View Full Version : OpenGL State Machine Diagram Update?

09-09-2004, 12:56 PM
Is there going to be an update for the OpenGL state diagram? The current one is for OpenGL 1.1 (http://www.opengl.org/documentation/spec.html). I would be especially interested to see exactly where the programmable processors (vertex / fragment) fit in and which OpenGL state they use from fixed functionality.

According to a thread with Jon Leech and Marcelo Magallon (http://oss.sgi.com/archives/mbox/ogl-sample/2004-01) an updated version is in the works.

I've found the state diagram very useful as is, but it is too outdate for many applications.

--Jeff Boody

09-12-2004, 04:27 PM
The Orange Book (OpenGL Shading Language) has some great diagrams which show the programmable shaders. I don't think they have an on-line resource though.

The site for the book is at:

09-13-2004, 06:42 AM
I have the orange book. It is a great resource, however as far as diagrams go, there is nothing in it that is comparable to the diagram that I mentioned. Thanks for the info, but I suspect what I want doesn't exist yet.


09-14-2004, 09:54 AM
AFAIK, the pixel pipeline remains unchanged. What *has* changed is your ability to program two parts of the pipeline now (i.e. the vertex and fragment processing parts).
The states that you set from your external app still change the OpenGL state machine. As far as what states these processors make us of from fixed functionality...well...none if you link in a program. There are built in uniforms for accessing OpenGL states. if there are any that aren't currently exposed by GLSL you can pass them in yourself.

09-14-2004, 05:10 PM
Well there are a few things that affect the fixed function OpenGL diagram significantly, like combiners and crossbar. Of course if you look at nvidia register combiners they are even more powerful and make a huge difference to the texture stages. Most people have sketched these out at some time or other.