GlScissor
_glScissor: define the scissor box
Contents
Syntax
SUB _glScissor (BYVAL x AS LONG, BYVAL y AS LONG, BYVAL width AS LONG, BYVAL height AS LONG) void _glScissor(GLint x, GLint y, GLsizei width, GLsizei height);
- x, y
- Specify the lower left corner of the scissor box. Initially (0, 0).
- width, height
- Specify the width and height of the scissor box. When a GL context is first attached to a window, width and height are set to the dimensions of that window.
Description
_glScissor defines a rectangle, called the scissor box, in window coordinates. The first two arguments, x and y, specify the lower left corner of the box. width and height specify the width and height of the box.
To enable and disable the scissor test, call _glEnable and _glDisable with argument _GL_SCISSOR_TEST. The test is initially disabled. While the test is enabled, only pixels that lie within the scissor box can be modified by drawing commands. Window coordinates have integer values at the shared corners of frame buffer pixels. Template:Code allows modification of only the lower left pixel in the window, and Template:Code doesn't allow modification of any pixels in the window.
When the scissor test is disabled, it is as though the scissor box includes the entire window.
Errors
_GL_INVALID_VALUE is generated if either width or height is negative.
Use With:
_glGet with argument _GL_SCISSOR_BOX
_glIsEnabled with argument _GL_SCISSOR_TEST
See also
SUB _GL (GL_SCISSOR_TEST), _glScissorArray, _glScissorIndexed, _glViewport
Copyright 1991-2006 Silicon Graphics, Inc. This document is licensed under the SGI Free Software B License. For details, see http://oss.sgi.com/projects/FreeB/.
