-  control  the  writing of individual bits in the stencil
       planes



C SPECIFICATION


PARAMETERS

       _param1  Specifies a bit mask to enable and disable  writ-
                ing  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
       _param1, 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 exe-
       cuted between the execution of glBegin and the correspond-
       ing execution of glEnd.


ASSOCIATED GETS

       glGet with argument GL_STENCIL_WRITEMASK
       glGet with argument GL_STENCIL_BITS


SEE ALSO

       glColorMask,   glDepthMask,   glIndexMask,  glStencilFunc,
       glStencilOp



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