upstream-doc/man3/glDrawElementsInstancedBaseVertex.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="glDrawElementsBaseVertex">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>2010</year>
   9                 <holder>Khronos Group</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glDrawElementsInstancedBaseVertex</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glDrawElementsInstancedBaseVertex</refname>
  17         <refpurpose>render multiple instances of a set of primitives from array data with a per-element offset</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glDrawElementsInstancedBaseVertex</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>GLvoid *<parameter>indices</parameter></paramdef>
  27                 <paramdef>GLsizei <parameter>primcount</parameter></paramdef>
  28                 <paramdef>GLint <parameter>basevertex</parameter></paramdef>
  29             </funcprototype>
  30         </funcsynopsis>
  31     </refsynopsisdiv>
  32     <!-- eqn: ignoring delim $$ -->
  33     <refsect1 id="parameters"><title>Parameters</title>
  34         <variablelist>
  35         <varlistentry>
  36             <term><parameter>mode</parameter></term>
  37             <listitem>
  38                 <para>
  39                     Specifies what kind of primitives to render.
  40                     Symbolic constants
  41                     <constant>GL_POINTS</constant>, <constant>GL_LINE_STRIP</constant>, <constant>GL_LINE_LOOP</constant>,
  42                     <constant>GL_LINES</constant>, <constant>GL_TRIANGLE_STRIP</constant>, <constant>GL_TRIANGLE_FAN</constant>,
  43                     and <constant>GL_TRIANGLES</constant> are accepted.
  44                 </para>
  45             </listitem>
  46         </varlistentry>
  47         <varlistentry>
  48             <term><parameter>count</parameter></term>
  49             <listitem>
  50                 <para>
  51                     Specifies the number of elements to be rendered.
  52                 </para>
  53             </listitem>
  54         </varlistentry>
  55         <varlistentry>
  56             <term><parameter>type</parameter></term>
  57             <listitem>
  58                 <para>
  59                     Specifies the type of the values in indices. Must be one of <constant>GL_UNSIGNED_BYTE</constant>,
  60                     <constant>GL_UNSIGNED_SHORT</constant>, or <constant>GL_UNSIGNED_INT</constant>.
  61                 </para>
  62             </listitem>
  63         </varlistentry>
  64         <varlistentry>
  65             <term><parameter>indices</parameter></term>
  66             <listitem>
  67                 <para>
  68                     Specifies a pointer to the location where the indices are stored.
  69                 </para>
  70             </listitem>
  71         </varlistentry>
  72         <varlistentry>
  73             <term><parameter>primcount</parameter></term>
  74             <listitem>
  75                 <para>
  76                     Specifies the number of instances of the indexed geometry that should be drawn.
  77                 </para>
  78             </listitem>
  79         </varlistentry>
  80         <varlistentry>
  81             <term><parameter>basevertex</parameter></term>
  82             <listitem>
  83                 <para>
  84                     Specifies a constant that should be added to each element of <parameter>indices</parameter>
  85                     when chosing elements from the enabled vertex arrays.
  86                 </para>
  87             </listitem>
  88         </varlistentry>
  89         </variablelist>
  90     </refsect1>
  91     <refsect1 id="description"><title>Description</title>
  92         <para>
  93             <function>glDrawElementsInstancedBaseVertex</function> behaves identically to
  94             <citerefentry><refentrytitle>glDrawElementsInstanced</refentrytitle></citerefentry> except that the <emphasis>i</emphasis>th element
  95             transferred by the corresponding draw call will be taken from element <parameter>indices</parameter>[i] + <parameter>basevertex</parameter>
  96             of each enabled array. If the resulting value is larger than the maximum value representable by <parameter>type</parameter>,
  97             it is as if the calculation were upconverted to 32-bit unsigned integers (with wrapping on overflow conditions).
  98             The operation is undefined if the sum would be negative.
  99         </para>
 100     </refsect1>
 101     <refsect1 id="notes"><title>Notes</title>
 102         <function>glDrawElementsInstancedBaseVertex</function> is only supported if the GL version is 3.2 or greater.
 103     </refsect1>
 104     <refsect1 id="errors"><title>Errors</title>
 105         <para>
 106             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>mode</parameter> is not an accepted value.
 107         </para>
 108         <para>
 109             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>count</parameter> or <parameter>primcount</parameter> is negative.
 110         </para>
 111         <para>
 112             <constant>GL_INVALID_OPERATION</constant> is generated if a geometry shader is active and <parameter>mode</parameter>
 113             is incompatible with the input primitive type of the geometry shader in the currently installed program object.
 114         </para>
 115         <para>
 116             <constant>GL_INVALID_OPERATION</constant> is generated if a non-zero buffer object name is bound to an
 117             enabled array or the element array and the buffer object's data store is currently mapped.
 118         </para>
 119     </refsect1>
 120     <refsect1 id="seealso"><title>See Also</title>
 121         <para>
 122             <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>,
 123             <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>,
 124             <citerefentry><refentrytitle>glDrawRangeElementsBaseVertex</refentrytitle></citerefentry>,
 125             <citerefentry><refentrytitle>glDrawElementsInstanced</refentrytitle></citerefentry>,
 126             <citerefentry><refentrytitle>glDrawElementsInstancedBaseVertex</refentrytitle></citerefentry>
 127         </para>
 128     </refsect1>
 129     <refsect1 id="Copyright"><title>Copyright</title>
 130         <para>
 131             Copyright <trademark class="copyright"></trademark> 2010 Khronos Group.
 132             This material may be distributed subject to the terms and conditions set forth in
 133             the Open Publication License, v 1.0, 8 June 1999.
 134             <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
 135         </para>
 136     </refsect1>
 137 </refentry>