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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="glWindowPos"> | |
5 | <refmeta> | |
6 | <refmetainfo> | |
7 | <copyright> | |
8 | <year>1991-2006</year> | |
9 | <holder>Silicon Graphics, Inc.</holder> | |
10 | </copyright> | |
11 | </refmetainfo> | |
12 | <refentrytitle>glWindowPos</refentrytitle> | |
13 | <manvolnum>3G</manvolnum> | |
14 | </refmeta> | |
15 | <refnamediv> | |
16 | <refname>glWindowPos</refname> | |
17 | <refpurpose>specify the raster position in window coordinates for pixel operations</refpurpose> | |
18 | </refnamediv> | |
19 | <refsynopsisdiv><title>C Specification</title> | |
20 | <funcsynopsis> | |
21 | <funcprototype> | |
22 | <funcdef>void <function>glWindowPos2s</function></funcdef> | |
23 | <paramdef>GLshort <parameter>x</parameter></paramdef> | |
24 | <paramdef>GLshort <parameter>y</parameter></paramdef> | |
25 | </funcprototype> | |
26 | </funcsynopsis> | |
27 | <funcsynopsis> | |
28 | <funcprototype> | |
29 | <funcdef>void <function>glWindowPos2i</function></funcdef> | |
30 | <paramdef>GLint <parameter>x</parameter></paramdef> | |
31 | <paramdef>GLint <parameter>y</parameter></paramdef> | |
32 | </funcprototype> | |
33 | </funcsynopsis> | |
34 | <funcsynopsis> | |
35 | <funcprototype> | |
36 | <funcdef>void <function>glWindowPos2f</function></funcdef> | |
37 | <paramdef>GLfloat <parameter>x</parameter></paramdef> | |
38 | <paramdef>GLfloat <parameter>y</parameter></paramdef> | |
39 | </funcprototype> | |
40 | </funcsynopsis> | |
41 | <funcsynopsis> | |
42 | <funcprototype> | |
43 | <funcdef>void <function>glWindowPos2d</function></funcdef> | |
44 | <paramdef>GLdouble <parameter>x</parameter></paramdef> | |
45 | <paramdef>GLdouble <parameter>y</parameter></paramdef> | |
46 | </funcprototype> | |
47 | </funcsynopsis> | |
48 | <funcsynopsis> | |
49 | <funcprototype> | |
50 | <funcdef>void <function>glWindowPos3s</function></funcdef> | |
51 | <paramdef>GLshort <parameter>x</parameter></paramdef> | |
52 | <paramdef>GLshort <parameter>y</parameter></paramdef> | |
53 | <paramdef>GLshort <parameter>z</parameter></paramdef> | |
54 | </funcprototype> | |
55 | </funcsynopsis> | |
56 | <funcsynopsis> | |
57 | <funcprototype> | |
58 | <funcdef>void <function>glWindowPos3i</function></funcdef> | |
59 | <paramdef>GLint <parameter>x</parameter></paramdef> | |
60 | <paramdef>GLint <parameter>y</parameter></paramdef> | |
61 | <paramdef>GLint <parameter>z</parameter></paramdef> | |
62 | </funcprototype> | |
63 | </funcsynopsis> | |
64 | <funcsynopsis> | |
65 | <funcprototype> | |
66 | <funcdef>void <function>glWindowPos3f</function></funcdef> | |
67 | <paramdef>GLfloat <parameter>x</parameter></paramdef> | |
68 | <paramdef>GLfloat <parameter>y</parameter></paramdef> | |
69 | <paramdef>GLfloat <parameter>z</parameter></paramdef> | |
70 | </funcprototype> | |
71 | </funcsynopsis> | |
72 | <funcsynopsis> | |
73 | <funcprototype> | |
74 | <funcdef>void <function>glWindowPos3d</function></funcdef> | |
75 | <paramdef>GLdouble <parameter>x</parameter></paramdef> | |
76 | <paramdef>GLdouble <parameter>y</parameter></paramdef> | |
77 | <paramdef>GLdouble <parameter>z</parameter></paramdef> | |
78 | </funcprototype> | |
79 | </funcsynopsis> | |
80 | </refsynopsisdiv> | |
81 | <!-- eqn: ignoring delim $$ --> | |
82 | <refsect1 id="parameters"><title>Parameters</title> | |
83 | <variablelist> | |
84 | <varlistentry> | |
85 | <term><parameter>x</parameter></term> | |
86 | <term><parameter>y</parameter></term> | |
87 | <term><parameter>z</parameter></term> | |
88 | <listitem> | |
89 | <para> | |
90 | Specify the | |
91 | <inlineequation><mml:math><mml:mi mathvariant="italic">x</mml:mi></mml:math></inlineequation>, | |
92 | <inlineequation><mml:math><mml:mi mathvariant="italic">y</mml:mi></mml:math></inlineequation>, | |
93 | <inlineequation><mml:math><mml:mi mathvariant="italic">z</mml:mi></mml:math></inlineequation> | |
94 | coordinates for the raster position. | |
95 | </para> | |
96 | </listitem> | |
97 | </varlistentry> | |
98 | </variablelist> | |
99 | </refsect1> | |
100 | <refsynopsisdiv><title>C Specification</title> | |
101 | <funcsynopsis> | |
102 | <funcprototype> | |
103 | <funcdef>void <function>glWindowPos2sv</function></funcdef> | |
104 | <paramdef>const GLshort * <parameter>v</parameter></paramdef> | |
105 | </funcprototype> | |
106 | </funcsynopsis> | |
107 | <funcsynopsis> | |
108 | <funcprototype> | |
109 | <funcdef>void <function>glWindowPos2iv</function></funcdef> | |
110 | <paramdef>const GLint * <parameter>v</parameter></paramdef> | |
111 | </funcprototype> | |
112 | </funcsynopsis> | |
113 | <funcsynopsis> | |
114 | <funcprototype> | |
115 | <funcdef>void <function>glWindowPos2fv</function></funcdef> | |
116 | <paramdef>const GLfloat * <parameter>v</parameter></paramdef> | |
117 | </funcprototype> | |
118 | </funcsynopsis> | |
119 | <funcsynopsis> | |
120 | <funcprototype> | |
121 | <funcdef>void <function>glWindowPos2dv</function></funcdef> | |
122 | <paramdef>const GLdouble * <parameter>v</parameter></paramdef> | |
123 | </funcprototype> | |
124 | </funcsynopsis> | |
125 | <funcsynopsis> | |
126 | <funcprototype> | |
127 | <funcdef>void <function>glWindowPos3sv</function></funcdef> | |
128 | <paramdef>const GLshort * <parameter>v</parameter></paramdef> | |
129 | </funcprototype> | |
130 | </funcsynopsis> | |
131 | <funcsynopsis> | |
132 | <funcprototype> | |
133 | <funcdef>void <function>glWindowPos3iv</function></funcdef> | |
134 | <paramdef>const GLint * <parameter>v</parameter></paramdef> | |
135 | </funcprototype> | |
136 | </funcsynopsis> | |
137 | <funcsynopsis> | |
138 | <funcprototype> | |
139 | <funcdef>void <function>glWindowPos3fv</function></funcdef> | |
140 | <paramdef>const GLfloat * <parameter>v</parameter></paramdef> | |
141 | </funcprototype> | |
142 | </funcsynopsis> | |
143 | <funcsynopsis> | |
144 | <funcprototype> | |
145 | <funcdef>void <function>glWindowPos3dv</function></funcdef> | |
146 | <paramdef>const GLdouble * <parameter>v</parameter></paramdef> | |
147 | </funcprototype> | |
148 | </funcsynopsis> | |
149 | </refsynopsisdiv> | |
150 | <refsect1 id="parameters2"><title>Parameters</title> | |
151 | <variablelist> | |
152 | <varlistentry> | |
153 | <term><parameter>v</parameter></term> | |
154 | <listitem> | |
155 | <para> | |
156 | Specifies a pointer to an array of two or three elements, | |
157 | specifying | |
158 | <inlineequation><mml:math><mml:mi mathvariant="italic">x</mml:mi></mml:math></inlineequation>, | |
159 | <inlineequation><mml:math><mml:mi mathvariant="italic">y</mml:mi></mml:math></inlineequation>, | |
160 | <inlineequation><mml:math><mml:mi mathvariant="italic">z</mml:mi></mml:math></inlineequation> | |
161 | coordinates, respectively. | |
162 | </para> | |
163 | </listitem> | |
164 | </varlistentry> | |
165 | </variablelist> | |
166 | </refsect1> | |
167 | <refsect1 id="description"><title>Description</title> | |
168 | <para> | |
169 | The GL maintains a 3D position in window coordinates. This position, | |
170 | called the raster position, is used to position pixel and bitmap write | |
171 | operations. It is maintained with subpixel accuracy. See <citerefentry><refentrytitle>glBitmap</refentrytitle></citerefentry>, | |
172 | <citerefentry><refentrytitle>glDrawPixels</refentrytitle></citerefentry>, and <citerefentry><refentrytitle>glCopyPixels</refentrytitle></citerefentry>. | |
173 | </para> | |
174 | <para> | |
175 | <function>glWindowPos2</function> specifies the | |
176 | <inlineequation><mml:math><mml:mi mathvariant="italic">x</mml:mi></mml:math></inlineequation> | |
177 | and | |
178 | <inlineequation><mml:math><mml:mi mathvariant="italic">y</mml:mi></mml:math></inlineequation> | |
179 | coordinates, while | |
180 | <inlineequation><mml:math><mml:mi mathvariant="italic">z</mml:mi></mml:math></inlineequation> | |
181 | is | |
182 | implicitly set to 0. <function>glWindowPos3</function> specifies all three coordinates. | |
183 | The | |
184 | <inlineequation><mml:math><mml:mi mathvariant="italic">w</mml:mi></mml:math></inlineequation> | |
185 | coordinate of the current raster position is always set to 1.0. | |
186 | </para> | |
187 | <para> | |
188 | <function>glWindowPos</function> directly updates the | |
189 | <inlineequation><mml:math><mml:mi mathvariant="italic">x</mml:mi></mml:math></inlineequation> | |
190 | and | |
191 | <inlineequation><mml:math><mml:mi mathvariant="italic">y</mml:mi></mml:math></inlineequation> | |
192 | coordinates of the current raster | |
193 | position with the values specified. That is, the values are neither | |
194 | transformed by the current modelview and projection matrices, nor by | |
195 | the viewport-to-window transform. The | |
196 | <inlineequation><mml:math><mml:mi mathvariant="italic">z</mml:mi></mml:math></inlineequation> | |
197 | coordinate of the current raster | |
198 | position is updated in the following manner: | |
199 | </para> | |
200 | <para> | |
201 | <informalequation><mml:math> | |
202 | <!-- eqn: z = left{ lpile { n above f above {n + z * (f - n)} } lpile { if z <= 0 above if z >= 1 above {roman otherwise} }:--> | |
203 | <mml:mrow> | |
204 | <mml:mi mathvariant="italic">z</mml:mi> | |
205 | <mml:mo>=</mml:mo> | |
206 | <mml:mfenced open="{" close=""> | |
207 | <mml:mrow> | |
208 | <mml:mtable> | |
209 | <mml:mtr><mml:mtd> | |
210 | <mml:mi mathvariant="italic">n</mml:mi> | |
211 | </mml:mtd></mml:mtr> | |
212 | <mml:mtr><mml:mtd> | |
213 | <mml:mi mathvariant="italic">f</mml:mi> | |
214 | </mml:mtd></mml:mtr> | |
215 | <mml:mtr><mml:mtd> | |
216 | <mml:mfenced open="" close=""> | |
217 | <mml:mrow> | |
218 | <mml:mi mathvariant="italic">n</mml:mi> | |
219 | <mml:mo>+</mml:mo> | |
220 | <mml:mrow> | |
221 | <mml:mi mathvariant="italic">z</mml:mi> | |
222 | <mml:mo>×</mml:mo> | |
223 | <mml:mfenced open="(" close=")"> | |
224 | <mml:mrow> | |
225 | <mml:mi mathvariant="italic">f</mml:mi> | |
226 | <mml:mo>-</mml:mo> | |
227 | <mml:mi mathvariant="italic">n</mml:mi> | |
228 | </mml:mrow> | |
229 | </mml:mfenced> | |
230 | </mml:mrow> | |
231 | </mml:mrow> | |
232 | </mml:mfenced> | |
233 | </mml:mtd></mml:mtr> | |
234 | </mml:mtable> | |
235 | <mml:mo>⁢</mml:mo> | |
236 | <mml:mtable> | |
237 | <mml:mtr><mml:mtd> | |
238 | <mml:mrow> | |
239 | <mml:mrow> | |
240 | <mml:mi mathvariant="italic">if</mml:mi> | |
241 | <mml:mo>⁢</mml:mo> | |
242 | <mml:mi mathvariant="italic">z</mml:mi> | |
243 | </mml:mrow> | |
244 | <mml:mo><=</mml:mo> | |
245 | <mml:mn>0</mml:mn> | |
246 | </mml:mrow> | |
247 | </mml:mtd></mml:mtr> | |
248 | <mml:mtr><mml:mtd> | |
249 | <mml:mrow> | |
250 | <mml:mrow> | |
251 | <mml:mi mathvariant="italic">if</mml:mi> | |
252 | <mml:mo>⁢</mml:mo> | |
253 | <mml:mi mathvariant="italic">z</mml:mi> | |
254 | </mml:mrow> | |
255 | <mml:mo>>=</mml:mo> | |
256 | <mml:mn>1</mml:mn> | |
257 | </mml:mrow> | |
258 | </mml:mtd></mml:mtr> | |
259 | <mml:mtr><mml:mtd> | |
260 | <mml:mfenced open="" close=""> | |
261 | <mml:mi mathvariant="normal">otherwise</mml:mi> | |
262 | </mml:mfenced> | |
263 | </mml:mtd></mml:mtr> | |
264 | </mml:mtable> | |
265 | </mml:mrow> | |
266 | </mml:mfenced> | |
267 | </mml:mrow> | |
268 | </mml:math></informalequation> | |
269 | </para> | |
270 | <para> | |
271 | </para> | |
272 | <para> | |
273 | where | |
274 | <inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation> | |
275 | is <constant>GL_DEPTH_RANGE</constant>'s near value, and | |
276 | <inlineequation><mml:math><mml:mi mathvariant="italic">f</mml:mi></mml:math></inlineequation> | |
277 | is | |
278 | <constant>GL_DEPTH_RANGE</constant>'s far value. See <citerefentry><refentrytitle>glDepthRange</refentrytitle></citerefentry>. | |
279 | </para> | |
280 | <para> | |
281 | The specified coordinates are not clip-tested, causing the raster position | |
282 | to always be valid. | |
283 | </para> | |
284 | <para> | |
285 | The current raster position also includes some associated color data and | |
286 | texture coordinates. If lighting is enabled, then | |
287 | <constant>GL_CURRENT_RASTER_COLOR</constant> (in RGBA mode) or <constant>GL_CURRENT_RASTER_INDEX</constant> | |
288 | (in color index mode) is set to the color produced by the lighting | |
289 | calculation (see <citerefentry><refentrytitle>glLight</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glLightModel</refentrytitle></citerefentry>, and <citerefentry><refentrytitle>glShadeModel</refentrytitle></citerefentry>). | |
290 | If lighting is disabled, current color (in RGBA mode, state variable | |
291 | <constant>GL_CURRENT_COLOR</constant>) or color index (in color index mode, state variable | |
292 | <constant>GL_CURRENT_INDEX</constant>) is used to update the current raster color. | |
293 | <constant>GL_CURRENT_RASTER_SECONDARY_COLOR</constant> (in RGBA mode) is likewise updated. | |
294 | </para> | |
295 | <para> | |
296 | Likewise, <constant>GL_CURRENT_RASTER_TEXTURE_COORDS</constant> is updated as a function of | |
297 | <constant>GL_CURRENT_TEXTURE_COORDS</constant>, based on the texture matrix and the texture | |
298 | generation functions (see <citerefentry><refentrytitle>glTexGen</refentrytitle></citerefentry>). The | |
299 | <constant>GL_CURRENT_RASTER_DISTANCE</constant> is set to the <constant>GL_CURRENT_FOG_COORD</constant>. | |
300 | </para> | |
301 | <para> | |
302 | </para> | |
303 | </refsect1> | |
304 | <refsect1 id="notes"><title>Notes</title> | |
305 | <para> | |
306 | <function>glWindowPos</function> is available only if the GL version is 1.4 or greater. | |
307 | </para> | |
308 | <para> | |
309 | The raster position is modified by <citerefentry><refentrytitle>glRasterPos</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glBitmap</refentrytitle></citerefentry>, and | |
310 | <function>glWindowPos</function>. | |
311 | </para> | |
312 | <para> | |
313 | Calling <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>, or <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry> may leave the | |
314 | current color or index indeterminate. | |
315 | If <function>glWindowPos</function> is executed while the current color or index is indeterminate, the | |
316 | current raster color or current raster index remains indeterminate. | |
317 | </para> | |
318 | <para> | |
319 | There are distinct raster texture coordinates for each texture unit. Each | |
320 | texture unit's current raster texture coordinates are updated by <function>glWindowPos</function>. | |
321 | </para> | |
322 | </refsect1> | |
323 | <refsect1 id="errors"><title>Errors</title> | |
324 | <para> | |
325 | <constant>GL_INVALID_OPERATION</constant> is generated if <function>glWindowPos</function> | |
326 | is executed between the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> | |
327 | and the corresponding execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>. | |
328 | </para> | |
329 | </refsect1> | |
330 | <refsect1 id="associatedgets"><title>Associated Gets</title> | |
331 | <para> | |
332 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_CURRENT_RASTER_POSITION</constant> | |
333 | </para> | |
334 | <para> | |
335 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_CURRENT_RASTER_POSITION_VALID</constant> | |
336 | </para> | |
337 | <para> | |
338 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_CURRENT_RASTER_DISTANCE</constant> | |
339 | </para> | |
340 | <para> | |
341 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_CURRENT_RASTER_COLOR</constant> | |
342 | </para> | |
343 | <para> | |
344 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_CURRENT_RASTER_SECONDARY_COLOR</constant> | |
345 | </para> | |
346 | <para> | |
347 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_CURRENT_RASTER_INDEX</constant> | |
348 | </para> | |
349 | <para> | |
350 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_CURRENT_RASTER_TEXTURE_COORDS</constant> | |
351 | </para> | |
352 | </refsect1> | |
353 | <refsect1 id="seealso"><title>See Also</title> | |
354 | <para> | |
355 | <citerefentry><refentrytitle>glBitmap</refentrytitle></citerefentry>, | |
356 | <citerefentry><refentrytitle>glCopyPixels</refentrytitle></citerefentry>, | |
357 | <citerefentry><refentrytitle>glDrawArrays</refentrytitle></citerefentry>, | |
358 | <citerefentry><refentrytitle>glDrawElements</refentrytitle></citerefentry>, | |
359 | <citerefentry><refentrytitle>glDrawRangeElements</refentrytitle></citerefentry>, | |
360 | <citerefentry><refentrytitle>glDrawPixels</refentrytitle></citerefentry>, | |
361 | <citerefentry><refentrytitle>glMultiTexCoord</refentrytitle></citerefentry>, | |
362 | <citerefentry><refentrytitle>glRasterPos</refentrytitle></citerefentry>, | |
363 | <citerefentry><refentrytitle>glTexCoord</refentrytitle></citerefentry>, | |
364 | <citerefentry><refentrytitle>glTexGen</refentrytitle></citerefentry>, | |
365 | <citerefentry><refentrytitle>glVertex</refentrytitle></citerefentry> | |
366 | </para> | |
367 | </refsect1> | |
368 | <refsect1 id="Copyright"><title>Copyright</title> | |
369 | <para> | |
370 | Copyright <trademark class="copyright"></trademark> 1991-2006 | |
371 | Silicon Graphics, Inc. This document is licensed under the SGI | |
372 | Free Software B License. For details, see | |
373 | <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>. | |
374 | </para> | |
375 | </refsect1> | |
376 | </refentry> |