GLSCISSOR(3G) UNIX Programmer's Manual GLSCISSOR(3G)
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. Ini-
tially (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 ini-
tially disabled. While the test is enabled, only pixels that
lie within the scissor box can be modified by drawing com-
mands. 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 scis-
sor box includes the entire window.
ERRORS
GL_INVALID_VALUE is generated if either width or height is
negative.
GL_INVALID_OPERATION is generated if glScissor is executed
between the execution of glBegin and the corresponding exe-
cution of glEnd.
MirBSD #10-current Printed 2021-12-07 1
GLSCISSOR(3G) UNIX Programmer's Manual GLSCISSOR(3G)
ASSOCIATED GETS
glGet with argument GL_SCISSOR_BOX
glIsEnabled with argument GL_SCISSOR_TEST
SEE ALSO
glEnable(3G), glViewport(3G)
MirBSD #10-current Printed 2021-12-07 2