Transform feedback buffer assignment

src/OpenGL/libGLESv2/Program.cpp

@@ -17,6 +17,7 @@
 #include "main.h"
 #include "Buffer.h"
 #include "Shader.h"
+#include "TransformFeedback.h"
 #include "utilities.h"
 #include "common/debug.h"
 #include "Shader/PixelShader.hpp"
@@ -1182,6 +1183,90 @@ namespace es2
 		}
 	}
 
+	void Program::applyTransformFeedback(TransformFeedback* transformFeedback)
+	{
+		// Make sure the flags will fit in a 64 bit unsigned int variable
+		ASSERT(sw::max<int>(MAX_TRANSFORM_FEEDBACK_SEPARATE_ATTRIBS, sw::MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS) <= 64);
+
+		BufferBinding* transformFeedbackBuffers = (transformFeedback && transformFeedback->isActive() && !transformFeedback->isPaused()) ? transformFeedback->getBuffers() : nullptr;
+
+		uint64_t enableTransformFeedback = 0;
+		if(!transformFeedbackBuffers)
+		{
+			for(unsigned int index = 0; index < sw::MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS; ++index)
+			{
+				device->VertexProcessor::setTransformFeedbackBuffer(index, nullptr, 0, 0, 0, 0, 0);
+			}
+			device->VertexProcessor::enableTransformFeedback(enableTransformFeedback);
+			return;
+		}
+
+		unsigned int maxVaryings = transformFeedbackLinkedVaryings.size();
+		switch(transformFeedbackBufferMode)
+		{
+		case GL_SEPARATE_ATTRIBS:
+		{
+			maxVaryings = sw::min(maxVaryings, (unsigned int)MAX_TRANSFORM_FEEDBACK_SEPARATE_ATTRIBS);
+			// Attribs go to separate buffers
+			for(unsigned int index = 0; index < maxVaryings; ++index)
+			{
+				int size = transformFeedbackLinkedVaryings[index].size;
+				int rowCount = VariableRowCount(transformFeedbackLinkedVaryings[index].type);
+				int colCount = VariableColumnCount(transformFeedbackLinkedVaryings[index].type);
+				int nbRegs = rowCount > 1 ? colCount * size : size;
+				int nbComponentsPerReg = rowCount > 1 ? rowCount : colCount;
+				int componentStride = rowCount * colCount * size;
+				int baseOffset = transformFeedback->vertexOffset() * componentStride * sizeof(float);
+				device->VertexProcessor::setTransformFeedbackBuffer(index,
+					transformFeedbackBuffers[index].get()->getResource(),
+					transformFeedbackBuffers[index].getOffset() + baseOffset,
+					transformFeedbackLinkedVaryings[index].reg * 4 + transformFeedbackLinkedVaryings[index].col,
+					nbRegs, nbComponentsPerReg, componentStride);
+				enableTransformFeedback |= 1ULL << index;
+			}
+		}
+			break;
+		case GL_INTERLEAVED_ATTRIBS:
+		{
+			// OpenGL ES 3.0.4 spec, section 2.15.2:
+			// In INTERLEAVED_ATTRIBS mode, the values of one or more output variables
+			// written by a vertex shader are written, interleaved, into the buffer object
+			// bound to the first transform feedback binding point (index = 0).
+			sw::Resource* resource = transformFeedbackBuffers[0].get()->getResource();
+			int componentStride = totalLinkedVaryingsComponents;
+			int baseOffset = transformFeedbackBuffers[0].getOffset() + (transformFeedback->vertexOffset() * componentStride * sizeof(float));
+			maxVaryings = sw::min(maxVaryings, (unsigned int)sw::MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS);
+			size_t totalComponents = 0;
+			for(unsigned int index = 0; index < maxVaryings; ++index)
+			{
+				int size = transformFeedbackLinkedVaryings[index].size;
+				int rowCount = VariableRowCount(transformFeedbackLinkedVaryings[index].type);
+				int colCount = VariableColumnCount(transformFeedbackLinkedVaryings[index].type);
+				int nbRegs = rowCount > 1 ? colCount * size : size;
+				int nbComponentsPerReg = rowCount > 1 ? rowCount : colCount;
+				device->VertexProcessor::setTransformFeedbackBuffer(index, resource,
+					baseOffset + (totalComponents * sizeof(float)),
+					transformFeedbackLinkedVaryings[index].reg * 4 + transformFeedbackLinkedVaryings[index].col,
+					nbRegs, nbComponentsPerReg, componentStride);
+				totalComponents += rowCount * colCount * size;
+				enableTransformFeedback |= 1ULL << index;
+			}
+		}
+			break;
+		default:
+			UNREACHABLE(transformFeedbackBufferMode);
+			break;
+		}
+
+		// Unset all other transform feedback buffers
+		for(unsigned int index = maxVaryings; index < sw::MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS; ++index)
+		{
+			device->VertexProcessor::setTransformFeedbackBuffer(index, nullptr, 0, 0, 0, 0, 0);
+		}
+
+		device->VertexProcessor::enableTransformFeedback(enableTransformFeedback);
+	}
+
 	bool Program::linkVaryings()
 	{
 		for(glsl::VaryingList::iterator input = fragmentShader->varyings.begin(); input != fragmentShader->varyings.end(); ++input)

src/OpenGL/libGLESv2/Program.h

@@ -171,6 +171,7 @@ namespace es2
 		void dirtyAllUniforms();
 		void applyUniforms();
 		void applyUniformBuffers(BufferBinding* uniformBuffers);
+		void applyTransformFeedback(TransformFeedback* transformFeedback);
 
 		void link();
 		bool isLinked() const;

src/OpenGL/libGLESv2/TransformFeedback.cpp

@@ -16,7 +16,7 @@
 namespace es2
 {
 
-TransformFeedback::TransformFeedback(GLuint name) : NamedObject(name), mActive(false), mPaused(false)
+TransformFeedback::TransformFeedback(GLuint name) : NamedObject(name), mActive(false), mPaused(false), mVertexOffset(0)
 {
 	mGenericBuffer = NULL;
 }
@@ -60,6 +60,19 @@ int TransformFeedback::getSize(GLuint index) const
 	return mBuffer[index].getSize();
 }
 
+void TransformFeedback::addVertexOffset(int count)
+{
+	if(isActive() && !isPaused())
+	{
+		mVertexOffset += count;
+	}
+}
+
+int TransformFeedback::vertexOffset() const
+{
+	return mVertexOffset;
+}
+
 bool TransformFeedback::isActive() const
 {
 	return mActive;
@@ -84,6 +97,7 @@ void TransformFeedback::end()
 {
 	mActive = false;
 	mPaused = false;
+	mVertexOffset = 0;
 }
 
 void TransformFeedback::setPaused(bool paused)

src/OpenGL/libGLESv2/TransformFeedback.h

@@ -27,10 +27,11 @@ namespace es2
 class TransformFeedback : public gl::NamedObject
 {
 public:
-	// FIXME: Change this when implementing transform feedback
 	TransformFeedback(GLuint name);
 	~TransformFeedback();
 
+	BufferBinding* getBuffers() { return mBuffer; }
+
 	Buffer* getGenericBuffer() const;
 	Buffer* getBuffer(GLuint index) const;
 	GLuint getGenericBufferName() const;
@@ -40,6 +41,7 @@ public:
 	bool isActive() const;
 	bool isPaused() const;
 	GLenum primitiveMode() const;
+	int vertexOffset() const;
 
 	void setGenericBuffer(Buffer* buffer);
 	void setBuffer(GLuint index, Buffer* buffer);
@@ -48,6 +50,7 @@ public:
 	void begin(GLenum primitiveMode);
 	void end();
 	void setPaused(bool paused);
+	void addVertexOffset(int count);
 
 private:
 	gl::BindingPointer<Buffer> mGenericBuffer;
@@ -56,6 +59,7 @@ private:
 	bool mActive;
 	bool mPaused;
 	GLenum mPrimitiveMode;
+	int mVertexOffset;
 };
 
 }