From 0c391fdbce5a079cf03e483eb6174dd47806163d Mon Sep 17 00:00:00 2001
From: chai <chaifix@163.com>
Date: Wed, 7 Aug 2019 21:08:47 +0800
Subject: *misc

---
 Source/modules/asura-core/Graphics/GPUBuffer.h | 93 ++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)
 create mode 100644 Source/modules/asura-core/Graphics/GPUBuffer.h

(limited to 'Source/modules/asura-core/Graphics/GPUBuffer.h')

diff --git a/Source/modules/asura-core/Graphics/GPUBuffer.h b/Source/modules/asura-core/Graphics/GPUBuffer.h
new file mode 100644
index 0000000..565db17
--- /dev/null
+++ b/Source/modules/asura-core/Graphics/GPUBuffer.h
@@ -0,0 +1,93 @@
+#ifndef _ASURA_GPU_BUFFER_H_
+#define _ASURA_GPU_BUFFER_H_
+
+#include <asura-base/Scripting/Scripting.h>
+#include <asura-base/Exception.h>
+#include <asura-base/type.h>
+
+#include "GfxDevice.h"
+
+namespace_begin(AsuraEngine)
+namespace_begin(Graphics)
+
+enum BufferType
+{
+	BUFFER_TYPE_VERTEX, ///< 顶点缓冲，保存position\tangent\normal\color\texcoord(n)
+	BUFFER_TYPE_INDEX,  ///< 索引缓冲
+};
+
+enum BufferUsage
+{
+	BUFFER_USAGE_STREAM,  ///< 修改一次，使用次数低
+	BUFFER_USAGE_DYNAMIC, ///< 修改一次，经常使用
+	BUFFER_USAGE_STATIC,  ///< 经常修改和使用
+};
+
+enum BufferDataType
+{
+	BUFFER_DATA_TYPE_INT,           
+	BUFFER_DATA_TYPE_FLOAT,         
+	BUFFER_DATA_TYPE_UNSIGNED_BYTE,
+};
+
+///
+/// VRAM缓冲，分顶点缓冲vbo和索引缓冲ebo两种，避免每次都从内存向显存上传数据。在framework的renderers中构建。
+///
+ASURA_ABSTRACT class GPUBuffer
+{
+public:
+
+	GPUBuffer(BufferType type, BufferUsage usage, BufferDataType datatype, size_t size);
+	virtual ~GPUBuffer();
+
+	static size_t GetDataTypeSize(GLenum datatype);
+
+	bool   Fill(const void* data, size_t size, uint offset = 0) ASURA_THROW(Exception);
+
+	void   Bind();
+	void   UnBind();
+
+	uint   GetBufferSize();
+	uint   GetBufferCount();
+	GLenum GetDataType();
+	size_t GetDataTypeSize();
+
+private:
+
+	GLenum ConvertBufferType(BufferType type);
+	GLenum ConvertBufferUsage(BufferUsage type);
+	GLenum ConvertBufferDataType(BufferDataType type);
+
+	GLenum m_Target;
+	GLuint m_Buffer;
+
+	/// opengl的显存缓冲并没有对数据类型的要求，只在glVertexAttribPointer时会指定，并在drawcall 时根据给定的数据起
+	/// 始地址和类型从buffer中取各类顶点数据，所以不同的数据类型可以保存在一个buffer中。但是为了保持接口的简洁，这里在
+	/// 初始化buffer时指明保存的数据类型，并在整个周期内保持数据类型的一致，所以不同的数据类型分属不同的buffer。
+
+	GLenum m_DataType;
+	GLuint m_Usage;
+	uint   m_Size;
+
+#if ASURA_DEBUG
+	byte* m_Data; 
+#endif
+
+luaxport:
+
+	LUAX_DECL_ABSTRACT_FACTORY(GPUBuffer);
+
+	LUAX_DECL_ENUM(BufferType, 1);
+	LUAX_DECL_ENUM(BufferUsage, 1);
+	LUAX_DECL_ENUM(BufferDataType, 2);
+
+	LUAX_DECL_METHOD(_Fill);
+	LUAX_DECL_METHOD(_GetSize);
+	LUAX_DECL_METHOD(_GetCount);
+
+};
+
+namespace_end
+namespace_end
+
+#endif
\ No newline at end of file
-- 
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