Hi everyone! :)
I'm trying to figure out how to replace parts of a block of solid color with transparent sections as a sprite passes over them. Here's a screenshot of what I have working so far:
Right now, players can move the orange sprites around to draw cyan lines over the black and green squares.
What I want to happen is for the cyan to instead be transparent, and to be drawn in place of the black and green it covers, such that what are now cyan lines would be transparent areas that would reveal an image behind the black and green squares. The cyan lines and the black and green squares have the same z-index, but the lines are drawn after the squares. I originally hoped that by making the cyan color transparent, it would replace the black and green because it has the same z-index, but instead if it's set to total transparency it just draws an invisible line over the black and green squares.
The game keeps track of all the places the orange sprites have ever been as a set of quads, which is how it knows where to draw the cyan lines.
Is there a way to do what I want to do, i.e. have the cyan lines be instead transparent "missing" sections of the black and green squares?