glScissor(3G)glScissor(3G)NAMEglScissor - define the scissor box
SYNOPSIS
void glScissor(
GLint x,
GLint y,
GLsizei width,
GLsizei height );
PARAMETERS
Specify the lower left corner of the scissor box. Initially (0, 0).
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.
DESCRIPTIONglScissor() 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 win‐
dow.
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.
GL_INVALID_OPERATION is generated if glScissor() is executed between
the execution of glBegin() and the corresponding execution of glEnd().
ASSOCIATED GETSglGet() with argument GL_SCISSOR_BOX
glIsEnabled() with argument GL_SCISSOR_TEST
SEE ALSOglEnable(), glViewport()glScissor(3G)