glViewport

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Set the viewport.

C Specification[edit]

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


Parameters[edit]

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[edit]

 glViewport specifies the affine transformation of [math]x[/math] and [math]y[/math] from normalized device coordinates to window coordinates. Let [math](x_{nd},y_{nd})[/math] be normalized device coordinates. Then the window coordinates [math](x_{w},y_{w})[/math] are computed as follows:

 [math]x_{w}=(x_{nd}+1)⁢(\frac{width}{2})+x[/math] 

 [math]y_{w}=(y_{nd}+1)⁢(\frac{height}{2})+y[/math] 

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[edit]

 GL_INVALID_VALUE is generated if either width or height is negative.


Associated Gets[edit]

 glGet with argument GL_VIEWPORT 

 glGet with argument GL_MAX_VIEWPORT_DIMS 


Version Support[edit]

 glViewport  2.0+

See Also[edit]

 glDepthRange 


Copyright[edit]

Copyright© 1991-2006 Silicon Graphics, Inc. Copyright© 2010-2014 Khronos Group. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.