glScissor

GLSCISSOR(3G)							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.	Initially (0,
	    0).

       width, height
	    Specify the width and height of the scissor box.  When a GL	 con-
	    text  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 coor-
       dinates.	  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 val-
       ues  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.

       GL_INVALID_OPERATION is generated if glScissor is executed between the
       execution of glBegin and the corresponding execution of glEnd.




















ASSOCIATED GETS
       glGet with argument GL_SCISSOR_BOX
       glIsEnabled with argument GL_SCISSOR_TEST

SEE ALSO
       glEnable(3G), glViewport(3G)



								GLSCISSOR(3G)