[OGL] Vertex buffer objects: not rendering.

This is a discussion on [OGL] Vertex buffer objects: not rendering. within the Game Programming forums, part of the General Programming Boards category; So, I've decided to switch my renderer over to vertex buffer objects, to help speed things up a bit. I've ...

  1. #1
    The Right Honourable psychopath's Avatar
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    [OGL] Vertex buffer objects: not rendering.

    So, I've decided to switch my renderer over to vertex buffer objects, to help speed things up a bit.

    I've formatted the arrays every which way, but for whatever reason, the thing isn't rendering.

    Note: Code is in C++/CLI. The concept is the same. I can post a standard C++ version if you wish, just let me know.

    In CModel:
    Code:
    //..//
    public:
    int vertexBufferID;
    array<float> ^vertexBuffer;
    //..//
    CreateBuffers() [Member of CModel]:
    Code:
    void CModel::CreateBuffers(){
    	vertexBuffer = gcnew array<float>(numVertices*9);
    	int vertIndex = 0;
    	for(int i=0; i<numMeshes; i++){
    		for(int j=0; j<mesh[i].numTriangles; j++){
    			int triangleIndex = mesh[i].triangleIndices[j];
    			const Triangle *triPtr = &triangle[triangleIndex];
    			int index[3];
    
    			index[0] = triPtr->vertexIndices[0];
    			index[1] = triPtr->vertexIndices[1];
    			index[2] = triPtr->vertexIndices[2];
    			
    			vertexBuffer[vertIndex+0] = vertex[index[0]].location[0];
    			vertexBuffer[vertIndex+1] = vertex[index[0]].location[1];
    			vertexBuffer[vertIndex+2] = vertex[index[0]].location[2];
    
    			vertexBuffer[vertIndex+3] = vertex[index[1]].location[0];
    			vertexBuffer[vertIndex+4] = vertex[index[1]].location[1];
    			vertexBuffer[vertIndex+5] = vertex[index[1]].location[2];
    
    			vertexBuffer[vertIndex+6] = vertex[index[2]].location[0];
    			vertexBuffer[vertIndex+7] = vertex[index[2]].location[1];
    			vertexBuffer[vertIndex+8] = vertex[index[2]].location[2];
    
    			vertIndex += 9;
    		}
    	}
    
    	int objectArraySizeOut;
    	int objectArraySize = vertexBuffer->Length*sizeof(float);
    	Gl::glGenBuffersARB(1, vertexBufferID);
    	Gl::glBindBufferARB(Gl::GL_ARRAY_BUFFER_ARB, vertexBufferID);
    	Gl::glBufferDataARB(Gl::GL_ARRAY_BUFFER_ARB, objectArraySize, vertexBuffer, Gl::GL_STATIC_DRAW_ARB);
    	
    	Gl::glGetBufferParameteriv(Gl::GL_ARRAY_BUFFER_ARB, Gl::GL_BUFFER_SIZE_ARB, objectArraySizeOut);
    	if(objectArraySizeOut <= 0){
    		CUtility::Log("Buffer error.");
    	}
    }
    Rendering code:
    Code:
    Gl::glEnableClientState(Gl::GL_VERTEX_ARRAY);
    
    Gl::glBindBufferARB(Gl::GL_ARRAY_BUFFER_ARB, vertexBufferID);
    Gl::glVertexPointer(3, Gl::GL_FLOAT, 0, IntPtr::Zero);
    Gl::glDrawArrays(Gl::GL_TRIANGLES, 0, numVertices);
    
    Gl::glDisableClientState(Gl::GL_VERTEX_ARRAY);
    CreateBuffers() is called on object init, after model data has been loaded.

    I've probably done something terribly stupid, but I can't figure out what. I've also tried using a multi-dimentional array to hold the buffer data, with the first dimention being the vertex index, and the second being the x,y or z, but it didn't work either.

    Thanks.
    Memorial University of Newfoundland
    Computer Science

    Mac and OpenGL evangelist.

  2. #2
    The Right Honourable psychopath's Avatar
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    Eh, nevermind. I was passing the buffer the address of the array, not the address of the first index of the array.

    Code:
    Gl::glBufferDataARB(Gl::GL_ARRAY_BUFFER_ARB, objectArraySize, vertexBuffer[0], Gl::GL_STATIC_DRAW_ARB);
    Memorial University of Newfoundland
    Computer Science

    Mac and OpenGL evangelist.

  3. #3
    Super Moderator VirtualAce's Avatar
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    Way to go.

    I never make mistakes like that.

    Yeah right. Usually those are the ones that take me hours to solve.

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