rename upstream-man-pages to upstream-doc
[clinton/guile-figl.git] / upstream-doc / man2 / gluUnProject.xml
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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="gluUnProject">
5 <refmeta>
6 <refmetainfo>
7 <copyright>
8 <year>1991-2006</year>
9 <holder>Silicon Graphics, Inc.</holder>
10 </copyright>
11 </refmetainfo>
12 <refentrytitle>gluUnProject</refentrytitle>
13 <manvolnum>3G</manvolnum>
14 </refmeta>
15 <refnamediv>
16 <refname>gluUnProject</refname>
17 <refpurpose>map window coordinates to object coordinates</refpurpose>
18 </refnamediv>
19 <refsynopsisdiv><title>C Specification</title>
20 <funcsynopsis>
21 <funcprototype>
22 <funcdef>GLint <function>gluUnProject</function></funcdef>
23 <paramdef>GLdouble <parameter>winX</parameter></paramdef>
24 <paramdef>GLdouble <parameter>winY</parameter></paramdef>
25 <paramdef>GLdouble <parameter>winZ</parameter></paramdef>
26 <paramdef>const GLdouble * <parameter>model</parameter></paramdef>
27 <paramdef>const GLdouble * <parameter>proj</parameter></paramdef>
28 <paramdef>const GLint * <parameter>view</parameter></paramdef>
29 <paramdef>GLdouble* <parameter>objX</parameter></paramdef>
30 <paramdef>GLdouble* <parameter>objY</parameter></paramdef>
31 <paramdef>GLdouble* <parameter>objZ</parameter></paramdef>
32 </funcprototype>
33 </funcsynopsis>
34 </refsynopsisdiv>
35 <!-- eqn: ignoring delim $$ -->
36 <refsect1 id="parameters"><title>Parameters</title>
37 <variablelist>
38 <varlistentry>
39 <term><parameter>winX</parameter></term>
40 <term><parameter>winY</parameter></term>
41 <term><parameter>winZ</parameter></term>
42 <listitem>
43 <para>
44 Specify the window coordinates to be mapped.
45 </para>
46 </listitem>
47 </varlistentry>
48 <varlistentry>
49 <term><parameter>model</parameter></term>
50 <listitem>
51 <para>
52 Specifies the modelview matrix (as from a <citerefentry><refentrytitle>glGetDoublev</refentrytitle></citerefentry> call).
53 </para>
54 </listitem>
55 </varlistentry>
56 <varlistentry>
57 <term><parameter>proj</parameter></term>
58 <listitem>
59 <para>
60 Specifies the projection matrix (as from a <citerefentry><refentrytitle>glGetDoublev</refentrytitle></citerefentry> call).
61 </para>
62 </listitem>
63 </varlistentry>
64 <varlistentry>
65 <term><parameter>view</parameter></term>
66 <listitem>
67 <para>
68 Specifies the viewport (as from a <citerefentry><refentrytitle>glGetIntegerv</refentrytitle></citerefentry> call).
69 </para>
70 </listitem>
71 </varlistentry>
72 <varlistentry>
73 <term><parameter>objX</parameter></term>
74 <term><parameter>objY</parameter></term>
75 <term><parameter>objZ</parameter></term>
76 <listitem>
77 <para>
78 Returns the computed object coordinates.
79 </para>
80 </listitem>
81 </varlistentry>
82 </variablelist>
83 </refsect1>
84 <refsect1 id="description"><title>Description</title>
85 <para>
86 <function>gluUnProject</function> maps the specified window coordinates into object
87 coordinates using <parameter>model</parameter>, <parameter>proj</parameter>, and <parameter>view</parameter>.
88 The result is stored in <parameter>objX</parameter>, <parameter>objY</parameter>, and <parameter>objZ</parameter>. A return value of
89 <constant>GLU_TRUE</constant> indicates success; a return value of <constant>GLU_FALSE</constant>
90 indicates failure.
91 </para>
92 <para>
93 To compute the coordinates
94 <inlineequation><mml:math>
95 <!-- eqn: (objX, objY, objZ):-->
96 <mml:mfenced open="(" close=")">
97 <mml:mi mathvariant="italic">objX</mml:mi>
98 <mml:mi mathvariant="italic">objY</mml:mi>
99 <mml:mi mathvariant="italic">objZ</mml:mi>
100 </mml:mfenced>
101 </mml:math></inlineequation>,
102 <function>gluUnProject</function> multiplies the normalized device coordinates by the inverse of
103 <parameter>model</parameter> * <parameter>proj</parameter> as follows:
104 </para>
105 <para>
106 <informalequation><mml:math>
107 <!-- eqn: left ( cpile { objX above objY above objZ above W} right ) = INV(P M) left ( cpile { {2(winX - view[0])} over {view [2]} - 1 above {2(winY - view[1])} over {view[3]} - 1 above 2(winZ) - 1 above 1 } right ):-->
108 <mml:mrow>
109 <mml:mfenced open="(" close=")">
110 <mml:mtable>
111 <mml:mtr><mml:mtd>
112 <mml:mi mathvariant="italic">objX</mml:mi>
113 </mml:mtd></mml:mtr>
114 <mml:mtr><mml:mtd>
115 <mml:mi mathvariant="italic">objY</mml:mi>
116 </mml:mtd></mml:mtr>
117 <mml:mtr><mml:mtd>
118 <mml:mi mathvariant="italic">objZ</mml:mi>
119 </mml:mtd></mml:mtr>
120 <mml:mtr><mml:mtd>
121 <mml:mi mathvariant="italic">W</mml:mi>
122 </mml:mtd></mml:mtr>
123 </mml:mtable>
124 </mml:mfenced>
125 <mml:mo>=</mml:mo>
126 <mml:mrow>
127 <mml:mrow>
128 <mml:mi mathvariant="italic">INV</mml:mi>
129 <mml:mo>&af;</mml:mo>
130 <mml:mfenced open="(" close=")">
131 <mml:mrow>
132 <mml:mi mathvariant="italic">P</mml:mi>
133 <mml:mo>&it;</mml:mo>
134 <mml:mi mathvariant="italic">M</mml:mi>
135 </mml:mrow>
136 </mml:mfenced>
137 </mml:mrow>
138 <mml:mo>&it;</mml:mo>
139 <mml:mfenced open="(" close=")">
140 <mml:mtable>
141 <mml:mtr><mml:mtd>
142 <mml:mrow>
143 <mml:mfrac>
144 <mml:mfenced open="" close="">
145 <mml:mrow>
146 <mml:mn>2</mml:mn>
147 <mml:mo>&af;</mml:mo>
148 <mml:mfenced open="(" close=")">
149 <mml:mrow>
150 <mml:mi mathvariant="italic">winX</mml:mi>
151 <mml:mo>-</mml:mo>
152 <mml:mrow>
153 <mml:mi mathvariant="italic">view</mml:mi>
154 <mml:mo>&af;</mml:mo>
155 <mml:mfenced open="[" close="]">
156 <mml:mn>0</mml:mn>
157 </mml:mfenced>
158 </mml:mrow>
159 </mml:mrow>
160 </mml:mfenced>
161 </mml:mrow>
162 </mml:mfenced>
163 <mml:mfenced open="" close="">
164 <mml:mrow>
165 <mml:mi mathvariant="italic">view</mml:mi>
166 <mml:mo>&af;</mml:mo>
167 <mml:mfenced open="[" close="]">
168 <mml:mn>2</mml:mn>
169 </mml:mfenced>
170 </mml:mrow>
171 </mml:mfenced>
172 </mml:mfrac>
173 <mml:mo>-</mml:mo>
174 <mml:mn>1</mml:mn>
175 </mml:mrow>
176 </mml:mtd></mml:mtr>
177 <mml:mtr><mml:mtd>
178 <mml:mrow>
179 <mml:mfrac>
180 <mml:mfenced open="" close="">
181 <mml:mrow>
182 <mml:mn>2</mml:mn>
183 <mml:mo>&af;</mml:mo>
184 <mml:mfenced open="(" close=")">
185 <mml:mrow>
186 <mml:mi mathvariant="italic">winY</mml:mi>
187 <mml:mo>-</mml:mo>
188 <mml:mrow>
189 <mml:mi mathvariant="italic">view</mml:mi>
190 <mml:mo>&af;</mml:mo>
191 <mml:mfenced open="[" close="]">
192 <mml:mn>1</mml:mn>
193 </mml:mfenced>
194 </mml:mrow>
195 </mml:mrow>
196 </mml:mfenced>
197 </mml:mrow>
198 </mml:mfenced>
199 <mml:mfenced open="" close="">
200 <mml:mrow>
201 <mml:mi mathvariant="italic">view</mml:mi>
202 <mml:mo>&af;</mml:mo>
203 <mml:mfenced open="[" close="]">
204 <mml:mn>3</mml:mn>
205 </mml:mfenced>
206 </mml:mrow>
207 </mml:mfenced>
208 </mml:mfrac>
209 <mml:mo>-</mml:mo>
210 <mml:mn>1</mml:mn>
211 </mml:mrow>
212 </mml:mtd></mml:mtr>
213 <mml:mtr><mml:mtd>
214 <mml:mrow>
215 <mml:mrow>
216 <mml:mn>2</mml:mn>
217 <mml:mo>&af;</mml:mo>
218 <mml:mfenced open="(" close=")">
219 <mml:mi mathvariant="italic">winZ</mml:mi>
220 </mml:mfenced>
221 </mml:mrow>
222 <mml:mo>-</mml:mo>
223 <mml:mn>1</mml:mn>
224 </mml:mrow>
225 </mml:mtd></mml:mtr>
226 <mml:mtr><mml:mtd>
227 <mml:mn>1</mml:mn>
228 </mml:mtd></mml:mtr>
229 </mml:mtable>
230 </mml:mfenced>
231 </mml:mrow>
232 </mml:mrow>
233 </mml:math></informalequation>
234 <inlineequation><mml:math><mml:mi mathvariant="italic">INV</mml:mi></mml:math></inlineequation>
235 denotes matrix inversion.
236 W is an unused variable, included for consistent matrix notation.
237 </para>
238 </refsect1>
239 <refsect1 id="seealso"><title>See Also</title>
240 <para>
241 <citerefentry><refentrytitle>gluProject</refentrytitle></citerefentry>,
242 <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry>
243 </para>
244 </refsect1>
245 <refsect1 id="Copyright"><title>Copyright</title>
246 <para>
247 Copyright <trademark class="copyright"></trademark> 1991-2006
248 Silicon Graphics, Inc. This document is licensed under the SGI
249 Free Software B License. For details, see
250 <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
251 </para>
252 </refsect1>
253</refentry>