glColorPointer and GL_BGRA

[riveranb]

I have a problem on color issue when using VBO.
I find my vertex color may be drawn incorrectly sometimes if I use glColorPointer (4, GL_UNSIGNED_BYTE , sizeof(SVertex***), buffer_offset(24));
But if I use glColorPointer( GL_BGRA, GL_UNSIGNED_BYTE, sizeof(SVertex***), buffer_offset(24));
The vertex colors are rendered correctly.

I am confused about the argument GL_BGRA.
Look at the spec.
http://www.opengl.org/sdk/docs/man/xhtm ... ointer.xml
There did not mention anything about GL_BGRA, the first argument should be the size of components.

So is there anyone know this ?
Any help would be appreciated.

[hybrid]

You probably have to look up the proper BGRA extension as well. In this case it's a relatively new one: GL_ARB_vertex_array_bgra or the EXT version of it. This allows to define the vertex colors in a new order, which uses the Irrlicht native BGRA scheme. So you can only specify that value if your OpenGL version supports this extension. Just check the COpenGLDriver.cpp file for how Irrlicht makes use of it.