Use the containsPoint() method of polygon to test point inclusion inside shape.

Shape.cpp

@@ -21,40 +21,40 @@
 
 bool Shape::includesPoint(int x, int y)
 {
-  Point *prev = NULL, *cur;
-  int left = 0, right = 0, maxy, miny;
-  for (std::vector<Point*>::iterator it = vertices.begin() ;
-      it != vertices.end(); it++)
-  {
-    if (!prev) {
-      prev = vertices.back();
-    }
-    cur = *it;
-    miny = std::min(cur->y(), prev->y());
-    maxy = std::max(cur->y(), prev->y());
-
-    if (y > miny && y < maxy) {
-      if (prev->x() == cur->x())
-      {
-        if (x < cur->x())
-          right++;
-        else left++;
-      }
-      else
-      {
-        double slope = (cur->y() - prev->y()) / (cur->x() - prev->x());
-        double offset = cur->y() - slope * cur->x();
-        int xintersect = int((y - offset ) / slope);
-        if (x < xintersect)
-          right++;
-        else left++;
-      }
-    }
-    prev = *it;
-  }
-  if (right % 2 && left % 2)
-    return true;
-  return false;
+  return toPolygon().containsPoint(QPointF(x, y), Qt::OddEvenFill);
+//  QVector<QPointF>::iterator prev;
+//  int left = 0, right = 0, maxy, miny;
+//  for (QVector<QPointF>::iterator it = vertices.begin() ;
+//      it != vertices.end(); it++)
+//  {
+//    if (!prev) {
+//      prev = vertices.back();
+//    }
+//    miny = qMin(it->y(), prev->y());
+//    maxy = qMax(it->y(), prev->y());
+//
+//    if (y > miny && y < maxy) {
+//      if (prev->x() == it->x())
+//      {
+//        if (x < it->x())
+//          right++;
+//        else left++;
+//      }
+//      else
+//      {
+//        double slope = (it->y() - prev->y()) / (it->x() - prev->x());
+//        double offset = it->y() - slope * it->x();
+//        int xintersect = int((y - offset ) / slope);
+//        if (x < xintersect)
+//          right++;
+//        else left++;
+//      }
+//    }
+//    prev = *it;
+//  }
+//  if (right % 2 && left % 2)
+//    return true;
+//  return false;
 }