Make fragDepth clamping conditional

Per the spec: If VkPipelineRasterizationStateCreateInfo::depthClampEnable is enabled, before the sample’s zf is compared to za, zf is clamped to [min(n,f),max(n,f)], where n and f are the minDepth and maxDepth depth range values of the viewport used by this fragment, respectively. So when we read oDepth back from a shader that sets fragDepth, it should only be clamped when depth clamping is enabled, and it should be clamped to the viewport depth clamp values, not [0, 1]. Bug: b/184063472 Change-Id: I92e99b80f3929b8b8030f41f6a3afbfebda4e737 Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/54408Reviewed-by: Alexis Hétu <sugoi@google.com> Reviewed-by: Nicolas Capens <nicolascapens@google.com> Presubmit-Ready: Alexis Hétu <sugoi@google.com> Commit-Queue: Sean Risser <srisser@google.com> Tested-by: Sean Risser <srisser@google.com>

Make fragDepth clamping conditional
024bf325 · Sean Risser · swiftshader-scoped@luci-project-accounts.iam.gserviceaccount.com · 3b9a1a79 · 024bf325
Commit 024bf325 authored May 18, 2021 by Sean Risser Committed by swiftshader-scoped@luci-project-accounts.iam.gserviceaccount.com May 21, 2021
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PixelProgram.cpp src/Pipeline/PixelProgram.cpp +5 -1

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--- a/src/Pipeline/PixelProgram.cpp
+++ b/src/Pipeline/PixelProgram.cpp
@@ -235,7 +235,11 @@ void PixelProgram::applyShader(Int cMask[4], Int sMask[4], Int zMask[4], int sam
 	it = spirvShader->outputBuiltins.find(spv::BuiltInFragDepth);
 	if(it != spirvShader->outputBuiltins.end())
 	{
-		oDepth = Min(Max(routine.getVariable(it->second.Id)[it->second.FirstComponent], Float4(0.0f)), Float4(1.0f));
+		oDepth = routine.getVariable(it->second.Id)[it->second.FirstComponent];
+		if(state.depthClamp)
+		{
+			oDepth = Min(Max(oDepth, Float4(state.minDepthClamp)), Float4(state.maxDepthClamp));
+		}
 	}
 }