Added nearest_rect()

dlib/geometry/rectangle.h

@@ -463,6 +463,36 @@ namespace dlib
         return temp;
     }
 
+// ----------------------------------------------------------------------------------------
+
+    inline size_t nearest_rect (
+        const std::vector<rectangle>& rects,
+        const point& p
+    )
+    {
+        DLIB_ASSERT(rects.size() > 0);
+        size_t idx = 0;
+        double best_dist = std::numeric_limits<double>::infinity();
+
+        for (size_t i = 0; i < rects.size(); ++i)
+        {
+            if (rects[i].contains(p))
+            {
+                return i;
+            }
+            else
+            {
+                double dist = (nearest_point(rects[i],p)-p).length();
+                if (dist < best_dist)
+                {
+                    best_dist = dist;
+                    idx = i;
+                }
+            }
+        }
+        return idx;
+    }
+
 // ----------------------------------------------------------------------------------------
 
     template <typename T, typename U>

dlib/geometry/rectangle_abstract.h

@@ -704,6 +704,22 @@ namespace dlib
                 - returns the point in rect that is closest to p
     !*/
 
+// ----------------------------------------------------------------------------------------
+
+    inline size_t nearest_rect (
+        const std::vector<rectangle>& rects,
+        const point& p
+    );
+    /*!
+        requires
+            - rects.size() > 0
+        ensures
+            - returns the index of the rectangle that is closest to the point p.  In
+              particular, this function returns an IDX such that:
+                length(nearest_point(rects[IDX],p) - p)
+              is minimized.
+    !*/
+
 // ----------------------------------------------------------------------------------------
 
     inline long distance_to_rect_edge (