NAME

glPolygonStipple - set the polygon stippling pattern

C SPECIFICATION

void ggllPPoollyyggoonnSSttiippppllee( const GLubyte _*_m_a_s_k )

        

delim $$

PARAMETERS

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

DESCRIPTION

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

_m_a_s_k is a pointer to a $32 ~times~ 32$ stipple pattern that is stored in memory just like the pixel data supplied to a ggllDDrraawwPPiixxeellss call with height and width both equal to 32, a pixel of GGLL__CCOOLLOORR__IINNDDEEXX, and data type of GGLL__BBIITTMMAAPP. That is, the stipple pattern is represented as a $32 ~times~ 32$ array of 1-bit color indices packed in unsigned bytes. ggllPPiixxeellSSttoorree parameters like GGLL__UUNNPPAACCKK__SSWWAAPP__BBYYTTEESS and GGLL__UUNNPPAACCKK__LLSSBB__FFIIRRSSTT 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 ggllEEnnaabbllee and ggllDDiissaabbllee with argument GGLL__PPOOLLYYGGOONN__SSTTIIPPPPLLEE. Polygon stippling is initially disabled. If it's enabled, a rasterized polygon fragment with window coordinates $x sub w$ 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 stippling is disabled, it is as if the stipple pattern consists of all 1's.

ERRORS

GGLL__IINNVVAALLIIDD__OOPPEERRAATTIIOONN is generated if ggllPPoollyyggoonnSSttiippppllee is executed between the execution of ggllBBeeggiinn and the corresponding execution of ggllEEnndd.

ASSOCIATED GETS

ggllGGeettPPoollyyggoonnSSttiippppllee
ggllIIssEEnnaabblleedd with argument GGLL__PPOOLLYYGGOONN__SSTTIIPPPPLLEE

SEE ALSO

ggllDDrraawwPPiixxeellss((33GG)), ggllLLiinneeSSttiippppllee((33GG)), ggllPPiixxeellSSttoorree((33GG)), ggllPPiixxeellTTrraannssffeerr((33GG))