Example #1
0
        public static bool Contains(int[] xPoints, int[] yPoints,
                                    int nPoints, RectBox bounds, int x1, int y1)
        {
            if ((bounds != null && bounds.Inside(x1, y1)) ||
                (bounds == null && GetBoundingBox(xPoints, yPoints, nPoints)
                 .Inside(x1, y1)))
            {
                int hits  = 0;
                int ySave = 0;
                int i     = 0;

                while (i < nPoints && yPoints[i] == y1)
                {
                    i++;
                }
                for (int n = 0; n < nPoints; n++)
                {
                    int j = (i + 1) % nPoints;

                    int dx = xPoints[j] - xPoints[i];
                    int dy = yPoints[j] - yPoints[i];

                    if (dy != 0)
                    {
                        int rx = x1 - xPoints[i];
                        int ry = y1 - yPoints[i];

                        if (yPoints[j] == y1 && xPoints[j] >= x1)
                        {
                            ySave = yPoints[i];
                        }
                        if (yPoints[i] == y1 && xPoints[i] >= x1)
                        {
                            if ((ySave > y1) != (yPoints[j] > y1))
                            {
                                hits--;
                            }
                        }
                        if (ry * dy >= 0 &&
                            (ry <= dy && ry >= 0 || ry >= dy && ry <= 0) &&
                            Round(dx * ry, dy) >= rx)
                        {
                            hits++;
                        }
                    }
                    i = j;
                }
                return((hits % 2) != 0);
            }

            return(false);
        }