NAME
	  fglDepthFunc - specify the value used	for depth buffer
	  comparisons


     FORTRAN SPECIFICATION
	  SUBROUTINE fglDepthFunc( INTEGER*4 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
	  fglDepthFunc 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 fglEnable and fglDisable 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 fglDepthFunc is
	  executed between the execution of fglBegin and the
	  corresponding	execution of fglEnd.

     ASSOCIATED	GETS
	  fglGet with argument GL_DEPTH_FUNC
	  fglIsEnabled with argument GL_DEPTH_TEST

     SEE ALSO
	  fglDepthRange, fglEnable, fglPolygonOffset