Discard operation doesn't improves performance, just tells the driver not to write anything to the output buffer. The reason is that the GPUs use vector processors, the entire GPU core must execute the same operation on all the pixels its processing, which is quite many. <snip> Interesting. I was u...

I've gotta say, mad props to you for worrying about stuff like getting your game performant on integrated graphics at 4k resolution. With the preponderance of ultrabooks with high pixel density displays and no discete graphics, I can totally see it becoming a more common use case. I used to play Fac...