20090501 - 32bpp HDR Blending Idea


The goal is to get 16-bit per channel HDR with only 32-bit per pixel and still have an additive blendable framebuffer.

...

If alpha is needed (for example doing particle blending), 
then a different color channel decimation will be required such as this one,

GA RA GA RA
BA GA BA GA
GA RA GA RA
BA GA BA GA

This is now much closer to the Bayer Grid seen on common digital cameras. 
Remember to keep 2 greens per one blue and one red. 
The result here is 1/4 area chrominance.

NOT FOR OLDER HARDWARE
======================
Unfortunately this trick requires a render target format (16-bit dual channel) 
  not available on a bunch of older hardware (like Geforce 7 series, PS3, etc). 
Will work on 360 however using an 16-bit integer format.