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"text/html; charset=UTF-8" /><title>glPolygonMode
</title><meta name=
"generator" content=
"DocBook XSL Stylesheets V1.73.2" /></head><body><div class=
"refentry" lang=
"en" xml:
lang=
"en"><a id=
"glPolygonMode"></a><div class=
"titlepage"></div><div class=
"refnamediv"><h2>Name
</h2><p>glPolygonMode — select a polygon rasterization mode
</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">glPolygonMode
</b>(
</code></td><td>GLenum
</td><td><var class=
"pdparam">face
</var>,
</td></tr><tr><td> </td><td>GLenum
</td><td><var class=
"pdparam">mode
</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>face
</code></em></span></dt><dd><p>
4 Specifies the polygons that
<em class=
"parameter"><code>mode
</code></em> applies to.
6 <code class=
"constant">GL_FRONT
</code> for front-facing polygons,
7 <code class=
"constant">GL_BACK
</code> for back-facing polygons,
8 or
<code class=
"constant">GL_FRONT_AND_BACK
</code> for front- and back-facing polygons.
9 </p></dd><dt><span class=
"term"><em class=
"parameter"><code>mode
</code></em></span></dt><dd><p>
10 Specifies how polygons will be rasterized.
12 <code class=
"constant">GL_POINT
</code>,
13 <code class=
"constant">GL_LINE
</code>, and
14 <code class=
"constant">GL_FILL
</code>.
15 The initial value is
<code class=
"constant">GL_FILL
</code> for both front- and back-facing polygons.
16 </p></dd></dl></div></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"description"></a><h2>Description
</h2><p>
17 <code class=
"function">glPolygonMode
</code> controls the interpretation of polygons for rasterization.
18 <em class=
"parameter"><code>face
</code></em> describes which polygons
<em class=
"parameter"><code>mode
</code></em> applies to:
19 front-facing polygons (
<code class=
"constant">GL_FRONT
</code>),
20 back-facing polygons (
<code class=
"constant">GL_BACK
</code>),
21 or both (
<code class=
"constant">GL_FRONT_AND_BACK
</code>).
22 The polygon mode affects only the final rasterization of polygons.
24 a polygon's vertices are lit and
25 the polygon is clipped and possibly culled before these modes are applied.
27 Three modes are defined and can be specified in
<em class=
"parameter"><code>mode
</code></em>:
28 </p><div class=
"variablelist"><dl><dt><span class=
"term"><code class=
"constant">GL_POINT
</code></span></dt><dd><p>
29 Polygon vertices that are marked as the start of a boundary edge
31 Point attributes such as
32 <code class=
"constant">GL_POINT_SIZE
</code> and
33 <code class=
"constant">GL_POINT_SMOOTH
</code> control
34 the rasterization of the points.
35 Polygon rasterization attributes other than
<code class=
"constant">GL_POLYGON_MODE
</code> have no effect.
36 </p></dd><dt><span class=
"term"><code class=
"constant">GL_LINE
</code></span></dt><dd><p>
37 Boundary edges of the polygon are drawn as line segments.
38 They are treated as connected line segments for line stippling;
39 the line stipple counter and pattern are not reset between segments
40 (see
<a class=
"citerefentry" href=
"glLineStipple.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glLineStipple
</span></span></a>).
41 Line attributes such as
42 <code class=
"constant">GL_LINE_WIDTH
</code> and
43 <code class=
"constant">GL_LINE_SMOOTH
</code> control
44 the rasterization of the lines.
45 Polygon rasterization attributes other than
<code class=
"constant">GL_POLYGON_MODE
</code> have no effect.
46 </p></dd><dt><span class=
"term"><code class=
"constant">GL_FILL
</code></span></dt><dd><p>
47 The interior of the polygon is filled.
48 Polygon attributes such as
49 <code class=
"constant">GL_POLYGON_STIPPLE
</code> and
50 <code class=
"constant">GL_POLYGON_SMOOTH
</code> control the rasterization of the polygon.
51 </p></dd></dl></div></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"examples"></a><h2>Examples
</h2><p>
52 To draw a surface with filled back-facing polygons
53 and outlined front-facing polygons,
55 </p><pre class=
"programlisting">
56 glPolygonMode(
<code class=
"constant">GL_FRONT
</code>,
<code class=
"constant">GL_LINE
</code>);
58 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"notes"></a><h2>Notes
</h2><p>
59 Vertices are marked as boundary or nonboundary with an edge flag.
60 Edge flags are generated internally by the GL when it decomposes
61 polygons; they can be set explicitly using
<a class=
"citerefentry" href=
"glEdgeFlag.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glEdgeFlag
</span></span></a>.
62 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"errors"></a><h2>Errors
</h2><p>
63 <code class=
"constant">GL_INVALID_ENUM
</code> is generated if either
<em class=
"parameter"><code>face
</code></em> or
<em class=
"parameter"><code>mode
</code></em> is not
66 <code class=
"constant">GL_INVALID_OPERATION
</code> is generated if
<code class=
"function">glPolygonMode
</code>
67 is executed between the execution of
<a class=
"citerefentry" href=
"glBegin.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glBegin
</span></span></a>
68 and the corresponding execution of
<a class=
"citerefentry" href=
"glEnd.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glEnd
</span></span></a>.
69 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"associatedgets"></a><h2>Associated Gets
</h2><p>
70 <a class=
"citerefentry" href=
"glGet.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glGet
</span></span></a> with argument
<code class=
"constant">GL_POLYGON_MODE
</code>
71 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"seealso"></a><h2>See Also
</h2><p>
72 <a class=
"citerefentry" href=
"glBegin.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glBegin
</span></span></a>,
73 <a class=
"citerefentry" href=
"glEdgeFlag.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glEdgeFlag
</span></span></a>,
74 <a class=
"citerefentry" href=
"glLineStipple.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glLineStipple
</span></span></a>,
75 <a class=
"citerefentry" href=
"glLineWidth.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glLineWidth
</span></span></a>,
76 <a class=
"citerefentry" href=
"glPointSize.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glPointSize
</span></span></a>,
77 <a class=
"citerefentry" href=
"glPolygonStipple.xml"><span class=
"citerefentry"><span class=
"refentrytitle">glPolygonStipple
</span></span></a>
78 </p></div><div class=
"refsect1" lang=
"en" xml:
lang=
"en"><a id=
"Copyright"></a><h2>Copyright
</h2><p>
79 Copyright
<span class=
"trademark"></span>©
1991-
2006
80 Silicon Graphics, Inc. This document is licensed under the SGI
81 Free Software B License. For details, see
82 <a class=
"ulink" href=
"http://oss.sgi.com/projects/FreeB/" target=
"_top">http://oss.sgi.com/projects/FreeB/
</a>.
83 </p></div></div></body></html>