1991-2006
Silicon Graphics, Inc.
glXCopyContext
3G

# glXCopyContext

copy state from one rendering context to another

## C Specification

                    void glXCopyContext
                    Display * dpy
                    GLXContext src
                    GLXContext dst
                    unsigned long mask

## Parameters

`dpy`

  Specifies the connection to the X server.

`src`

  Specifies the source context.

`dst`

  Specifies the destination context.

`mask`

  Specifies which portions of `src` state are to be copied to `dst`.

## Description

`glXCopyContext` copies selected groups of state variables from `src` to `dst`. `mask` indicates which groups of state variables are to be copied. `mask` contains the bitwise OR of the same symbolic names that are passed to the GL command glPushAttrib. The single symbolic constant `GLX_ALL_ATTRIB_BITS` can be used to copy the maximum possible portion of rendering state.

The copy can be done only if the renderers named by `src` and `dst` share an address space. Two rendering contexts share an address space if both are nondirect using the same server, or if both are direct and owned by a single process. Note that in the nondirect case it is not necessary for the calling threads to share an address space, only for their related rendering contexts to share an address space.

Not all values for GL state can be copied. For example, pixel pack and unpack state, render mode state, and select and feedback state are not copied. The state that can be copied is exactly the state that is manipulated by the GL command glPushAttrib.

An implicit glFlush is done by `glXCopyContext` if `src` is the current context for the calling thread.

## Notes

A process is a single execution environment, implemented in a single address space, consisting of one or more threads.

A thread is one of a set of subprocesses that share a single address space, but maintain separate program counters, stack spaces, and other related global data. A thread that is the only member of its subprocess group is equivalent to a process.

## Errors

`BadMatch` is generated if rendering contexts `src` and `dst` do not share an address space or were not created with respect to the same screen.

`BadAccess` is generated if `dst` is current to any thread (including the calling thread) at the time `glXCopyContext` is called.

`GLXBadCurrentWindow` is generated if `src` is the current context and the current drawable is a window that is no longer valid.

`GLXBadContext` is generated if either `src` or `dst` is not a valid GLX context.

## See Also

glPushAttrib, glXCreateContext, glXIsDirect

## Copyright

Copyright 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.