upstream-doc/man2/glNormalPointer.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="glNormalPointer">
   5     <refmeta>
   6         <refmetainfo>
   7             <copyright>
   8                 <year>1991-2006</year>
   9                 <holder>Silicon Graphics, Inc.</holder>
  10             </copyright>
  11         </refmetainfo>
  12         <refentrytitle>glNormalPointer</refentrytitle>
  13         <manvolnum>3G</manvolnum>
  14     </refmeta>
  15     <refnamediv>
  16         <refname>glNormalPointer</refname>
  17         <refpurpose>define an array of normals</refpurpose>
  18     </refnamediv>
  19     <refsynopsisdiv><title>C Specification</title>
  20         <funcsynopsis>
  21             <funcprototype>
  22                 <funcdef>void <function>glNormalPointer</function></funcdef>
  23                 <paramdef>GLenum <parameter>type</parameter></paramdef>
  24                 <paramdef>GLsizei <parameter>stride</parameter></paramdef>
  25                 <paramdef>const GLvoid * <parameter>pointer</parameter></paramdef>
  26             </funcprototype>
  27         </funcsynopsis>
  28     </refsynopsisdiv>
  29     <!-- eqn: ignoring delim $$ -->
  30     <refsect1 id="parameters"><title>Parameters</title>
  31         <variablelist>
  32         <varlistentry>
  33             <term><parameter>type</parameter></term>
  34             <listitem>
  35                 <para>
  36                     Specifies the data type of each coordinate in the array.
  37                     Symbolic constants
  38                     <constant>GL_BYTE</constant>,
  39                     <constant>GL_SHORT</constant>,
  40                     <constant>GL_INT</constant>,
  41                     <constant>GL_FLOAT</constant>, and
  42                     <constant>GL_DOUBLE</constant>
  43                     are accepted. The initial value is <constant>GL_FLOAT</constant>.
  44                 </para>
  45             </listitem>
  46         </varlistentry>
  47         <varlistentry>
  48             <term><parameter>stride</parameter></term>
  49             <listitem>
  50                 <para>
  51                     Specifies the byte offset between consecutive normals. If <parameter>stride</parameter> is
  52                     0, the normals are understood to be tightly packed in
  53                     the array. The initial value is 0.
  54                 </para>
  55             </listitem>
  56         </varlistentry>
  57         <varlistentry>
  58             <term><parameter>pointer</parameter></term>
  59             <listitem>
  60                 <para>
  61                     Specifies a pointer to the first coordinate of the first normal in the
  62                     array. The initial value is 0.
  63                 </para>
  64             </listitem>
  65         </varlistentry>
  66         </variablelist>
  67     </refsect1>
  68     <refsect1 id="description"><title>Description</title>
  69         <para>
  70             <function>glNormalPointer</function> specifies the location and data format of an array of normals
  71             to use when rendering.
  72             <parameter>type</parameter> specifies the data type of each normal coordinate,
  73             and <parameter>stride</parameter> specifies the byte stride from one
  74             normal to the next, allowing vertices and attributes
  75             to be packed into a single array or stored in separate arrays.
  76             (Single-array storage may be more efficient on some implementations;
  77             see <citerefentry><refentrytitle>glInterleavedArrays</refentrytitle></citerefentry>.)
  78         </para>
  79         <para>
  80             If a non-zero named buffer object is bound to the <constant>GL_ARRAY_BUFFER</constant> target
  81             (see <citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>) while a normal array is
  82             specified, <parameter>pointer</parameter> is treated as a byte offset into the buffer object's data store.
  83             Also, the buffer object binding (<constant>GL_ARRAY_BUFFER_BINDING</constant>) is saved as normal vertex array
  84             client-side state (<constant>GL_NORMAL_ARRAY_BUFFER_BINDING</constant>).
  85         </para>
  86         <para>
  87             When a normal array is specified,
  88             <parameter>type</parameter>, <parameter>stride</parameter>, and <parameter>pointer</parameter> are saved as client-side
  89             state, in addition to the current vertex array buffer object binding.
  90         </para>
  91         <para>
  92             To enable and disable the normal array, call
  93             <citerefentry><refentrytitle>glEnableClientState</refentrytitle></citerefentry> and <citerefentry><refentrytitle>glDisableClientState</refentrytitle></citerefentry> with the argument
  94             <constant>GL_NORMAL_ARRAY</constant>. If
  95             enabled, the normal array is used
  96             when <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glMultiDrawArrays</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>,
  97             <citerefentry><refentrytitle>glMultiDrawElements</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>, or
  98             <citerefentry><refentrytitle>glArrayElement</refentrytitle></citerefentry> is called.
  99         </para>
 100     </refsect1>
 101     <refsect1 id="notes"><title>Notes</title>
 102         <para>
 103             <function>glNormalPointer</function> is available only if the GL version is 1.1 or greater.
 104         </para>
 105         <para>
 106             The normal array is initially disabled and isn't accessed when
 107             <citerefentry><refentrytitle>glArrayElement</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>,
 108             <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glMultiDrawArrays</refentrytitle></citerefentry>, or <citerefentry><refentrytitle>glMultiDrawElements</refentrytitle></citerefentry>
 109             is called.
 110         </para>
 111         <para>
 112             Execution of <function>glNormalPointer</function> is not allowed between
 113             <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> and the corresponding <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>,
 114             but an error may or may not be generated. If an error is not generated,
 115             the operation is undefined.
 116         </para>
 117         <para>
 118             <function>glNormalPointer</function> is typically implemented on the client side.
 119         </para>
 120         <para>
 121             Normal array parameters are client-side state and are therefore not
 122             saved or restored by <citerefentry><refentrytitle>glPushAttrib</refentrytitle></citerefentry> and <citerefentry><refentrytitle>glPopAttrib</refentrytitle></citerefentry>.
 123             Use <citerefentry><refentrytitle>glPushClientAttrib</refentrytitle></citerefentry> and
 124             <citerefentry><refentrytitle>glPopClientAttrib</refentrytitle></citerefentry> instead.
 125         </para>
 126     </refsect1>
 127     <refsect1 id="errors"><title>Errors</title>
 128         <para>
 129             <constant>GL_INVALID_ENUM</constant> is generated if <parameter>type</parameter> is not an accepted value.
 130         </para>
 131         <para>
 132             <constant>GL_INVALID_VALUE</constant> is generated if <parameter>stride</parameter> is negative.
 133         </para>
 134     </refsect1>
 135     <refsect1 id="associatedgets"><title>Associated Gets</title>
 136         <para>
 137             <citerefentry><refentrytitle>glIsEnabled</refentrytitle></citerefentry> with argument <constant>GL_NORMAL_ARRAY</constant>
 138         </para>
 139         <para>
 140             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_NORMAL_ARRAY_TYPE</constant>
 141         </para>
 142         <para>
 143             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_NORMAL_ARRAY_STRIDE</constant>
 144         </para>
 145         <para>
 146             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_NORMAL_ARRAY_BUFFER_BINDING</constant>
 147         </para>
 148         <para>
 149             <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_ARRAY_BUFFER_BINDING</constant>
 150         </para>
 151         <para>
 152             <citerefentry><refentrytitle>glGetPointerv</refentrytitle></citerefentry> with argument <constant>GL_NORMAL_ARRAY_POINTER</constant>
 153         </para>
 154     </refsect1>
 155     <refsect1 id="seealso"><title>See Also</title>
 156         <para>
 157             <citerefentry><refentrytitle>glArrayElement</refentrytitle></citerefentry>,
 158             <citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>,
 159             <citerefentry><refentrytitle>glColorPointer</refentrytitle></citerefentry>,
 160             <citerefentry><refentrytitle>glDisableClientState</refentrytitle></citerefentry>,
 161             <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>,
 162             <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>,
 163             <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>,
 164             <citerefentry><refentrytitle>glEdgeFlagPointer</refentrytitle></citerefentry>,
 165             <citerefentry><refentrytitle>glEnableClientState</refentrytitle></citerefentry>,
 166             <citerefentry><refentrytitle>glFogCoordPointer</refentrytitle></citerefentry>,
 167             <citerefentry><refentrytitle>glIndexPointer</refentrytitle></citerefentry>,
 168             <citerefentry><refentrytitle>glInterleavedArrays</refentrytitle></citerefentry>,
 169             <citerefentry><refentrytitle>glMultiDrawArrays</refentrytitle></citerefentry>,
 170             <citerefentry><refentrytitle>glMultiDrawElements</refentrytitle></citerefentry>,
 171             <citerefentry><refentrytitle>glNormal</refentrytitle></citerefentry>,
 172             <citerefentry><refentrytitle>glPopClientAttrib</refentrytitle></citerefentry>,
 173             <citerefentry><refentrytitle>glPushClientAttrib</refentrytitle></citerefentry>,
 174             <citerefentry><refentrytitle>glSecondaryColorPointer</refentrytitle></citerefentry>,
 175             <citerefentry><refentrytitle>glTexCoordPointer</refentrytitle></citerefentry>,
 176             <citerefentry><refentrytitle>glVertexAttribPointer</refentrytitle></citerefentry>,
 177             <citerefentry><refentrytitle>glVertexPointer</refentrytitle></citerefentry>
 178         </para>
 179     </refsect1>
 180     <refsect1 id="Copyright"><title>Copyright</title>
 181         <para>
 182             Copyright <trademark class="copyright"></trademark> 1991-2006
 183             Silicon Graphics, Inc. This document is licensed under the SGI
 184             Free Software B License. For details, see
 185             <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
 186         </para>
 187     </refsect1>
 188 </refentry>