gluUnProject()gluUnProject()NAMEgluUnProject - map window coordinates to object coordinates
SYNOPSIS
GLint gluUnProject(
GLdouble winX,
GLdouble winY,
GLdouble winZ,
const GLdouble *model,
const GLdouble *proj,
const GLint *view,
GLdouble* objX,
GLdouble* objY,
GLdouble* objZ );
PARAMETERS
Specify the window coordinates to be mapped. Specifies the modelview
matrix (as from a glGetDoublev() call). Specifies the projection
matrix (as from a glGetDoublev() call). Specifies the viewport (as
from a glGetIntegerv() call). Returns the computed object coordinates.
DESCRIPTIONgluUnProject() maps the specified window coordinates into object coor‐
dinates 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() mul‐
tiplies the normalized device coordinates by the inverse of model*proj
as follows:
(2(winX - view[0]) / view[2]) -1 objX
(2(winY - view[1]) / view[3]) -1 objY = INV(PM) objZ
2(winZ)-1 W 1
INV() denotes matrix inversion. W is an unused variable, included for
consistent matrix notation.
SEE ALSOglGet(3), gluProject(3)gluUnProject()