1GLVIEWPORT(3G)                                                  GLVIEWPORT(3G)
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NAME

6       glViewport - set the viewport
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C SPECIFICATION

10       void glViewport( GLint x,
11                        GLint y,
12                        GLsizei width,
13                        GLsizei height )
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PARAMETERS

17       x, y Specify  the  lower left corner of the viewport rectangle, in pix‐
18            els. The initial value is (0,0).
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20       width, height
21            Specify the width and height of the viewport.  When a  GL  context
22            is  first  attached  to  a window, width and height are set to the
23            dimensions of that window.
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DESCRIPTION

26       glViewport specifies the affine transformation of x and y from  normal‐
27       ized  device coordinates to window coordinates.  Let (xnd, ynd) be nor‐
28       malized device coordinates.  Then the window coordinates (xw,  yw)  are
29       computed as follows:
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31                                 xw=(xnd+1)⎛⎝w_i_d2_t_h_⎞⎠+x
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33                                yw=(ynd+1)⎛⎝h_e_i_g2_h_t_⎞⎠+y
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35Viewport  width and height are silently clamped to a range that depends on the
36implementation.    To   query   this   range,   call   glGet   with   argument

GL_MAX_VIEWPORT_DIMS.

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ERRORS

40       GL_INVALID_VALUE is generated if either width or height is negative.
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42       GL_INVALID_OPERATION is generated if glViewport is executed between the
43       execution of glBegin and the corresponding execution of glEnd.
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ASSOCIATED GETS

46       glGet with argument GL_VIEWPORT
47       glGet with argument GL_MAX_VIEWPORT_DIMS
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SEE ALSO

50       glDepthRange(3G)
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54                                                                GLVIEWPORT(3G)