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gluProject(3)                                                  gluProject(3)




NAME

       gluProject - map object coordinates to window coordinates



C SPECIFICATION

       GLint gluProject( GLdouble objX,
                         GLdouble objY,
                         GLdouble objZ,
                         const GLdouble *model,
                         const GLdouble *proj,
                         const GLint *view,
                         GLdouble* winX,
                         GLdouble* winY,
                         GLdouble* winZ )



PARAMETERS

       objX, objY, objZ
                       Specify the object coordinates.

       model           Specifies  the  current  modelview  matrix  (as  from a
                       glGetDoublev call).

       proj            Specifies the current  projection  matrix  (as  from  a
                       glGetDoublev call).

       view            Specifies the current viewport (as from a glGetIntegerv
                       call).

       winX, winY, winZ
                       Return the computed window coordinates.


DESCRIPTION

       gluProject transforms the  specified  object  coordinates  into  window
       coordinates  using model, proj, and view. The result is stored in winX,
       winY, and winZ. A return value of GL_TRUE indicates success,  a  return
       value of GL_FALSE indicates failure.

       To compute the coordinates, let v = (objX, objY, objZ, 1.0) represented
       as a matrix with 4 rows and 1 column.  Then gluProject computes  v'  as
       follows:

                                   v' = P X M X v

       where  P  is  the current projection matrix proj, M is the current mod-
       elview matrix model (both represented as 4x4 matrices  in  column-major
       order) 'X' represents matrix multiplication.

       The window coordinates are then computed as follows:

       winX = view(0) + view(2) * (v'(0)+1)/2

       winY = view(1) + view(3) * (v'(1)+1)/2

       winZ = (v'(2) + 1) / 2




SEE ALSO

       glGet(3), gluUnProject(3)




                                                                gluProject(3)

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