Wire up NoPerspective to interpolation

src/Device/Context.cpp

@@ -24,8 +24,6 @@
 
 namespace sw
 {
-	extern bool perspectiveCorrection;
-
 	bool booleanFaceRegister = false;
 	bool fullPixelPositionRegister = false;
 
@@ -619,26 +617,6 @@ namespace sw
 		}
 	}
 
-	bool Context::perspectiveActive() const
-	{
-		if(!colorUsed())
-		{
-			return false;
-		}
-
-		if(!perspectiveCorrection)
-		{
-			return false;
-		}
-
-		if(isDrawPoint())
-		{
-			return false;
-		}
-
-		return true;
-	}
-
 	VkFormat Context::renderTargetInternalFormat(int index) const
 	{
 		if(renderTarget[index])

src/Device/Context.hpp

@@ -121,8 +121,6 @@ namespace sw
 		bool depthBufferActive() const;
 		bool stencilActive() const;
 
-		bool perspectiveActive() const;
-
 		bool allTargetsColorClamp() const;
 		bool alphaBlendActive() const;
 		VkBlendFactor sourceBlendFactor() const;

src/Device/PixelProcessor.cpp

@@ -25,7 +25,6 @@
 namespace sw
 {
 	extern TransparencyAntialiasing transparencyAntialiasing;
-	extern bool perspectiveCorrection;
 
 	bool precachePixel = false;
 
@@ -164,11 +163,6 @@ namespace sw
 		factor.invBlendConstant4F[3][3] = 1 - blendConstant.a;
 	}
 
-	void PixelProcessor::setPerspectiveCorrection(bool perspectiveEnable)
-	{
-		perspectiveCorrection = perspectiveEnable;
-	}
-
 	void PixelProcessor::setRoutineCacheSize(int cacheSize)
 	{
 		delete routineCache;
@@ -208,8 +202,6 @@ namespace sw
 		}
 
 		state.occlusionEnabled = context->occlusionEnabled;
-
-		state.perspective = context->perspectiveActive();
 		state.depthClamp = (context->depthBias != 0.0f) || (context->slopeDepthBias != 0.0f);
 
 		if(context->alphaBlendActive())

src/Device/PixelProcessor.hpp

@@ -126,8 +126,6 @@ namespace sw
 
 		void setBlendConstant(const Color<float> &blendConstant);
 
-		void setPerspectiveCorrection(bool perspectiveCorrection);
-
 	protected:
 		const State update(const Context* context) const;
 		Routine *routine(const State &state, vk::PipelineLayout const *pipelineLayout,

src/Device/QuadRasterizer.cpp

@@ -257,6 +257,8 @@ namespace sw
 
 	bool QuadRasterizer::interpolateW() const
 	{
-		return state.perspective || (spirvShader && spirvShader->hasBuiltinInput(spv::BuiltInPosition));
+		// Note: could optimize cases where there is a fragment shader but it has no
+		// perspective-correct inputs, but that's vanishingly rare.
+		return spirvShader != nullptr;
 	}
 }

src/Device/Renderer.cpp

@@ -68,7 +68,6 @@ namespace sw
 	TranscendentalPrecision expPrecision = ACCURATE;
 	TranscendentalPrecision rcpPrecision = ACCURATE;
 	TranscendentalPrecision rsqPrecision = ACCURATE;
-	bool perspectiveCorrection = true;
 
 	static void setGlobalRenderingSettings(Conventions conventions, bool exactColorRounding)
 	{
@@ -1470,8 +1469,6 @@ namespace sw
 			PixelProcessor::setRoutineCacheSize(configuration.pixelRoutineCacheSize);
 			SetupProcessor::setRoutineCacheSize(configuration.setupRoutineCacheSize);
 
-			setPerspectiveCorrection(configuration.perspectiveCorrection);
-
 			switch(configuration.transcendentalPrecision)
 			{
 			case 0:

src/Device/Renderer.hpp

@@ -57,7 +57,6 @@ namespace sw
 	extern TranscendentalPrecision expPrecision;
 	extern TranscendentalPrecision rcpPrecision;
 	extern TranscendentalPrecision rsqPrecision;
-	extern bool perspectiveCorrection;
 
 	struct Conventions  // FIXME(capn): Eliminate. Only support Vulkan 1.1 conventions.
 	{

src/Device/SetupProcessor.cpp

@@ -79,8 +79,7 @@ namespace sw
 		state.isDrawLine = context->isDrawLine();
 		state.isDrawTriangle = context->isDrawTriangle();
 		state.interpolateZ = context->depthBufferActive() || vPosZW;
-		state.interpolateW = context->perspectiveActive() || vPosZW;
-		state.perspective = context->perspectiveActive();
+		state.interpolateW = context->pixelShader != nullptr;
 		state.frontFacingCCW = context->frontFacingCCW;
 		state.cullMode = context->cullMode;
 		state.twoSidedStencil = context->stencilActive() && context->twoSidedStencil;

src/Device/SetupProcessor.hpp

@@ -41,7 +41,6 @@ namespace sw
 			bool isDrawTriangle            : 1;
 			bool interpolateZ              : 1;
 			bool interpolateW              : 1;
-			bool perspective               : 1;
 			bool frontFacingCCW            : 1;
 			VkCullModeFlags cullMode       : BITS(VK_CULL_MODE_FLAG_BITS_MAX_ENUM);
 			bool twoSidedStencil           : 1;

src/Device/SwiftConfig.cpp

@@ -352,11 +352,6 @@ namespace sw
 		html += "<option value='1'" + (config.mipmapQuality == 1 ? selected : empty) + ">Linear (default)</option>\n";
 		html += "</select></td>\n";
 		html += "</tr>\n";
-		html += "<tr><td>Perspective correction:</td><td><select name='perspectiveCorrection' title='Enables or disables perspective correction. Disabling it is faster but can causes distortion. Recommended for 2D applications only.'>\n";
-		html += "<option value='0'" + (config.perspectiveCorrection == 0 ? selected : empty) + ">Off</option>\n";
-		html += "<option value='1'" + (config.perspectiveCorrection == 1 ? selected : empty) + ">On (default)</option>\n";
-		html += "</select></td>\n";
-		html += "</tr>\n";
 		html += "<tr><td>Transcendental function precision:</td><td><select name='transcendentalPrecision' title='The precision at which log/exp/pow/rcp/rsq/nrm shader instructions are computed. Lower settings can be faster but cause visual artifacts.'>\n";
 		html += "<option value='0'" + (config.transcendentalPrecision == 0 ? selected : empty) + ">Approximate</option>\n";
 		html += "<option value='1'" + (config.transcendentalPrecision == 1 ? selected : empty) + ">Partial</option>\n";
@@ -592,10 +587,6 @@ namespace sw
 			{
 				config.mipmapQuality = integer;
 			}
-			else if(sscanf(post, "perspectiveCorrection=%d", &integer))
-			{
-				config.perspectiveCorrection = integer != 0;
-			}
 			else if(sscanf(post, "transcendentalPrecision=%d", &integer))
 			{
 				config.transcendentalPrecision = integer;
@@ -721,7 +712,6 @@ namespace sw
 		config.vertexCacheSize = ini.getInteger("Caches", "VertexCacheSize", 64);
 		config.textureSampleQuality = ini.getInteger("Quality", "TextureSampleQuality", 2);
 		config.mipmapQuality = ini.getInteger("Quality", "MipmapQuality", 1);
-		config.perspectiveCorrection = ini.getBoolean("Quality", "PerspectiveCorrection", true);
 		config.transcendentalPrecision = ini.getInteger("Quality", "TranscendentalPrecision", 2);
 		config.transparencyAntialiasing = ini.getInteger("Quality", "TransparencyAntialiasing", 0);
 		config.threadCount = ini.getInteger("Processor", "ThreadCount", DEFAULT_THREAD_COUNT);
@@ -778,7 +768,6 @@ namespace sw
 		ini.addValue("Caches", "VertexCacheSize", itoa(config.vertexCacheSize));
 		ini.addValue("Quality", "TextureSampleQuality", itoa(config.textureSampleQuality));
 		ini.addValue("Quality", "MipmapQuality", itoa(config.mipmapQuality));
-		ini.addValue("Quality", "PerspectiveCorrection", itoa(config.perspectiveCorrection));
 		ini.addValue("Quality", "TranscendentalPrecision", itoa(config.transcendentalPrecision));
 		ini.addValue("Quality", "TransparencyAntialiasing", itoa(config.transparencyAntialiasing));
 		ini.addValue("Processor", "ThreadCount", itoa(config.threadCount));

src/Device/SwiftConfig.hpp

@@ -40,7 +40,6 @@ namespace sw
 			int vertexCacheSize;
 			int textureSampleQuality;
 			int mipmapQuality;
-			bool perspectiveCorrection;
 			int transcendentalPrecision;
 			int threadCount;
 			bool enableSSE;

src/Pipeline/PixelRoutine.cpp

@@ -161,14 +161,14 @@ namespace sw
 						routine.inputs[interpolant] =
 								interpolateCentroid(XXXX, YYYY, rhwCentroid,
 													primitive + OFFSET(Primitive, V[interpolant]),
-													input.Flat, state.perspective);
+													input.Flat, !input.NoPerspective);
 					}
 					else
 					{
 						routine.inputs[interpolant] =
 								interpolate(xxxx, Dv[interpolant], rhw,
 											primitive + OFFSET(Primitive, V[interpolant]),
-											input.Flat, state.perspective, false);
+											input.Flat, !input.NoPerspective, false);
 					}
 				}
 			}

src/Pipeline/SetupRoutine.cpp

@@ -439,8 +439,6 @@ namespace sw
 
 			for (int interpolant = 0; interpolant < MAX_INTERFACE_COMPONENTS; interpolant++)
 			{
-				// TODO: fix `perspective` throughout interpolation code to consider NoPerspective-decorated interpolants,
-				// which were not individually-controllable in the GLES implementation.
 				// Note: `sprite` mode controls whether to replace this interpolant with the point sprite PointCoord value.
 				// This was an interesting thing to support for old GL because any texture coordinate could be replaced in this way.
 				// In modern GL and in Vulkan, the [gl_]PointCoord builtin variable to the fragment shader is used instead.
@@ -450,7 +448,7 @@ namespace sw
 							OFFSET(Primitive, V[interpolant]),
 							state.gradient[interpolant].Flat,
 							false /* is pointcoord */,
-							state.perspective, 0);
+							!state.gradient[interpolant].NoPerspective, 0);
 			}
 
 			Return(1);