glScissor(3G)		       OpenGL Reference			 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 context
	  is first attached to a window, width and height are set to the
	  dimensions of	that window.


DESCRIPTION
     The glScissor routine 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.

     The scissor test is enabled and disabled using glEnable and glDisable
     with argument GL_SCISSOR_TEST.  While the scissor 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, so	 glScissor(0,0,1,1) allows only	the lower left
     pixel in the window to be modified,  and glScissor(0,0,0,0) disallows
     modification to all 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, glViewport





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