glPolygonStipple(3)

NAME

       glPolygonStipple - set the polygon stippling pattern

C SPECIFICATION

       void glPolygonStipple( const GLubyte *mask )

       delim $$

PARAMETERS

       mask  Specifies  a  pointer  to  a $32 ~times~ 32$ stipple pattern that
             will be unpacked from memory in the same  way  that  glDrawPixels
             unpacks pixels.

DESCRIPTION

       Polygon  stippling,  like line stippling (see glLineStipple), masks out
       certain fragments produced by rasterization, creating a pattern.  Stip-
       pling is independent of polygon antialiasing.

       mask  is  a pointer to a $32 ~times~ 32$ stipple pattern that is stored
       in memory just like the pixel data supplied to a glDrawPixels call with
       height  and width both equal to 32, a pixel of GL_COLOR_INDEX, and data
       type of GL_BITMAP.  That is, the stipple pattern is  represented  as  a
       $32  ~times~ 32$ array of 1-bit color indices packed in unsigned bytes.
       glPixelStore     parameters     like      GL_UNPACK_SWAP_BYTES      and
       GL_UNPACK_LSB_FIRST  affect  the  assembling of the bits into a stipple
       pattern.  Pixel transfer operations (shift, offset, pixel map) are  not
       applied to the stipple image, however.

       To  enable  and  disable polygon stippling, call glEnable and glDisable
       with argument GL_POLYGON_STIPPLE. Polygon stippling is  initially  dis-
       abled. If it's enabled, a rasterized polygon fragment with window coor-
       dinates $x sub w$ and $y sub w$ is sent to the next stage of the GL  if
       and  only  if the ($x sub w~roman mod~32$)th bit in the ($y sub w~roman
       mod~32$)th row of the stipple pattern is 1 (one).  When  polygon  stip-
       pling is disabled, it is as if the stipple pattern consists of all 1's.

ERRORS

       GL_INVALID_OPERATION  is  generated  if  glPolygonStipple  is  executed
       between  the  execution  of  glBegin and the corresponding execution of
       glEnd.

ASSOCIATED GETS

       glGetPolygonStipple
       glIsEnabled with argument GL_POLYGON_STIPPLE

SEE ALSO

       glDrawPixels(3G),         glLineStipple(3G),          glPixelStore(3G),
       glPixelTransfer(3G)

                                                          GLPOLYGONSTIPPLE(3G)