mirror of
https://github.com/QB64Official/qb64.git
synced 2024-08-22 11:25:08 +00:00
52 lines
1.4 KiB
Markdown
52 lines
1.4 KiB
Markdown
**_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:
|
|
|
|
glapi viewport equations
|
|
|
|
Viewport width and height are silently clamped to a range that depends on the implementation. To query this range, call [_glGet](_glGet) with argument [_GL_MAX_VIEWPORT_DIMS](_GL_MAX_VIEWPORT_DIMS).
|
|
|
|
|
|
## Error(s)
|
|
|
|
|
|
[_GL_INVALID_VALUE](_GL_INVALID_VALUE) is generated if either width or height is negative.
|
|
|
|
|
|
## Use With
|
|
|
|
|
|
[_glGet](_glGet) with argument [_GL_VIEWPORT](_GL_VIEWPORT)
|
|
|
|
[_glGet](_glGet) with argument [_GL_MAX_VIEWPORT_DIMS](_GL_MAX_VIEWPORT_DIMS)
|
|
|
|
|
|
## See Also
|
|
|
|
|
|
[_GL](_GL)
|
|
[_glDepthRange](_glDepthRange), [_glViewportArray](_glViewportArray), [_glViewportIndexed](_glViewportIndexed)
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|