NAME
	  glDepthFunc -	specify	the value used for depth buffer
	  comparisons


     C SPECIFICATION
	  void glDepthFunc( GLenum func	)


     PARAMETERS
	  func	Specifies the depth comparison function.  Symbolic
		constants GL_NEVER, GL_LESS, GL_EQUAL, GL_LEQUAL,
		GL_GREATER, GL_NOTEQUAL, GL_GEQUAL, and	GL_ALWAYS are
		accepted.  The initial value is	GL_LESS.

     DESCRIPTION
	  glDepthFunc specifies	the function used to compare each
	  incoming pixel depth value with the depth value present in
	  the depth buffer.  The comparison is performed only if depth
	  testing is enabled.  (See glEnable and glDisable of
	  GL_DEPTH_TEST.)

	  func specifies the conditions	under which the	pixel will be
	  drawn.  The comparison functions are as follows:

	  GL_NEVER	  Never	passes.

	  GL_LESS	  Passes if the	incoming depth value is	less
			  than the stored depth	value.

	  GL_EQUAL	  Passes if the	incoming depth value is	equal
			  to the stored	depth value.

	  GL_LEQUAL	  Passes if the	incoming depth value is	less
			  than or equal	to the stored depth value.

	  GL_GREATER	  Passes if the	incoming depth value is
			  greater than the stored depth	value.

	  GL_NOTEQUAL	  Passes if the	incoming depth value is	not
			  equal	to the stored depth value.

	  GL_GEQUAL	  Passes if the	incoming depth value is
			  greater than or equal	to the stored depth
			  value.

	  GL_ALWAYS	  Always passes.

	  The initial value of func is GL_LESS.	 Initially, depth
	  testing is disabled.	Even if	the depth buffer exists	and
	  the depth mask is non-zero, the depth	buffer is not updated
	  if the depth test is disabled.
     ERRORS
	  GL_INVALID_ENUM is generated if func is not an accepted
	  value.

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

     ASSOCIATED	GETS
	  glGet	with argument GL_DEPTH_FUNC
	  glIsEnabled with argument GL_DEPTH_TEST

     SEE ALSO
	  glDepthRange,	glEnable, glPolygonOffset