I want to know when we have R11G11B10 type of render target format and we are doing additive blending with blend one one operation.
1. Does mali render or call pixel shader only for the front layer per pixel ?
Since all layers are opaque with alpha 1. However, in the streamline counter for blend unit cycles I see blend happening for all layers p[er pixel.
2.Does mali broadcast front layer pixel value to the back layers and do blending?
3. what is the benefit for hardware accelerated blending for R11G11B10 RTV type on mali G1 Ultra architecture?
Others may have more detail, but if layers are opaque/alpha=1, do not put blending on, that's just wasted cycles. Accelerated blending does blending faster, putting it on a dedicated path, but it does not eliminate it. It's always going to have to do some work to check opacity, and blending being on means it can't qualify for fast paths that eliminate parts early without those checks.
To add on top of Ben's reply, Mali does have hidden surface removal (HSR), but it will only remove opaque overdraw. If you enable blending the primitive doesn't count as opaque for the purposes of HSR, even if the alpha value eventally is functionally opaque. Full explaination and technical guidance doe our latest HSR hardware here:* developer.arm.com/.../immortalis-g925-the-fragment-prepass
Thanks a lot! That make sense