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gluunproject4(3g) [centos man page]

GLUUNPROJECT4(3G)						   OpenGL Manual						 GLUUNPROJECT4(3G)

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 nearVal, GLdouble farVal, 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).

       nearVal, farVal
	   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 coordinatesi: 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
       GLU_4D_COLOR_TEXTURE is returned. This also handles the case where the nearVal and farVal planes are different from the default, 0 and 1,
       respectively. A return value of GLU_TRUE indicates success; a return value of GLU_FALSE indicates failure.

       To compute the coordinates objX objY objZ objW, gluUnProject4 multiplies the normalized device coordinates by the inverse of model * proj
       as follows:

       objX objY objZ objW = INV  P  M	2  winX - view	0 view	2 - 1 2  winY - view  1 view  3 - 1 2  winZ - nearVal farVal - nearVal - 1 clipW

       INV denotes matrix inversion.

       gluUnProject4 is equivalent to gluUnProject() when clipW is 1, nearVal is 0, and farVal is 1.

NOTES

       gluUnProject4 is available only if the GLU version is 1.3 or greater.

SEE ALSO

       gluProject(), gluUnProject(), glFeedbackBuffer(), glGet()

COPYRIGHT

       Copyright (C) 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see
       http://oss.sgi.com/projects/FreeB/.

AUTHORS

       opengl.org

opengl.org							    06/10/2014							 GLUUNPROJECT4(3G)

Check Out this Related Man Page

GLUPROJECT(3G)															    GLUPROJECT(3G)

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 )

       delim $$

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 $v sup prime$ as follows:

       v sup prime ~=~ P ~times~ M ~times~ v

       where  $P$  is  the  current projection matrix proj, $M$ is the current modelview matrix model (both represented as $4 times 4$ matrices in
       column-major order) and '$times$' represents matrix multiplication.

       The window coordinates are then computed as follows:

       "winX" ~=~ "view" (0) ~+~ "view" (2) ~*~ (v sup prime(0) ~+~ 1)~/~2

       "winY" ~=~ "view" (1) ~+~ "view" (3)~*~(v sup prime(1) ~+~ 1)~/~2

       "winZ" ~=~ (v sup prime(2)  ~+~ 1)~/~ 2

SEE ALSO

       glGet(3G), gluUnProject(3G)

																    GLUPROJECT(3G)
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