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#include "GLES2RendererIndexBuffer.h"

#if defined(RENDERER_ENABLE_GLES2) 
#include <RendererIndexBufferDesc.h>

namespace SampleRenderer
{

GLES2RendererIndexBuffer::GLES2RendererIndexBuffer(const RendererIndexBufferDesc &desc) :
	RendererIndexBuffer(desc)
{
	m_indexSize  = getFormatByteSize(getFormat());
	RENDERER_ASSERT(GLEW_ARB_vertex_buffer_object, "Vertex Buffer Objects not supported on this machine!");
	if(GLEW_ARB_vertex_buffer_object)
	{
		RENDERER_ASSERT(desc.maxIndices > 0 && desc.maxIndices > 0, "Cannot create zero size Index Buffer.");
		if(desc.maxIndices > 0 && desc.maxIndices > 0)
		{
			GLenum usage = GL_STATIC_DRAW_ARB;
			if(getHint() == HINT_DYNAMIC)
			{
				usage = GL_DYNAMIC_DRAW_ARB;
			}
			
			glGenBuffersARB(1, &m_ibo);
			RENDERER_ASSERT(m_ibo, "Failed to create Index Buffer.");
			if(m_ibo)
			{
				m_maxIndices = desc.maxIndices;
				const PxU32 bufferSize = m_indexSize * m_maxIndices;
			
				glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, m_ibo);
				glBufferDataARB(GL_ELEMENT_ARRAY_BUFFER_ARB, bufferSize, 0, usage);
				glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 0);
			}
		}
    }
}

GLES2RendererIndexBuffer::~GLES2RendererIndexBuffer(void)
{
	if(m_ibo)
	{
		glDeleteBuffersARB(1, &m_ibo);
	}
}

void *GLES2RendererIndexBuffer::lock(void)
{
	void *buffer = 0;
	if(m_ibo)
	{
		glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, m_ibo);
		buffer = glMapBufferOES(GL_ELEMENT_ARRAY_BUFFER_ARB, GL_WRITE_ONLY);
		glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 0);
	}
	return buffer;
}

void GLES2RendererIndexBuffer::unlock(void)
{
	if(m_ibo)
	{
		glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, m_ibo);
		glUnmapBufferOES(GL_ELEMENT_ARRAY_BUFFER_ARB);
		glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 0);
	}
}

void GLES2RendererIndexBuffer::bind(void) const
{
	if(m_ibo)
	{
		glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, m_ibo);
	}
}

void GLES2RendererIndexBuffer::unbind(void) const
{
	if(m_ibo)
	{
		glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 0);
	}
	}
}

#endif // #if defined(RENDERER_ENABLE_GLES2)