GlViewport

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_glViewport: set the viewport


Syntax

 SUB _glViewport (BYVAL x AS LONG, BYVAL y AS LONG, BYVAL width AS LONG, BYVAL height AS LONG)
 void _glViewport(GLint x, GLint y, GLsizei width, GLsizei height);


x, y
Specify the lower left corner of the viewport rectangle, in pixels. 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 normalized device coordinates to window coordinates. Let (x<sub>nd</sub>, y<sub>nd</sub>) be normalized device coordinates. Then the window coordinates (x<sub>w</sub>, y<sub>w</sub>) are computed as follows:

Template:Glapi viewport equations

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.


Use With:

_glGet with argument _GL_VIEWPORT

_glGet with argument _GL_MAX_VIEWPORT_DIMS


See also

SUB _GL _glDepthRange, _glViewportArray, _glViewportIndexed


Copyright: 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/.



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Copyright 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/.