| 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="gluProject"> |
| 5 | <refmeta> |
| 6 | <refmetainfo> |
| 7 | <copyright> |
| 8 | <year>1991-2006</year> |
| 9 | <holder>Silicon Graphics, Inc.</holder> |
| 10 | </copyright> |
| 11 | </refmetainfo> |
| 12 | <refentrytitle>gluProject</refentrytitle> |
| 13 | <manvolnum>3G</manvolnum> |
| 14 | </refmeta> |
| 15 | <refnamediv> |
| 16 | <refname>gluProject</refname> |
| 17 | <refpurpose>map object coordinates to window coordinates</refpurpose> |
| 18 | </refnamediv> |
| 19 | <refsynopsisdiv><title>C Specification</title> |
| 20 | <funcsynopsis> |
| 21 | <funcprototype> |
| 22 | <funcdef>GLint <function>gluProject</function></funcdef> |
| 23 | <paramdef>GLdouble <parameter>objX</parameter></paramdef> |
| 24 | <paramdef>GLdouble <parameter>objY</parameter></paramdef> |
| 25 | <paramdef>GLdouble <parameter>objZ</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>winX</parameter></paramdef> |
| 30 | <paramdef>GLdouble* <parameter>winY</parameter></paramdef> |
| 31 | <paramdef>GLdouble* <parameter>winZ</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>objX</parameter></term> |
| 40 | <term><parameter>objY</parameter></term> |
| 41 | <term><parameter>objZ</parameter></term> |
| 42 | <listitem> |
| 43 | <para> |
| 44 | Specify the object coordinates. |
| 45 | </para> |
| 46 | </listitem> |
| 47 | </varlistentry> |
| 48 | <varlistentry> |
| 49 | <term><parameter>model</parameter></term> |
| 50 | <listitem> |
| 51 | <para> |
| 52 | Specifies the current 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 current 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 current viewport (as from a <citerefentry><refentrytitle>glGetIntegerv</refentrytitle></citerefentry> call). |
| 69 | </para> |
| 70 | </listitem> |
| 71 | </varlistentry> |
| 72 | <varlistentry> |
| 73 | <term><parameter>winX</parameter></term> |
| 74 | <term><parameter>winY</parameter></term> |
| 75 | <term><parameter>winZ</parameter></term> |
| 76 | <listitem> |
| 77 | <para> |
| 78 | Return the computed window coordinates. |
| 79 | </para> |
| 80 | </listitem> |
| 81 | </varlistentry> |
| 82 | </variablelist> |
| 83 | </refsect1> |
| 84 | <refsect1 id="description"><title>Description</title> |
| 85 | <para> |
| 86 | <function>gluProject</function> transforms the specified object coordinates into window coordinates |
| 87 | using <parameter>model</parameter>, <parameter>proj</parameter>, and <parameter>view</parameter>. The result is stored |
| 88 | in <parameter>winX</parameter>, <parameter>winY</parameter>, and <parameter>winZ</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 | let |
| 95 | <inlineequation><mml:math> |
| 96 | <!-- eqn: v = (objX, objY, objZ, 1.0):--> |
| 97 | <mml:mrow> |
| 98 | <mml:mi mathvariant="italic">v</mml:mi> |
| 99 | <mml:mo>=</mml:mo> |
| 100 | <mml:mfenced open="(" close=")"> |
| 101 | <mml:mi mathvariant="italic">objX</mml:mi> |
| 102 | <mml:mi mathvariant="italic">objY</mml:mi> |
| 103 | <mml:mi mathvariant="italic">objZ</mml:mi> |
| 104 | <mml:mn>1.0</mml:mn> |
| 105 | </mml:mfenced> |
| 106 | </mml:mrow> |
| 107 | </mml:math></inlineequation> |
| 108 | represented as a matrix with 4 rows and 1 column. |
| 109 | Then <function>gluProject</function> computes |
| 110 | <inlineequation><mml:math> |
| 111 | <!-- eqn: v sup prime:--> |
| 112 | <mml:msup><mml:mi mathvariant="italic">v</mml:mi> |
| 113 | <mml:mo>″</mml:mo> |
| 114 | </mml:msup> |
| 115 | </mml:math></inlineequation> |
| 116 | as follows: |
| 117 | </para> |
| 118 | <para> |
| 119 | <informalequation><mml:math> |
| 120 | <!-- eqn: v sup prime = P times M times v:--> |
| 121 | <mml:mrow> |
| 122 | <mml:msup><mml:mi mathvariant="italic">v</mml:mi> |
| 123 | <mml:mo>″</mml:mo> |
| 124 | </mml:msup> |
| 125 | <mml:mo>=</mml:mo> |
| 126 | <mml:mrow> |
| 127 | <mml:mi mathvariant="italic">P</mml:mi> |
| 128 | <mml:mo>×</mml:mo> |
| 129 | <mml:mi mathvariant="italic">M</mml:mi> |
| 130 | <mml:mo>×</mml:mo> |
| 131 | <mml:mi mathvariant="italic">v</mml:mi> |
| 132 | </mml:mrow> |
| 133 | </mml:mrow> |
| 134 | </mml:math></informalequation> |
| 135 | </para> |
| 136 | <para> |
| 137 | where |
| 138 | <inlineequation><mml:math><mml:mi mathvariant="italic">P</mml:mi></mml:math></inlineequation> |
| 139 | is the current projection matrix <parameter>proj</parameter> and |
| 140 | <inlineequation><mml:math><mml:mi mathvariant="italic">M</mml:mi></mml:math></inlineequation> |
| 141 | is the current |
| 142 | modelview matrix <parameter>model</parameter> (both represented as |
| 143 | <inlineequation><mml:math> |
| 144 | <!-- eqn: 4 times 4:--> |
| 145 | <mml:mrow> |
| 146 | <mml:mn>4</mml:mn> |
| 147 | <mml:mo>×</mml:mo> |
| 148 | <mml:mn>4</mml:mn> |
| 149 | </mml:mrow> |
| 150 | </mml:math></inlineequation> |
| 151 | matrices in column-major order). |
| 152 | </para> |
| 153 | <para> |
| 154 | The window coordinates are then computed as follows: |
| 155 | </para> |
| 156 | <para> |
| 157 | <informalequation><mml:math> |
| 158 | <!-- eqn: winX = view (0) + view (2) * (v sup prime (0) + 1) / 2:--> |
| 159 | <mml:mrow> |
| 160 | <mml:mi mathvariant="italic">winX</mml:mi> |
| 161 | <mml:mo>=</mml:mo> |
| 162 | <mml:mrow> |
| 163 | <mml:mrow> |
| 164 | <mml:mi mathvariant="italic">view</mml:mi> |
| 165 | <mml:mo>⁡</mml:mo> |
| 166 | <mml:mfenced open="(" close=")"> |
| 167 | <mml:mn>0</mml:mn> |
| 168 | </mml:mfenced> |
| 169 | </mml:mrow> |
| 170 | <mml:mo>+</mml:mo> |
| 171 | <mml:mfrac> |
| 172 | <mml:mrow> |
| 173 | <mml:mrow> |
| 174 | <mml:mi mathvariant="italic">view</mml:mi> |
| 175 | <mml:mo>⁡</mml:mo> |
| 176 | <mml:mfenced open="(" close=")"> |
| 177 | <mml:mn>2</mml:mn> |
| 178 | </mml:mfenced> |
| 179 | </mml:mrow> |
| 180 | <mml:mo>×</mml:mo> |
| 181 | <mml:mfenced open="(" close=")"> |
| 182 | <mml:mrow> |
| 183 | <mml:mrow> |
| 184 | <mml:msup><mml:mi mathvariant="italic">v</mml:mi> |
| 185 | <mml:mo>″</mml:mo> |
| 186 | </mml:msup> |
| 187 | <mml:mo>⁡</mml:mo> |
| 188 | <mml:mfenced open="(" close=")"> |
| 189 | <mml:mn>0</mml:mn> |
| 190 | </mml:mfenced> |
| 191 | </mml:mrow> |
| 192 | <mml:mo>+</mml:mo> |
| 193 | <mml:mn>1</mml:mn> |
| 194 | </mml:mrow> |
| 195 | </mml:mfenced> |
| 196 | </mml:mrow> |
| 197 | <mml:mn>2</mml:mn> |
| 198 | </mml:mfrac> |
| 199 | </mml:mrow> |
| 200 | </mml:mrow> |
| 201 | </mml:math></informalequation> |
| 202 | <para> |
| 203 | <informalequation><mml:math> |
| 204 | <!-- eqn: winY = view (1) + view (3) * (v sup prime (1) + 1) / 2:--> |
| 205 | <mml:mrow> |
| 206 | <mml:mi mathvariant="italic">winY</mml:mi> |
| 207 | <mml:mo>=</mml:mo> |
| 208 | <mml:mrow> |
| 209 | <mml:mrow> |
| 210 | <mml:mi mathvariant="italic">view</mml:mi> |
| 211 | <mml:mo>⁡</mml:mo> |
| 212 | <mml:mfenced open="(" close=")"> |
| 213 | <mml:mn>1</mml:mn> |
| 214 | </mml:mfenced> |
| 215 | </mml:mrow> |
| 216 | <mml:mo>+</mml:mo> |
| 217 | <mml:mfrac> |
| 218 | <mml:mrow> |
| 219 | <mml:mrow> |
| 220 | <mml:mi mathvariant="italic">view</mml:mi> |
| 221 | <mml:mo>⁡</mml:mo> |
| 222 | <mml:mfenced open="(" close=")"> |
| 223 | <mml:mn>3</mml:mn> |
| 224 | </mml:mfenced> |
| 225 | </mml:mrow> |
| 226 | <mml:mo>×</mml:mo> |
| 227 | <mml:mfenced open="(" close=")"> |
| 228 | <mml:mrow> |
| 229 | <mml:mrow> |
| 230 | <mml:msup><mml:mi mathvariant="italic">v</mml:mi> |
| 231 | <mml:mo>″</mml:mo> |
| 232 | </mml:msup> |
| 233 | <mml:mo>⁡</mml:mo> |
| 234 | <mml:mfenced open="(" close=")"> |
| 235 | <mml:mn>1</mml:mn> |
| 236 | </mml:mfenced> |
| 237 | </mml:mrow> |
| 238 | <mml:mo>+</mml:mo> |
| 239 | <mml:mn>1</mml:mn> |
| 240 | </mml:mrow> |
| 241 | </mml:mfenced> |
| 242 | </mml:mrow> |
| 243 | <mml:mn>2</mml:mn> |
| 244 | </mml:mfrac> |
| 245 | </mml:mrow> |
| 246 | </mml:mrow> |
| 247 | </mml:math></informalequation> |
| 248 | </para> |
| 249 | <para> |
| 250 | <informalequation><mml:math> |
| 251 | <!-- eqn: winZ = (v sup prime (2) + 1) / 2:--> |
| 252 | <mml:mrow> |
| 253 | <mml:mi mathvariant="italic">winZ</mml:mi> |
| 254 | <mml:mo>=</mml:mo> |
| 255 | <mml:mfrac> |
| 256 | <mml:mfenced open="(" close=")"> |
| 257 | <mml:mrow> |
| 258 | <mml:mrow> |
| 259 | <mml:msup><mml:mi mathvariant="italic">v</mml:mi> |
| 260 | <mml:mo>″</mml:mo> |
| 261 | </mml:msup> |
| 262 | <mml:mo>⁡</mml:mo> |
| 263 | <mml:mfenced open="(" close=")"> |
| 264 | <mml:mn>2</mml:mn> |
| 265 | </mml:mfenced> |
| 266 | </mml:mrow> |
| 267 | <mml:mo>+</mml:mo> |
| 268 | <mml:mn>1</mml:mn> |
| 269 | </mml:mrow> |
| 270 | </mml:mfenced> |
| 271 | <mml:mn>2</mml:mn> |
| 272 | </mml:mfrac> |
| 273 | </mml:mrow> |
| 274 | </mml:math></informalequation> |
| 275 | </para> |
| 276 | </para> |
| 277 | <para> |
| 278 | </para> |
| 279 | </refsect1> |
| 280 | <refsect1 id="seealso"><title>See Also</title> |
| 281 | <para> |
| 282 | <citerefentry><refentrytitle>gluUnProject</refentrytitle></citerefentry>, |
| 283 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> |
| 284 | </para> |
| 285 | </refsect1> |
| 286 | <refsect1 id="Copyright"><title>Copyright</title> |
| 287 | <para> |
| 288 | Copyright <trademark class="copyright"></trademark> 1991-2006 |
| 289 | Silicon Graphics, Inc. This document is licensed under the SGI |
| 290 | Free Software B License. For details, see |
| 291 | <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>. |
| 292 | </para> |
| 293 | </refsect1> |
| 294 | </refentry> |