glXCreateContextWithConfigSGIX(3G)			OpenGL Reference - GLX



NAME
     glXCreateContextWithConfigSGIX - create a new GLX rendering context with
     specified frame buffer configuration


C SPECIFICATION
     GLXContext	glXCreateContextWithConfigSGIX(	Display	*dpy,
						 GLXFBConfigSGIX config,
						int render_type,
						GLXContext share_list,
						Bool direct )


PARAMETERS
     dpy	  Specifies the	connection to the X server.


     config	  Specifies the	GLX frame buffer configuration that defines
		  the frame buffer resources available to the rendering
		  context.


     render_type  Specifies the	type of	rendering context desired. Must	be one
		  of GLX_RGBA_TYPE_SGIX	or GLX_COLOR_INDEX_TYPE_SGIX.


     share_list	  Specifies the	context	with which to share display lists and
		  texture objects.  NULL indicates that	no sharing is to take
		  place.


     direct	  Specifies whether rendering is to be done with a direct
		  connection to	the graphics system if possible	(True) or
		  through the X	server (False).


DESCRIPTION
     glXCreateContextWithConfigSGIX creates a GLX rendering context and
     returns its handle.  If glXCreateContextWithConfigSGIX fails to create a
     rendering context,	NULL is	returned.

     If	direct is True,	then a direct rendering	context	is created if the
     implementation supports direct rendering and the connection is to an X
     server that is local.  If direct is False,	then a rendering context that
     renders through the X server is always created.  Direct rendering
     provides a	performance advantage.	However, direct	rendering contexts
     cannot be shared outside a	single process,	and they cannot	be used	to
     render to GLX pixmaps.

     If	share_list is not NULL,	then all display-list and texture object
     indexes and definitions are shared	by context share_list and by the newly
     created context.  An arbitrary number of contexts can share a single



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glXCreateContextWithConfigSGIX(3G)			OpenGL Reference - GLX



     display-list and texture object space, as long as these contexts exist in
     the same 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.

     The context created by glXCreateContextWithConfigSGIX can be used to
     render into windows, GLX pixmaps and/or GLX pbuffers. Before rendering,
     the context must be made current to a thread and GLX drawable by calling
     glXMakeCurrent. The context can only be made current to a drawable	that
     is	compatible with	it. This requires the following	conditions to be met:

	  The context's	render_type attribute (either GLX_RGBA_TYPE_SGIX or
	  GLX_COLOR_INDEX_TYPE_SGIX) is	supported by the GLXFBConfigSGIX that
	  the drawable was created with. For example, if the context's
	  render_type attribute	is GLX_RGBA_TYPE_SGIX, then the
	  GLX_RENDER_TYPE_SGIX attribute of the	drawable's GLXFBConfigSGIX
	  must have the	GLX_RGBA_BIT_SGIX bit set.

	  All color buffers and	ancillary buffers that exist in	both the
	  drawable's and context's GLXFBConfigSGIX have	the same depth.	For
	  example, a GLXFBConfigSGIX that has a	front left buffer and a	back
	  left buffer with red,	green and blue sizes of	4 is not compatible
	  with a GLXFBConfigSGIX that has only a front left buffer with	red,
	  green	and blue sizes of 8. However, it is compatible with a
	  GLXFBConfigSGIX that has only	a front	left buffer if the red,	green
	  and blue sizes are 4.


NOTES
     glXCreateContextWithConfigSGIX is part of the GLX_SGIX_fbconfig
     extension.

     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
     NULL is returned if execution fails on the	client side.

     BadMatch is generated if the context to be	created	would not share	the
     address space or the screen of the	context	specified by share_list.

     GLXBadFBConfigSGIX	is generated if	config is not a	valid GLXFBConfig.





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glXCreateContextWithConfigSGIX(3G)			OpenGL Reference - GLX



     GLXBadContext is generated	if share_list is not a GLX context and is not
     NULL.

     BadAlloc is generated if the server does not have enough resources	to
     allocate the new context.

     BadValue if render_type does not refer to a valid rendering type.



SEE ALSO
     glXDestroyContext,	glXIsDirect, glXCreateContext, glXMakeCurrent,
     glXGetFBConfigAttribSGIX, glXChooseFBConfigSGIX










































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