NAME
	  glStencilMask	- control the writing of individual bits in
	  the stencil planes


     C SPECIFICATION
	  void glStencilMask( GLuint mask )


     PARAMETERS
	  mask	Specifies a bit	mask to	enable and disable writing of
		individual bits	in the stencil planes.	Initially, the
		mask is	all 1's.

     DESCRIPTION
	  glStencilMask	controls the writing of	individual bits	in the
	  stencil planes.  The least significant n bits	of mask, where
	  n is the number of bits in the stencil buffer, specify a
	  mask.	 Where a 1 appears in the mask,	it's possible to write
	  to the corresponding bit in the stencil buffer.  Where a 0
	  appears, the corresponding bit is write-protected.
	  Initially, all bits are enabled for writing.

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

     ASSOCIATED	GETS
	  glGet	with argument GL_STENCIL_WRITEMASK
	  glGet	with argument GL_STENCIL_BITS

     SEE ALSO
	  glColorMask, glDepthMask, glIndexMask, glStencilFunc,
	  glStencilOp