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glViewport(3)                                                  glViewport(3)




NAME

       glViewport - set the viewport



C SPECIFICATION

       void glViewport( GLint x,
                        GLint y,
                        GLsizei width,
                        GLsizei height )



PARAMETERS

       x, y Specify  the  lower left corner of the viewport rectangle, in pix-
            els. The initial value is (0,0).

       width, height
            Specify the width and height of the viewport.  When a  GL  context
            is  first  attached  to  a window, width and height are set to the
            dimensions of that window.


DESCRIPTION

       glViewport specifies the affine transformation of x and y from  normal-
       ized  device coordinates to window coordinates.  Let (xnd, ynd) be nor-
       malized device coordinates.  Then the window coordinates (xw,  yw)  are
       computed as follows:

                             xw = (xnd+1) (width/2) + x

                             yw = (ynd+1) (height/2) + y


       Viewport  width and height are silently clamped to a range that depends
       on the implementation.  To query this range, call glGet  with  argument
       GL_MAX_VIEWPORT_DIMS.


ERRORS

       GL_INVALID_VALUE is generated if either width or height is negative.

       GL_INVALID_OPERATION is generated if glViewport is executed between the
       execution of glBegin and the corresponding execution of glEnd.


ASSOCIATED GETS

       glGet with argument GL_VIEWPORT
       glGet with argument GL_MAX_VIEWPORT_DIMS


SEE ALSO

       glDepthRange(3)



                                                                glViewport(3)

Mac OS X 10.6 - Generated Thu Sep 17 20:20:31 CDT 2009
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