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ade-the-heat

vbos to draw cube problem(easy but wordy)

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Here's the arrays: FIRSTLY SET UP THE ARRAYS ========================================================== //m_bldg contains the vertices of each corner on the cube at 0,0,0: //eg vertices 4, 5, 6, 7 //vertex=4 m_bdlg[4][0] = 0.0f; m_bdlg[4][1] = 0.0f; m_bdlg[4][2] = 1.0f; //vertex=5 m_bdlg[5][0] = 1.0f; m_bdlg[5][1] = 0.0f; m_bdlg[5][2] = 1.0f; //vertex=6 m_bdlg[6][0] = 1.0f; m_bdlg[6][1] = 1.0f; m_bdlg[6][2] = 1.0f; //vertex=7 m_bdlg[7][0] = 0.0f; m_bdlg[7][1] = 1.0f; m_bdlg[7][2] = 1.0f; .... etc for all 8 vertices //index arrays to draw each face: //eg below gives the 4 corners on the front face which would be array elemenst //4, 5, 6 and 7 of the m_bldg array m_indexFrontArray[0] = 4; m_indexFrontArray[1] = 5; m_indexFrontArray[2] = 6; m_indexFrontArray[3] = 7; //VBO for this: glGenBuffersARB( 1, &vboVertexData ); glBindBufferARB( GL_ARRAY_BUFFER_ARB , vboVertexData); // Bind The Buffer glBufferDataARB( GL_ARRAY_BUFFER_ARB ,8*3*sizeof(float), m_bdlg, GL_STATIC_DRAW_ARB ); ================================================================ NOW DRAW THE ARRAYS: glBindBufferARB( GL_ARRAY_BUFFER_ARB , vboVertexData ); glVertexPointer( 3, GL_FLOAT, 0, NULL ); glEnableClientState(GL_VERTEX_ARRAY); //DRAW COMMAND (etc for each face) glDrawElements(GL_QUADS, 4, GL_UNSIGNED_BYTE, m_indexFrontArray); ... glDisableClientState(GL_VERTEX_ARRAY); ======================================= nothing is there !! other things I'm drawing are there but not this cube ? It must be easy to fix but i can't see it ! cheers

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I tend to stick with the basics:


void drawFlatCube(){
GLfloat cpoints[] = {
//front
-1.0f,-1.0f,+1.0f,
+1.0f,-1.0f,+1.0f,
+1.0f,+1.0f,+1.0f,
-1.0f,+1.0f,+1.0f,
//back
-1.0f,-1.0f,-1.0f,
+1.0f,-1.0f,-1.0f,
+1.0f,+1.0f,-1.0f,
-1.0f,+1.0f,-1.0f
};
GLuint quadIndices[] = {
//front back
0,1,2,3, 5,4,7,6,
//left right
4,0,3,7, 1,5,6,2,
//top bottom
3,2,6,7, 4,5,1,0
};
glInterleavedArrays(GL_V3F,0,cpoints);
glDrawElements(GL_QUADS,24,GL_UNSIGNED_INT,quadIndices);
}

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It looks like you're enabling the client state AFTER you're setting the glVertexPointer. I *think* you have to enable the client state before that.

Also, I think you want to create a VBO for your indicies, as well. Try something like:
//VBO for this:
glGenBuffersARB( 1, &vboVertexData );
glBindBufferARB( GL_ARRAY_BUFFER_ARB , vboVertexData); // Bind The Buffer
glBufferDataARB( GL_ARRAY_BUFFER_ARB ,8*3*sizeof(float),
m_bdlg, GL_STATIC_DRAW_ARB );

glGenBuffersARB( 1, &vboIndicies );
glBindBufferARB( GL_ELEMENT_ARRAY_BUFFER_ARB , vboVertexData); // Bind The Buffer
glBufferDataARB( GL_ELEMENT_ARRAY_BUFFER_ARB ,(number_of_quads * 4)*sizeof(m_indexFrontArray type),
m_bdlg, GL_STATIC_DRAW_ARB );

================================================================

NOW DRAW THE ARRAYS:

glEnableClientState(GL_VERTEX_ARRAY);

glBindBufferARB( GL_ARRAY_BUFFER_ARB , vboVertexData );
glVertexPointer( 3, GL_FLOAT, 0, NULL );

glBindBufferARB( GL_ELEMENT_ARRAY_BUFFER_ARB, vboIndicies );

//DRAW COMMAND (for all faces)
glDrawElements(GL_QUADS, number_of_quads * 4, GL_m_indexFrontArray_type, m_indexFrontArray);
...

glDisableClientState(GL_VERTEX_ARRAY);

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