Posted by Braindrool on Dec 01, 2012; 11:12pm
URL: https://forum.jogamp.org/Requesting-help-with-VBO-s-tp4027348p4027370.html

Looks useful. But a few questions stand.

//================================================================
/**
 * Creates vertex buffer object used to store vertices and colors
 * (if it doesn't exist). Fills the object with the latest
 * vertices and colors from the data store.
 *
 * @param gl2 GL object used to access all GL functions.
 * @return the number of vertices in each of the buffers.
 */
protected int [] createAndFillVertexBuffer( GL2 gl2, List<DataObject> listDataObjects ) {

    int [] aiNumOfVertices = new int [] {listDataObjects.size() * 4};
       
    // create vertex buffer object if needed
    if( aiVertexBufferIndices[0] == -1 ) {
        // check for VBO support
        if(    !gl2.isFunctionAvailable( "glGenBuffers" )
            || !gl2.isFunctionAvailable( "glBindBuffer" )
            || !gl2.isFunctionAvailable( "glBufferData" )
            || !gl2.isFunctionAvailable( "glDeleteBuffers" ) ) {
            Activator.openError( "Error", "Vertex buffer objects not supported." );
        }

        gl2.glGenBuffers( 1, aiVertexBufferIndices, 0 );

        // create vertex buffer data store without initial copy
        gl2.glBindBuffer( GL.GL_ARRAY_BUFFER, aiVertexBufferIndices[0] );
        gl2.glBufferData( GL.GL_ARRAY_BUFFER,
                          aiNumOfVertices[0] * 3 * Buffers.SIZEOF_FLOAT * 2,
                          null,
                          GL2.GL_DYNAMIC_DRAW );
    }

    // map the buffer and write vertex and color data directly into it
    gl2.glBindBuffer( GL.GL_ARRAY_BUFFER, aiVertexBufferIndices[0] );
    ByteBuffer bytebuffer = gl2.glMapBuffer( GL.GL_ARRAY_BUFFER, GL2.GL_WRITE_ONLY );
    FloatBuffer floatbuffer = bytebuffer.order( ByteOrder.nativeOrder() ).asFloatBuffer();

    for( DataObject dataobject : listDataObjects )
        storeVerticesAndColors( floatbuffer, dataobject );

    gl2.glUnmapBuffer( GL.GL_ARRAY_BUFFER );

    return( aiNumOfVertices );
}

1. listDataObjects is just the vertex data?

2. aiVertexBufferIndices is?

3. Could you do the traditional Byte / FloatBuffer as in X = Bytebuffer.allocateDirect( size ).asFloatBuffer().order(Buffer.nativeOrder())? Or however that goes.