int imagefilledpolygon ( int im, array points, int num_points, int col)
ImageFilledPolygon() creates a filled polygon
in image im.
Points is a PHP array containing the
polygon's vertices, ie. points[0] = x0, points[1] = y0, points[2]
= x1, points[3] = y1, etc. Num_points is
the total number of vertices.