NAME    [Toc]    [Back]

       glScissor - define the scissor box

SYNOPSIS    [Toc]    [Back]

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

PARAMETERS    [Toc]    [Back]

       Specify  the  lower  left  corner of the scissor box. Initially
 (0, 0).  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().

ASSOCIATED GETS    [Toc]    [Back]

       glGet() with argument GL_SCISSOR_BOX
       glIsEnabled() with argument GL_SCISSOR_TEST

SEE ALSO    [Toc]    [Back]

       glEnable(), glViewport()



                                                    glScissor(3G)