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glViewport: set the viewport.

C Specification | Parameters | Description | Errors | Associated Gets | See Also

[Up] C Specification

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

[Up] Parameters

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.

[Up] 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:

xw = (xnd + 1) · (width / 2) + x
yw = (ynd + 1) · (height / 2) + y

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.

[Up] Errors

[Up] Associated Gets

glGet with argument GL_VIEWPORT
glGet with argument GL_MAX_VIEWPORT_DIMS

[Up] See Also


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