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
     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
     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