HCoop / clinton / guile-figl.git / blame
? search:
summary | shortlog | log | commit | commitdiff | tree
blob | blame (incremental) | history | HEAD
update upstream sources
[clinton/guile-figl.git] / upstream-doc / man4 / xhtml / glReadPixels.xml
CommitLineData
7faf1d71
AW		 1<?xml version="1.0" encoding="UTF-8"?>
2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
3<!-- saved from url=(0013)about:internet -->
4<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>glReadPixels - OpenGL 4 Reference Pages</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glReadPixels"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glReadPixels — read a block of pixels from the frame buffer</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glReadPixels</b>(</code></td><td>GLint  </td><td><var class="pdparam">x</var>, </td></tr><tr><td> </td><td>GLint  </td><td><var class="pdparam">y</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">width</var>, </td></tr><tr><td> </td><td>GLsizei  </td><td><var class="pdparam">height</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">format</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">type</var>, </td></tr><tr><td> </td><td>GLvoid *  </td><td><var class="pdparam">data</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>x</code></em>, </span><span class="term"><em class="parameter"><code>y</code></em></span></dt><dd><p>
5 Specify the window coordinates of the first pixel
6 that is read from the frame buffer.
7 This location is the lower left corner of a rectangular block of pixels.
8 </p></dd><dt><span class="term"><em class="parameter"><code>width</code></em>, </span><span class="term"><em class="parameter"><code>height</code></em></span></dt><dd><p>
9 Specify the dimensions of the pixel rectangle.
10 <em class="parameter"><code>width</code></em> and <em class="parameter"><code>height</code></em> of one correspond to a single pixel.
11 </p></dd><dt><span class="term"><em class="parameter"><code>format</code></em></span></dt><dd><p>
12 Specifies the format of the pixel data.
13 The following symbolic values are accepted:
14 <code class="constant">GL_STENCIL_INDEX</code>,
15 <code class="constant">GL_DEPTH_COMPONENT</code>,
16 <code class="constant">GL_DEPTH_STENCIL</code>,
17 <code class="constant">GL_RED</code>,
18 <code class="constant">GL_GREEN</code>,
19 <code class="constant">GL_BLUE</code>,
20 <code class="constant">GL_RGB</code>,
21 <code class="constant">GL_BGR</code>,
22 <code class="constant">GL_RGBA</code>, and
23 <code class="constant">GL_BGRA</code>.
24 </p></dd><dt><span class="term"><em class="parameter"><code>type</code></em></span></dt><dd><p>
25 Specifies the data type of the pixel data.
26 Must be one of
27 <code class="constant">GL_UNSIGNED_BYTE</code>,
28 <code class="constant">GL_BYTE</code>,
29 <code class="constant">GL_UNSIGNED_SHORT</code>,
30 <code class="constant">GL_SHORT</code>,
31 <code class="constant">GL_UNSIGNED_INT</code>,
32 <code class="constant">GL_INT</code>,
33 <code class="constant">GL_HALF_FLOAT</code>,
34 <code class="constant">GL_FLOAT</code>,
35 <code class="constant">GL_UNSIGNED_BYTE_3_3_2</code>,
36 <code class="constant">GL_UNSIGNED_BYTE_2_3_3_REV</code>,
37 <code class="constant">GL_UNSIGNED_SHORT_5_6_5</code>,
38 <code class="constant">GL_UNSIGNED_SHORT_5_6_5_REV</code>,
39 <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4</code>,
40 <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4_REV</code>,
41 <code class="constant">GL_UNSIGNED_SHORT_5_5_5_1</code>,
42 <code class="constant">GL_UNSIGNED_SHORT_1_5_5_5_REV</code>,
43 <code class="constant">GL_UNSIGNED_INT_8_8_8_8</code>,
44 <code class="constant">GL_UNSIGNED_INT_8_8_8_8_REV</code>,
45 <code class="constant">GL_UNSIGNED_INT_10_10_10_2</code>,
46 <code class="constant">GL_UNSIGNED_INT_2_10_10_10_REV</code>,
47 <code class="constant">GL_UNSIGNED_INT_24_8</code>,
48 <code class="constant">GL_UNSIGNED_INT_10F_11F_11F_REV</code>,
49 <code class="constant">GL_UNSIGNED_INT_5_9_9_9_REV</code>, or
50 <code class="constant">GL_FLOAT_32_UNSIGNED_INT_24_8_REV</code>.
51 </p></dd><dt><span class="term"><em class="parameter"><code>data</code></em></span></dt><dd><p>
52 Returns the pixel data.
53 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
54 <code class="function">glReadPixels</code> returns pixel data from the frame buffer,
55 starting with the pixel whose lower left corner
56 is at location (<em class="parameter"><code>x</code></em>, <em class="parameter"><code>y</code></em>),
57 into client memory starting at location <em class="parameter"><code>data</code></em>.
58 Several parameters control the processing of the pixel data before
59 it is placed into client memory.
60 These parameters are set with <a href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>.
61 This reference page describes the effects on <code class="function">glReadPixels</code> of most,
62 but not all of the parameters specified by these three commands.
63 </p><p>
64 If a non-zero named buffer object is bound to the <code class="constant">GL_PIXEL_PACK_BUFFER</code> target
65 (see <a href="glBindBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glBindBuffer</span></span></a>) while a block of pixels is
66 requested, <em class="parameter"><code>data</code></em> is treated as a byte offset into the buffer object's data store
67 rather than a pointer to client memory.
68 </p><p>
69 <code class="function">glReadPixels</code> returns values from each pixel with lower left corner at
70 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
71
72 <mml:mfenced open="(" close=")">
73 <mml:mrow>
74 <mml:mi mathvariant="italic">x</mml:mi>
75 <mml:mo>+</mml:mo>
76 <mml:mi mathvariant="italic">i</mml:mi>
77 </mml:mrow>
78 <mml:mrow>
79 <mml:mi mathvariant="italic">y</mml:mi>
80 <mml:mo>+</mml:mo>
81 <mml:mi mathvariant="italic">j</mml:mi>
82 </mml:mrow>
83 </mml:mfenced>
84 </mml:math>
85 for
86 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
87
88 <mml:mrow>
89 <mml:mn>0</mml:mn>
90 <mml:mo>&lt;=</mml:mo>
91 <mml:mi mathvariant="italic">i</mml:mi>
92 <mml:mo>&lt;</mml:mo>
93 <mml:mi mathvariant="italic">width</mml:mi>
94 </mml:mrow>
95 </mml:math>
96 and
97 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
98
99 <mml:mrow>
100 <mml:mn>0</mml:mn>
101 <mml:mo>&lt;=</mml:mo>
102 <mml:mi mathvariant="italic">j</mml:mi>
103 <mml:mo>&lt;</mml:mo>
104 <mml:mi mathvariant="italic">height</mml:mi>
105 </mml:mrow>
106 </mml:math>.
107 This pixel is said to be the
108 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>th
109 pixel in the
110 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">j</mml:mi></mml:math>th
111 row.
112 Pixels are returned in row order from the lowest to the highest row,
113 left to right in each row.
114 </p><p>
115 <em class="parameter"><code>format</code></em> specifies the format for the returned pixel values;
116 accepted values are:
117 </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_STENCIL_INDEX</code></span></dt><dd><p>
118 Stencil values are read from the stencil buffer.
7faf1d71
AW		 119 </p></dd><dt><span class="term"><code class="constant">GL_DEPTH_COMPONENT</code></span></dt><dd><p>
120 Depth values are read from the depth buffer.
121 Each component is converted to floating point such that the minimum depth
122 value maps to 0 and the maximum value maps to 1.
c7b31271 123 Each component is clamped to the range
7faf1d71
AW		 124 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
125
126 <mml:mfenced open="[" close="]">
127 <mml:mn>0</mml:mn>
128 <mml:mn>1</mml:mn>
129 </mml:mfenced>
130 </mml:math>.
131 </p></dd><dt><span class="term"><code class="constant">GL_DEPTH_STENCIL</code></span></dt><dd><p>
132 Values are taken from both the depth and stencil buffers. The <em class="parameter"><code>type</code></em> parameter
133 must be <code class="constant">GL_UNSIGNED_INT_24_8</code> or <code class="constant">GL_FLOAT_32_UNSIGNED_INT_24_8_REV</code>.
134 </p></dd><dt><span class="term"><code class="constant">GL_RED</code></span></dt><dd></dd><dt><span class="term"><code class="constant">GL_GREEN</code></span></dt><dd></dd><dt><span class="term"><code class="constant">GL_BLUE</code></span></dt><dd></dd><dt><span class="term"><code class="constant">GL_RGB</code></span></dt><dd></dd><dt><span class="term"><code class="constant">GL_BGR</code></span></dt><dd></dd><dt><span class="term"><code class="constant">GL_RGBA</code></span></dt><dd></dd><dt><span class="term"><code class="constant">GL_BGRA</code></span></dt><dd></dd></dl></div><p>
135 Finally, the indices or components
136 are converted to the proper format,
137 as specified by <em class="parameter"><code>type</code></em>.
138 If <em class="parameter"><code>format</code></em> is <code class="constant">GL_STENCIL_INDEX</code>
139 and <em class="parameter"><code>type</code></em> is not <code class="constant">GL_FLOAT</code>,
140 each index is masked with the mask value given in the following table.
141 If <em class="parameter"><code>type</code></em> is <code class="constant">GL_FLOAT</code>, then each integer index is converted to
142 single-precision floating-point format.
143 </p><p>
144 If <em class="parameter"><code>format</code></em> is
145 <code class="constant">GL_RED</code>,
146 <code class="constant">GL_GREEN</code>,
147 <code class="constant">GL_BLUE</code>,
148 <code class="constant">GL_RGB</code>,
149 <code class="constant">GL_BGR</code>,
150 <code class="constant">GL_RGBA</code>, or
151 <code class="constant">GL_BGRA</code> and <em class="parameter"><code>type</code></em> is not <code class="constant">GL_FLOAT</code>,
152 each component is multiplied by the multiplier shown in the following table.
153 If type is <code class="constant">GL_FLOAT</code>, then each component is passed as is
154 (or converted to the client's single-precision floating-point format if
155 it is different from the one used by the GL).
156 </p><p>
157 </p><div class="informaltable"><table border="1"><colgroup><col align="left" /><col align="center" /><col align="center" /></colgroup><thead><tr><th align="left">
158 <em class="parameter"><code>type</code></em>
159 </th><th align="center"><span class="bold"><strong>
160 Index Mask
161 </strong></span></th><th align="center"><span class="bold"><strong>
162 Component Conversion
163 </strong></span></th></tr></thead><tbody><tr><td align="left">
164 <code class="constant">GL_UNSIGNED_BYTE</code>
165 </td><td align="center">
166 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
167
168 <mml:mrow>
169 <mml:msup><mml:mn>2</mml:mn>
170 <mml:mn>8</mml:mn>
171 </mml:msup>
172 <mml:mo>-</mml:mo>
173 <mml:mn>1</mml:mn>
174 </mml:mrow>
175 </mml:math>
176 </td><td align="center">
177 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
178
179 <mml:mrow>
180 <mml:mfenced open="(" close=")">
181 <mml:mrow>
182 <mml:msup><mml:mn>2</mml:mn>
183 <mml:mn>8</mml:mn>
184 </mml:msup>
185 <mml:mo>-</mml:mo>
186 <mml:mn>1</mml:mn>
187 </mml:mrow>
188 </mml:mfenced>
189 <mml:mo>⁢</mml:mo>
190 <mml:mi mathvariant="italic">c</mml:mi>
191 </mml:mrow>
192 </mml:math>
193 </td></tr><tr><td align="left">
194 <code class="constant">GL_BYTE</code>
195 </td><td align="center">
196 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
197
198 <mml:mrow>
199 <mml:msup><mml:mn>2</mml:mn>
200 <mml:mn>7</mml:mn>
201 </mml:msup>
202 <mml:mo>-</mml:mo>
203 <mml:mn>1</mml:mn>
204 </mml:mrow>
205 </mml:math>
206 </td><td align="center">
207 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
208
209 <mml:mfrac>
210 <mml:mfenced open="" close="">
211 <mml:mrow>
212 <mml:mfenced open="(" close=")">
213 <mml:mrow>
214 <mml:msup><mml:mn>2</mml:mn>
215 <mml:mn>8</mml:mn>
216 </mml:msup>
217 <mml:mo>-</mml:mo>
218 <mml:mn>1</mml:mn>
219 </mml:mrow>
220 </mml:mfenced>
221 <mml:mo>⁢</mml:mo>
222 <mml:mi mathvariant="italic">c</mml:mi>
223 <mml:mo>-</mml:mo>
224 <mml:mn>1</mml:mn>
225 </mml:mrow>
226 </mml:mfenced>
227 <mml:mn>2</mml:mn>
228 </mml:mfrac>
229 </mml:math>
230 </td></tr><tr><td align="left">
231 <code class="constant">GL_UNSIGNED_SHORT</code>
232 </td><td align="center">
233 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
234
235 <mml:mrow>
236 <mml:msup><mml:mn>2</mml:mn>
237 <mml:mn>16</mml:mn>
238 </mml:msup>
239 <mml:mo>-</mml:mo>
240 <mml:mn>1</mml:mn>
241 </mml:mrow>
242 </mml:math>
243 </td><td align="center">
244 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
245
246 <mml:mrow>
247 <mml:mfenced open="(" close=")">
248 <mml:mrow>
249 <mml:msup><mml:mn>2</mml:mn>
250 <mml:mn>16</mml:mn>
251 </mml:msup>
252 <mml:mo>-</mml:mo>
253 <mml:mn>1</mml:mn>
254 </mml:mrow>
255 </mml:mfenced>
256 <mml:mo>⁢</mml:mo>
257 <mml:mi mathvariant="italic">c</mml:mi>
258 </mml:mrow>
259 </mml:math>
260 </td></tr><tr><td align="left">
261 <code class="constant">GL_SHORT</code>
262 </td><td align="center">
263 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
264
265 <mml:mrow>
266 <mml:msup><mml:mn>2</mml:mn>
267 <mml:mn>15</mml:mn>
268 </mml:msup>
269 <mml:mo>-</mml:mo>
270 <mml:mn>1</mml:mn>
271 </mml:mrow>
272 </mml:math>
273 </td><td align="center">
274 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
275
276 <mml:mfrac>
277 <mml:mfenced open="" close="">
278 <mml:mrow>
279 <mml:mfenced open="(" close=")">
280 <mml:mrow>
281 <mml:msup><mml:mn>2</mml:mn>
282 <mml:mn>16</mml:mn>
283 </mml:msup>
284 <mml:mo>-</mml:mo>
285 <mml:mn>1</mml:mn>
286 </mml:mrow>
287 </mml:mfenced>
288 <mml:mo>⁢</mml:mo>
289 <mml:mi mathvariant="italic">c</mml:mi>
290 <mml:mo>-</mml:mo>
291 <mml:mn>1</mml:mn>
292 </mml:mrow>
293 </mml:mfenced>
294 <mml:mn>2</mml:mn>
295 </mml:mfrac>
296 </mml:math>
297 </td></tr><tr><td align="left">
298 <code class="constant">GL_UNSIGNED_INT</code>
299 </td><td align="center">
300 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
301
302 <mml:mrow>
303 <mml:msup><mml:mn>2</mml:mn>
304 <mml:mn>32</mml:mn>
305 </mml:msup>
306 <mml:mo>-</mml:mo>
307 <mml:mn>1</mml:mn>
308 </mml:mrow>
309 </mml:math>
310 </td><td align="center">
311 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
312
313 <mml:mrow>
314 <mml:mfenced open="(" close=")">
315 <mml:mrow>
316 <mml:msup><mml:mn>2</mml:mn>
317 <mml:mn>32</mml:mn>
318 </mml:msup>
319 <mml:mo>-</mml:mo>
320 <mml:mn>1</mml:mn>
321 </mml:mrow>
322 </mml:mfenced>
323 <mml:mo>⁢</mml:mo>
324 <mml:mi mathvariant="italic">c</mml:mi>
325 </mml:mrow>
326 </mml:math>
327 </td></tr><tr><td align="left">
328 <code class="constant">GL_INT</code>
329 </td><td align="center">
330 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
331
332 <mml:mrow>
333 <mml:msup><mml:mn>2</mml:mn>
334 <mml:mn>31</mml:mn>
335 </mml:msup>
336 <mml:mo>-</mml:mo>
337 <mml:mn>1</mml:mn>
338 </mml:mrow>
339 </mml:math>
340 </td><td align="center">
341 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
342
343 <mml:mfrac>
344 <mml:mfenced open="" close="">
345 <mml:mrow>
346 <mml:mfenced open="(" close=")">
347 <mml:mrow>
348 <mml:msup><mml:mn>2</mml:mn>
349 <mml:mn>32</mml:mn>
350 </mml:msup>
351 <mml:mo>-</mml:mo>
352 <mml:mn>1</mml:mn>
353 </mml:mrow>
354 </mml:mfenced>
355 <mml:mo>⁢</mml:mo>
356 <mml:mi mathvariant="italic">c</mml:mi>
357 <mml:mo>-</mml:mo>
358 <mml:mn>1</mml:mn>
359 </mml:mrow>
360 </mml:mfenced>
361 <mml:mn>2</mml:mn>
362 </mml:mfrac>
363 </mml:math>
364 </td></tr><tr><td align="left">
365 <code class="constant">GL_HALF_FLOAT</code>
366 </td><td align="center">
367 none
368 </td><td align="center">
369 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">c</mml:mi></mml:math>
370 </td></tr><tr><td align="left">
371 <code class="constant">GL_FLOAT</code>
372 </td><td align="center">
373 none
374 </td><td align="center">
375 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">c</mml:mi></mml:math>
376 </td></tr><tr><td align="left">
377 <code class="constant">GL_UNSIGNED_BYTE_3_3_2</code>
378 </td><td align="center">
379 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
380
381 <mml:mrow>
382 <mml:msup><mml:mn>2</mml:mn>
383 <mml:mn>N</mml:mn>
384 </mml:msup>
385 <mml:mo>-</mml:mo>
386 <mml:mn>1</mml:mn>
387 </mml:mrow>
388 </mml:math>
389 </td><td align="center">
390 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
391
392 <mml:mrow>
393 <mml:mfenced open="(" close=")">
394 <mml:mrow>
395 <mml:msup><mml:mn>2</mml:mn>
396 <mml:mn>N</mml:mn>
397 </mml:msup>
398 <mml:mo>-</mml:mo>
399 <mml:mn>1</mml:mn>
400 </mml:mrow>
401 </mml:mfenced>
402 <mml:mo>⁢</mml:mo>
403 <mml:mi mathvariant="italic">c</mml:mi>
404 </mml:mrow>
405 </mml:math>
406 </td></tr><tr><td align="left">
407 <code class="constant">GL_UNSIGNED_BYTE_2_3_3_REV</code>
408 </td><td align="center">
409 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
410
411 <mml:mrow>
412 <mml:msup><mml:mn>2</mml:mn>
413 <mml:mn>N</mml:mn>
414 </mml:msup>
415 <mml:mo>-</mml:mo>
416 <mml:mn>1</mml:mn>
417 </mml:mrow>
418 </mml:math>
419 </td><td align="center">
420 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
421
422 <mml:mrow>
423 <mml:mfenced open="(" close=")">
424 <mml:mrow>
425 <mml:msup><mml:mn>2</mml:mn>
426 <mml:mn>N</mml:mn>
427 </mml:msup>
428 <mml:mo>-</mml:mo>
429 <mml:mn>1</mml:mn>
430 </mml:mrow>
431 </mml:mfenced>
432 <mml:mo>⁢</mml:mo>
433 <mml:mi mathvariant="italic">c</mml:mi>
434 </mml:mrow>
435 </mml:math>
436 </td></tr><tr><td align="left">
437 <code class="constant">GL_UNSIGNED_SHORT_5_6_5</code>
438 </td><td align="center">
439 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
440
441 <mml:mrow>
442 <mml:msup><mml:mn>2</mml:mn>
443 <mml:mn>N</mml:mn>
444 </mml:msup>
445 <mml:mo>-</mml:mo>
446 <mml:mn>1</mml:mn>
447 </mml:mrow>
448 </mml:math>
449 </td><td align="center">
450 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
451
452 <mml:mrow>
453 <mml:mfenced open="(" close=")">
454 <mml:mrow>
455 <mml:msup><mml:mn>2</mml:mn>
456 <mml:mn>N</mml:mn>
457 </mml:msup>
458 <mml:mo>-</mml:mo>
459 <mml:mn>1</mml:mn>
460 </mml:mrow>
461 </mml:mfenced>
462 <mml:mo>⁢</mml:mo>
463 <mml:mi mathvariant="italic">c</mml:mi>
464 </mml:mrow>
465 </mml:math>
466 </td></tr><tr><td align="left">
467 <code class="constant">GL_UNSIGNED_SHORT_5_6_5_REV</code>
468 </td><td align="center">
469 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
470
471 <mml:mrow>
472 <mml:msup><mml:mn>2</mml:mn>
473 <mml:mn>N</mml:mn>
474 </mml:msup>
475 <mml:mo>-</mml:mo>
476 <mml:mn>1</mml:mn>
477 </mml:mrow>
478 </mml:math>
479 </td><td align="center">
480 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
481
482 <mml:mrow>
483 <mml:mfenced open="(" close=")">
484 <mml:mrow>
485 <mml:msup><mml:mn>2</mml:mn>
486 <mml:mn>N</mml:mn>
487 </mml:msup>
488 <mml:mo>-</mml:mo>
489 <mml:mn>1</mml:mn>
490 </mml:mrow>
491 </mml:mfenced>
492 <mml:mo>⁢</mml:mo>
493 <mml:mi mathvariant="italic">c</mml:mi>
494 </mml:mrow>
495 </mml:math>
496 </td></tr><tr><td align="left">
497 <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4</code>
498 </td><td align="center">
499 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
500
501 <mml:mrow>
502 <mml:msup><mml:mn>2</mml:mn>
503 <mml:mn>N</mml:mn>
504 </mml:msup>
505 <mml:mo>-</mml:mo>
506 <mml:mn>1</mml:mn>
507 </mml:mrow>
508 </mml:math>
509 </td><td align="center">
510 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
511
512 <mml:mrow>
513 <mml:mfenced open="(" close=")">
514 <mml:mrow>
515 <mml:msup><mml:mn>2</mml:mn>
516 <mml:mn>N</mml:mn>
517 </mml:msup>
518 <mml:mo>-</mml:mo>
519 <mml:mn>1</mml:mn>
520 </mml:mrow>
521 </mml:mfenced>
522 <mml:mo>⁢</mml:mo>
523 <mml:mi mathvariant="italic">c</mml:mi>
524 </mml:mrow>
525 </mml:math>
526 </td></tr><tr><td align="left">
527 <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4_REV</code>
528 </td><td align="center">
529 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
530
531 <mml:mrow>
532 <mml:msup><mml:mn>2</mml:mn>
533 <mml:mn>N</mml:mn>
534 </mml:msup>
535 <mml:mo>-</mml:mo>
536 <mml:mn>1</mml:mn>
537 </mml:mrow>
538 </mml:math>
539 </td><td align="center">
540 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
541
542 <mml:mrow>
543 <mml:mfenced open="(" close=")">
544 <mml:mrow>
545 <mml:msup><mml:mn>2</mml:mn>
546 <mml:mn>N</mml:mn>
547 </mml:msup>
548 <mml:mo>-</mml:mo>
549 <mml:mn>1</mml:mn>
550 </mml:mrow>
551 </mml:mfenced>
552 <mml:mo>⁢</mml:mo>
553 <mml:mi mathvariant="italic">c</mml:mi>
554 </mml:mrow>
555 </mml:math>
556 </td></tr><tr><td align="left">
557 <code class="constant">GL_UNSIGNED_SHORT_5_5_5_1</code>
558 </td><td align="center">
559 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
560
561 <mml:mrow>
562 <mml:msup><mml:mn>2</mml:mn>
563 <mml:mn>N</mml:mn>
564 </mml:msup>
565 <mml:mo>-</mml:mo>
566 <mml:mn>1</mml:mn>
567 </mml:mrow>
568 </mml:math>
569 </td><td align="center">
570 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
571
572 <mml:mrow>
573 <mml:mfenced open="(" close=")">
574 <mml:mrow>
575 <mml:msup><mml:mn>2</mml:mn>
576 <mml:mn>N</mml:mn>
577 </mml:msup>
578 <mml:mo>-</mml:mo>
579 <mml:mn>1</mml:mn>
580 </mml:mrow>
581 </mml:mfenced>
582 <mml:mo>⁢</mml:mo>
583 <mml:mi mathvariant="italic">c</mml:mi>
584 </mml:mrow>
585 </mml:math>
586 </td></tr><tr><td align="left">
587 <code class="constant">GL_UNSIGNED_SHORT_1_5_5_5_REV</code>
588 </td><td align="center">
589 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
590
591 <mml:mrow>
592 <mml:msup><mml:mn>2</mml:mn>
593 <mml:mn>N</mml:mn>
594 </mml:msup>
595 <mml:mo>-</mml:mo>
596 <mml:mn>1</mml:mn>
597 </mml:mrow>
598 </mml:math>
599 </td><td align="center">
600 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
601
602 <mml:mrow>
603 <mml:mfenced open="(" close=")">
604 <mml:mrow>
605 <mml:msup><mml:mn>2</mml:mn>
606 <mml:mn>N</mml:mn>
607 </mml:msup>
608 <mml:mo>-</mml:mo>
609 <mml:mn>1</mml:mn>
610 </mml:mrow>
611 </mml:mfenced>
612 <mml:mo>⁢</mml:mo>
613 <mml:mi mathvariant="italic">c</mml:mi>
614 </mml:mrow>
615 </mml:math>
616 </td></tr><tr><td align="left">
617 <code class="constant">GL_UNSIGNED_INT_8_8_8_8</code>
618 </td><td align="center">
619 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
620
621 <mml:mrow>
622 <mml:msup><mml:mn>2</mml:mn>
623 <mml:mn>N</mml:mn>
624 </mml:msup>
625 <mml:mo>-</mml:mo>
626 <mml:mn>1</mml:mn>
627 </mml:mrow>
628 </mml:math>
629 </td><td align="center">
630 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
631
632 <mml:mrow>
633 <mml:mfenced open="(" close=")">
634 <mml:mrow>
635 <mml:msup><mml:mn>2</mml:mn>
636 <mml:mn>N</mml:mn>
637 </mml:msup>
638 <mml:mo>-</mml:mo>
639 <mml:mn>1</mml:mn>
640 </mml:mrow>
641 </mml:mfenced>
642 <mml:mo>⁢</mml:mo>
643 <mml:mi mathvariant="italic">c</mml:mi>
644 </mml:mrow>
645 </mml:math>
646 </td></tr><tr><td align="left">
647 <code class="constant">GL_UNSIGNED_INT_8_8_8_8_REV</code>
648 </td><td align="center">
649 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
650
651 <mml:mrow>
652 <mml:msup><mml:mn>2</mml:mn>
653 <mml:mn>N</mml:mn>
654 </mml:msup>
655 <mml:mo>-</mml:mo>
656 <mml:mn>1</mml:mn>
657 </mml:mrow>
658 </mml:math>
659 </td><td align="center">
660 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
661
662 <mml:mrow>
663 <mml:mfenced open="(" close=")">
664 <mml:mrow>
665 <mml:msup><mml:mn>2</mml:mn>
666 <mml:mn>N</mml:mn>
667 </mml:msup>
668 <mml:mo>-</mml:mo>
669 <mml:mn>1</mml:mn>
670 </mml:mrow>
671 </mml:mfenced>
672 <mml:mo>⁢</mml:mo>
673 <mml:mi mathvariant="italic">c</mml:mi>
674 </mml:mrow>
675 </mml:math>
676 </td></tr><tr><td align="left">
677 <code class="constant">GL_UNSIGNED_INT_10_10_10_2</code>
678 </td><td align="center">
679 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
680
681 <mml:mrow>
682 <mml:msup><mml:mn>2</mml:mn>
683 <mml:mn>N</mml:mn>
684 </mml:msup>
685 <mml:mo>-</mml:mo>
686 <mml:mn>1</mml:mn>
687 </mml:mrow>
688 </mml:math>
689 </td><td align="center">
690 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
691
692 <mml:mrow>
693 <mml:mfenced open="(" close=")">
694 <mml:mrow>
695 <mml:msup><mml:mn>2</mml:mn>
696 <mml:mn>N</mml:mn>
697 </mml:msup>
698 <mml:mo>-</mml:mo>
699 <mml:mn>1</mml:mn>
700 </mml:mrow>
701 </mml:mfenced>
702 <mml:mo>⁢</mml:mo>
703 <mml:mi mathvariant="italic">c</mml:mi>
704 </mml:mrow>
705 </mml:math>
706 </td></tr><tr><td align="left">
707 <code class="constant">GL_UNSIGNED_INT_2_10_10_10_REV</code>
708 </td><td align="center">
709 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
710
711 <mml:mrow>
712 <mml:msup><mml:mn>2</mml:mn>
713 <mml:mn>N</mml:mn>
714 </mml:msup>
715 <mml:mo>-</mml:mo>
716 <mml:mn>1</mml:mn>
717 </mml:mrow>
718 </mml:math>
719 </td><td align="center">
720 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
721
722 <mml:mrow>
723 <mml:mfenced open="(" close=")">
724 <mml:mrow>
725 <mml:msup><mml:mn>2</mml:mn>
726 <mml:mn>N</mml:mn>
727 </mml:msup>
728 <mml:mo>-</mml:mo>
729 <mml:mn>1</mml:mn>
730 </mml:mrow>
731 </mml:mfenced>
732 <mml:mo>⁢</mml:mo>
733 <mml:mi mathvariant="italic">c</mml:mi>
734 </mml:mrow>
735 </mml:math>
736 </td></tr><tr><td align="left">
737 <code class="constant">GL_UNSIGNED_INT_24_8</code>
738 </td><td align="center">
739 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
740
741 <mml:mrow>
742 <mml:msup><mml:mn>2</mml:mn>
743 <mml:mn>N</mml:mn>
744 </mml:msup>
745 <mml:mo>-</mml:mo>
746 <mml:mn>1</mml:mn>
747 </mml:mrow>
748 </mml:math>
749 </td><td align="center">
750 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
751
752 <mml:mrow>
753 <mml:mfenced open="(" close=")">
754 <mml:mrow>
755 <mml:msup><mml:mn>2</mml:mn>
756 <mml:mn>N</mml:mn>
757 </mml:msup>
758 <mml:mo>-</mml:mo>
759 <mml:mn>1</mml:mn>
760 </mml:mrow>
761 </mml:mfenced>
762 <mml:mo>⁢</mml:mo>
763 <mml:mi mathvariant="italic">c</mml:mi>
764 </mml:mrow>
765 </mml:math>
766 </td></tr><tr><td align="left">
767 <code class="constant">GL_UNSIGNED_INT_10F_11F_11F_REV</code>
768 </td><td align="center">
769 --
770 </td><td align="left">
771 Special
772 </td></tr><tr><td align="left">
773 <code class="constant">GL_UNSIGNED_INT_5_9_9_9_REV</code>
774 </td><td align="center">
775 --
776 </td><td align="left">
777 Special
778 </td></tr><tr><td align="left">
779 <code class="constant">GL_FLOAT_32_UNSIGNED_INT_24_8_REV</code>
780 </td><td align="center">
781 none
782 </td><td align="center">
783 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">c</mml:mi></mml:math> (Depth Only)
784 </td></tr></tbody></table></div><p>
785 Return values are placed in memory as follows.
786 If <em class="parameter"><code>format</code></em> is
787 <code class="constant">GL_STENCIL_INDEX</code>,
788 <code class="constant">GL_DEPTH_COMPONENT</code>,
789 <code class="constant">GL_RED</code>,
790 <code class="constant">GL_GREEN</code>, or
791 <code class="constant">GL_BLUE</code>,
792 a single value is returned and the data for the
793 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>th
794 pixel in the
795 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">j</mml:mi></mml:math>th
796 row
797 is placed in location
798 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
799
800 <mml:mrow>
801 <mml:mfenced open="(" close=")">
802 <mml:mi mathvariant="italic">j</mml:mi>
803 </mml:mfenced>
804 <mml:mo>⁢</mml:mo>
805 <mml:mi mathvariant="italic">width</mml:mi>
806 <mml:mo>+</mml:mo>
807 <mml:mi mathvariant="italic">i</mml:mi>
808 </mml:mrow>
809 </mml:math>.
810 <code class="constant">GL_RGB</code> and <code class="constant">GL_BGR</code> return three values,
811 <code class="constant">GL_RGBA</code> and <code class="constant">GL_BGRA</code> return four values for each pixel,
812 with all values corresponding to a single pixel occupying contiguous space
813 in <em class="parameter"><code>data</code></em>.
814 Storage parameters set by <a href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>,
815 such as <code class="constant">GL_PACK_LSB_FIRST</code> and <code class="constant">GL_PACK_SWAP_BYTES</code>,
816 affect the way that data is written into memory.
817 See <a href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a> for a description.
818 </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
819 Values for pixels that lie outside the window
820 connected to the current GL context are undefined.
821 </p><p>
822 If an error is generated,
823 no change is made to the contents of <em class="parameter"><code>data</code></em>.
824 </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
825 <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>format</code></em> or <em class="parameter"><code>type</code></em> is not an
826 accepted value.
827 </p><p>
828 <code class="constant">GL_INVALID_VALUE</code> is generated if either <em class="parameter"><code>width</code></em> or <em class="parameter"><code>height</code></em> is negative.
829 </p><p>
830 <code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>format</code></em> is <code class="constant">GL_STENCIL_INDEX</code>
831 and there is no stencil buffer.
832 </p><p>
833 <code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>format</code></em> is <code class="constant">GL_DEPTH_COMPONENT</code>
834 and there is no depth buffer.
835 </p><p>
836 <code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>format</code></em> is <code class="constant">GL_DEPTH_STENCIL</code>
837 and there is no depth buffer or if there is no stencil buffer.
838 </p><p>
839 <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>format</code></em> is <code class="constant">GL_DEPTH_STENCIL</code>
840 and <em class="parameter"><code>type</code></em> is not <code class="constant">GL_UNSIGNED_INT_24_8</code> or <code class="constant">GL_FLOAT_32_UNSIGNED_INT_24_8_REV</code>.
841 </p><p>
842 <code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>type</code></em> is one of
843 <code class="constant">GL_UNSIGNED_BYTE_3_3_2</code>,
844 <code class="constant">GL_UNSIGNED_BYTE_2_3_3_REV</code>,
845 <code class="constant">GL_UNSIGNED_SHORT_5_6_5</code>, or
846 <code class="constant">GL_UNSIGNED_SHORT_5_6_5_REV</code>
847 and <em class="parameter"><code>format</code></em> is not <code class="constant">GL_RGB</code>.
848 </p><p>
849 <code class="constant">GL_INVALID_OPERATION</code> is generated if <em class="parameter"><code>type</code></em> is one of
850 <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4</code>,
851 <code class="constant">GL_UNSIGNED_SHORT_4_4_4_4_REV</code>,
852 <code class="constant">GL_UNSIGNED_SHORT_5_5_5_1</code>,
853 <code class="constant">GL_UNSIGNED_SHORT_1_5_5_5_REV</code>,
854 <code class="constant">GL_UNSIGNED_INT_8_8_8_8</code>,
855 <code class="constant">GL_UNSIGNED_INT_8_8_8_8_REV</code>,
856 <code class="constant">GL_UNSIGNED_INT_10_10_10_2</code>, or
857 <code class="constant">GL_UNSIGNED_INT_2_10_10_10_REV</code>
858 and <em class="parameter"><code>format</code></em> is neither <code class="constant">GL_RGBA</code> nor <code class="constant">GL_BGRA</code>.
859 </p><p>
860 <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the
861 <code class="constant">GL_PIXEL_PACK_BUFFER</code> target and the buffer object's data store is currently mapped.
862 </p><p>
863 <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the
864 <code class="constant">GL_PIXEL_PACK_BUFFER</code> target and the data would be packed to the buffer
865 object such that the memory writes required would exceed the data store size.
866 </p><p>
867 <code class="constant">GL_INVALID_OPERATION</code> is generated if a non-zero buffer object name is bound to the
868 <code class="constant">GL_PIXEL_PACK_BUFFER</code> target and <em class="parameter"><code>data</code></em> is not evenly divisible
869 into the number of bytes needed to store in memory a datum indicated by <em class="parameter"><code>type</code></em>.
870 </p><p>
871 <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="constant">GL_READ_FRAMEBUFFER_BINDING</code>
872 is non-zero, the read framebuffer is complete, and the value of <code class="constant">GL_SAMPLE_BUFFERS</code>
873 for the read framebuffer is greater than zero.
874 </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
7faf1d71
AW		 875 <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PIXEL_PACK_BUFFER_BINDING</code>
876 </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
877 <a href="glPixelStore.xml"><span class="citerefentry"><span class="refentrytitle">glPixelStore</span></span></a>,
878 <a href="glReadBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glReadBuffer</span></span></a>
879 </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
880 Copyright <span class="trademark"></span>© 1991-2006
881 Silicon Graphics, Inc. This document is licensed under the SGI
882 Free Software B License. For details, see
883 <a href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
884 </p></div></div></body></html>
Unnamed repository; edit this file 'description' to name the repository.