1991-2006
Silicon Graphics, Inc.
glXMakeCurrent
3G
glXMakeCurrent
attach a GLX context to a window or a GLX pixmap
C Specification
Bool glXMakeCurrent
Display * dpy
GLXDrawable drawable
GLXContext ctx
Parameters
dpy
Specifies the connection to the X server.
drawable
Specifies a GLX drawable.
Must be either an X window ID or a GLX pixmap ID.
ctx
Specifies a GLX rendering context that is to be attached to drawable.
Description
glXMakeCurrent does two things:
It makes ctx the current GLX rendering context of the calling thread,
replacing the previously current context if there was one,
and it attaches ctx to a GLX drawable,
either a window or a GLX pixmap.
As a result of these two actions,
subsequent GL rendering calls
use rendering context ctx to modify GLX drawable drawable (for
reading and writing).
Because glXMakeCurrent always replaces the current rendering context with ctx,
there can be only one current context per thread.
Pending commands to the
previous context, if any, are flushed before it is released.
The first time ctx is made current to any thread,
its viewport is set to the full size of drawable.
Subsequent calls by any thread to glXMakeCurrent with ctx
have no effect on its viewport.
To release the current context without assigning a new one,
call glXMakeCurrent with drawable set to None and ctx
set to NULL.
glXMakeCurrent returns True if it is successful,
False otherwise.
If False is returned, the previously current rendering context
and drawable (if any) remain unchanged.
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 drawable was not
created with the same X screen and visual as ctx.
It is also generated if drawable is None and ctx is not
NULL.
BadAccess is generated if ctx was current to another thread
at the time glXMakeCurrent was called.
GLXBadDrawable is generated if drawable is not a valid GLX drawable.
GLXBadContext is generated if ctx is not a valid GLX context.
GLXBadContextState is generated if glXMakeCurrent is executed between
the execution of glBegin and the corresponding execution of glEnd.
GLXBadContextState is also generated if the rendering context current
to the calling thread has GL renderer state GLX_FEEDBACK or
GLX_SELECT.
GLXBadCurrentWindow is generated if there are pending GL
commands for the previous context and the current drawable is
a window that is no longer valid.
BadAlloc may be generated if the server has delayed allocation
of ancillary buffers until glXMakeCurrent is called, only to find that it has
insufficient resources to complete the allocation.
See Also
glXCreateContext,
glXCreateGLXPixmap
glXGetCurrentContext,
glXGetCurrentDisplay,
glXGetCurrentDrawable,
glXGetCurrentReadDrawable,
glXMakeContextCurrent
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/.