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gluUnProject()
NAME
  gluUnProject - 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
  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:

			   (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 ALSO
  glGet(3), gluProject(3)

Index for Section 3

Alphabetical listing for G

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