Non HDR FP16 blending effects

[KimB]

Yes, but you'd need extra on-chip memory to handle it. Otherwise you still have to do the blending in external memory.

Regardless, when done in the pixel shader, there are not only ways to reduce the memory bandwidth load for current processors, but to actually reduce the total amount of processing that is done.

 

[OpenGL guy]

If it's done in external memory, is it really hardware accelerated accumulation buffer support? I know that various drivers for various video cards have had it in software for quite a while. . . AFAIK, starting with the R300 ATI accumulation buffer blending and storage is all on-card.

Considering you have to do it at the frame level, it's not really feasible to do it in local memory with most architectures.

A 32-bit accumulation buffer occupies no more storage than a 32-bit Z buffer or 32-bit render target, so I am not sure what you mean. Do you really think it's feasible for a card to store an accumulation buffer in main memory (i.e. AGP) and still get good performance?

 

[KimB]

Sorry, I misworded that statement. Corrected.