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<HTML><BODY><PRE> <STRONG>NAME</STRONG> <STRONG>fglLineStipple</STRONG> - specify the line stipple pattern <STRONG>FORTRAN</STRONG> <STRONG>SPECIFICATION</STRONG> SUBROUTINE <STRONG>fglLineStipple</STRONG>( INTEGER*4 <EM>factor</EM>, INTEGER*2 <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>fglBegin</STRONG> is called, and before each line segment of a <STRONG>fglBegin</STRONG>(<STRONG>GL_LINES</STRONG>)/<STRONG>fglEnd</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>fglEnable</STRONG> and <STRONG>fglDisable</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>fglLineStipple</STRONG> is executed between the execution of <STRONG>fglBegin</STRONG> and the corresponding execution of <STRONG>fglEnd</STRONG>. <STRONG>ASSOCIATED</STRONG> <STRONG>GETS</STRONG> <STRONG>fglGet</STRONG> with argument <STRONG>GL_LINE_STIPPLE_PATTERN</STRONG> <STRONG>fglGet</STRONG> with argument <STRONG>GL_LINE_STIPPLE_REPEAT</STRONG> <STRONG>fglIsEnabled</STRONG> with argument <STRONG>GL_LINE_STIPPLE</STRONG> <STRONG>SEE</STRONG> <STRONG>ALSO</STRONG> <STRONG>fglLineWidth</STRONG>, <STRONG>fglPolygonStipple</STRONG></PRE></BODY></HTML>⌨️ 快捷键说明
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