glViewport

Name

glViewport â set the viewport

C Specification

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

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. +

Description

+ glViewport specifies the affine transformation of + x + and + y + from + normalized device coordinates to window coordinates. + Let + + + + x + nd + + y + nd + + + + be normalized device coordinates. + Then the window coordinates + + + + x + w + + y + w + + + + are computed as follows: +

+ + + x + w + + = + + + + x + nd + + + + 1 + + + â¢ + + + width + 2 + + + + + x + + +

+ + + y + w + + = + + + + y + nd + + + + 1 + + + â¢ + + + 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. +

Errors

+ GL_INVALID_VALUE is generated if either width or height is negative. +

Associated Gets

+ glGet with argument GL_VIEWPORT +

+ glGet with argument GL_MAX_VIEWPORT_DIMS +