NAME
	  glSelectBuffer - establish a buffer for selection mode
	  values


     C SPECIFICATION
	  void glSelectBuffer( GLsizei size,
			       GLuint *buffer )


     PARAMETERS
	  size	  Specifies the	size of	buffer.

	  buffer  Returns the selection	data.

     DESCRIPTION
	  glSelectBuffer has two arguments:  buffer is a pointer to an
	  array	of unsigned integers, and size indicates the size of
	  the array.  buffer returns values from the name stack	(see
	  glInitNames, glLoadName, glPushName) when the	rendering mode
	  is GL_SELECT (see glRenderMode).  glSelectBuffer must	be
	  issued before	selection mode is enabled, and it must not be
	  issued while the rendering mode is GL_SELECT.

	  A programmer can use selection to determine which primitives
	  are drawn into some region of	a window.  The region is
	  defined by the current modelview and perspective matrices.

	  In selection mode, no	pixel fragments	are produced from
	  rasterization.  Instead, if a	primitive or a raster position
	  intersects the clipping volume defined by the	viewing
	  frustum and the user-defined clipping	planes,	this primitive
	  causes a selection hit.  (With polygons, no hit occurs if
	  the polygon is culled.)  When	a change is made to the	name
	  stack, or when glRenderMode is called, a hit record is
	  copied to buffer if any hits have occurred since the last
	  such event (name stack change	or glRenderMode	call).	The
	  hit record consists of the number of names in	the name stack
	  at the time of the event, followed by	the minimum and
	  maximum depth	values of all vertices that hit	since the
	  previous event, followed by the name stack contents, bottom
	  name first.

	  Depth	values (which are in the range [0,1]) are multiplied
	  by 2^32 - 1, before being placed in the hit record.

	  An internal index into buffer	is reset to 0 whenever
	  selection mode is entered.  Each time	a hit record is	copied
	  into buffer, the index is incremented	to point to the	cell
	  just past the	end of the block of names - that is, to	the
	  next available cell.	If the hit record is larger than the
	  number of remaining locations	in buffer, as much data	as can
	  fit is copied, and the overflow flag is set.	If the name
	  stack	is empty when a	hit record is copied, that record
	  consists of 0	followed by the	minimum	and maximum depth
	  values.

	  To exit selection mode, call glRenderMode with an argument
	  other	than GL_SELECT.	 Whenever glRenderMode is called while
	  the render mode is GL_SELECT,	it returns the number of hit
	  records copied to buffer, resets the overflow	flag and the
	  selection buffer pointer, and	initializes the	name stack to
	  be empty.  If	the overflow bit was set when glRenderMode was
	  called, a negative hit record	count is returned.

     NOTES
	  The contents of buffer is undefined until glRenderMode is
	  called with an argument other	than GL_SELECT.

	  glBegin/glEnd	primitives and calls to	glRasterPos can	result
	  in hits.

     ERRORS
	  GL_INVALID_VALUE is generated	if size	is negative.

	  GL_INVALID_OPERATION is generated if glSelectBuffer is
	  called while the render mode is GL_SELECT, or	if
	  glRenderMode is called with argument GL_SELECT before
	  glSelectBuffer is called at least once.

	  GL_INVALID_OPERATION is generated if glSelectBuffer is
	  executed between the execution of glBegin and	the
	  corresponding	execution of glEnd.

     ASSOCIATED	GETS
	  glGet	with argument GL_NAME_STACK_DEPTH

     SEE ALSO
	  glFeedbackBuffer, glInitNames, glLoadName, glPushName,
	  glRenderMode