upstream-man-pages/man2/glDrawElements.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="glDrawElements">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glDrawElements</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glDrawElements</refname>
  17         <refpurpose>render primitives from array data</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glDrawElements</function></funcdef>
  23                 <paramdef>GLenum <parameter>mode</parameter></paramdef>
  24                 <paramdef>GLsizei <parameter>count</parameter></paramdef>
  25                 <paramdef>GLenum <parameter>type</parameter></paramdef>
  26                 <paramdef>const GLvoid * <parameter>indices</parameter></paramdef>
  27             </funcprototype>
  28         </funcsynopsis>
  29     </refsynopsisdiv>
  30     <!-- eqn: ignoring delim $$ -->
  31     <refsect1 id="parameters"><title>Parameters</title>
  32         <variablelist>
  33         <varlistentry>
  34             <term><parameter>mode</parameter></term>
  35             <listitem>
  36                 <para>
  37                     Specifies what kind of primitives to render.
  38                     Symbolic constants
  39                     <constant>GL_POINTS</constant>,
  40                     <constant>GL_LINE_STRIP</constant>,
  41                     <constant>GL_LINE_LOOP</constant>,
  42                     <constant>GL_LINES</constant>,
  43                     <constant>GL_TRIANGLE_STRIP</constant>,
  44                     <constant>GL_TRIANGLE_FAN</constant>,
  45                     <constant>GL_TRIANGLES</constant>,
  46                     <constant>GL_QUAD_STRIP</constant>,
  47                     <constant>GL_QUADS</constant>,
  48                     and <constant>GL_POLYGON</constant> are accepted.
  49                 </para>
  50             </listitem>
  51         </varlistentry>
  52         <varlistentry>
  53             <term><parameter>count</parameter></term>
  54             <listitem>
  55                 <para>
  56                     Specifies the number of elements to be rendered.
  57                 </para>
  58             </listitem>
  59         </varlistentry>
  60         <varlistentry>
  61             <term><parameter>type</parameter></term>
  62             <listitem>
  63                 <para>
  64                     Specifies the type of the values in <parameter>indices</parameter>. Must be one of
  65                     <constant>GL_UNSIGNED_BYTE</constant>, <constant>GL_UNSIGNED_SHORT</constant>, or
  66                     <constant>GL_UNSIGNED_INT</constant>.
  67                 </para>
  68             </listitem>
  69         </varlistentry>
  70         <varlistentry>
  71             <term><parameter>indices</parameter></term>
  72             <listitem>
  73                 <para>
  74                     Specifies a pointer to the location where the indices are stored.
  75                 </para>
  76             </listitem>
  77         </varlistentry>
  78         </variablelist>
  79     </refsect1>
  80     <refsect1 id="description"><title>Description</title>
  81         <para>
  82             <function>glDrawElements</function> specifies multiple geometric primitives
  83             with very few subroutine calls. Instead of calling a GL function
  84             to pass each individual vertex, normal, texture coordinate, edge
  85             flag, or color, you can prespecify
  86             separate arrays of vertices, normals, and so on, and use them to
  87             construct a sequence of primitives with a single
  88             call to <function>glDrawElements</function>.
  89         </para>
  90         <para>
  91             When <function>glDrawElements</function> is called, it uses <parameter>count</parameter> sequential elements from an
  92             enabled array, starting at <parameter>indices</parameter> to construct a sequence of
  93             geometric primitives. <parameter>mode</parameter> specifies what kind of primitives are
  94             constructed and how the array elements construct these primitives. If
  95             more than one array is enabled, each is used. If
  96             <constant>GL_VERTEX_ARRAY</constant> is not enabled, no geometric primitives are
  97             constructed.
  98         </para>
  99         <para>
 100             Vertex attributes that are modified by <function>glDrawElements</function> have an
 101             unspecified value after <function>glDrawElements</function> returns. For example, if
 102             <constant>GL_COLOR_ARRAY</constant> is enabled, the value of the current color is
 103             undefined after <function>glDrawElements</function> executes. Attributes that aren't
 104             modified maintain their previous values.
 105         </para>
 106     </refsect1>
 107     <refsect1 id="notes"><title>Notes</title>
 108         <para>
 109             <function>glDrawElements</function> is available only if the GL version is 1.1 or greater.
 110         </para>
 111         <para>
 112             <function>glDrawElements</function> is included in display lists. If <function>glDrawElements</function> is entered into a
 113             display list,
 114             the necessary array data (determined by the array pointers and
 115             enables) is also
 116             entered into the display list. Because the array pointers and
 117             enables are client-side state, their values affect display lists
 118             when the lists are created, not when the lists are executed.
 119         </para>
 120     </refsect1>
 121     <refsect1 id="errors"><title>Errors</title>
 122         <para>
 123             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>mode</parameter> is not an accepted value.
 124         </para>
 125         <para>
 126             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>count</parameter> is negative.
 127         </para>
 128         <para>
 129             <constant>GL_INVALID_OPERATION</constant> is generated if a non-zero buffer object name is bound to an
 130             enabled array or the element array and the buffer object's data store is currently mapped.
 131         </para>
 132         <para>
 133             <constant>GL_INVALID_OPERATION</constant> is generated if <function>glDrawElements</function> is executed between
 134             the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> and the corresponding <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
 135         </para>
 136     </refsect1>
 137     <refsect1 id="seealso"><title>See Also</title>
 138         <para>
 139             <citerefentry><refentrytitle>glArrayElement</refentrytitle></citerefentry>,
 140             <citerefentry><refentrytitle>glColorPointer</refentrytitle></citerefentry>,
 141             <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>,
 142             <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>,
 143             <citerefentry><refentrytitle>glEdgeFlagPointer</refentrytitle></citerefentry>,
 144             <citerefentry><refentrytitle>glFogCoordPointer</refentrytitle></citerefentry>,
 145             <citerefentry><refentrytitle>glGetPointerv</refentrytitle></citerefentry>,
 146             <citerefentry><refentrytitle>glIndexPointer</refentrytitle></citerefentry>,
 147             <citerefentry><refentrytitle>glInterleavedArrays</refentrytitle></citerefentry>,
 148             <citerefentry><refentrytitle>glNormalPointer</refentrytitle></citerefentry>,
 149             <citerefentry><refentrytitle>glSecondaryColorPointer</refentrytitle></citerefentry>,
 150             <citerefentry><refentrytitle>glTexCoordPointer</refentrytitle></citerefentry>,
 151             <citerefentry><refentrytitle>glVertexPointer</refentrytitle></citerefentry>
 152         </para>
 153     </refsect1>
 154     <refsect1 id="Copyright"><title>Copyright</title>
 155         <para>
 156             Copyright <trademark class="copyright"></trademark> 1991-2006
 157             Silicon Graphics, Inc. This document is licensed under the SGI
 158             Free Software B License. For details, see
 159             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 160         </para>
 161     </refsect1>
 162 </refentry>