src by scaling by
scale.x and scale.y then translating by offset.x and offset.y,
then composites the rectangle (dest.x ,dest.y, dest.width,
dest.height) of the resulting image with a checkboard of the
colors color1 and color2 and renders it onto the destination
image.gdkPixbufCompositeColor(object, dest, dest.x, dest.y, dest.width, dest.height, offset.x, offset.y, scale.x, scale.y, interp.type, overall.alpha, check.x, check.y, check.size, color1, color2)gdkPixbufCompositeColorSimple for a simpler variant of this
function suitable for many tasks.