gluunproject4(3) - Linux man page

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, respectively. 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:

$INV()$ denotes matrix inversion.

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

Notes