G3D 9 Immediate-Mode GPU Model

This diagram depicts the relationship between the OpenGL/GLSL and G3D APIs and the hardware graphics pipeline as implemented by a modern GPU. The G3D calls correspond directly to OpenGL calls; they just abstract a lot of boilerplate that frequently changes with every GL version anyway, and add type safety.
The most interesting parts of the relationship are:

• the specific mixture of fixed-function (purple) and programmable (blue) elements
• where state (blue and purple) enters the pipeline
• where control lines (black) affect the pipeline.