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
|
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html><html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>glTransformFeedbackVaryings - OpenGL 4 Reference Pages</title>
<link rel="stylesheet" type="text/css" href="opengl-man.css"/>
<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"/>
<script type="text/x-mathjax-config">
MathJax.Hub.Config({
MathML: {
extensions: ["content-mathml.js"]
},
tex2jax: {
inlineMath: [['$','$'], ['\\(','\\)']]
}
});
</script>
<script type="text/javascript" src="https://c328740.ssl.cf1.rackcdn.com/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"/>
</head>
<body>
<header/>
<div class="refentry" id="glTransformFeedbackVaryings">
<div class="titlepage"/>
<div class="refnamediv">
<h2>Name</h2>
<p>glTransformFeedbackVaryings — specify values to record in transform feedback buffers</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">void <strong class="fsfunc">glTransformFeedbackVaryings</strong>(</code>
</td>
<td>GLuint<var class="pdparam">program</var>, </td>
</tr>
<tr>
<td> </td>
<td>GLsizei<var class="pdparam">count</var>, </td>
</tr>
<tr>
<td> </td>
<td>const char **<var class="pdparam">varyings</var>, </td>
</tr>
<tr>
<td> </td>
<td>GLenum<var class="pdparam">bufferMode</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>program</code>
</em>
</span>
</dt>
<dd>
<p>
The name of the target program object.
</p>
</dd>
<dt>
<span class="term">
<em class="parameter">
<code>count</code>
</em>
</span>
</dt>
<dd>
<p>
The number of varying variables used for transform feedback.
</p>
</dd>
<dt>
<span class="term">
<em class="parameter">
<code>varyings</code>
</em>
</span>
</dt>
<dd>
<p>
An array of <em class="parameter"><code>count</code></em> zero-terminated strings specifying the
names of the varying variables to use for transform feedback.
</p>
</dd>
<dt>
<span class="term">
<em class="parameter">
<code>bufferMode</code>
</em>
</span>
</dt>
<dd>
<p>
Identifies the mode used to capture the varying variables when transform feedback is active.
<em class="parameter"><code>bufferMode</code></em> must be <code class="constant">GL_INTERLEAVED_ATTRIBS</code> or <code class="constant">GL_SEPARATE_ATTRIBS</code>.
</p>
</dd>
</dl>
</div>
</div>
<div class="refsect1" id="description">
<h2>Description</h2>
<p>
The names of the vertex or geometry shader outputs to be recorded in transform feedback mode
are specified using <code class="function">glTransformFeedbackVaryings</code>. When a geometry shader
is active, transform feedback records the values of selected geometry shader output variables
from the emitted vertices. Otherwise, the values of the selected vertex shader outputs are
recorded.
</p>
<p>
The state set by <code class="function">glTranformFeedbackVaryings</code> is stored and takes effect
next time <a class="citerefentry" href="glLinkProgram.xhtml"><span class="citerefentry"><span class="refentrytitle">glLinkProgram</span></span></a> is called
on <em class="parameter"><code>program</code></em>. When <a class="citerefentry" href="glLinkProgram.xhtml"><span class="citerefentry"><span class="refentrytitle">glLinkProgram</span></span></a>
is called, <em class="parameter"><code>program</code></em> is linked so that the values of the specified varying variables
for the vertices of each primitive generated by the GL are written to a single buffer
object if <em class="parameter"><code>bufferMode</code></em> is <code class="constant">GL_INTERLEAVED_ATTRIBS</code> or multiple
buffer objects if <em class="parameter"><code>bufferMode</code></em> is <code class="constant">GL_SEPARATE_ATTRIBS</code>.
</p>
<p>
In addition to the errors generated by <code class="function">glTransformFeedbackVaryings</code>, the
program <em class="parameter"><code>program</code></em> will fail to link if:
</p>
<div class="itemizedlist">
<ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
<p>
The count specified by <code class="function">glTransformFeedbackVaryings</code> is non-zero, but the
program object has no vertex or geometry shader.
</p>
</li>
<li class="listitem">
<p>
Any variable name specified in the <em class="parameter"><code>varyings</code></em> array is not declared as an output
in the vertex shader (or the geometry shader, if active).
</p>
</li>
<li class="listitem">
<p>
Any two entries in the <em class="parameter"><code>varyings</code></em> array specify the same varying variable.
</p>
</li>
<li class="listitem">
<p>
The total number of components to capture in any varying variable in <em class="parameter"><code>varyings</code></em>
is greater than the constant <code class="constant">GL_MAX_TRANSFORM_FEEDBACK_SEPARATE_COMPONENTS</code>
and the buffer mode is <code class="constant">GL_SEPARATE_ATTRIBS</code>.
</p>
</li>
<li class="listitem">
<p>
The total number of components to capture is greater than the constant
<code class="constant">GL_MAX_TRANSFORM_FEEDBACK_INTERLEAVED_COMPONENTS</code> and the buffer
mode is <code class="constant">GL_INTERLEAVED_ATTRIBS</code>.
</p>
</li>
</ul>
</div>
<p>
</p>
</div>
<div class="refsect1" id="notes">
<h2>Notes</h2>
<p>
<code class="function">glGetTransformFeedbackVarying</code> is available only if the GL version is 3.0 or greater.
</p>
</div>
<div class="refsect1" id="errors">
<h2>Errors</h2>
<p>
<code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>program</code></em> is not
the name of a program object.
</p>
<p>
<code class="constant">GL_INVALID_VALUE</code> is generated if <em class="parameter"><code>bufferMode</code></em> is <code class="constant">GL_SEPARATE_ATTRIBS</code>
and <em class="parameter"><code>count</code></em> is greater than the implementation-dependent limit <code class="constant">GL_MAX_TRANSFORM_FEEDBACK_SEPARATE_ATTRIBS</code>.
</p>
</div>
<div class="refsect1" id="associatedgets">
<h2>Associated Gets</h2>
<p>
<a class="citerefentry" href="glGetTransformFeedbackVarying.xhtml"><span class="citerefentry"><span class="refentrytitle">glGetTransformFeedbackVarying</span></span></a>
</p>
</div>
<div class="refsect1" id="versions">
<h2>Version Support</h2>
<div class="informaltable">
<table style="border-collapse: collapse; border-top: 2px solid ; border-bottom: 2px solid ; border-left: 2px solid ; border-right: 2px solid ; ">
<colgroup>
<col style="text-align: left; "/>
<col style="text-align: center; " class="firstvers"/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; "/>
<col style="text-align: center; " class="lastvers"/>
</colgroup>
<thead>
<tr>
<th style="text-align: left; border-right: 2px solid ; ">
</th>
<th style="text-align: center; border-bottom: 2px solid ; " colspan="12">
<span class="bold"><strong>OpenGL Version</strong></span>
</th>
</tr>
<tr>
<th style="text-align: left; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>Function / Feature Name</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>2.0</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>2.1</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>3.0</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>3.1</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>3.2</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>3.3</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>4.0</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>4.1</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>4.2</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>4.3</strong></span>
</th>
<th style="text-align: center; border-right: 2px solid ; border-bottom: 2px solid ; ">
<span class="bold"><strong>4.4</strong></span>
</th>
<th style="text-align: center; border-bottom: 2px solid ; ">
<span class="bold"><strong>4.5</strong></span>
</th>
</tr>
</thead>
<tbody>
<tr>
<td style="text-align: left; border-right: 2px solid ; ">
<code class="function">glTransformFeedbackVaryings</code>
</td>
<td style="text-align: center; border-right: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; ">-</td>
<td style="text-align: center; border-right: 2px solid ; ">✔</td>
<td style="text-align: center; border-right: 2px solid ; ">✔</td>
<td style="text-align: center; border-right: 2px solid ; ">✔</td>
<td style="text-align: center; border-right: 2px solid ; ">✔</td>
<td style="text-align: center; border-right: 2px solid ; ">✔</td>
<td style="text-align: center; border-right: 2px solid ; ">✔</td>
<td style="text-align: center; border-right: 2px solid ; ">✔</td>
<td style="text-align: center; border-right: 2px solid ; ">✔</td>
<td style="text-align: center; border-right: 2px solid ; ">✔</td>
<td style="text-align: center; ">✔</td>
</tr>
</tbody>
</table>
</div>
</div>
<div class="refsect1" id="seealso">
<h2>See Also</h2>
<p>
<a class="citerefentry" href="glBeginTransformFeedback.xhtml"><span class="citerefentry"><span class="refentrytitle">glBeginTransformFeedback</span></span></a>,
<a class="citerefentry" href="glEndTransformFeedback.xhtml"><span class="citerefentry"><span class="refentrytitle">glEndTransformFeedback</span></span></a>,
<a class="citerefentry" href="glGetTransformFeedbackVarying.xhtml"><span class="citerefentry"><span class="refentrytitle">glGetTransformFeedbackVarying</span></span></a>
</p>
</div>
<div class="refsect1" id="Copyright">
<h2>Copyright</h2>
<p>
Copyright <span class="trademark"/>© 2010-2014 Khronos Group.
This material may be distributed subject to the terms and conditions set forth in
the Open Publication License, v 1.0, 8 June 1999.
<a class="link" href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
</p>
</div>
</div>
<footer/>
</body>
</html>
|
