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


     C SPECIFICATION
	  void glColorMask( GLboolean red,
			    GLboolean green,
			    GLboolean blue,
			    GLboolean 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
	  glColorMask 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 glColorMask is executed
	  between the execution	of glBegin and the corresponding
	  execution of glEnd.

     ASSOCIATED	GETS
	  glGet	with argument GL_COLOR_WRITEMASK
	  glGet	with argument GL_RGBA_MODE

     SEE ALSO
	  glColor, glColorPointer, glDepthMask,	glIndex,
	  glIndexPointer, glIndexMask, glStencilMask