NAME
	  fgluUnProject	- map window coordinates to object coordinates


     FORTRAN SPECIFICATION
	  INTEGER*4 fgluUnProject( REAL*8 winX,
				   REAL*8 winY,
				   REAL*8 winZ,
				   CHARACTER*8 model,
				   CHARACTER*8 proj,
				   CHARACTER*8 view,
				   CHARACTER*8 objX,
				   CHARACTER*8 objY,
				   CHARACTER*8 objZ )


     PARAMETERS
	  winX,	winY, winZ
			  Specify the window coordinates to be mapped.

	  model		  Specifies the	modelview matrix (as from a
			  glGetDoublev call).

	  proj		  Specifies the	projection matrix (as from a
			  glGetDoublev call).

	  view		  Specifies the	viewport (as from a
			  glGetIntegerv	call).

	  objX,	objY, objZ
			  Returns the computed object coordinates.

     DESCRIPTION
	  fgluUnProject	maps the specified window coordinates into
	  object coordinates using model, proj,	and view.  The result
	  is stored in objX, objY, and objZ. A return value of GL_TRUE
	  indicates success; a return value of GL_FALSE	indicates
	  failure.

	  To compute the coordinates (objX, objY, and objZ),
	  fgluUnProject	multiplies the normalized device coordinates
	  by the inverse of model*proj as follows:










				     |			     |
				     |_________________	     |
		  (	  )	     |	   view[2]	- 1  |
		  | objX  |	     |			     |
		  | objY  | = INV(PM)|_________________	- 1  |
		  |	  |	     |	   view[3]	     |
		  | objZ  |	     |	   2(winZ) - 1	     |
		  (  W	  )	     |			     |
				     (		1	     )

	  INV()	denotes	matrix inversion. W is an unused variable,
	  included for consistent matrix notation.

     SEE ALSO
	  glGet, fgluProject