upstream-man-pages/man3/glPolygonMode.xml

   1 <?xml version="1.0" encoding="UTF-8"?>
   2 <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
   3               "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
   4 <refentry id="glPolygonMode">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glPolygonMode</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glPolygonMode</refname>
  17         <refpurpose>select a polygon rasterization mode</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glPolygonMode</function></funcdef>
  23                 <paramdef>GLenum <parameter>face</parameter></paramdef>
  24                 <paramdef>GLenum <parameter>mode</parameter></paramdef>
  25             </funcprototype>
  26         </funcsynopsis>
  27     </refsynopsisdiv>
  28     <refsect1 id="parameters"><title>Parameters</title>
  29         <variablelist>
  30         <varlistentry>
  31             <term><parameter>face</parameter></term>
  32             <listitem>
  33                 <para>
  34                     Specifies the polygons that <parameter>mode</parameter> applies to.
  35                     Must be <constant>GL_FRONT_AND_BACK</constant> for front- and back-facing polygons.
  36                 </para>
  37             </listitem>
  38         </varlistentry>
  39         <varlistentry>
  40             <term><parameter>mode</parameter></term>
  41             <listitem>
  42                 <para>
  43                     Specifies how polygons will be rasterized.
  44                     Accepted values are
  45                     <constant>GL_POINT</constant>,
  46                     <constant>GL_LINE</constant>, and
  47                     <constant>GL_FILL</constant>.
  48                     The initial value is <constant>GL_FILL</constant> for both front- and back-facing polygons.
  49                 </para>
  50             </listitem>
  51         </varlistentry>
  52         </variablelist>
  53     </refsect1>
  54     <refsect1 id="description"><title>Description</title>
  55         <para>
  56             <function>glPolygonMode</function> controls the interpretation of polygons for rasterization.
  57             <parameter>face</parameter> describes which polygons <parameter>mode</parameter> applies to:
  58             both front and back-facing polygons (<constant>GL_FRONT_AND_BACK</constant>).
  59             The polygon mode affects only the final rasterization of polygons.
  60             In particular,
  61             a polygon's vertices are lit and
  62             the polygon is clipped and possibly culled before these modes are applied.
  63         </para>
  64         <para>
  65             Three modes are defined and can be specified in <parameter>mode</parameter>:
  66         </para>
  67         <variablelist>
  68             <varlistentry>
  69                 <term><constant>GL_POINT</constant></term>
  70                 <listitem>
  71                     <para>
  72                         Polygon vertices that are marked as the start of a boundary edge
  73                         are drawn as points.
  74                         Point attributes such as
  75                         <constant>GL_POINT_SIZE</constant> and
  76                         <constant>GL_POINT_SMOOTH</constant> control
  77                         the rasterization of the points.
  78                         Polygon rasterization attributes other than <constant>GL_POLYGON_MODE</constant> have no effect.
  79                     </para>
  80                 </listitem>
  81             </varlistentry>
  82             <varlistentry>
  83                 <term><constant>GL_LINE</constant></term>
  84                 <listitem>
  85                     <para>
  86                         Boundary edges of the polygon are drawn as line segments.
  87                         Line attributes such as
  88                         <constant>GL_LINE_WIDTH</constant> and
  89                         <constant>GL_LINE_SMOOTH</constant> control
  90                         the rasterization of the lines.
  91                         Polygon rasterization attributes other than <constant>GL_POLYGON_MODE</constant> have no effect.
  92                     </para>
  93                 </listitem>
  94             </varlistentry>
  95             <varlistentry>
  96                 <term><constant>GL_FILL</constant></term>
  97                 <listitem>
  98                     <para>
  99                         The interior of the polygon is filled.
 100                         Polygon attributes such as <constant>GL_POLYGON_SMOOTH</constant> control the rasterization of the polygon.
 101                     </para>
 102                 </listitem>
 103             </varlistentry>
 104         </variablelist>
 105     </refsect1>
 106     <refsect1 id="examples"><title>Examples</title>
 107         <para>
 108             To draw a surface with outlined polygons,
 109             call
 110             <programlisting>
 111 glPolygonMode(<constant>GL_FRONT_AND_BACK</constant>, <constant>GL_LINE</constant>);
 112             </programlisting>
 113         </para>
 114     </refsect1>
 115     <refsect1 id="notes"><title>Notes</title>
 116         <para>
 117             Vertices are marked as boundary or nonboundary with an edge flag.
 118             Edge flags are generated internally by the GL when it decomposes
 119             triangle stips and fans.
 120         </para>
 121     </refsect1>
 122     <refsect1 id="errors"><title>Errors</title>
 123         <para>
 124             <constant>GL_INVALID_ENUM</constant> is generated if either <parameter>face</parameter> or <parameter>mode</parameter> is not
 125             an accepted value.
 126         </para>
 127     </refsect1>
 128     <refsect1 id="associatedgets"><title>Associated Gets</title>
 129         <para>
 130             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_POLYGON_MODE</constant>
 131         </para>
 132     </refsect1>
 133     <refsect1 id="seealso"><title>See Also</title>
 134         <para>
 135             <citerefentry><refentrytitle>glLineWidth</refentrytitle></citerefentry>,
 136             <citerefentry><refentrytitle>glPointSize</refentrytitle></citerefentry>
 137         </para>
 138     </refsect1>
 139     <refsect1 id="Copyright"><title>Copyright</title>
 140         <para>
 141             Copyright <trademark class="copyright"></trademark> 1991-2006
 142             Silicon Graphics, Inc. This document is licensed under the SGI
 143             Free Software B License. For details, see
 144             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 145         </para>
 146     </refsect1>
 147 </refentry>