1.4 KiB
_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 (xnd, ynd) be normalized device coordinates. Then the window coordinates (xw, yw) 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 with argument _GL_MAX_VIEWPORT_DIMS.
Error(s)
_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