fp16 blendig, bad values

OpenGL OpenGL: Advanced Coding
1

i am back with another fp16 blending problem.

i render lines. use ONE, ONE blending (from -2047.0 up to 2048.0). color is (1.0, 0.0, 0.0, 0.0). after rendering all lines i get the max value from red channel (through reductions. i get same values with reading back the texture). the problem is the max value, it is many times incorrect, some times twice as high, as it should be. when i resize the window, the max value is “jumping” up and down. ay ideas how this could happen?

pci-e gf6600gt, 81.98, win xp sp2
drivers down to 79.70 do this

2

no one?

3

are you using any kind of AA? supersampling the image? or maybe MSAA on an ATI card? Because drawing lines will always go weird on you with AA, you expect them to be something, but theyre not that :slight_smile: I was just observing something similar!

4

i don’t use any kind of anti-aliasing. just plain lines. supersampling is disabled, also line smooth is disabled.