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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="gluUnProject4"> | |
5 | <refmeta> | |
6 | <refmetainfo> | |
7 | <copyright> | |
8 | <year>1991-2006</year> | |
9 | <holder>Silicon Graphics, Inc.</holder> | |
10 | </copyright> | |
11 | </refmetainfo> | |
12 | <refentrytitle>gluUnProject4</refentrytitle> | |
13 | <manvolnum>3G</manvolnum> | |
14 | </refmeta> | |
15 | <refnamediv> | |
16 | <refname>gluUnProject4</refname> | |
17 | <refpurpose>map window and clip coordinates to object coordinates</refpurpose> | |
18 | </refnamediv> | |
19 | <refsynopsisdiv><title>C Specification</title> | |
20 | <funcsynopsis> | |
21 | <funcprototype> | |
22 | <funcdef>GLint <function>gluUnProject4</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>GLdouble <parameter>clipW</parameter></paramdef> | |
27 | <paramdef>const GLdouble * <parameter>model</parameter></paramdef> | |
28 | <paramdef>const GLdouble * <parameter>proj</parameter></paramdef> | |
29 | <paramdef>const GLint * <parameter>view</parameter></paramdef> | |
30 | <paramdef>GLdouble <parameter>nearVal</parameter></paramdef> | |
31 | <paramdef>GLdouble <parameter>farVal</parameter></paramdef> | |
32 | <paramdef>GLdouble* <parameter>objX</parameter></paramdef> | |
33 | <paramdef>GLdouble* <parameter>objY</parameter></paramdef> | |
34 | <paramdef>GLdouble* <parameter>objZ</parameter></paramdef> | |
35 | <paramdef>GLdouble* <parameter>objW</parameter></paramdef> | |
36 | </funcprototype> | |
37 | </funcsynopsis> | |
38 | </refsynopsisdiv> | |
39 | <!-- eqn: ignoring delim $$ --> | |
40 | <refsect1 id="parameters"><title>Parameters</title> | |
41 | <variablelist> | |
42 | <varlistentry> | |
43 | <term><parameter>winX</parameter></term> | |
44 | <term><parameter>winY</parameter></term> | |
45 | <term><parameter>winZ</parameter></term> | |
46 | <listitem> | |
47 | <para> | |
48 | Specify the window coordinates to be mapped. | |
49 | </para> | |
50 | </listitem> | |
51 | </varlistentry> | |
52 | <varlistentry> | |
53 | <term><parameter>clipW</parameter></term> | |
54 | <listitem> | |
55 | <para> | |
56 | Specify the clip w coordinate to be mapped. | |
57 | </para> | |
58 | </listitem> | |
59 | </varlistentry> | |
60 | <varlistentry> | |
61 | <term><parameter>model</parameter></term> | |
62 | <listitem> | |
63 | <para> | |
64 | Specifies the modelview matrix (as from a <citerefentry><refentrytitle>glGetDoublev</refentrytitle></citerefentry> call). | |
65 | </para> | |
66 | </listitem> | |
67 | </varlistentry> | |
68 | <varlistentry> | |
69 | <term><parameter>proj</parameter></term> | |
70 | <listitem> | |
71 | <para> | |
72 | Specifies the projection matrix (as from a <citerefentry><refentrytitle>glGetDoublev</refentrytitle></citerefentry> call). | |
73 | </para> | |
74 | </listitem> | |
75 | </varlistentry> | |
76 | <varlistentry> | |
77 | <term><parameter>view</parameter></term> | |
78 | <listitem> | |
79 | <para> | |
80 | Specifies the viewport (as from a <citerefentry><refentrytitle>glGetIntegerv</refentrytitle></citerefentry> call). | |
81 | </para> | |
82 | </listitem> | |
83 | </varlistentry> | |
84 | <varlistentry> | |
85 | <term><parameter>nearVal</parameter></term> | |
86 | <term><parameter>farVal</parameter></term> | |
87 | <listitem> | |
88 | <para> | |
89 | Specifies the near and far planes (as from a <citerefentry><refentrytitle>glGetDoublev</refentrytitle></citerefentry> call). | |
90 | </para> | |
91 | </listitem> | |
92 | </varlistentry> | |
93 | <varlistentry> | |
94 | <term><parameter>objX</parameter></term> | |
95 | <term><parameter>objY</parameter></term> | |
96 | <term><parameter>objZ</parameter></term> | |
97 | <term><parameter>objW</parameter></term> | |
98 | <listitem> | |
99 | <para> | |
100 | Returns the computed object coordinates. | |
101 | </para> | |
102 | </listitem> | |
103 | </varlistentry> | |
104 | </variablelist> | |
105 | </refsect1> | |
106 | <refsect1 id="description"><title>Description</title> | |
107 | <para> | |
108 | <function>gluUnProject4</function> maps the specified window coordinatesi: <parameter>winX</parameter>, <parameter>winY</parameter>, and <parameter>winZ</parameter> | |
109 | and its clip w coordinate <parameter>clipW</parameter> | |
110 | into object | |
111 | coordinates | |
112 | <inlineequation><mml:math> | |
113 | <!-- eqn: (objX, objY, objZ, objW):--> | |
114 | <mml:mfenced open="(" close=")"> | |
115 | <mml:mi mathvariant="italic">objX</mml:mi> | |
116 | <mml:mi mathvariant="italic">objY</mml:mi> | |
117 | <mml:mi mathvariant="italic">objZ</mml:mi> | |
118 | <mml:mi mathvariant="italic">objW</mml:mi> | |
119 | </mml:mfenced> | |
120 | </mml:math></inlineequation> | |
121 | using <parameter>model</parameter>, <parameter>proj</parameter>, and <parameter>view</parameter>. <parameter>clipW</parameter> can be other than | |
122 | 1 as for vertices in <citerefentry><refentrytitle>glFeedbackBuffer</refentrytitle></citerefentry> when data type | |
123 | <constant>GLU_4D_COLOR_TEXTURE</constant> is returned. | |
124 | This also handles the case | |
125 | where the <parameter>nearVal</parameter> and <parameter>farVal</parameter> planes are different from the default, | |
126 | 0 and 1, respectively. | |
127 | A return | |
128 | value of <constant>GLU_TRUE</constant> indicates success; a return value of <constant>GLU_FALSE</constant> | |
129 | indicates failure. | |
130 | </para> | |
131 | <para> | |
132 | To compute the coordinates | |
133 | <inlineequation><mml:math> | |
134 | <!-- eqn: (objX, objY, objZ, objW):--> | |
135 | <mml:mfenced open="(" close=")"> | |
136 | <mml:mi mathvariant="italic">objX</mml:mi> | |
137 | <mml:mi mathvariant="italic">objY</mml:mi> | |
138 | <mml:mi mathvariant="italic">objZ</mml:mi> | |
139 | <mml:mi mathvariant="italic">objW</mml:mi> | |
140 | </mml:mfenced> | |
141 | </mml:math></inlineequation>, | |
142 | <function>gluUnProject4</function> multiplies the normalized device coordinates by the inverse of | |
143 | <parameter>model</parameter> * <parameter>proj</parameter> as follows: | |
144 | </para> | |
145 | <para> | |
146 | <informalequation><mml:math> | |
147 | <!-- eqn: left ( cpile { objX above objY above objZ above objW} 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 - nearVal)} over {(farVal - nearVal)} - 1 above clipW} right ):--> | |
148 | <mml:mrow> | |
149 | <mml:mfenced open="(" close=")"> | |
150 | <mml:mtable> | |
151 | <mml:mtr><mml:mtd> | |
152 | <mml:mi mathvariant="italic">objX</mml:mi> | |
153 | </mml:mtd></mml:mtr> | |
154 | <mml:mtr><mml:mtd> | |
155 | <mml:mi mathvariant="italic">objY</mml:mi> | |
156 | </mml:mtd></mml:mtr> | |
157 | <mml:mtr><mml:mtd> | |
158 | <mml:mi mathvariant="italic">objZ</mml:mi> | |
159 | </mml:mtd></mml:mtr> | |
160 | <mml:mtr><mml:mtd> | |
161 | <mml:mi mathvariant="italic">objW</mml:mi> | |
162 | </mml:mtd></mml:mtr> | |
163 | </mml:mtable> | |
164 | </mml:mfenced> | |
165 | <mml:mo>=</mml:mo> | |
166 | <mml:mrow> | |
167 | <mml:mrow> | |
168 | <mml:mi mathvariant="italic">INV</mml:mi> | |
169 | <mml:mo>⁡</mml:mo> | |
170 | <mml:mfenced open="(" close=")"> | |
171 | <mml:mrow> | |
172 | <mml:mi mathvariant="italic">P</mml:mi> | |
173 | <mml:mo>⁢</mml:mo> | |
174 | <mml:mi mathvariant="italic">M</mml:mi> | |
175 | </mml:mrow> | |
176 | </mml:mfenced> | |
177 | </mml:mrow> | |
178 | <mml:mo>⁢</mml:mo> | |
179 | <mml:mfenced open="(" close=")"> | |
180 | <mml:mtable> | |
181 | <mml:mtr><mml:mtd> | |
182 | <mml:mrow> | |
183 | <mml:mfrac> | |
184 | <mml:mfenced open="" close=""> | |
185 | <mml:mrow> | |
186 | <mml:mn>2</mml:mn> | |
187 | <mml:mo>⁡</mml:mo> | |
188 | <mml:mfenced open="(" close=")"> | |
189 | <mml:mrow> | |
190 | <mml:mi mathvariant="italic">winX</mml:mi> | |
191 | <mml:mo>-</mml:mo> | |
192 | <mml:mrow> | |
193 | <mml:mi mathvariant="italic">view</mml:mi> | |
194 | <mml:mo>⁡</mml:mo> | |
195 | <mml:mfenced open="[" close="]"> | |
196 | <mml:mn>0</mml:mn> | |
197 | </mml:mfenced> | |
198 | </mml:mrow> | |
199 | </mml:mrow> | |
200 | </mml:mfenced> | |
201 | </mml:mrow> | |
202 | </mml:mfenced> | |
203 | <mml:mfenced open="" close=""> | |
204 | <mml:mrow> | |
205 | <mml:mi mathvariant="italic">view</mml:mi> | |
206 | <mml:mo>⁡</mml:mo> | |
207 | <mml:mfenced open="[" close="]"> | |
208 | <mml:mn>2</mml:mn> | |
209 | </mml:mfenced> | |
210 | </mml:mrow> | |
211 | </mml:mfenced> | |
212 | </mml:mfrac> | |
213 | <mml:mo>-</mml:mo> | |
214 | <mml:mn>1</mml:mn> | |
215 | </mml:mrow> | |
216 | </mml:mtd></mml:mtr> | |
217 | <mml:mtr><mml:mtd> | |
218 | <mml:mrow> | |
219 | <mml:mfrac> | |
220 | <mml:mfenced open="" close=""> | |
221 | <mml:mrow> | |
222 | <mml:mn>2</mml:mn> | |
223 | <mml:mo>⁡</mml:mo> | |
224 | <mml:mfenced open="(" close=")"> | |
225 | <mml:mrow> | |
226 | <mml:mi mathvariant="italic">winY</mml:mi> | |
227 | <mml:mo>-</mml:mo> | |
228 | <mml:mrow> | |
229 | <mml:mi mathvariant="italic">view</mml:mi> | |
230 | <mml:mo>⁡</mml:mo> | |
231 | <mml:mfenced open="[" close="]"> | |
232 | <mml:mn>1</mml:mn> | |
233 | </mml:mfenced> | |
234 | </mml:mrow> | |
235 | </mml:mrow> | |
236 | </mml:mfenced> | |
237 | </mml:mrow> | |
238 | </mml:mfenced> | |
239 | <mml:mfenced open="" close=""> | |
240 | <mml:mrow> | |
241 | <mml:mi mathvariant="italic">view</mml:mi> | |
242 | <mml:mo>⁡</mml:mo> | |
243 | <mml:mfenced open="[" close="]"> | |
244 | <mml:mn>3</mml:mn> | |
245 | </mml:mfenced> | |
246 | </mml:mrow> | |
247 | </mml:mfenced> | |
248 | </mml:mfrac> | |
249 | <mml:mo>-</mml:mo> | |
250 | <mml:mn>1</mml:mn> | |
251 | </mml:mrow> | |
252 | </mml:mtd></mml:mtr> | |
253 | <mml:mtr><mml:mtd> | |
254 | <mml:mrow> | |
255 | <mml:mfrac> | |
256 | <mml:mfenced open="" close=""> | |
257 | <mml:mrow> | |
258 | <mml:mn>2</mml:mn> | |
259 | <mml:mo>⁡</mml:mo> | |
260 | <mml:mfenced open="(" close=")"> | |
261 | <mml:mrow> | |
262 | <mml:mi mathvariant="italic">winZ</mml:mi> | |
263 | <mml:mo>-</mml:mo> | |
264 | <mml:mi mathvariant="italic">nearVal</mml:mi> | |
265 | </mml:mrow> | |
266 | </mml:mfenced> | |
267 | </mml:mrow> | |
268 | </mml:mfenced> | |
269 | <mml:mfenced open="" close=""> | |
270 | <mml:mfenced open="(" close=")"> | |
271 | <mml:mrow> | |
272 | <mml:mi mathvariant="italic">farVal</mml:mi> | |
273 | <mml:mo>-</mml:mo> | |
274 | <mml:mi mathvariant="italic">nearVal</mml:mi> | |
275 | </mml:mrow> | |
276 | </mml:mfenced> | |
277 | </mml:mfenced> | |
278 | </mml:mfrac> | |
279 | <mml:mo>-</mml:mo> | |
280 | <mml:mn>1</mml:mn> | |
281 | </mml:mrow> | |
282 | </mml:mtd></mml:mtr> | |
283 | <mml:mtr><mml:mtd> | |
284 | <mml:mi mathvariant="italic">clipW</mml:mi> | |
285 | </mml:mtd></mml:mtr> | |
286 | </mml:mtable> | |
287 | </mml:mfenced> | |
288 | </mml:mrow> | |
289 | </mml:mrow> | |
290 | </mml:math></informalequation> | |
291 | </para> | |
292 | <para> | |
293 | <inlineequation><mml:math><mml:mi mathvariant="italic">INV</mml:mi></mml:math></inlineequation> | |
294 | denotes matrix inversion. | |
295 | </para> | |
296 | <para> | |
297 | <function>gluUnProject4</function> is equivalent to <citerefentry><refentrytitle>gluUnProject</refentrytitle></citerefentry> when <parameter>clipW</parameter> is 1, <parameter>nearVal</parameter> is 0, and | |
298 | <parameter>farVal</parameter> is 1. | |
299 | </para> | |
300 | </refsect1> | |
301 | <refsect1 id="notes"><title>Notes</title> | |
302 | <para> | |
303 | <function>gluUnProject4</function> is available only if the GLU version is 1.3 or greater. | |
304 | </para> | |
305 | </refsect1> | |
306 | <refsect1 id="seealso"><title>See Also</title> | |
307 | <para> | |
308 | <citerefentry><refentrytitle>gluProject</refentrytitle></citerefentry>, | |
309 | <citerefentry><refentrytitle>gluUnProject</refentrytitle></citerefentry>, | |
310 | <citerefentry><refentrytitle>glFeedbackBuffer</refentrytitle></citerefentry>, | |
311 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> | |
312 | </para> | |
313 | </refsect1> | |
314 | <refsect1 id="Copyright"><title>Copyright</title> | |
315 | <para> | |
316 | Copyright <trademark class="copyright"></trademark> 1991-2006 | |
317 | Silicon Graphics, Inc. This document is licensed under the SGI | |
318 | Free Software B License. For details, see | |
319 | <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>. | |
320 | </para> | |
321 | </refsect1> | |
322 | </refentry> |