glXMakeCurrent(3G)	    OpenGL Reference - GLX	    glXMakeCurrent(3G)



NAME
     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 OpenGL
     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
     glXMakeCurrent with ctx have no effect on its viewport.

     To	release	the current context without assigning a	new one, call
     glXMakeCurrent with drawable and ctx set to None and NULL respectively.

     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.





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glXMakeCurrent(3G)	    OpenGL Reference - GLX	    glXMakeCurrent(3G)



     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 None.

     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 called between a
     glBegin and the corresponding call	to glEnd.

     GLXBadContextState	is also	generated if the rendering context current to
     the calling thread	has OpenGL renderer state GL_FEEDBACK or GL_SELECT.

     GLXBadCurrentWindow is generated if there are pending OpenGL 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.



MACHINE	DEPENDENCIES
     On	RealityEngine, RealityEngine2, and VTX systems and on InfiniteReality
     systems it	is not possible	to use a context for rendering to both windows
     and pixmaps.


SEE ALSO
     glXCreateContext, glXCreateGLXPixmap













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