a88b98419e8f5320b53e342b90d612ddf621c94c
[clinton/guile-figl.git] / upstream-man-pages / man2 / glPassThrough.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="glPassThrough">
5 <refmeta>
6 <refmetainfo>
7 <copyright>
8 <year>1991-2006</year>
9 <holder>Silicon Graphics, Inc.</holder>
10 </copyright>
11 </refmetainfo>
12 <refentrytitle>glPassThrough</refentrytitle>
13 <manvolnum>3G</manvolnum>
14 </refmeta>
15 <refnamediv>
16 <refname>glPassThrough</refname>
17 <refpurpose>place a marker in the feedback buffer</refpurpose>
18 </refnamediv>
19 <refsynopsisdiv><title>C Specification</title>
20 <funcsynopsis>
21 <funcprototype>
22 <funcdef>void <function>glPassThrough</function></funcdef>
23 <paramdef>GLfloat <parameter>token</parameter></paramdef>
24 </funcprototype>
25 </funcsynopsis>
26 </refsynopsisdiv>
27 <refsect1 id="parameters"><title>Parameters</title>
28 <variablelist>
29 <varlistentry>
30 <term><parameter>token</parameter></term>
31 <listitem>
32 <para>
33 Specifies a marker value to be placed in the feedback buffer
34 following a <constant>GL_PASS_THROUGH_TOKEN</constant>.
35 </para>
36 </listitem>
37 </varlistentry>
38 </variablelist>
39 </refsect1>
40 <refsect1 id="description"><title>Description</title>
41 <para>
42 </para>
43 <para>
44 Feedback is a GL render mode.
45 The mode is selected by calling
46 <citerefentry><refentrytitle>glRenderMode</refentrytitle></citerefentry> with <constant>GL_FEEDBACK</constant>.
47 When the GL is in feedback mode,
48 no pixels are produced by rasterization.
49 Instead,
50 information about primitives that would have been rasterized
51 is fed back to the application using the GL.
52 See the <citerefentry><refentrytitle>glFeedbackBuffer</refentrytitle></citerefentry> reference page for a description of the
53 feedback buffer and the values in it.
54 </para>
55 <para>
56 <function>glPassThrough</function> inserts a user-defined marker in the feedback buffer
57 when it is executed in feedback mode.
58 <parameter>token</parameter> is returned as if it were a primitive;
59 it is indicated with its own unique identifying value:
60 <constant>GL_PASS_THROUGH_TOKEN</constant>.
61 The order of <function>glPassThrough</function> commands with respect to the specification
62 of graphics primitives is maintained.
63 </para>
64 </refsect1>
65 <refsect1 id="notes"><title>Notes</title>
66 <para>
67 <function>glPassThrough</function> is ignored if the GL is not in feedback mode.
68 </para>
69 </refsect1>
70 <refsect1 id="errors"><title>Errors</title>
71 <para>
72 <constant>GL_INVALID_OPERATION</constant> is generated if <function>glPassThrough</function> is executed between
73 the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> and the corresponding execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
74 </para>
75 </refsect1>
76 <refsect1 id="associatedgets"><title>Associated Gets</title>
77 <para>
78 <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_RENDER_MODE</constant>
79 </para>
80 </refsect1>
81 <refsect1 id="seealso"><title>See Also</title>
82 <para>
83 <citerefentry><refentrytitle>glFeedbackBuffer</refentrytitle></citerefentry>,
84 <citerefentry><refentrytitle>glRenderMode</refentrytitle></citerefentry>
85 </para>
86 </refsect1>
87 <refsect1 id="Copyright"><title>Copyright</title>
88 <para>
89 Copyright <trademark class="copyright"></trademark> 1991-2006
90 Silicon Graphics, Inc. This document is licensed under the SGI
91 Free Software B License. For details, see
92 <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
93 </para>
94 </refsect1>
95 </refentry>