glViewport
- set the viewport
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 surface (e.g. window), width
and height
are set to the dimensions of that surface.
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
.
GL_INVALID_VALUE
is generated if either width
or height
is negative.
glGet
with argument GL_MAX_VIEWPORT_DIMS
Copyright © 2003-2004 Silicon Graphics, Inc.
This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.