_glViewport
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_glViewport: set the viewport
Syntax
- QB64
- SUB _glViewport (BYVAL x AS LONG, BYVAL y AS LONG, BYVAL width AS LONG, BYVAL height AS LONG)
- C/C++
- 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 Template:KW with argument Template:KW.
Template:KW is generated if either width or height is negative.
Template:KW with argument Template:KW
Template:KW with argument Template:KW
See also
SUB _GL Template:KW, Template:KW, Template:KW