gluUnProject(3) gluUnProject(3)
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 coordi- nates 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 multi- plies 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) - 1 1 INV() denotes matrix inversion. W is an unused variable, included for consistent matrix notation.
SEE ALSO
glGet(3), gluProject(3) gluUnProject(3)
Mac OS X 10.6 - Generated Thu Sep 17 20:20:37 CDT 2009