NAME¶
glScissor - define the scissor box
C SPECIFICATION¶
void
glScissor(GLint x, GLint y,
GLsizei width,
GLsizei height);
PARAMETERS¶
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. glScissor(0,0,1,1) allows
modification of only the lower left pixel in the window, and
glScissor(0,0,0,0) 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.
ASSOCIATED GETS¶
glGet() with argument
GL_SCISSOR_BOX
glIsEnabled() with argument
GL_SCISSOR_TEST
SEE ALSO¶
glEnable(),
glViewport()
COPYRIGHT¶
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/.
