Add support for BuiltInFrontFacing

src/Device/Primitive.hpp

@@ -50,8 +50,6 @@ namespace sw
 			PlaneEquation V[MAX_INTERFACE_COMPONENTS];
 		};
 
-		float area;
-
 		// Masks for two-sided stencil
 		int64_t clockwiseMask;
 		int64_t invClockwiseMask;

src/Pipeline/PixelProgram.cpp

@@ -33,6 +33,14 @@ namespace sw
 		routine.descriptorDynamicOffsets = data + OFFSET(DrawData, descriptorDynamicOffsets);
 		routine.pushConstants = data + OFFSET(DrawData, pushConstants);
 
+		auto it = spirvShader->inputBuiltins.find(spv::BuiltInFrontFacing);
+		if (it != spirvShader->inputBuiltins.end())
+		{
+			ASSERT(it->second.SizeInComponents == 1);
+			auto frontFacing = Int4(*Pointer<Int>(primitive + OFFSET(Primitive, clockwiseMask)));
+			routine.getVariable(it->second.Id)[it->second.FirstComponent] = As<Float4>(frontFacing);
+		}
+
 		auto activeLaneMask = SIMD::Int(0xFFFFFFFF); // TODO: Control this.
 		spirvShader->emit(&routine, activeLaneMask, descriptorSets);
 		spirvShader->emitEpilog(&routine);

src/Pipeline/SetupRoutine.cpp

@@ -107,8 +107,6 @@ namespace sw
 
 				d = IfThenElse(A > 0.0f, d, Int(0));
 
-				if(state.twoSidedStencil)
-				{
 				If(frontFacing)
 				{
 					*Pointer<Byte8>(primitive + OFFSET(Primitive,clockwiseMask)) = Byte8(0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF);
@@ -120,20 +118,11 @@ namespace sw
 					*Pointer<Byte8>(primitive + OFFSET(Primitive,invClockwiseMask)) = Byte8(0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF);
 				}
 			}
-
-				if(state.vFace)
-				{
-					*Pointer<Float>(primitive + OFFSET(Primitive,area)) = 0.5f * A;
-				}
-			}
 			else
 			{
-				if(state.twoSidedStencil)
-				{
 				*Pointer<Byte8>(primitive + OFFSET(Primitive,clockwiseMask)) = Byte8(0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF);
 				*Pointer<Byte8>(primitive + OFFSET(Primitive,invClockwiseMask)) = Byte8(0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00);
 			}
-			}
 
 			Int n = *Pointer<Int>(polygon + OFFSET(Polygon,n));
 			Int m = *Pointer<Int>(polygon + OFFSET(Polygon,i));