glxgetcurrentcontext(3x) [redhat man page]

GLXGETCURRENTCONTEXT()													    GLXGETCURRENTCONTEXT()

NAME

       glXGetCurrentContext - return the current context

C SPECIFICATION

       GLXContext glXGetCurrentContext( void )

DESCRIPTION

       glXGetCurrentContext returns the current context, as specified by glXMakeCurrent.  If there is no current context, NULL is returned.

       glXGetCurrentContext returns client-side information.  It does not make a round trip to the server.

SEE ALSO

       glXCreateContext, glXMakeCurrent

															    GLXGETCURRENTCONTEXT()

GLXMAKECURRENT()														  GLXMAKECURRENT()

NAME

       glXMakeCurrent - attach a GLX context to a window or a GLX pixmap

C SPECIFICATION

       Bool glXMakeCurrent( Display *dpy,
			    GLXDrawable drawable,
			    GLXContext ctx )

       delim $$

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 con-
       text 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,  subse-
       quent  GL  rendering  calls  use rendering context ctx to modify GLX drawable drawable.	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 glX-
       MakeCurrent with ctx have no effect on its viewport.

       To release the current context without assigning a new one, call glXMakeCurrent with drawable set 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 draw-
       able (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 GL_FEEDBACK or GL_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

																  GLXMAKECURRENT()