The only correct geometry buffer is the CEGUI logo.
Here is what I see on the screen and the logo render call.

OpenGL3 render calls for reference.

The first draw call should have 108 vertices.
But mine only have 12.

Here is my Geometry Buffer code: https://bitbucket.org/manhnt9/cegui/src ... Buffer.cpp
Could you give me some suggestions for further investigation?