I've been struggling with this for a couple hours now and looked around... my problem seems to be this bug (
https://github.com/processing/processing/issues/1738) that was fixed by late May, but I'm still having the problem using 2.0.1 from late June.
I'm trying to mask one PGraphics object with another, or ideally I'd like to mask the main window with the PGraphics (which I'm guessing is the same thing). If I just draw the mask on top, I can see that the mask is fine, but when I try to use it as a mask, then nothing happens: the original image just remains completely unmasked.
Also, when I do try to mask, I get the error "mask() is not available with this renderer." I've tried using both the default renderer and P2D, and both get the same error.
I'm applying the mask correctly as far as I can tell... is there something I'm doing wrong here? Do I need to go grab and compile the version off of Github to get that bug fix?
Here's the main file:
PGraphics rotate_light; PGraphics frame; int playerX, playerY;
// ERROR HERE ------------------------------- // This shows that the mask is the image expected frame.image(rotate_light, width/2, height/2); // This shows that using it as a mask doesn't //frame.mask(rotate_light); // END --------------------------------------