Getting started with Shaders

[neilcsmith]

@justin_lincoln

Eventually I want to write a shader that will basically act like a blend(MULTIPLY) filter on video. I’ve gotten that kind of code running without a shader but it really puts a strain on my computer.

You know that OpenGL can support MULTIPLY with the built-in blend functions, so you could just use blendMode(MULTIPLY)? Note that due to Processing’s use of un-premultiplied alpha, multiply is a bit broken with translucent images, but if they’re opaque it’s fine.