NAME
	  glMatrixMode - specify which matrix is the current matrix
     C SPECIFICATION
	  void glMatrixMode( GLenum mode )
     PARAMETERS
	  mode	Specifies which	matrix stack is	the target for
		subsequent matrix operations.  Three values are
		accepted:  GL_MODELVIEW, GL_PROJECTION,	and
		GL_TEXTURE.  The initial value is GL_MODELVIEW.
     DESCRIPTION
	  glMatrixMode sets the	current	matrix mode.  mode can assume
	  one of three values:
	  GL_MODELVIEW		   Applies subsequent matrix
				   operations to the modelview matrix
				   stack.
	  GL_PROJECTION		   Applies subsequent matrix
				   operations to the projection	matrix
				   stack.
	  GL_TEXTURE		   Applies subsequent matrix
				   operations to the texture matrix
				   stack.
	  To find out which matrix stack is currently the target of
	  all matrix operations, call glGet with argument
	  GL_MATRIX_MODE. The initial value is GL_MODELVIEW.
     ERRORS
	  GL_INVALID_ENUM is generated if mode is not an accepted
	  value.
	  GL_INVALID_OPERATION is generated if glMatrixMode is
	  executed between the execution of glBegin and	the
	  corresponding	execution of glEnd.
     ASSOCIATED	GETS
	  glGet	with argument GL_MATRIX_MODE
     SEE ALSO
	  glLoadMatrix,	glPushMatrix