This question is hard to explain, so I will try my best. I know that you can create a mask by just building a .png with a transparent window, then put whatever I want inside that so it shows through.
My question is, can I somehow mask an area? Say I have a background image with a second "mask" image over it. I want to marque some text in the window of that mask image. But, since I don't want it to come out the other side after it passes through the window, I need to create a mask of that area.
So, images or text should be able to pass through that mask and get chopped off if they come outside of the image mask.