Creates a rectangle filled with color in the given
image starting at point 1 and ending at point 2.
0, 0 is the top left corner of the image.
imageAn image resource, returned by one of the image creation functions, such as imagecreatetruecolor().
x1x-coordinate for point 1
y1y-coordinate for point 1
x2x-coordinate for point 2
y2y-coordinate for point 2
colorThe fill color. A color identifier created with imagecolorallocate()