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Source/Engine/GraphicsDevice/OpenGL/VAOCache.cpp

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+// Copyright (c) 2012-2020 Wojciech Figat. All rights reserved.
+
+#include "VAOCache.h"
+
+#if GRAPHICS_API_OPENGL
+
+#include "TextureOGL.h"
+#include "BufferOGL.h"
+#include "RenderToolsOGL.h"
+#include "Shaders/GPUShaderProgramOGL.h"
+
+VAOCache::VAOCache()
+	: Table(2048)
+{
+}
+
+VAOCache::~VAOCache()
+{
+	Dispose();
+}
+
+GLuint VAOCache::GetVAO(GPUShaderProgramVSOGL* vs, BufferOGL* indexBuffer, uint32 streamsCount, StreamData streams[])
+{
+	Key key(vs, indexBuffer, streamsCount, streams);
+	GLuint vao;
+
+	if (!Table.TryGet(key, vao))
+	{
+		// Create new VAO
+		glGenVertexArrays(1, &vao);
+		VALIDATE_OPENGL_RESULT();
+
+		// Bind VAO
+		glBindVertexArray(vao);
+		VALIDATE_OPENGL_RESULT();
+		
+		// Initialize VAO
+		for (int32 i = 0; i < vs->Layout.Count(); i++)
+		{
+			auto& item = vs->Layout[i];
+
+			auto bufferSlot = item.BufferSlot;
+			if (bufferSlot >= streamsCount)
+			{
+				LOG(Error, "Incorrect input buffer slot");
+				continue;
+			}
+
+			auto& stream = streams[bufferSlot];
+			ASSERT(stream.Buffer != nullptr && stream.Buffer->BufferId != 0);
+
+			glBindBuffer(GL_ARRAY_BUFFER, stream.Buffer->BufferId);
+			VALIDATE_OPENGL_RESULT();
+			
+			GLvoid* DataStartOffset = reinterpret_cast<GLvoid*>(static_cast<size_t>(stream.Offset + item.RelativeOffset));
+			if (item.IsInteger)
+				glVertexAttribIPointer(i, item.TypeCount, item.GlType, stream.Stride, DataStartOffset);
+			else
+				glVertexAttribPointer(i, item.TypeCount, item.GlType, item.Normalized, stream.Stride, DataStartOffset);
+			VALIDATE_OPENGL_RESULT();
+
+			glVertexAttribDivisor(i, item.InstanceDataStepRate);
+			VALIDATE_OPENGL_RESULT();
+
+			glEnableVertexAttribArray(i);
+			VALIDATE_OPENGL_RESULT();
+		}
+		if (indexBuffer)
+		{
+			glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, indexBuffer->BufferId);
+		}
+
+		// Register in cache
+		Table.Add(key, vao);
+	}
+
+	return vao;
+}
+
+void VAOCache::OnObjectRelease(GPUShaderProgramVSOGL* obj)
+{
+	for (auto i = Table.Begin(); i.IsNotEnd(); ++i)
+	{
+		if (i->Key.HasReference(obj))
+		{
+			GLuint fbo = i->Value;
+			glDeleteVertexArrays(1, &fbo);
+			Table.Remove(i);
+		}
+	}
+}
+
+void VAOCache::OnObjectRelease(BufferOGL* obj)
+{
+	for (auto i = Table.Begin(); i.IsNotEnd(); ++i)
+	{
+		if (i->Key.HasReference(obj))
+		{
+			GLuint fbo = i->Value;
+			glDeleteVertexArrays(1, &fbo);
+			Table.Remove(i);
+		}
+	}
+}
+
+void VAOCache::Dispose()
+{
+	for (auto i = Table.Begin(); i.IsNotEnd(); ++i)
+	{
+		GLuint fbo = i->Value;
+		glDeleteVertexArrays(1, &fbo);
+	}
+	Table.Clear();
+}
+
+VAOCache::Key::Key(GPUShaderProgramVSOGL* vs, BufferOGL* indexBuffer, uint32 streamsCount, StreamData streams[])
+{
+	VS = vs;
+	IndexBuffer = indexBuffer;
+	StreamsCount = streamsCount;
+
+	Hash = streamsCount * 371;
+	HashCombinePointer(Hash, vs);
+	HashCombinePointer(Hash, indexBuffer);
+
+	for (int32 i = 0; i < streamsCount; i++)
+	{
+		Streams[i] = streams[i];
+		HashCombinePointer(Hash, streams[i].Buffer);
+		HashCombine(Hash, streams[i].Offset);
+		HashCombine(Hash, streams[i].Stride);
+	}
+}
+
+bool VAOCache::Key::HasReference(GPUShaderProgramVSOGL* obj)
+{
+	return obj == VS;
+}
+
+bool VAOCache::Key::HasReference(BufferOGL* obj)
+{
+	for (int32 i = 0; i < ARRAY_COUNT(Streams); i++)
+	{
+		if (Streams[i].Buffer == obj)
+			return true;
+	}
+	return IndexBuffer == obj;
+}
+
+bool VAOCache::Key::operator==(const Key & other) const
+{
+	if (Hash != 0 && other.Hash != 0 && Hash != other.Hash)
+		return false;
+
+	if (StreamsCount != other.StreamsCount || IndexBuffer != other.IndexBuffer)
+		return false;
+
+	for (int32 rt = 0; rt < StreamsCount; rt++)
+	{
+		if (Streams[rt] != other.Streams[rt])
+			return false;
+	}
+
+	return true;
+}
+
+#endif