Opentk/Source/Bind/Specifications/Docs/glNormalPointer.xml
2009-03-08 00:46:58 +00:00

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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
"http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
<refentry id="glNormalPointer">
<refmeta>
<refmetainfo>
<copyright>
<year>1991-2006</year>
<holder>Silicon Graphics, Inc.</holder>
</copyright>
</refmetainfo>
<refentrytitle>glNormalPointer</refentrytitle>
<manvolnum>3G</manvolnum>
</refmeta>
<refnamediv>
<refname>glNormalPointer</refname>
<refpurpose>define an array of normals</refpurpose>
</refnamediv>
<refsynopsisdiv><title>C Specification</title>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>glNormalPointer</function></funcdef>
<paramdef>GLenum <parameter>type</parameter></paramdef>
<paramdef>GLsizei <parameter>stride</parameter></paramdef>
<paramdef>const GLvoid * <parameter>pointer</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<!-- eqn: ignoring delim $$ -->
<refsect1 id="parameters"><title>Parameters</title>
<variablelist>
<varlistentry>
<term><parameter>type</parameter></term>
<listitem>
<para>
Specifies the data type of each coordinate in the array.
Symbolic constants
<constant>GL_BYTE</constant>,
<constant>GL_SHORT</constant>,
<constant>GL_INT</constant>,
<constant>GL_FLOAT</constant>, and
<constant>GL_DOUBLE</constant>
are accepted. The initial value is <constant>GL_FLOAT</constant>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>stride</parameter></term>
<listitem>
<para>
Specifies the byte offset between consecutive normals. If <parameter>stride</parameter> is
0, the normals are understood to be tightly packed in
the array. The initial value is 0.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>pointer</parameter></term>
<listitem>
<para>
Specifies a pointer to the first coordinate of the first normal in the
array. The initial value is 0.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id="description"><title>Description</title>
<para>
<function>glNormalPointer</function> specifies the location and data format of an array of normals
to use when rendering.
<parameter>type</parameter> specifies the data type of each normal coordinate,
and <parameter>stride</parameter> specifies the byte stride from one
normal to the next, allowing vertices and attributes
to be packed into a single array or stored in separate arrays.
(Single-array storage may be more efficient on some implementations;
see <citerefentry><refentrytitle>glInterleavedArrays</refentrytitle></citerefentry>.)
</para>
<para>
If a non-zero named buffer object is bound to the <constant>GL_ARRAY_BUFFER</constant> target
(see <citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>) while a normal array is
specified, <parameter>pointer</parameter> is treated as a byte offset into the buffer object's data store.
Also, the buffer object binding (<constant>GL_ARRAY_BUFFER_BINDING</constant>) is saved as normal vertex array
client-side state (<constant>GL_NORMAL_ARRAY_BUFFER_BINDING</constant>).
</para>
<para>
When a normal array is specified,
<parameter>type</parameter>, <parameter>stride</parameter>, and <parameter>pointer</parameter> are saved as client-side
state, in addition to the current vertex array buffer object binding.
</para>
<para>
To enable and disable the normal array, call
<citerefentry><refentrytitle>glEnableClientState</refentrytitle></citerefentry> and <citerefentry><refentrytitle>glDisableClientState</refentrytitle></citerefentry> with the argument
<constant>GL_NORMAL_ARRAY</constant>. If
enabled, the normal array is used
when <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glMultiDrawArrays</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glMultiDrawElements</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>, or
<citerefentry><refentrytitle>glArrayElement</refentrytitle></citerefentry> is called.
</para>
</refsect1>
<refsect1 id="notes"><title>Notes</title>
<para>
<function>glNormalPointer</function> is available only if the GL version is 1.1 or greater.
</para>
<para>
The normal array is initially disabled and isn't accessed when
<citerefentry><refentrytitle>glArrayElement</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glMultiDrawArrays</refentrytitle></citerefentry>, or <citerefentry><refentrytitle>glMultiDrawElements</refentrytitle></citerefentry>
is called.
</para>
<para>
Execution of <function>glNormalPointer</function> is not allowed between
<citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> and the corresponding <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>,
but an error may or may not be generated. If an error is not generated,
the operation is undefined.
</para>
<para>
<function>glNormalPointer</function> is typically implemented on the client side.
</para>
<para>
Normal array parameters are client-side state and are therefore not
saved or restored by <citerefentry><refentrytitle>glPushAttrib</refentrytitle></citerefentry> and <citerefentry><refentrytitle>glPopAttrib</refentrytitle></citerefentry>.
Use <citerefentry><refentrytitle>glPushClientAttrib</refentrytitle></citerefentry> and
<citerefentry><refentrytitle>glPopClientAttrib</refentrytitle></citerefentry> instead.
</para>
</refsect1>
<refsect1 id="errors"><title>Errors</title>
<para>
<constant>GL_INVALID_ENUM</constant> is generated if <parameter>type</parameter> is not an accepted value.
</para>
<para>
<constant>GL_INVALID_VALUE</constant> is generated if <parameter>stride</parameter> is negative.
</para>
</refsect1>
<refsect1 id="associatedgets"><title>Associated Gets</title>
<para>
<citerefentry><refentrytitle>glIsEnabled</refentrytitle></citerefentry> with argument <constant>GL_NORMAL_ARRAY</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_NORMAL_ARRAY_TYPE</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_NORMAL_ARRAY_STRIDE</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_NORMAL_ARRAY_BUFFER_BINDING</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_ARRAY_BUFFER_BINDING</constant>
</para>
<para>
<citerefentry><refentrytitle>glGetPointerv</refentrytitle></citerefentry> with argument <constant>GL_NORMAL_ARRAY_POINTER</constant>
</para>
</refsect1>
<refsect1 id="seealso"><title>See Also</title>
<para>
<citerefentry><refentrytitle>glArrayElement</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glColorPointer</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glDisableClientState</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glEdgeFlagPointer</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glEnableClientState</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glFogCoordPointer</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glIndexPointer</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glInterleavedArrays</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glMultiDrawArrays</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glMultiDrawElements</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glNormal</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glPopClientAttrib</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glPushClientAttrib</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glSecondaryColorPointer</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glTexCoordPointer</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glVertexAttribPointer</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glVertexPointer</refentrytitle></citerefentry>
</para>
</refsect1>
<refsect1 id="Copyright"><title>Copyright</title>
<para>
Copyright <trademark class="copyright"></trademark> 1991-2006
Silicon Graphics, Inc. This document is licensed under the SGI
Free Software B License. For details, see
<ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
</para>
</refsect1>
</refentry>