OpenGL PipeLine

[awaso]

I've been reading the OpenGL Reference manual and was having a hard time seperating what commands executes on the processor verses the video controller, and which block diagrams represent HW verses SW.

I'm specifically looking at the pipeline diagram shown here: http://www.rush3d.com/reference/opengl-bluebook-1.0/ch02.html#id5363512

For Example:
They show a Frame Buffer block. I'm guessing the Frame Buffer block represents memory on the video controller. Not too positive though.

Are most video cards aware of opengl commands? Or does the opengl library/driver executing on the main processor handle commands, translating the commands to something more generic before passing it off to the video controller?

[dorbie]

OpenGL maps to hardware pretty directly for most useful stuff. About the only thing that happens in software is commands tend to be buffered up for efficient dispatch to graphics but that depends on what you use, stuff like DrawArrays can be even more efficient.

On most implementations (with a decent graphics card) the OpenGL pipeline is implemented in hardware pretty directly, either with fixed function hardware of with equivalent microcode running on highly specialized hardware designed to run OpenGL.

Just to be clear here hardware is designed to implement graphics using the OpenGL API (and the similar D3D API), there is no better underlying layer you should be considering using.