gluunproject(3g) [redhat man page]

GLUUNPROJECT(3G)														  GLUUNPROJECT(3G)

NAME

       gluUnProject - map window coordinates to object coordinates

C SPECIFICATION

       GLint gluUnProject( GLdouble winX,
			   GLdouble winY,
			   GLdouble winZ,
			   const GLdouble *model,
			   const GLdouble *proj,
			   const GLint *view,
			   GLdouble* objX,
			   GLdouble* objY,
			   GLdouble* 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

       gluUnProject  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), gluUnProject multiplies the normalized device coordinates by the inverse  of	model*proj
       as follows:

							     objX
							    (objY)=INV(PM)(_______________-1)
							     objZ	   _______________-1
							      W 	       2(winZ)-1
										   1
       INV() denotes matrix inversion.	W is an unused variable, included for consistent matrix notation.

SEE ALSO

       glGet(3G), gluProject(3G)

																  GLUUNPROJECT(3G)

GLUUNPROJECT4(3G)														 GLUUNPROJECT4(3G)

NAME

       gluUnProject4 - map window and clip coordinates to object coordinates

C SPECIFICATION

       GLint gluUnProject4( GLdouble winX,
			    GLdouble winY,
			    GLdouble winZ,
			    GLdouble clipW,
			    const GLdouble *model,
			    const GLdouble *proj,
			    const GLint *view,
			    GLdouble near,
			    GLdouble far,
			    GLdouble* objX,
			    GLdouble* objY,
			    GLdouble* objZ,
			    GLdouble* objW )

PARAMETERS

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

       clipW	       Specify the clip w coordinate 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).

       near, far       Specifies the near and far planes (as from a glGetDoublev call).

       objX, objY, objZ, objW
		       Returns the computed object coordinates.

DESCRIPTION

       gluUnProject4  maps  the  specified  window  coordinates winX, winY and winZ and its clip w coordinate clipW into object coordinates (objX,
       objY, objZ, objW) using model,  proj  and  view.  clipW	can  be  other	than  1  as  for  vertices  in	glFeedbackBuffer  when	data  type
       GL_4D_COLOR_TEXTURE is returned.  This also handles the case where the near and far planes are different from the default, 0 and 1, respec-
       tively.	A return value of GL_TRUE indicates success; a return value of GL_FALSE indicates failure.

       To compute the coordinates (objX, objY, objZ and objW), gluUnProject4 multiplies the  normalized  device  coordinates  by  the  inverse	of
       model*proj as follows:

				2(winX - view[0])
				-----------------  - 1
				     view[2]

	   objX 		2(winY - view[1])
	   objY   =  INV(PM)	-----------------  - 1
	   objZ 		     view[3]
	    W
				  2(winZ - near)
				-----------------  - 1
				    (far - near)

				      clipW

       INV() denotes matrix inversion.

       gluUnProject4 is equivalent to gluUnProject when clipW is 1, near is 0 and far is 1.

NOTES

       gluUnProject4 is available only if the GLU version is 1.3 or greater.

SEE ALSO

       glGet, glFeedbackBuffer, gluProject, gluUnProject

																 GLUUNPROJECT4(3G)