OpenGL VertexBuffer code

OGLVertexBuffer.cpp

/**
 *  @file       OGLVertexBuffer.cpp
 *  @brief	Vertex data buffer to be sent to the graphic card.
 *  @author     Sébastien Lussier.
 *  @date       07/01/04.
 */
/*
 *  Copyright (C) 2004 Gamedesk
 *
 *  This program 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.
 *
 *  This program 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 this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 *  Gamedesk
 *  http://gamedesk.type-cast.com
 *
 */
#include "OGLGraphic.h"
#include "OGLVertexBuffer.h"


namespace Gamedesk {
	
	
IMPLEMENT_CLASS(OGLHWVertexBuffer);


const GLenum    GDToGLVertexBufferUsage[] =
                    {
                        GL_STATIC_DRAW_ARB,     // Usage_Static
                        GL_DYNAMIC_DRAW_ARB,    // Usage_Dynamic
                        GL_STREAM_DRAW_ARB      // Usage_Stream
                    };

const GLenum    GDToGLVertexBufferLockType[] =
                    {
                        GL_READ_ONLY_ARB,       // Lock_Read
                        GL_WRITE_ONLY_ARB,      // Lock_Write
                        GL_READ_WRITE_ARB       // Lock_Full
                    };


OGLHWVertexBuffer::OGLHWVertexBuffer() :
    mBufferID( NULL )
{
}

OGLHWVertexBuffer::~OGLHWVertexBuffer()
{
    Destroy();
} 

void OGLHWVertexBuffer::Create( UInt32 pItemCount, UInt32 pItemSize, VertexBuffer::Usage pUsage  )
{
    Super::Create( pItemCount, pItemSize, pUsage );

    // Allocate a Buffer object.
    glGenBuffersARB( 1, &mBufferID );                       

    // Set the actual buffer to use.
    glBindBufferARB( GL_ARRAY_BUFFER_ARB, mBufferID );      

    // Setup the usage and amount of memory this vertex buffer will need.
    glBufferDataARB( GL_ARRAY_BUFFER_ARB, 
                     mItemSize * mItemCount, 
                     NULL, 
                     GDToGLVertexBufferUsage[mUsage] );
}

void OGLHWVertexBuffer::Destroy()
{
    if( mBufferID )
    {
        glDeleteBuffersARB( 1, &mBufferID );
        mBufferID = NULL;
    }
    
    Super::Destroy();
}

   

void* OGLHWVertexBuffer::Lock( VertexBuffer::LockType pLockType ) 
{
    glBindBufferARB( GL_ARRAY_BUFFER_ARB, mBufferID );  
    return glMapBufferARB( GL_ARRAY_BUFFER_ARB, GDToGLVertexBufferLockType[pLockType] );
}

void OGLHWVertexBuffer::Unlock()
{
    glBindBufferARB( GL_ARRAY_BUFFER_ARB, mBufferID );     
    glUnmapBufferARB( GL_ARRAY_BUFFER_ARB );
}

GLuint OGLHWVertexBuffer::GetBufferID()
{
    return mBufferID;
}


} // namespace Gamedesk

OGLVertexBuffer.h

/**
 *  @file       OGLVertexBuffer.h
 *  @brief	Vertex data buffer to be sent to the graphic card.
 *  @author     Sébastien Lussier.
 *  @date       07/01/04.
 */
/*
 *  Copyright (C) 2004 Gamedesk
 *
 *  This program 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.
 *
 *  This program 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 this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 *  Gamedesk
 *  http://gamedesk.type-cast.com
 *
 */
#ifndef     _OGL_VERTEX_BUFFER_H_
#define     _OGL_VERTEX_BUFFER_H_


#include "Graphic/Buffer/VertexBuffer.h"


namespace Gamedesk {


/**
 *  OpenGL vertex buffer class that use the ARB_vertex_buffer_object extension.
 */
class OGLGRAPHIC_API OGLHWVertexBuffer : public VertexBuffer
{
    DECLARE_CLASS(OGLHWVertexBuffer, VertexBuffer);
    
public:
    //! Constructor.
    OGLHWVertexBuffer();

    //! Destructor.
    virtual ~OGLHWVertexBuffer();

    /**
     *  Create a vertex buffer by specifying it's properties.
     *  @param  pItemCount  The number of items this buffer will contain.
     *  @param  pItemSize   The size of each item, in bytes.
     *  @param  pUsage      Define the way this buffer will be used.
     */
    virtual void    Create( UInt32 pItemCount, UInt32 pItemSize, Usage pUsage = Usage_Static );

    /**
     *  Destroy the buffer, releasing the memory associated to it.
     */
    virtual void    Destroy();

    /**
     *  Provides a pointer corresponding to the memory mapped area of this buffer.
     *  @param  pLockType   Specify the kind of lock that should be applied on the buffer.
     *  @return A pointer to the mapped area of memory for this buffer, of (GetItemCount()*GetItemSize()) bytes.
     */
    virtual void*   Lock( LockType pLockType );

    /**
     *  Release the lock on a previously locked buffer.
     */
    virtual void    Unlock();

public:
    /** 
     *  Get the OpenGL buffer ID for this vertex buffer.
     *  @return     The buffer ID.
     */
    GLuint  GetBufferID();

private:
    GLuint      mBufferID;      //!< The OpenGL buffer ID.
};


} // namespace Gamedesk


#endif  //  _OGL_VERTEX_BUFFER_H_