Multi pass

apps/LoopThroughWithOpenGLCompositing/gl/pipeline/OpenGLRenderPass.cpp

@@ -2,6 +2,8 @@
 
 #include "GlRenderConstants.h"
 
+#include <map>
+
 OpenGLRenderPass::OpenGLRenderPass(OpenGLRenderer& renderer) :
 	mRenderer(renderer)
 {
@@ -93,7 +95,10 @@ std::vector<RenderPassDescriptor> OpenGLRenderPass::BuildLayerPassDescriptors(
 {
 	std::vector<RenderPassDescriptor> passes;
 	const std::size_t passCount = layerStates.size() < layerPrograms.size() ? layerStates.size() : layerPrograms.size();
-	passes.reserve(passCount);
+	std::size_t descriptorCount = 0;
+	for (std::size_t index = 0; index < passCount; ++index)
+		descriptorCount += layerPrograms[index].passes.size();
+	passes.reserve(descriptorCount);
 
 	GLuint sourceTexture = mRenderer.DecodedTexture();
 	GLuint sourceFramebuffer = mRenderer.DecodeFramebuffer();
@@ -105,25 +110,90 @@ std::vector<RenderPassDescriptor> OpenGLRenderPass::BuildLayerPassDescriptors(
 			continue;
 		const std::size_t remaining = layerStates.size() - index;
 		const bool writeToMain = (remaining % 2) == 1;
+		const GLuint layerOutputTexture = writeToMain ? mRenderer.CompositeTexture() : mRenderer.LayerTempTexture();
+		const GLuint layerOutputFramebuffer = writeToMain ? mRenderer.CompositeFramebuffer() : mRenderer.LayerTempFramebuffer();
+		const RenderPassOutputTarget layerOutputTarget = writeToMain ? RenderPassOutputTarget::Composite : RenderPassOutputTarget::LayerTemp;
 
-		RenderPassDescriptor pass;
-		pass.kind = RenderPassKind::LayerEffect;
-		pass.outputTarget = writeToMain ? RenderPassOutputTarget::Composite : RenderPassOutputTarget::LayerTemp;
-		pass.passIndex = index;
-		pass.passId = state.layerId;
-		pass.layerId = state.layerId;
-		pass.shaderId = state.shaderId;
-		pass.sourceTexture = sourceTexture;
-		pass.sourceFramebuffer = sourceFramebuffer;
-		pass.destinationFramebuffer = writeToMain ? mRenderer.CompositeFramebuffer() : mRenderer.LayerTempFramebuffer();
-		pass.layerProgram = &layerProgram;
-		pass.passProgram = &layerProgram.passes.front();
-		pass.layerState = &state;
-		pass.capturePreLayerHistory = state.temporalHistorySource == TemporalHistorySource::PreLayerInput;
-		passes.push_back(pass);
+		const GLuint layerInputTexture = sourceTexture;
+		const GLuint layerInputFramebuffer = sourceFramebuffer;
+		GLuint previousPassTexture = layerInputTexture;
+		GLuint previousPassFramebuffer = layerInputFramebuffer;
+		std::map<std::string, std::pair<GLuint, GLuint>> namedOutputs;
+		std::size_t temporaryTargetIndex = 0;
 
-		sourceTexture = writeToMain ? mRenderer.CompositeTexture() : mRenderer.LayerTempTexture();
-		sourceFramebuffer = writeToMain ? mRenderer.CompositeFramebuffer() : mRenderer.LayerTempFramebuffer();
+		for (std::size_t passIndex = 0; passIndex < layerProgram.passes.size(); ++passIndex)
+		{
+			PassProgram& passProgram = layerProgram.passes[passIndex];
+			const bool lastPassForLayer = passIndex + 1 == layerProgram.passes.size();
+			const std::string outputName = passProgram.outputName.empty() ? passProgram.passId : passProgram.outputName;
+			const bool writesLayerOutput = outputName == "layerOutput" || lastPassForLayer;
+
+			GLuint passSourceTexture = previousPassTexture;
+			GLuint passSourceFramebuffer = previousPassFramebuffer;
+			if (!passProgram.inputNames.empty())
+			{
+				const std::string& inputName = passProgram.inputNames.front();
+				if (inputName == "layerInput")
+				{
+					passSourceTexture = layerInputTexture;
+					passSourceFramebuffer = layerInputFramebuffer;
+				}
+				else if (inputName == "previousPass")
+				{
+					passSourceTexture = previousPassTexture;
+					passSourceFramebuffer = previousPassFramebuffer;
+				}
+				else
+				{
+					auto namedOutputIt = namedOutputs.find(inputName);
+					if (namedOutputIt != namedOutputs.end())
+					{
+						passSourceTexture = namedOutputIt->second.first;
+						passSourceFramebuffer = namedOutputIt->second.second;
+					}
+				}
+			}
+
+			GLuint passDestinationTexture = layerOutputTexture;
+			GLuint passDestinationFramebuffer = layerOutputFramebuffer;
+			RenderPassOutputTarget outputTarget = layerOutputTarget;
+			if (!writesLayerOutput)
+			{
+				if (temporaryTargetIndex < mRenderer.TemporaryRenderTargetCount())
+				{
+					const RenderTarget& temporaryTarget = mRenderer.TemporaryRenderTarget(temporaryTargetIndex);
+					++temporaryTargetIndex;
+					passDestinationTexture = temporaryTarget.texture;
+					passDestinationFramebuffer = temporaryTarget.framebuffer;
+					outputTarget = RenderPassOutputTarget::Temporary;
+				}
+			}
+
+			RenderPassDescriptor pass;
+			pass.kind = RenderPassKind::LayerEffect;
+			pass.outputTarget = outputTarget;
+			pass.passIndex = passes.size();
+			pass.passId = passProgram.passId;
+			pass.layerId = state.layerId;
+			pass.shaderId = state.shaderId;
+			pass.sourceTexture = passSourceTexture;
+			pass.sourceFramebuffer = passIndex == 0 ? layerInputFramebuffer : passSourceFramebuffer;
+			pass.destinationTexture = passDestinationTexture;
+			pass.destinationFramebuffer = passDestinationFramebuffer;
+			pass.layerProgram = &layerProgram;
+			pass.passProgram = &passProgram;
+			pass.layerState = &state;
+			pass.capturePreLayerHistory = passIndex == 0 && state.temporalHistorySource == TemporalHistorySource::PreLayerInput;
+			passes.push_back(pass);
+
+			namedOutputs[outputName] = std::make_pair(passDestinationTexture, passDestinationFramebuffer);
+			namedOutputs[passProgram.passId] = std::make_pair(passDestinationTexture, passDestinationFramebuffer);
+			previousPassTexture = passDestinationTexture;
+			previousPassFramebuffer = passDestinationFramebuffer;
+		}
+
+		sourceTexture = layerOutputTexture;
+		sourceFramebuffer = layerOutputFramebuffer;
 	}
 
 	return passes;

apps/LoopThroughWithOpenGLCompositing/gl/pipeline/RenderPassDescriptor.h

@@ -15,6 +15,7 @@ enum class RenderPassKind
 
 enum class RenderPassOutputTarget
 {
+	Temporary,
 	LayerTemp,
 	Composite
 };
@@ -29,6 +30,7 @@ struct RenderPassDescriptor
 	std::string shaderId;
 	GLuint sourceTexture = 0;
 	GLuint sourceFramebuffer = 0;
+	GLuint destinationTexture = 0;
 	GLuint destinationFramebuffer = 0;
 	OpenGLRenderer::LayerProgram* layerProgram = nullptr;
 	OpenGLRenderer::LayerProgram::PassProgram* passProgram = nullptr;