Draw image on top of another image with blending mode color

Question

In Photoshop you can select \"Color\" (the second from the bottom) to set the blending mode to the next lower layer:

Answer 1

You will have to restructure your code so that you draw your gradient on a temporary bitmap, read each pixel from the temporary bitmap and canvas, and write a composed pixel to canvas. You should be able to find code converting between RGB and HSL colors, and once you can do that, setting the hue and saturation of pixels in canvas to the values from your temporary bitmap is trivial (though it's a bit harder if you want to use alpha values).