NAME
	  fglEvalCoord1d, fglEvalCoord1f, fglEvalCoord2d,
	  fglEvalCoord2f, fglEvalCoord1dv, fglEvalCoord1fv,
	  fglEvalCoord2dv, fglEvalCoord2fv - evaluate enabled one- and
	  two-dimensional maps


     FORTRAN SPECIFICATION
	  SUBROUTINE fglEvalCoord1d( REAL*8 u )
	  SUBROUTINE fglEvalCoord1f( REAL*4 u )
	  SUBROUTINE fglEvalCoord2d( REAL*8 u,
				     REAL*8 v )
	  SUBROUTINE fglEvalCoord2f( REAL*4 u,
				     REAL*4 v )


     PARAMETERS
	  u  Specifies a value that is the domain coordinate u to the
	     basis function defined in a previous fglMap1 or fglMap2
	     command.

	  v  Specifies a value that is the domain coordinate v to the
	     basis function defined in a previous fglMap2 command.
	     This argument is not present in a fglEvalCoord1 command.

     FORTRAN SPECIFICATION
	  SUBROUTINE fglEvalCoord1dv( CHARACTER*8 u )
	  SUBROUTINE fglEvalCoord1fv( CHARACTER*8 u )
	  SUBROUTINE fglEvalCoord2dv( CHARACTER*8 u )
	  SUBROUTINE fglEvalCoord2fv( CHARACTER*8 u )


     PARAMETERS
	  u    Specifies a pointer to an array containing either one
	       or two domain coordinates.  The first coordinate	is u.
	       The second coordinate is	v, which is present only in
	       fglEvalCoord2 versions.

     DESCRIPTION
	  fglEvalCoord1	evaluates enabled one-dimensional maps at
	  argument u.  fglEvalCoord2 does the same for two-dimensional
	  maps using two domain	values,	u and v.  To define a map,
	  call fglMap1 and fglMap2; to enable and disable it, call
	  fglEnable and	fglDisable.

	  When one of the fglEvalCoord commands	is issued, all
	  currently enabled maps of the	indicated dimension are
	  evaluated.  Then, for	each enabled map, it is	as if the
	  corresponding	GL command had been issued with	the computed
	  value.  That is, if GL_MAP1_INDEX or GL_MAP2_INDEX is
	  enabled, a fglIndex command is simulated.  If
	  GL_MAP1_COLOR_4 or GL_MAP2_COLOR_4 is	enabled, a fglColor
	  command is simulated.	 If GL_MAP1_NORMAL or GL_MAP2_NORMAL
	  is enabled, a	normal vector is produced, and if any of
	  GL_MAP1_TEXTURE_COORD_1, GL_MAP1_TEXTURE_COORD_2,
	  GL_MAP1_TEXTURE_COORD_3, GL_MAP1_TEXTURE_COORD_4,
	  GL_MAP2_TEXTURE_COORD_1, GL_MAP2_TEXTURE_COORD_2,
	  GL_MAP2_TEXTURE_COORD_3, or GL_MAP2_TEXTURE_COORD_4 is
	  enabled, then	an appropriate fglTexCoord command is
	  simulated.

	  For color, color index, normal, and texture coordinates the
	  GL uses evaluated values instead of current values for those
	  evaluations that are enabled,	and current values otherwise,
	  However, the evaluated values	do not update the current
	  values.  Thus, if fglVertex commands are interspersed	with
	  fglEvalCoord commands, the color, normal, and	texture
	  coordinates associated with the fglVertex commands are not
	  affected by the values generated by the fglEvalCoord
	  commands, but	only by	the most recent	fglColor, fglIndex,
	  fglNormal, and fglTexCoord commands.

	  No commands are issued for maps that are not enabled.	 If
	  more than one	texture	evaluation is enabled for a particular
	  dimension (for example, GL_MAP2_TEXTURE_COORD_1 and
	  GL_MAP2_TEXTURE_COORD_2), then only the evaluation of	the
	  map that produces the	larger number of coordinates (in this
	  case,	GL_MAP2_TEXTURE_COORD_2) is carried out.
	  GL_MAP1_VERTEX_4 overrides GL_MAP1_VERTEX_3, and
	  GL_MAP2_VERTEX_4 overrides GL_MAP2_VERTEX_3, in the same
	  manner.  If neither a	three- nor a four-component vertex map
	  is enabled for the specified dimension, the fglEvalCoord
	  command is ignored.

	  If you have enabled automatic	normal generation, by calling
	  fglEnable with argument GL_AUTO_NORMAL, fglEvalCoord2
	  generates surface normals analytically, regardless of	the
	  contents or enabling of the GL_MAP2_NORMAL map.  Let

	      Pp   Pp
	  m = -- X --
	      Pu   Pv

	  Then the generated normal n is

	      _
	  n=_____
	    ||m||

	  If automatic normal generation is disabled, the
	  corresponding	normal map GL_MAP2_NORMAL, if enabled, is used
	  to produce a normal.	If neither automatic normal generation
	  nor a	normal map is enabled, no normal is generated for
	  fglEvalCoord2	commands.
     ASSOCIATED	GETS
	  fglIsEnabled with argument GL_MAP1_VERTEX_3
	  fglIsEnabled with argument GL_MAP1_VERTEX_4
	  fglIsEnabled with argument GL_MAP1_INDEX
	  fglIsEnabled with argument GL_MAP1_COLOR_4
	  fglIsEnabled with argument GL_MAP1_NORMAL
	  fglIsEnabled with argument GL_MAP1_TEXTURE_COORD_1
	  fglIsEnabled with argument GL_MAP1_TEXTURE_COORD_2
	  fglIsEnabled with argument GL_MAP1_TEXTURE_COORD_3
	  fglIsEnabled with argument GL_MAP1_TEXTURE_COORD_4
	  fglIsEnabled with argument GL_MAP2_VERTEX_3
	  fglIsEnabled with argument GL_MAP2_VERTEX_4
	  fglIsEnabled with argument GL_MAP2_INDEX
	  fglIsEnabled with argument GL_MAP2_COLOR_4
	  fglIsEnabled with argument GL_MAP2_NORMAL
	  fglIsEnabled with argument GL_MAP2_TEXTURE_COORD_1
	  fglIsEnabled with argument GL_MAP2_TEXTURE_COORD_2
	  fglIsEnabled with argument GL_MAP2_TEXTURE_COORD_3
	  fglIsEnabled with argument GL_MAP2_TEXTURE_COORD_4
	  fglIsEnabled with argument GL_AUTO_NORMAL
	  fglGetMap

     SEE ALSO
	  fglBegin, fglColor, fglEnable, fglEvalMesh, fglEvalPoint,
	  fglIndex, fglMap1, fglMap2, fglMapGrid, fglNormal,
	  fglTexCoord, fglVertex