fglScissor(3G)

NAME
     fglScissor - define the scissor box


FORTRAN SPECIFICATION
     SUBROUTINE fglScissor( INTEGER*4 x,
                            INTEGER*4 y,
                            INTEGER*4 width,
                            INTEGER*4 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
     fglScissor 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 fglEnable and fglDisable
     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
     GL_INVALID_VALUE is generated if either width or height is negative.

     GL_INVALID_OPERATION is generated if fglScissor is executed between the
     execution of fglBegin and the corresponding execution of fglEnd.
ASSOCIATED GETS
     fglGet with argument GL_SCISSOR_BOX
     fglIsEnabled with argument GL_SCISSOR_TEST


SEE ALSO
     fglEnable, fglViewport