1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
|
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title xmlns:xlink="http://www.w3.org/1999/xlink">eglCreatePbufferFromClientBuffer - EGL Reference Pages</title>
<link rel="stylesheet" type="text/css" href="khronos-man.css"/>
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"/>
</head>
<body>
<header/>
<div class="refentry" id="eglCreatePbufferFromClientBuffer">
<div class="titlepage"/>
<div class="refnamediv">
<h2>Name</h2>
<p>eglCreatePbufferFromClientBuffer —
create a new <abbr class="acronym">EGL</abbr> pixel buffer surface
bound to an OpenVG image
</p>
</div>
<div class="refsynopsisdiv">
<h2>C Specification</h2>
<div class="funcsynopsis">
<table style="border: 0; cellspacing: 0; cellpadding: 0;" class="funcprototype-table">
<tr>
<td>
<code class="funcdef">EGLSurface <strong class="fsfunc">eglCreatePbufferFromClientBuffer</strong>(</code>
</td>
<td>EGLDisplay <var class="pdparam">display</var>, </td>
</tr>
<tr>
<td> </td>
<td>EGLenum <var class="pdparam">buftype</var>, </td>
</tr>
<tr>
<td> </td>
<td>EGLClientBuffer <var class="pdparam">buffer</var>, </td>
</tr>
<tr>
<td> </td>
<td>EGLConfig <var class="pdparam">config</var>, </td>
</tr>
<tr>
<td> </td>
<td>EGLint const * <var class="pdparam">attrib_list</var><code>)</code>;</td>
</tr>
</table>
<div class="funcprototype-spacer"> </div>
</div>
</div>
<div class="refsect1" id="parameters">
<h2>Parameters</h2>
<div class="variablelist">
<dl class="variablelist">
<dt>
<span class="term">
<em class="parameter">
<code>display</code>
</em>
</span>
</dt>
<dd>
<p>Specifies the EGL display connection.</p>
</dd>
<dt>
<span class="term">
<em class="parameter">
<code>buftype</code>
</em>
</span>
</dt>
<dd>
<p>
Specifies the type of client API buffer to be bound.
Must be <code class="constant">EGL_OPENVG_IMAGE</code>,
corresponding to an OpenVG <span class="type">VGImage</span>
buffer.
</p>
</dd>
<dt>
<span class="term">
<em class="parameter">
<code>buffer</code>
</em>
</span>
</dt>
<dd>
<p>
Specifies the OpenVG <span class="type">VGImage</span> handle of
the buffer to be bound.
</p>
</dd>
<dt>
<span class="term">
<em class="parameter">
<code>config</code>
</em>
</span>
</dt>
<dd>
<p>
Specifies the EGL frame buffer configuration that defines the
frame buffer resource available to the surface.
</p>
</dd>
<dt>
<span class="term">
<em class="parameter">
<code>attrib_list</code>
</em>
</span>
</dt>
<dd>
<p>
Specifies pixel buffer surface attributes.
May be <code class="constant">NULL</code> or empty
(first attribute is <code class="constant">EGL_NONE</code>).
</p>
</dd>
</dl>
</div>
</div>
<div class="refsect1" id="description">
<h2>Description</h2>
<p>
<code class="function">eglCreatePbufferFromClientBuffer</code> creates an
off-screen pixel buffer surface and returns its handle. If
<code class="function">eglCreatePbufferFromClientBuffer</code> fails to create
a pixel buffer surface, <code class="constant">EGL_NO_SURFACE</code>
is returned.
</p>
<p>
The new pixel buffer surface is similar to a pixel buffer
created with
<a class="citerefentry" href="eglCreatePbufferSurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglCreatePbufferSurface</span></span></a>,
but storage for the color buffer is provided by a client API
buffer. Other buffer required by
<em class="parameter"><code>config</code></em>, such as depth, stencil, and
alpha mask, are allocated by EGL.
</p>
<p>
<em class="parameter"><code>buftype</code></em> must be
<code class="constant">EGL_OPENVG_IMAGE</code>, corresponding to an
OpenVG <span class="type">VGImage</span> buffer.
<em class="parameter"><code>buffer</code></em> must be a valid
<span class="type">VGImage</span> handle in the current OpenVG context,
cast into the type <span class="type">EGLClientBuffer</span>.
</p>
<p>
The height, width,, OpenVG alpha format, and OpenVG
colorspace (surface attributes
<code class="constant">EGL_HEIGHT</code>,
<code class="constant">EGL_WIDTH</code>,
<code class="constant">EGL_VG_ALPHA_FORMAT</code>, and
<code class="constant">EGL_VG_COLORSPACE</code>, respectively) of the
resulting surface are determined by the size and format of
<em class="parameter"><code>buffer</code></em>.
</p>
<p>
Surface attributes are specified as a list of
attribute-value pairs, terminated with
<code class="constant">EGL_NONE</code>. Accepted attributes are:
</p>
<div class="variablelist">
<dl class="variablelist">
<dt>
<span class="term">
<code class="constant">EGL_MIPMAP_TEXTURE</code>
</span>
</dt>
<dd>
<p>
Specifies whether storage for mipmaps should be
allocated. Space for mipmaps will be set aside if
the attribute value is <code class="constant">EGL_TRUE</code>
and <code class="constant">EGL_TEXTURE_FORMAT</code> is not
<code class="constant">EGL_NO_TEXTURE</code>. The default
value is <code class="constant">EGL_FALSE</code>.
</p>
</dd>
<dt>
<span class="term">
<code class="constant">EGL_TEXTURE_FORMAT</code>
</span>
</dt>
<dd>
<p>
Specifies the format of the texture that will be
created when a pbuffer is bound to a texture map.
Possible values are
<code class="constant">EGL_NO_TEXTURE</code>,
<code class="constant">EGL_TEXTURE_RGB</code>, and
<code class="constant">EGL_TEXTURE_RGBA</code>. The default
value is <code class="constant">EGL_NO_TEXTURE</code>.
</p>
</dd>
<dt>
<span class="term">
<code class="constant">EGL_TEXTURE_TARGET</code>
</span>
</dt>
<dd>
<p>
Specifies the target for the texture that will be
created when the pbuffer is created with a texture
format of <code class="constant">EGL_TEXTURE_RGB</code> or
<code class="constant">EGL_TEXTURE_RGBA</code>. Possible
values are <code class="constant">EGL_NO_TEXTURE</code>, or
<code class="constant">EGL_TEXTURE_2D</code>. The default
value is <code class="constant">EGL_NO_TEXTURE</code>.
</p>
</dd>
</dl>
</div>
<p>
Any EGL rendering context that was created with respect to
<em class="parameter"><code>config</code></em> can be used to render into the
surface. Use
<a class="citerefentry" href="eglMakeCurrent.xhtml"><span class="citerefentry"><span class="refentrytitle">eglMakeCurrent</span></span></a>
to attach an EGL rendering context to the surface.
</p>
<p>
Use
<a class="citerefentry" href="eglQuerySurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglQuerySurface</span></span></a>
to retrieve the dimensions of the allocated pixel buffer
surface or the ID of <em class="parameter"><code>config</code></em>.
</p>
<p>
Use <a class="citerefentry" href="eglDestroySurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglDestroySurface</span></span></a>
to destroy the surface.
</p>
</div>
<div class="refsect1" id="notes">
<h2>Notes</h2>
<p>
<code class="function">eglCreatePbufferFromClientBuffer</code> is
supported only if the EGL version is 1.2 or greater, and if
the EGL implementation supports the OpenVG client API.
</p>
<p>
Currently
<code class="function">eglCreatePbufferFromClientBuffer</code> only
supports binding OpenVG <span class="type">VGImage</span> buffers to
pixel buffers. While other client API resources could be
supported in the future, mechanisms such as OpenGL ES
framebuffer objects, and the family of EGL and client API
extensions for defining and using <span class="type">EGLImageKHR</span>
images, are a more flexible and general framework to satisfy
most of the same needs.
</p>
<p>
If the value of <em class="parameter"><code>config</code></em> attribute
<code class="constant">EGL_TEXTURE_FORMAT</code> is not
<code class="constant">EGL_NO_TEXTURE</code>, then the pbuffer width
and height specify the size of the level zero texture image
</p>
<p>
If <code class="constant">EGL_LARGEST_PBUFFER</code> is specified and
if the pbuffer will be used as a texture (i.e. the value of
<code class="constant">EGL_TEXTURE_TARGET</code> is
<code class="constant">EGL_TEXTURE_2D</code>, and the value of
<code class="constant">EGL_TEXTURE FORMAT</code> is
<code class="constant">EGL_TEXTURE_RGB</code> or
<code class="constant">EGL_TEXTURE_RGBA</code>), then the aspect
ratio will be preserved and the new width and height will be
valid sizes for the texture target (e.g. if the underlying
OpenGL ES implementation does not support non-power-of-two
textures, both the width and height will be a power of 2).
</p>
<p>
The contents of the depth and stencil buffers may not be
preserved when rendering a texture to the pbuffer and
switching which image of the texture is rendered to (e.g.,
switching from rendering one mipmap level to rendering
another).
</p>
<p>
Binding client API buffers to EGL pbuffers create the
possibility of race conditions, and of buffers being deleted
through one API while still in use in another API. To avoid
these problems, a number of constraints apply to bound
client API buffers:
</p>
<div class="orderedlist">
<ol class="orderedlist" type="1">
<li class="listitem">
<p>
Bound buffers may be used exclusively by either EGL,
or the client API that originally created them. For
example, if a <span class="type">VGImage</span> is bound to a
pbuffer, and that pbuffer is bound to any client API
rendering context, then the <span class="type">VGImage</span> may
not be used as the explicit source or destination of
any OpenVG operation. Errors resulting from such use
are described in client API specifications.
Similarly, while a <span class="type">VGImage</span> is in use by
OpenVG, the pbuffer it is bound to may not be made
current to any client API context using
<a class="citerefentry" href="eglMakeCurrent.xhtml"><span class="citerefentry"><span class="refentrytitle">eglMakeCurrent</span></span></a>.
</p>
</li>
<li class="listitem">
<p>
Binding a buffer creates an additional reference to
it, and implementations must respect outstanding
references when destroying objects. For example, if
a <span class="type">VGImage</span> is bound to a pbuffer,
destroying the image with
<code class="function">vgDestroyImage</code> will not free
the underlying buffer, because it is still in use by
EGL. However, following
<code class="function">vgDestroyImage</code> the buffer may
only be referred to via the EGL pbuffer handle,
since the OpenVG handle to that buffer no longer
exists. Similarly, destroying the pbuffer with
<code class="function">eglDestroySurface</code> will not free
the underlying buffer, because it is still in use by
OpenVG . However, following
<code class="function">eglDestroySurface</code> the buffer
may only be referred to via the OpenVG
<span class="type">VGImage</span> handle, since the EGL pbuffer
handle no longer exists.
</p>
</li>
</ol>
</div>
<p>
</p>
</div>
<div class="refsect1" id="errors">
<h2>Errors</h2>
<p>
<code class="constant">EGL_NO_SURFACE</code> is returned if creation of
the context fails.
</p>
<p>
<code class="constant">EGL_BAD_DISPLAY</code> is generated if
<em class="parameter"><code>display</code></em> is not an EGL display connection.
</p>
<p>
<code class="constant">EGL_NOT_INITIALIZED</code> is generated if
<em class="parameter"><code>display</code></em> has not been initialized.
</p>
<p>
<code class="constant">EGL_BAD_CONFIG</code> is generated if
<em class="parameter"><code>config</code></em> is not an EGL frame buffer configuration.
</p>
<p>
<code class="constant">EGL_BAD_PARAMETER</code> is generated if
<em class="parameter"><code>buftype</code></em> is not
<code class="constant">EGL_OPENVG_IMAGE</code>, or if
<em class="parameter"><code>buffer</code></em> is not a valid handle to a
<span class="type">VGImage</span> object in the currently bound OpenVG
context.
</p>
<p>
<code class="constant">EGL_BAD_ACCESS</code> is generated if there is
no current OpenVG context, or if
<em class="parameter"><code>buffer</code></em> is already bound to another
pixel buffer or in use by OpenVG as discussed in the Notes
section above.
</p>
<p>
<code class="constant">EGL_BAD_ACCESS</code> is generated if the buffers
contained in <em class="parameter"><code>buffer</code></em> consist of any
<span class="type">EGLImage</span> siblings.
</p>
<p>
<code class="constant">EGL_BAD_ALLOC</code> is generated if there are not
enough resources to allocate the new surface.
</p>
<p>
<code class="constant">EGL_BAD_ATTRIBUTE</code> is generated if
<em class="parameter"><code>attrib_list</code></em> contains an invalid pixel
buffer attribute or if an attribute value is not recognized
or out of range.
</p>
<p>
<code class="constant">EGL_BAD_ATTRIBUTE</code> is generated if
<em class="parameter"><code>attrib_list</code></em> contains any of the
attributes <code class="constant">EGL_MIPMAP_TEXTURE</code>,
<code class="constant">EGL_TEXTURE_FORMAT</code>, or
<code class="constant">EGL_TEXTURE_TARGET</code>, and
<em class="parameter"><code>config</code></em> does not support OpenGL ES
rendering (e.g. the EGL version is 1.2 or later, and the
<code class="constant">EGL_RENDERABLE_TYPE</code> attribute of
<em class="parameter"><code>config</code></em> does not include at least one
of <code class="constant">EGL_OPENGL_ES_BIT</code> or
<code class="constant">EGL_OPENGL_ES2_BIT</code>).
</p>
<p>
<code class="constant">EGL_BAD_MATCH</code> is generated if
<em class="parameter"><code>config</code></em> does not support rendering to
pixel buffers (the <code class="constant">EGL_SURFACE_TYPE</code>
attribute does not contain
<code class="constant">EGL_PBUFFER_BIT</code>).
</p>
<p>
<code class="constant">EGL_BAD_MATCH</code> is generated if the
buffers contained in <em class="parameter"><code>buffer</code></em> do not
match the bit depths for those buffers specified by
<em class="parameter"><code>config</code></em>.
</p>
<p>
<code class="constant">EGL_BAD_MATCH</code> is generated if the
<code class="constant">EGL_TEXTURE_FORMAT</code> attribute is not
<code class="constant">EGL_NO_TEXTURE</code>, and
<code class="constant">EGL_WIDTH</code> and/or
<code class="constant">EGL_HEIGHT</code> specify an invalid size
(e.g., the texture size is not a power of 2, and the
underlying OpenGL ES implementation does not support
non-power-of-two textures).
</p>
<p>
<code class="constant">EGL_BAD_MATCH</code> is generated if
the <code class="constant">EGL_TEXTURE_FORMAT</code> attribute is
<code class="constant">EGL_NO_TEXTURE</code>, and
<code class="constant">EGL_TEXTURE_TARGET</code> is something other
than <code class="constant">EGL_NO_TEXTURE</code>; or,
<code class="constant">EGL_TEXTURE_FORMAT</code> is something other
than <code class="constant">EGL_NO_TEXTURE</code>, and
<code class="constant">EGL_TEXTURE_TARGET</code> is
<code class="constant">EGL_NO_TEXTURE</code>.
</p>
<p>
<code class="constant">EGL_BAD_MATCH</code> is generated if the
implementation has additional constraints on which types of
client API buffers may be bound to pixel buffer surfaces.
For example, it is possible that the OpenVG implementation
might not support a <span class="type">VGImage</span> being bound to a
pixel buffer which will be used as a mipmapped OpenGL ES
texture (e.g. whose <code class="constant">EGL_MIPMAP_TEXTURE</code>
attribute is <code class="constant">TRUE</code>). Any such
constraints should be documented by the implementation
release notes.
</p>
</div>
<div class="refsect1" id="seealso">
<h2>See Also</h2>
<p>
<a class="citerefentry" href="eglDestroySurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglDestroySurface</span></span></a>,
<a class="citerefentry" href="eglChooseConfig.xhtml"><span class="citerefentry"><span class="refentrytitle">eglChooseConfig</span></span></a>,
<a class="citerefentry" href="eglCreatePbufferSurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglCreatePbufferSurface</span></span></a>,
<a class="citerefentry" href="eglGetConfigs.xhtml"><span class="citerefentry"><span class="refentrytitle">eglGetConfigs</span></span></a>,
<a class="citerefentry" href="eglMakeCurrent.xhtml"><span class="citerefentry"><span class="refentrytitle">eglMakeCurrent</span></span></a>,
<a class="citerefentry" href="eglQuerySurface.xhtml"><span class="citerefentry"><span class="refentrytitle">eglQuerySurface</span></span></a>
</p>
</div>
<p>
</p>
<div class="refsect3" id="copyright">
<img src="KhronosLogo.jpg"/>
<p>
Copyright © 2003-2014 The Khronos Group Inc.
Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and/or associated documentation files (the
"Materials"), to deal in the Materials without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
distribute, sublicense, and/or sell copies of the Materials, and to
permit persons to whom the Materials are furnished to do so, subject to
the condition that this copyright notice and permission notice shall be included
in all copies or substantial portions of the Materials.
</p>
</div>
<p>
</p>
</div>
<footer/>
</body>
</html>
|
