  }
+  area = fabs(float(area / 2.0));
+
+  distance = area * unclip_ratio / dist;
+}
+
+cv::RotatedRect PostProcessor::UnClip(std::vector<std::vector<float>> box,
+                                      const float &unclip_ratio) {
+  float distance = 1.0;
+
+  GetContourArea(box, unclip_ratio, distance);
+
+  ClipperLib::ClipperOffset offset;
+  ClipperLib::Path p;
+  p << ClipperLib::IntPoint(int(box[0][0]), int(box[0][1]))
+    << ClipperLib::IntPoint(int(box[1][0]), int(box[1][1]))
+    << ClipperLib::IntPoint(int(box[2][0]), int(box[2][1]))
+    << ClipperLib::IntPoint(int(box[3][0]), int(box[3][1]));
+  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.size() <= 0) {
+    res = cv::RotatedRect(cv::Point2f(0, 0), cv::Size2f(1, 1), 0);
+  } else {
+    res = cv::minAreaRect(points);
+  }
+  return res;
+}
+
+float **PostProcessor::Mat2Vec(cv::Mat mat) {
+  auto **array = new float *[mat.rows];
+  for (int i = 0; i < mat.rows; ++i)
+    array[i] = new float[mat.cols];
+  for (int i = 0; i < mat.rows; ++i) {
+    for (int j = 0; j < mat.cols; ++j) {
+      array[i][j] = mat.at<float>(i, j);
+    }
+  }
+
+  return array;
+}
+
+std::vector<std::vector<int>>
+PostProcessor::OrderPointsClockwise(std::vector<std::vector<int>> pts) {
+  std::vector<std::vector<int>> box = pts;
+  std::sort(box.begin(), box.end(), XsortInt);
+
+  std::vector<std::vector<int>> leftmost = {box[0], box[1]};
+  std::vector<std::vector<int>> rightmost = {box[2], box[3]};
+
+  if (leftmost[0][1] > leftmost[1][1])
+    std::swap(leftmost[0], leftmost[1]);
+
+  if (rightmost[0][1] > rightmost[1][1])
+    std::swap(rightmost[0], rightmost[1]);
+
+  std::vector<std::vector<int>> rect = {leftmost[0], rightmost[0], rightmost[1],
+                                        leftmost[1]};
+  return rect;
+}
+
+std::vector<std::vector<float>> PostProcessor::Mat2Vector(cv::Mat mat) {
+  std::vector<std::vector<float>> img_vec;
+  std::vector<float> tmp;
+
+  for (int i = 0; i < mat.rows; ++i) {
+    tmp.clear();
+    for (int j = 0; j < mat.cols; ++j) {
+      tmp.push_back(mat.at<float>(i, j));
+    }
+    img_vec.push_back(tmp);
+  }
+  return img_vec;
+}
+
+bool PostProcessor::XsortFp32(std::vector<float> a, std::vector<float> b) {
+  if (a[0] != b[0])
+    return a[0] < b[0];
+  return false;
+}
+
+bool PostProcessor::XsortInt(std::vector<int> a, std::vector<int> b) {
+  if (a[0] != b[0])
+    return a[0] < b[0];
+  return false;
+}
+
+std::vector<std::vector<float>> PostProcessor::GetMiniBoxes(cv::RotatedRect box,
+                                                            float &ssid) {
+  ssid = std::max(box.size.width, box.size.height);
+
+  cv::Mat points;
+  cv::boxPoints(box, points);
+
+  auto array = Mat2Vector(points);
+  std::sort(array.begin(), array.end(), XsortFp32);
+
+  std::vector<float> idx1 = array[0], idx2 = array[1], idx3 = array[2],
+                     idx4 = array[3];
+  if (array[3][1] <= array[2][1]) {
+    idx2 = array[3];
+    idx3 = array[2];
+  } else {
+    idx2 = array[2];
+    idx3 = array[3];
+  }
+  if (array[1][1] <= array[0][1]) {
+    idx1 = array[1];
+    idx4 = array[0];
+  } else {
+    idx1 = array[0];
+    idx4 = array[1];
+  }
+
+  array[0] = idx1;
+  array[1] = idx2;
+  array[2] = idx3;
+  array[3] = idx4;
+
+  return array;
+}
+
+float PostProcessor::BoxScoreFast(std::vector<std::vector<float>> box_array,
+                                  cv::Mat pred) {
+  auto array = box_array;
+  int width = pred.cols;
+  int height = pred.rows;
+
+  float box_x[4] = {array[0][0], array[1][0], array[2][0], array[3][0]};
+  float box_y[4] = {array[0][1], array[1][1], array[2][1], array[3][1]};
+
+  int xmin = clamp(int(std::floor(*(std::min_element(box_x, box_x + 4)))), 0,
+                   width - 1);
+  int xmax = clamp(int(std::ceil(*(std::max_element(box_x, box_x + 4)))), 0,
+                   width - 1);
+  int ymin = clamp(int(std::floor(*(std::min_element(box_y, box_y + 4)))), 0,
+                   height - 1);
+  int ymax = clamp(int(std::ceil(*(std::max_element(box_y, box_y + 4)))), 0,
+                   height - 1);
+
+  cv::Mat mask;
+  mask = cv::Mat::zeros(ymax - ymin + 1, xmax - xmin + 1, CV_8UC1);
+
+  cv::Point root_point[4];
+  root_point[0] = cv::Point(int(array[0][0]) - xmin, int(array[0][1]) - ymin);
+  root_point[1] = cv::Point(int(array[1][0]) - xmin, int(array[1][1]) - ymin);
+  root_point[2] = cv::Point(int(array[2][0]) - xmin, int(array[2][1]) - ymin);
+  root_point[3] = cv::Point(int(array[3][0]) - xmin, int(array[3][1]) - ymin);
+  const cv::Point *ppt[1] = {root_point};
+  int npt[] = {4};
+  cv::fillPoly(mask, ppt, npt, 1, cv::Scalar(1));
+
+  cv::Mat croppedImg;
+  pred(cv::Rect(xmin, ymin, xmax - xmin + 1, ymax - ymin + 1))
+      .copyTo(croppedImg);
+
+  auto score = cv::mean(croppedImg, mask)[0];
+  return score;
+}
+
+std::vector<std::vector<std::vector<int>>>
+PostProcessor::BoxesFromBitmap(const cv::Mat pred, const cv::Mat bitmap,
+                               const float &box_thresh,
+                               const float &det_db_unclip_ratio) {
+  const int min_size = 3;
+  const int max_candidates = 1000;
+
+  int width = bitmap.cols;
+  int height = bitmap.rows;
+
+  std::vector<std::vector<cv::Point>> contours;
+  std::vector<cv::Vec4i> hierarchy;
+
+  cv::findContours(bitmap, contours, hierarchy, cv::RETR_LIST,
+                   cv::CHAIN_APPROX_SIMPLE);
+
+  int num_contours =
+      contours.size() >= max_candidates ? max_candidates : contours.size();
+
+  std::vector<std::vector<std::vector<int>>> boxes;
+
+  for (int _i = 0; _i < num_contours; _i++) {
+    if (contours[_i].size() <= 2) {
+      continue;
+    }
+    float ssid;
+    cv::RotatedRect box = cv::minAreaRect(contours[_i]);
+    auto array = GetMiniBoxes(box, ssid);
+
+    auto box_for_unclip = array;
+    // end get_mini_box
+
+    if (ssid < min_size) {
+      continue;
+    }
+
+    float score;
+    score = BoxScoreFast(array, pred);
+    if (score < box_thresh)
+      continue;
+
+    // start for unclip
+    cv::RotatedRect points = UnClip(box_for_unclip, det_db_unclip_ratio);
+    if (points.size.height < 1.001 && points.size.width < 1.001) {
+      continue;
+    }
+    // end for unclip
+
+    cv::RotatedRect clipbox = points;
+    auto cliparray = GetMiniBoxes(clipbox, ssid);
+
+    if (ssid < min_size + 2)
+      continue;
+
+    int dest_width = pred.cols;
+    int dest_height = pred.rows;
+    std::vector<std::vector<int>> intcliparray;
+
+    for (int num_pt = 0; num_pt < 4; num_pt++) {
+      std::vector<int> a{int(clampf(roundf(cliparray[num_pt][0] / float(width) *
+                                           float(dest_width)),
+                                    0, float(dest_width))),
+                         int(clampf(roundf(cliparray[num_pt][1] /
+                                           float(height) * float(dest_height)),
+                                    0, float(dest_height)))};
+      intcliparray.push_back(a);
+    }
+    boxes.push_back(intcliparray);
+
+  } // end for
+  return boxes;
+}
+
+std::vector<std::vector<std::vector<int>>>
+PostProcessor::FilterTagDetRes(std::vector<std::vector<std::vector<int>>> boxes,
+                               float ratio_h, float ratio_w, cv::Mat srcimg) {
+  int oriimg_h = srcimg.rows;
+  int oriimg_w = srcimg.cols;
+
+  std::vector<std::vector<std::vector<int>>> root_points;
+  for (int n = 0; n < boxes.size(); n++) {
+    boxes[n] = OrderPointsClockwise(boxes[n]);
+    for (int m = 0; m < boxes[0].size(); m++) {
+      boxes[n][m][0] /= ratio_w;
+      boxes[n][m][1] /= ratio_h;
+
+      boxes[n][m][0] = int(_min(_max(boxes[n][m][0], 0), oriimg_w - 1));
+      boxes[n][m][1] = int(_min(_max(boxes[n][m][1], 0), oriimg_h - 1));
+    }
+  }
+
+  for (int n = 0; n < boxes.size(); n++) {
+    int rect_width, rect_height;
+    rect_width = int(sqrt(pow(boxes[n][0][0] - boxes[n][1][0], 2) +
+                          pow(boxes[n][0][1] - boxes[n][1][1], 2)));
+    rect_height = int(sqrt(pow(boxes[n][0][0] - boxes[n][3][0], 2) +
+                           pow(boxes[n][0][1] - boxes[n][3][1], 2)));
+    if (rect_width <= 10 || rect_height <= 10)
+      continue;
+    root_points.push_back(boxes[n]);
+  }
+  return root_points;
+}
+
+} // namespace PaddleOCR

deploy/cpp_infer/src/preprocess_op.cpp

+// Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "opencv2/core.hpp"
+#include "opencv2/imgcodecs.hpp"
+#include "opencv2/imgproc.hpp"
+#include "paddle_api.h"
+#include "paddle_inference_api.h"
+#include <chrono>
+#include <iomanip>
+#include <iostream>
+#include <ostream>
+#include <vector>
+
+#include <cstring>
+#include <fstream>
+#include <numeric>
+
+#include <include/preprocess_op.h>
+
+namespace PaddleOCR {
+
+void Permute::Run(const cv::Mat *im, float *data) {
+  int rh = im->rows;
+  int rw = im->cols;
+  int rc = im->channels();
+  for (int i = 0; i < rc; ++i) {
+    cv::extractChannel(*im, cv::Mat(rh, rw, CV_32FC1, data + i * rh * rw), i);
+  }
+}
+
+void Normalize::Run(cv::Mat *im, const std::vector<float> &mean,
+                    const std::vector<float> &scale, const bool is_scale) {
+  double e = 1.0;
+  if (is_scale) {
+    e /= 255.0;
+  }
+  (*im).convertTo(*im, CV_32FC3, e);
+  for (int h = 0; h < im->rows; h++) {
+    for (int w = 0; w < im->cols; w++) {
+      im->at<cv::Vec3f>(h, w)[0] =
+          (im->at<cv::Vec3f>(h, w)[0] - mean[0]) * scale[0];
+      im->at<cv::Vec3f>(h, w)[1] =
+          (im->at<cv::Vec3f>(h, w)[1] - mean[1]) * scale[1];
+      im->at<cv::Vec3f>(h, w)[2] =
+          (im->at<cv::Vec3f>(h, w)[2] - mean[2]) * scale[2];
+    }
+  }
+}
+
+void ResizeImgType0::Run(const cv::Mat &img, cv::Mat &resize_img,
+                         int max_size_len, float &ratio_h, float &ratio_w) {
+  int w = img.cols;
+  int h = img.rows;
+
+  float ratio = 1.f;
+  int max_wh = w >= h ? w : h;
+  if (max_wh > max_size_len) {
+    if (h > w) {
+      ratio = float(max_size_len) / float(h);
+    } else {
+      ratio = float(max_size_len) / float(w);
+    }
+  }
+
+  int resize_h = int(float(h) * ratio);
+  int resize_w = int(float(w) * ratio);
+  if (resize_h % 32 == 0)
+    resize_h = resize_h;
+  else if (resize_h / 32 < 1 + 1e-5)
+    resize_h = 32;
+  else
+    resize_h = (resize_h / 32 - 1) * 32;
+
+  if (resize_w % 32 == 0)
+    resize_w = resize_w;
+  else if (resize_w / 32 < 1)
+    resize_w = 32;
+  else
+    resize_w = (resize_w / 32 - 1) * 32;
+
+  cv::resize(img, resize_img, cv::Size(resize_w, resize_h));
+
+  ratio_h = float(resize_h) / float(h);
+  ratio_w = float(resize_w) / float(w);
+}
+
+void CrnnResizeImg::Run(const cv::Mat &img, cv::Mat &resize_img, float wh_ratio,
+                        const std::vector<int> &rec_image_shape) {
+  int imgC, imgH, imgW;
+  imgC = rec_image_shape[0];
+  imgH = rec_image_shape[1];
+  imgW = rec_image_shape[2];
+
+  imgW = int(32 * wh_ratio);
+
+  float ratio = float(img.cols) / float(img.rows);
+  int resize_w, resize_h;
+  if (ceilf(imgH * ratio) > imgW)
+    resize_w = imgW;
+  else
+    resize_w = int(ceilf(imgH * ratio));
+
+  cv::resize(img, resize_img, cv::Size(resize_w, imgH), 0.f, 0.f,
+             cv::INTER_LINEAR);
+}
+
+} // namespace PaddleOCR
\ No newline at end of file

deploy/cpp_infer/src/utility.cpp

+// Copyright (c) 2020 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <iostream>
+#include <ostream>
+#include <vector>
+
+#include <include/utility.h>
+
+namespace PaddleOCR {
+
+std::vector<std::string> Utility::ReadDict(const std::string &path) {
+  std::ifstream in(path);
+  std::string line;
+  std::vector<std::string> m_vec;
+  if (in) {
+    while (getline(in, line)) {
+      m_vec.push_back(line);
+    }
+  } else {
+    std::cout << "no such label file: " << path << ", exit the program..."
+              << std::endl;
+    exit(1);
+  }
+  return m_vec;
+}
+
+void Utility::VisualizeBboxes(
+    const cv::Mat &srcimg,
+    const std::vector<std::vector<std::vector<int>>> &boxes) {
+  cv::Mat img_vis;
+  srcimg.copyTo(img_vis);
+  for (int n = 0; n < boxes.size(); n++) {
+    cv::Point rook_points[4];
+    for (int m = 0; m < boxes[n].size(); m++) {
+      rook_points[m] = cv::Point(int(boxes[n][m][0]), int(boxes[n][m][1]));
+    }
+
+    const cv::Point *ppt[1] = {rook_points};
+    int npt[] = {4};
+    cv::polylines(img_vis, ppt, npt, 1, 1, CV_RGB(0, 255, 0), 2, 8, 0);
+  }
+
+  cv::imwrite("./ocr_vis.png", img_vis);
+  std::cout << "The detection visualized image saved in ./ocr_vis.png"
+            << std::endl;
+}
+
+} // namespace PaddleOCR
\ No newline at end of file

deploy/cpp_infer/tools/build.sh

+OPENCV_DIR=your_opencv_dir
+LIB_DIR=your_paddle_inference_dir
+CUDA_LIB_DIR=your_cuda_lib_dir
+CUDNN_LIB_DIR=your_cudnn_lib_dir
+
+BUILD_DIR=build
+rm -rf ${BUILD_DIR}
+mkdir ${BUILD_DIR}
+cd ${BUILD_DIR}
+cmake .. \
+    -DPADDLE_LIB=${LIB_DIR} \
+    -DWITH_MKL=ON \
+    -DWITH_GPU=OFF \
+    -DWITH_STATIC_LIB=OFF \
+    -DUSE_TENSORRT=OFF \
+    -DOPENCV_DIR=${OPENCV_DIR} \
+    -DCUDNN_LIB=${CUDNN_LIB_DIR} \
+    -DCUDA_LIB=${CUDA_LIB_DIR} \
+
+make -j

deploy/cpp_infer/tools/config.txt

+# model load config
+use_gpu  0
+gpu_id  0
+gpu_mem  4000
+cpu_math_library_num_threads  10
+use_mkldnn 0
+
+# det config
+max_side_len  960
+det_db_thresh  0.3
+det_db_box_thresh  0.5
+det_db_unclip_ratio  2.0
+det_model_dir  ./inference/det_db
+
+# rec config
+rec_model_dir  ./inference/rec_crnn
+char_list_file ../../ppocr/utils/ppocr_keys_v1.txt
+
+# show the detection results
+visualize 1
+

deploy/cpp_infer/tools/run.sh

+
+./build/ocr_system ./tools/config.txt ../../doc/imgs/12.jpg

deploy/hubserving/ocr_det/config.json

+{
+    "modules_info": {
+        "ocr_det": {
+            "init_args": {
+                "version": "1.0.0",
+                "use_gpu": true
+            },
+            "predict_args": {
+            }
+        }
+    },
+    "port": 8866,
+    "use_multiprocess": false,
+    "workers": 2    
+}

deploy/hubserving/ocr_det/module.py

+# -*- coding:utf-8 -*-
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+import argparse
+import ast
+import copy
+import math
+import os
+import time
+
+from paddle.fluid.core import AnalysisConfig, create_paddle_predictor, PaddleTensor
+from paddlehub.common.logger import logger
+from paddlehub.module.module import moduleinfo, runnable, serving
+from PIL import Image
+import cv2
+import numpy as np
+import paddle.fluid as fluid
+import paddlehub as hub
+
+from tools.infer.utility import base64_to_cv2
+from tools.infer.predict_det import TextDetector
+
+
+@moduleinfo(
+    name="ocr_det",
+    version="1.0.0",
+    summary="ocr detection service",
+    author="paddle-dev",
+    author_email="paddle-dev@baidu.com",
+    type="cv/text_recognition")
+class OCRDet(hub.Module):
+    def _initialize(self, use_gpu=False, enable_mkldnn=False):
+        """
+        initialize with the necessary elements
+        """
+        from ocr_det.params import read_params
+        cfg = read_params()
+
+        cfg.use_gpu = use_gpu
+        if use_gpu:
+            try:
+                _places = os.environ["CUDA_VISIBLE_DEVICES"]
+                int(_places[0])
+                print("use gpu: ", use_gpu)
+                print("CUDA_VISIBLE_DEVICES: ", _places)
+                cfg.gpu_mem = 8000
+            except:
+                raise RuntimeError(
+                    "Environment Variable CUDA_VISIBLE_DEVICES is not set correctly. If you wanna use gpu, please set CUDA_VISIBLE_DEVICES via export CUDA_VISIBLE_DEVICES=cuda_device_id."
+                )
+        cfg.ir_optim = True
+        cfg.enable_mkldnn = enable_mkldnn
+
+        self.text_detector = TextDetector(cfg)
+
+    def read_images(self, paths=[]):
+        images = []
+        for img_path in paths:
+            assert os.path.isfile(
+                img_path), "The {} isn't a valid file.".format(img_path)
+            img = cv2.imread(img_path)
+            if img is None:
+                logger.info("error in loading image:{}".format(img_path))
+                continue
+            images.append(img)
+        return images
+
+    def predict(self,
+                images=[],
+                paths=[]):
+        """
+        Get the text box in the predicted images.
+        Args:
+            images (list(numpy.ndarray)): images data, shape of each is [H, W, C]. If images not paths
+            paths (list[str]): The paths of images. If paths not images
+        Returns:
+            res (list): The result of text detection box and save path of images.
+        """
+
+        if images != [] and isinstance(images, list) and paths == []:
+            predicted_data = images
+        elif images == [] and isinstance(paths, list) and paths != []:
+            predicted_data = self.read_images(paths)
+        else:
+            raise TypeError("The input data is inconsistent with expectations.")
+
+        assert predicted_data != [], "There is not any image to be predicted. Please check the input data."
+        
+        all_results = []
+        for img in predicted_data:
+            if img is None:
+                logger.info("error in loading image")
+                all_results.append([])
+                continue
+            dt_boxes, elapse = self.text_detector(img)
+            logger.info("Predict time : {}".format(elapse))
+
+            rec_res_final = []
+            for dno in range(len(dt_boxes)):
+                rec_res_final.append(
+                    {
+                        'text_region': dt_boxes[dno].astype(np.int).tolist()
+                    }
+                )
+            all_results.append(rec_res_final)
+        return all_results
+
+    @serving
+    def serving_method(self, images, **kwargs):
+        """
+        Run as a service.
+        """
+        images_decode = [base64_to_cv2(image) for image in images]
+        results = self.predict(images_decode, **kwargs)
+        return results
+
+   
+if __name__ == '__main__':
+    ocr = OCRDet()
+    image_path = [
+        './doc/imgs/11.jpg',
+        './doc/imgs/12.jpg',
+    ]
+    res = ocr.predict(paths=image_path)
+    print(res)
\ No newline at end of file

deploy/hubserving/ocr_det/params.py

+# -*- coding:utf-8 -*-
+from __future__ import absolute_import
+from __future__ import division
+from __future__ import print_function
+
+
+class Config(object):
+    pass
+
+
+def read_params():
+    cfg = Config()
+    
+    #params for text detector
+    cfg.det_algorithm = "DB"
+    cfg.det_model_dir = "./inference/ch_det_mv3_db/"
+    cfg.det_max_side_len = 960
+
+    #DB parmas
+    cfg.det_db_thresh =0.3
+    cfg.det_db_box_thresh =0.5
+    cfg.det_db_unclip_ratio =2.0
+
+    # #EAST parmas
+    # cfg.det_east_score_thresh = 0.8
+    # cfg.det_east_cover_thresh = 0.1
+    # cfg.det_east_nms_thresh = 0.2
+
+    # #params for text recognizer
+    # cfg.rec_algorithm = "CRNN"
+    # cfg.rec_model_dir = "./inference/ch_det_mv3_crnn/"
+
+    # cfg.rec_image_shape = "3, 32, 320"
+    # cfg.rec_char_type = 'ch'
+    # cfg.rec_batch_num = 30
+    # cfg.rec_char_dict_path = "./ppocr/utils/ppocr_keys_v1.txt"
+    # cfg.use_space_char = True
+
+    return cfg
\ No newline at end of file

deploy/hubserving/ocr_rec/config.json

+{
+    "modules_info": {
+        "ocr_rec": {
+            "init_args": {
+                "version": "1.0.0",
+                "use_gpu": true
+            },
+            "predict_args": {
+            }
+        }
+    },
+    "port": 8867,
+    "use_multiprocess": false,
+    "workers": 2
+}