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1 | <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd"> |
2 | <!-- saved from url=(0013)about:internet --> | |
3 | <?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>glPolygonStipple</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glPolygonStipple"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glPolygonStipple — set the polygon stippling pattern</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glPolygonStipple</b>(</code></td><td>const GLubyte * </td><td><var class="pdparam">pattern</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>pattern</code></em></span></dt><dd><p> | |
4 | Specifies a pointer to a | |
5 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
6 | ||
7 | <mml:mrow> | |
8 | <mml:mn>32</mml:mn> | |
9 | <mml:mo>×</mml:mo> | |
10 | <mml:mn>32</mml:mn> | |
11 | </mml:mrow> | |
12 | </mml:math> | |
13 | stipple pattern that will be unpacked | |
14 | from memory in the same way that <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a> unpacks pixels. | |
15 | </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p> | |
16 | Polygon stippling, | |
17 | like line stippling | |
18 | (see <a class="citerefentry" href="glLineStipple.xml"><span class="citerefentry"><span class="refentrytitle">glLineStipple</span></span></a>), | |
19 | masks out certain fragments produced by rasterization, | |
20 | creating a pattern. | |
21 | Stippling is independent of polygon antialiasing. | |
22 | </p><p> | |
23 | <em class="parameter"><code>pattern</code></em> is a pointer to a | |
24 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
25 | ||
26 | <mml:mrow> | |
27 | <mml:mn>32</mml:mn> | |
28 | <mml:mo>×</mml:mo> | |
29 | <mml:mn>32</mml:mn> | |
30 | </mml:mrow> | |
31 | </mml:math> | |
32 | stipple pattern that is stored | |
33 | in memory just like the pixel data supplied to a <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a> | |
34 | call with | |
35 | <span class="emphasis"><em></em></span> | |
36 | height | |
37 | and | |
38 | <span class="emphasis"><em>width</em></span> | |
39 | both equal to 32, a pixel format | |
40 | of <code class="constant">GL_COLOR_INDEX</code>, and data type | |
41 | of <code class="constant">GL_BITMAP</code>. | |
42 | That is, | |
43 | the stipple pattern is represented as a | |
44 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
45 | ||
46 | <mml:mrow> | |
47 | <mml:mn>32</mml:mn> | |
48 | <mml:mo>×</mml:mo> | |
49 | <mml:mn>32</mml:mn> | |
50 | </mml:mrow> | |
51 | </mml:math> | |
52 | array | |
53 | of 1-bit color indices packed in unsigned bytes. | |
54 | <a class="citerefentry" href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a> parameters like <code class="constant">GL_UNPACK_SWAP_BYTES</code> | |
55 | and <code class="constant">GL_UNPACK_LSB_FIRST</code> affect the assembling of the bits into a | |
56 | stipple pattern. | |
57 | Pixel transfer operations | |
58 | (shift, offset, pixel map) | |
59 | are not applied to the stipple image, | |
60 | however. | |
61 | </p><p> | |
62 | If a non-zero named buffer object is bound to the <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target | |
63 | (see <a class="citerefentry" href="glBindBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>) while a stipple pattern is | |
64 | specified, <em class="parameter"><code>pattern</code></em> is treated as a byte offset into the buffer object's data store. | |
65 | </p><p> | |
66 | To enable and disable polygon stippling, call | |
67 | <a class="citerefentry" href="glEnable.xml"><span class="citerefentry"><span class="refentrytitle">glEnable</span></span></a> and <a class="citerefentry" href="glDisable.xml"><span class="citerefentry"><span class="refentrytitle">glDisable</span></span></a> | |
68 | with argument <code class="constant">GL_POLYGON_STIPPLE</code>. Polygon stippling is initially | |
69 | disabled. If it's enabled, | |
70 | a rasterized polygon fragment with window coordinates | |
71 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
72 | ||
73 | <mml:msub><mml:mi mathvariant="italic">x</mml:mi> | |
74 | <mml:mi mathvariant="italic">w</mml:mi> | |
75 | </mml:msub> | |
76 | </mml:math> | |
77 | and | |
78 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
79 | ||
80 | <mml:msub><mml:mi mathvariant="italic">y</mml:mi> | |
81 | <mml:mi mathvariant="italic">w</mml:mi> | |
82 | </mml:msub> | |
83 | </mml:math> | |
84 | is sent to the next stage of the GL if and only if the | |
85 | (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
86 | ||
87 | <mml:mrow> | |
88 | <mml:msub><mml:mi mathvariant="italic">x</mml:mi> | |
89 | <mml:mi mathvariant="italic">w</mml:mi> | |
90 | </mml:msub> | |
91 | <mml:mo>%</mml:mo> | |
92 | <mml:mn>32</mml:mn> | |
93 | </mml:mrow> | |
94 | </mml:math>)th | |
95 | bit in the | |
96 | (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
97 | ||
98 | <mml:mrow> | |
99 | <mml:msub><mml:mi mathvariant="italic">y</mml:mi> | |
100 | <mml:mi mathvariant="italic">w</mml:mi> | |
101 | </mml:msub> | |
102 | <mml:mo>%</mml:mo> | |
103 | <mml:mn>32</mml:mn> | |
104 | </mml:mrow> | |
105 | </mml:math>)th | |
106 | row | |
107 | of the stipple pattern is 1 (one). | |
108 | When polygon stippling is disabled, it is as if the stipple pattern | |
109 | consists of all 1's. | |
110 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p> | |
111 | <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the | |
112 | <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target and the buffer object's data store is currently mapped. | |
113 | </p><p> | |
114 | <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the | |
115 | <code class="constant">GL_PIXEL_UNPACK_BUFFER</code> target and the data would be unpacked from the buffer | |
116 | object such that the memory reads required would exceed the data store size. | |
117 | </p><p> | |
118 | <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glPolygonStipple</code> | |
119 | is executed between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> | |
120 | and the corresponding execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>. | |
121 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p> | |
122 | <a class="citerefentry" href="glGetPolygonStipple.xml"><span class="citerefentry"><span class="refentrytitle">glGetPolygonStipple</span></span></a> | |
123 | </p><p> | |
124 | <a class="citerefentry" href="glIsEnabled.xml"><span class="citerefentry"><span class="refentrytitle">glIsEnabled</span></span></a> with argument <code class="constant">GL_POLYGON_STIPPLE</code> | |
125 | </p><p> | |
126 | <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PIXEL_UNPACK_BUFFER_BINDING</code> | |
127 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p> | |
128 | <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a>, | |
129 | <a class="citerefentry" href="glLineStipple.xml"><span class="citerefentry"><span class="refentrytitle">glLineStipple</span></span></a>, | |
130 | <a class="citerefentry" href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>, | |
131 | <a class="citerefentry" href="glPixelTransfer.xml"><span class="citerefentry"><span class="refentrytitle">glPixelTransfer</span></span></a> | |
132 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p> | |
133 | Copyright <span class="trademark"></span>© 1991-2006 | |
134 | Silicon Graphics, Inc. This document is licensed under the SGI | |
135 | Free Software B License. For details, see | |
136 | <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>. | |
137 | </p></div></div></body></html> |