glXGetFBConfigAttribSGIX(3G)				OpenGL Reference - GLX



NAME
     glXGetFBConfigAttribSGIX -	return information about a GLX frame buffer
     configuraton


C SPECIFICATION
     int glXGetFBConfigAttribSGIX( Display *dpy,
				   GLXFBConfigSGIX config,
				   int attribute,
				   int *value )


PARAMETERS
     dpy	Specifies the connection to the	X server.


     config	Specifies the GLX frame	buffer configuration to	be queried.


     attribute	Specifies the attribute	to be returned.


     value	Returns	the requested value.


DESCRIPTION
     glXGetFBConfigAttribSGIX sets value to the	attribute value	of GLX
     drawables created with respect to config.	glXGetFBConfigAttribSGIX
     returns an	error code if it fails for any reason.	Otherwise, zero	is
     returned.

     attribute is one of the following:

     GLX_BUFFER_SIZE	   Number of bits per color buffer.  If	the frame
			   buffer configuration	supports RGBA contexts then
			   GLX_BUFFER_SIZE is the sum of GLX_RED_SIZE,
			   GLX_GREEN_SIZE, GLX_BLUE_SIZE, and GLX_ALPHA_SIZE.
			   If the frame	buffer configuration supports only
			   color index contexts, GLX_BUFFER_SIZE is the	size
			   of the color	indexes.

     GLX_LEVEL		   Frame buffer	level of the configuration.  Level
			   zero	is the default frame buffer.  Positive levels
			   correspond to frame buffers that overlay the
			   default buffer, and negative	levels correspond to
			   frame buffers that underlay the default buffer.

     GLX_DOUBLEBUFFER	   True	if color buffers exist in front/back pairs
			   that	can be swapped,	False otherwise.






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glXGetFBConfigAttribSGIX(3G)				OpenGL Reference - GLX



     GLX_STEREO		   True	if color buffers exist in left/right pairs,
			   False otherwise.

     GLX_AUX_BUFFERS	   Number of auxiliary color buffers that are
			   available.  Zero indicates that no auxiliary	color
			   buffers exist.

     GLX_RED_SIZE	   Number of bits of red stored	in each	color buffer.
			   Undefined if	RGBA contexts are not supported	by the
			   frame buffer	configuration.

     GLX_GREEN_SIZE	   Number of bits of green stored in each color
			   buffer.  Undefined if RGBA contexts are not
			   supported by	the frame buffer configuration.

     GLX_BLUE_SIZE	   Number of bits of blue stored in each color buffer.
			   Undefined if	RGBA contexts are not supported	by the
			   frame buffer	configuration.

     GLX_ALPHA_SIZE	   Number of bits of alpha stored in each color
			   buffer.  Undefined if RGBA contexts are not
			   supported by	the frame buffer configuration.

     GLX_DEPTH_SIZE	   Number of bits in the depth buffer.

     GLX_STENCIL_SIZE	   Number of bits in the stencil buffer.

     GLX_ACCUM_RED_SIZE	   Number of bits of red stored	in the accumulation
			   buffer.

     GLX_ACCUM_GREEN_SIZE  Number of bits of green stored in the accumulation
			   buffer.

     GLX_ACCUM_BLUE_SIZE   Number of bits of blue stored in the	accumulation
			   buffer.

     GLX_ACCUM_ALPHA_SIZE  Number of bits of alpha stored in the accumulation
			   buffer.

     GLX_SAMPLE_BUFFERS_SGIS
			   Number of multisample buffers.

     GLX_SAMPLES_SGIS	   Number of samples per pixel in multisample buffers.

     GLX_TRANSPARENT_TYPE_EXT
			   One of GLX_NONE_EXT,	GLX_TRANSPARENT_RGB_EXT,
			   GLX_TRANSPARENT_INDEX_EXT, indicating that the
			   frame buffer	configuration is opaque, is
			   transparent for particular values of	red, green and
			   blue	or is transparent for particular index values,
			   respectively.




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glXGetFBConfigAttribSGIX(3G)				OpenGL Reference - GLX



     GLX_TRANSPARENT_INDEX_VALUE_EXT
			   Integer value between 0 and the maximum frame
			   buffer value	for indices, indicating	the
			   transparent index value for the frame buffer
			   configuration. Undefined if
			   GLX_TRANSPARENT_TYPE_EXT is not
			   GLX_TRANSPARENT_INDEX_EXT.

     GLX_TRANSPARENT_RED_VALUE_EXT
			   Integer value between 0 and the maximum frame
			   buffer value	for red, indicating the	transparent
			   red value for the frame buffer configuration.
			   Undefined if	GLX_TRANSPARENT_TYPE_EXT is not
			   GLX_TRANSPARENT_RGB_EXT.

     GLX_TRANSPARENT_GREEN_VALUE_EXT
			   Integer value between 0 and the maximum frame
			   buffer value	for green, indicating the transparent
			   green value for the frame buffer configuration.
			   Undefined if	GLX_TRANSPARENT_TYPE_EXT is not
			   GLX_TRANSPARENT_RGB_EXT.

     GLX_TRANSPARENT_BLUE_VALUE_EXT
			   Integer value between 0 and the maximum frame
			   buffer value	for blue, indicating the transparent
			   blue	value for the frame buffer configuration.
			   Undefined if	GLX_TRANSPARENT_TYPE_EXT is not
			   GLX_TRANSPARENT_RGB_EXT.

     GLX_TRANSPARENT_ALPHA_VALUE_EXT
			   Currently unused.

     GLX_VISUAL_CAVEAT_EXT One of GLX_NONE_EXT,	GLX_SLOW_VISUAL_EXT,
			   GLX_NON_CONFORMANT_EXT indicating that the frame
			   buffer configuration	has no caveats,	some aspect of
			   the frame buffer configuration runs slower than
			   other frame buffer configurations, or some aspect
			   of the frame	buffer configuration is	non-confomant,
			   respectively.

     GLX_DRAWABLE_TYPE_SGIX
			   Mask	indicating what	drawable types the frame
			   buffer configuration	supports. Valid	bits are
			   GLX_WINDOW_BIT_SGIX,	GLX_PIXMAP_BIT_SGIX and
			   GLX_PBUFFER_BIT_SGIX.

     GLX_RENDER_TYPE_SGIX  Mask	indicating what	type of	GLX contexts can be
			   made	current	to the frame buffer configuration.
			   Valid bits are GLX_RGBA_BIT_SGIX and
			   GLX_COLOR_INDEX_SGIX.





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glXGetFBConfigAttribSGIX(3G)				OpenGL Reference - GLX



     GLX_X_VISUAL_TYPE_EXT Visual type of associated visual.  Undefined	if
			   there is no associated visual (i.e.,	if
			   GLX_X_RENDERABLE_SGIX is False or
			   GLX_DRAWABLE_TYPE_SGIX does not have	the
			   GLX_WINDOW_BIT_SGIX bit set.)

     GLX_X_RENDERABLE_SGIX True	if drawables created with the frame buffer
			   configuration can be	rendered to by X.

     Applications should choose	the frame buffer configuration that most
     closely meets their requirements.	Creating windows, GLX pixmaps or GLX
     pixel buffers with	unnecessary buffers can	result in reduced rendering
     performance as well as poor resource allocation.


NOTES
     glXGetFBConfigAttribSGIX is part of the GLX_SGIX_fbconfig extension.

     glXGetFBConfigAttribSGIX is implemented as	a client-side utility; it does
     not require a round-trip to the X server.

     GLX_SAMPLE_BUFFERS_SGIS and GLX_SAMPLES_SGIS are not valid	attributes
     unless the	SGIS_multisample extension is supported.

     GLX_X_VISUAL_TYPE_EXT, GLX_TRANSPARENT_TYPE_EXT,
     GLX_TRANSPARENT_INDEX_VALUE_EXT, GLX_TRANSPARENT_RED_VALUE_EXT,
     GLX_TRANSPARENT_GREEN_VALUE_EXT, GLX_TRANSPARENT_BLUE_VALUE_EXT, and
     GLX_TRANSPARENT_ALPHA_VALUE_EXT are not valid attributes unless the
     EXT_visual_info extension is supported.

     GLX_VISUAL_CAVEAT_EXT is not a valid attribute unless the
     EXT_visual_rating extension is supported.


ERRORS
     GLX_NO_EXTENSION is returned if dpy does not support the GLX extension.

     GLX_BAD_ATTRIB is returned	if attribute is	not a valid GLX	attribute.



MACHINE	DEPENDENCIES
     The SGIS_multisample extension is supported only on RealityEngine,
     RealityEngine2, and VTX systems and InfiniteReality systems.


SEE ALSO
     glXGetConfig, glXChooseFBConfigSGIX, glXCreateGLXPixmapWithConfigSGIX,
     glXCreateContextWithConfigSGIX, glXGetVisualFromFBConfigSGIX,
     glXGetFBConfigFromVisualSGIX.





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