glScissor(3G)		       OpenGL Reference			 glScissor(3G)

NAME    [Toc]    [Back]

     glScissor - define	the scissor box

C SPECIFICATION    [Toc]    [Back]

     void glScissor( GLint x,
		     GLint y,
		     GLsizei width,
		     GLsizei height )

PARAMETERS    [Toc]    [Back]

     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    [Toc]    [Back]

     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    [Toc]    [Back]

     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.













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glScissor(3G)		       OpenGL Reference			 glScissor(3G)

ASSOCIATED GETS    [Toc]    [Back]

     glGet with	argument GL_SCISSOR_BOX
     glIsEnabled with argument GL_SCISSOR_TEST

SEE ALSO    [Toc]    [Back]

     glEnable, glViewport


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