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forked from 0ad/0ad
0ad/source/renderer/VertexBuffer.h
Ykkrosh fc2c54c39f # Optimise terrain renderer.
Batch patch splats by texture match.
Use VBOs for patch indices.
Fixes #722.

This was SVN commit r9053.
2011-03-13 19:06:33 +00:00

103 lines
3.1 KiB
C++

/* Copyright (C) 2011 Wildfire Games.
* This file is part of 0 A.D.
*
* 0 A.D. is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* 0 A.D. is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* encapsulation of VBOs with batching and sharing
*/
#ifndef INCLUDED_VERTEXBUFFER
#define INCLUDED_VERTEXBUFFER
#include "lib/res/graphics/ogl_tex.h"
#include <list>
#include <vector>
// absolute maximum (bytewise) size of each GL vertex buffer object
#define MAX_VB_SIZE_BYTES (512*1024)
///////////////////////////////////////////////////////////////////////////////
// CVertexBuffer: encapsulation of ARB_vertex_buffer_object, also supplying
// some additional functionality for sharing buffers between multiple objects
class CVertexBuffer
{
public:
// VBChunk: describes a portion of this vertex buffer
struct VBChunk
{
// owning buffer
CVertexBuffer* m_Owner;
// start index of this chunk in owner
size_t m_Index;
// number of vertices used by chunk
size_t m_Count;
};
public:
// constructor, destructor
CVertexBuffer(size_t vertexSize, GLenum usage, GLenum target);
~CVertexBuffer();
// bind to this buffer; return pointer to address required as parameter
// to glVertexPointer ( + etc) calls
u8* Bind();
// get the address that Bind() will return, without actually binding
u8* GetBindAddress();
// unbind any currently-bound buffer, so glVertexPointer etc calls will not attempt to use it
static void Unbind();
// update vertex data for given chunk
void UpdateChunkVertices(VBChunk* chunk, void* data);
size_t GetVertexSize() const { return m_VertexSize; }
size_t GetBytesReserved() const;
size_t GetBytesAllocated() const;
protected:
friend class CVertexBufferManager; // allow allocate only via CVertexBufferManager
// try to allocate a buffer of given number of vertices (each of given size),
// and with the given type - return null if no free chunks available
VBChunk* Allocate(size_t vertexSize, size_t numVertices, GLenum usage, GLenum target);
// return given chunk to this buffer
void Release(VBChunk* chunk);
private:
// vertex size of this vertex buffer
size_t m_VertexSize;
// number of vertices of above size in this buffer
size_t m_MaxVertices;
// list of free chunks in this buffer
std::list<VBChunk*> m_FreeList;
// available free vertices - total of all free vertices in the free list
size_t m_FreeVertices;
// handle to the actual GL vertex buffer object
GLuint m_Handle;
// raw system memory for systems not supporting VBOs
u8* m_SysMem;
// usage type of the buffer (GL_STATIC_DRAW etc)
GLenum m_Usage;
// buffer target (GL_ARRAY_BUFFER, GL_ELEMENT_ARRAY_BUFFER)
GLenum m_Target;
};
#endif