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<STRONG>NAME</STRONG>
<STRONG>glLineStipple</STRONG> - specify the line stipple pattern
<STRONG>C</STRONG> <STRONG>SPECIFICATION</STRONG>
void <STRONG>glLineStipple</STRONG>( GLint <EM>factor</EM>,
GLushort <EM>pattern</EM> )
<STRONG>PARAMETERS</STRONG>
<EM>factor</EM> Specifies a multiplier for each bit in the line
stipple pattern. If <EM>factor</EM> is 3, for example, each
bit in the pattern is used three times before the
next bit in the pattern is used. <EM>factor</EM> is clamped
to the range [1, 256] and defaults to 1.
<EM>pattern</EM> Specifies a 16-bit integer whose bit pattern
determines which fragments of a line will be drawn
when the line is rasterized. Bit zero is used
first; the default pattern is all 1's.
<STRONG>DESCRIPTION</STRONG>
Line stippling masks out certain fragments produced by
rasterization; those fragments will not be drawn. The
masking is achieved by using three parameters: the 16-bit
line stipple pattern <EM>pattern</EM>, the repeat count <EM>factor</EM>, and
an integer stipple counter s.
Counter s is reset to 0 whenever <STRONG>glBegin</STRONG> is called, and
before each line segment of a <STRONG>glBegin</STRONG>(<STRONG>GL_LINES</STRONG>)/<STRONG>glEnd</STRONG>
sequence is generated. It is incremented after each
fragment of a unit width aliased line segment is generated,
or after each i fragments of an i width line segment are
generated. The i fragments associated with count s are
masked out if
<EM>pattern</EM> bit (s / factor) mod 16
is 0, otherwise these fragments are sent to the frame
buffer. Bit zero of <EM>pattern</EM> is the least significant bit.
Antialiased lines are treated as a sequence of 1xwidth
rectangles for purposes of stippling. Whether rectagle s is
rasterized or not depends on the fragment rule described for
aliased lines, counting rectangles rather than groups of
fragments.
To enable and disable line stippling, call <STRONG>glEnable</STRONG> and
<STRONG>glDisable</STRONG> with argument <STRONG>GL_LINE_STIPPLE</STRONG>. When enabled, the
line stipple pattern is applied as described above. When
disabled, it is as if the pattern were all 1's. Initially,
line stippling is disabled.
<STRONG>ERRORS</STRONG>
<STRONG>GL_INVALID_OPERATION</STRONG> is generated if <STRONG>glLineStipple</STRONG> is
executed between the execution of <STRONG>glBegin</STRONG> and the
corresponding execution of <STRONG>glEnd</STRONG>.
<STRONG>ASSOCIATED</STRONG> <STRONG>GETS</STRONG>
<STRONG>glGet</STRONG> with argument <STRONG>GL_LINE_STIPPLE_PATTERN</STRONG>
<STRONG>glGet</STRONG> with argument <STRONG>GL_LINE_STIPPLE_REPEAT</STRONG>
<STRONG>glIsEnabled</STRONG> with argument <STRONG>GL_LINE_STIPPLE</STRONG>
<STRONG>SEE</STRONG> <STRONG>ALSO</STRONG>
<STRONG>glLineWidth</STRONG>, <STRONG>glPolygonStipple</STRONG>
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