OpenGL Programming Guide

Appendix DThe OpenGL Extension to the X Window System

Controlling Rendering

Managing an OpenGL Rendering Context

An OpenGL rendering context is created with glXCreateContext(). One of the arguments to this routine allows you to request a direct rendering context that bypasses the X server as described previously. (Note that to do direct rendering, the X server connection must be local, and the OpenGL implementation needs to support direct rendering.) You can determine whether a GLX context is direct with glXIsDirect().

To make a rendering context current, use glXMakeCurrent(); glXGetCurrentContext() returns the current context. You can also obtain the current drawable with glXGetCurrentDrawable(). Remember that only one context can be current for any thread at any one time. If you have multiple contexts, you can copy selected groups of OpenGL state variables from one context to another with glXCopyContext(). When you're finished with a particular context, destroy it with glXDestroyContext().

OpenGL Programming Guide