Creates a transformation of the source image this by scaling by
then translating by
offset_y, then alpha blends the rectangle (
dest_height) of the resulting image with a checkboard of the colors
and renders it onto the destination image.
If the source image has no alpha channel, and
overall_alpha is 255, a fast path is used which omits the alpha blending and just
performs the scaling.
See composite_color_simple for a simpler variant of this function suitable for many tasks.
the Pixbuf into which to render the results
the left coordinate for region to render
the top coordinate for region to render
the width of the region to render
the height of the region to render
the offset in the X direction (currently rounded to an integer)
the offset in the Y direction (currently rounded to an integer)
the scale factor in the X direction
the scale factor in the Y direction
the interpolation type for the transformation.
overall alpha for source image (0..255)
the X offset for the checkboard (origin of checkboard is at -
the Y offset for the checkboard
the size of checks in the checkboard (must be a power of two)
the color of check at upper left
the color of the other check