NAME
	  fglColorMask - enable	and disable writing of frame buffer
	  color	components


     FORTRAN SPECIFICATION
	  SUBROUTINE fglColorMask( LOGICAL*1 red,
				   LOGICAL*1 green,
				   LOGICAL*1 blue,
				   LOGICAL*1 alpha )


     PARAMETERS
	  red, green, blue, alpha
				Specify	whether	red, green, blue, and
				alpha can or cannot be written into
				the frame buffer.  The initial values
				are all	GL_TRUE, indicating that the
				color components can be	written.

     DESCRIPTION
	  fglColorMask specifies whether the individual	color
	  components in	the frame buffer can or	cannot be written.  If
	  red is GL_FALSE, for example,	no change is made to the red
	  component of any pixel in any	of the color buffers,
	  regardless of	the drawing operation attempted.

	  Changes to individual	bits of	components cannot be
	  controlled.  Rather, changes are either enabled or disabled
	  for entire color components.

     ERRORS
	  GL_INVALID_OPERATION is generated if fglColorMask is
	  executed between the execution of fglBegin and the
	  corresponding	execution of fglEnd.

     ASSOCIATED	GETS
	  fglGet with argument GL_COLOR_WRITEMASK
	  fglGet with argument GL_RGBA_MODE

     SEE ALSO
	  fglColor, fglColorPointer, fglDepthMask, fglIndex,
	  fglIndexPointer, fglIndexMask, fglStencilMask