GLUUNPROJECT(3G) OpenGL Manual 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 GLU_TRUE indicates success; a return value of GLU_FALSE indicates failure.
To compute the coordinates objX objY objZ, gluUnProject multiplies the normalized device coordinates by the inverse of model * proj as
follows:
objX objY objZ W = INV P M 2 winX - view 0 view 2 - 1 2 winY - view 1 view 3 - 1 2 winZ - 1 1INV denotes matrix inversion. W is
an unused variable, included for consistent matrix notation.
SEE ALSO
gluProject(), glGet()
COPYRIGHT
Copyright (C) 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see
http://oss.sgi.com/projects/FreeB/.
AUTHORS
opengl.org
opengl.org 06/10/2014 GLUUNPROJECT(3G)