Possible forgotten use of FSR_RCAS_DENOISE?

[CptLucky8]

Hi,

We're implementing FSR in our project https://github.com/mbucchia/OpenXR-Toolkit and you have done an amazing job. It has been very easy to integrate and it is giving very good results in VR.

I might be wrong but unless the shader compiler optimizes this out, it seems to me the following 3 lines of code could be enclosed in a #ifdef FSR_RCAS_DENOISE block, otherwise the shader is computing the nz value for nothing:

FidelityFX-FSR/ffx-fsr/ffx_fsr1.h

Lines 737 to 739 in a21ffb8

	AF1 nz=AF1_(0.25)*bL+AF1_(0.25)*dL+AF1_(0.25)*fL+AF1_(0.25)*hL-eL;
	nz=ASatF1(abs(nz)*APrxMedRcpF1(AMax3F1(AMax3F1(bL,dL,eL),fL,hL)-AMin3F1(AMin3F1(bL,dL,eL),fL,hL)));
	nz=AF1_(-0.5)*nz+AF1_(1.0);

Thanks!

[Calinou]

I might be wrong but unless the shader compiler optimizes this out

It might be worth checking the generated assembly with http://shader-playground.timjones.io/ to make sure 🙂

[CptLucky8]

@Calinou Thank you for the hint.

I might be wrong but unless the shader compiler optimizes this out,...

I've just tried for the sake of it and it did optimize this out.
The #ifdef block would have probably expressed this directly, saving time by just glancing at the source code though 🙂