Commit | Line | Data |
---|---|---|
7faf1d71 AW |
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="glVertexAttrib"> | |
5 | <refmeta> | |
6 | <refentrytitle>glVertexAttrib</refentrytitle> | |
7 | <manvolnum>3G</manvolnum> | |
8 | </refmeta> | |
9 | <refnamediv> | |
10 | <refname>glVertexAttrib</refname> | |
11 | <refpurpose>Specifies the value of a generic vertex attribute</refpurpose> | |
12 | </refnamediv> | |
13 | <refsynopsisdiv><title>C Specification</title> | |
14 | <funcsynopsis> | |
15 | <funcprototype> | |
16 | <funcdef>void <function>glVertexAttrib1f</function></funcdef> | |
17 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
18 | <paramdef>GLfloat <parameter>v0</parameter></paramdef> | |
19 | </funcprototype> | |
20 | <funcprototype> | |
21 | <funcdef>void <function>glVertexAttrib1s</function></funcdef> | |
22 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
23 | <paramdef>GLshort <parameter>v0</parameter></paramdef> | |
24 | </funcprototype> | |
25 | <funcprototype> | |
26 | <funcdef>void <function>glVertexAttrib1d</function></funcdef> | |
27 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
28 | <paramdef>GLdouble <parameter>v0</parameter></paramdef> | |
29 | </funcprototype> | |
30 | <funcprototype> | |
31 | <funcdef>void <function>glVertexAttrib2f</function></funcdef> | |
32 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
33 | <paramdef>GLfloat <parameter>v0</parameter></paramdef> | |
34 | <paramdef>GLfloat <parameter>v1</parameter></paramdef> | |
35 | </funcprototype> | |
36 | <funcprototype> | |
37 | <funcdef>void <function>glVertexAttrib2s</function></funcdef> | |
38 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
39 | <paramdef>GLshort <parameter>v0</parameter></paramdef> | |
40 | <paramdef>GLshort <parameter>v1</parameter></paramdef> | |
41 | </funcprototype> | |
42 | <funcprototype> | |
43 | <funcdef>void <function>glVertexAttrib2d</function></funcdef> | |
44 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
45 | <paramdef>GLdouble <parameter>v0</parameter></paramdef> | |
46 | <paramdef>GLdouble <parameter>v1</parameter></paramdef> | |
47 | </funcprototype> | |
48 | <funcprototype> | |
49 | <funcdef>void <function>glVertexAttrib3f</function></funcdef> | |
50 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
51 | <paramdef>GLfloat <parameter>v0</parameter></paramdef> | |
52 | <paramdef>GLfloat <parameter>v1</parameter></paramdef> | |
53 | <paramdef>GLfloat <parameter>v2</parameter></paramdef> | |
54 | </funcprototype> | |
55 | <funcprototype> | |
56 | <funcdef>void <function>glVertexAttrib3s</function></funcdef> | |
57 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
58 | <paramdef>GLshort <parameter>v0</parameter></paramdef> | |
59 | <paramdef>GLshort <parameter>v1</parameter></paramdef> | |
60 | <paramdef>GLshort <parameter>v2</parameter></paramdef> | |
61 | </funcprototype> | |
62 | <funcprototype> | |
63 | <funcdef>void <function>glVertexAttrib3d</function></funcdef> | |
64 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
65 | <paramdef>GLdouble <parameter>v0</parameter></paramdef> | |
66 | <paramdef>GLdouble <parameter>v1</parameter></paramdef> | |
67 | <paramdef>GLdouble <parameter>v2</parameter></paramdef> | |
68 | </funcprototype> | |
69 | <funcprototype> | |
70 | <funcdef>void <function>glVertexAttrib4f</function></funcdef> | |
71 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
72 | <paramdef>GLfloat <parameter>v0</parameter></paramdef> | |
73 | <paramdef>GLfloat <parameter>v1</parameter></paramdef> | |
74 | <paramdef>GLfloat <parameter>v2</parameter></paramdef> | |
75 | <paramdef>GLfloat <parameter>v3</parameter></paramdef> | |
76 | </funcprototype> | |
77 | <funcprototype> | |
78 | <funcdef>void <function>glVertexAttrib4s</function></funcdef> | |
79 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
80 | <paramdef>GLshort <parameter>v0</parameter></paramdef> | |
81 | <paramdef>GLshort <parameter>v1</parameter></paramdef> | |
82 | <paramdef>GLshort <parameter>v2</parameter></paramdef> | |
83 | <paramdef>GLshort <parameter>v3</parameter></paramdef> | |
84 | </funcprototype> | |
85 | <funcprototype> | |
86 | <funcdef>void <function>glVertexAttrib4d</function></funcdef> | |
87 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
88 | <paramdef>GLdouble <parameter>v0</parameter></paramdef> | |
89 | <paramdef>GLdouble <parameter>v1</parameter></paramdef> | |
90 | <paramdef>GLdouble <parameter>v2</parameter></paramdef> | |
91 | <paramdef>GLdouble <parameter>v3</parameter></paramdef> | |
92 | </funcprototype> | |
93 | <funcprototype> | |
94 | <funcdef>void <function>glVertexAttrib4Nub</function></funcdef> | |
95 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
96 | <paramdef>GLubyte <parameter>v0</parameter></paramdef> | |
97 | <paramdef>GLubyte <parameter>v1</parameter></paramdef> | |
98 | <paramdef>GLubyte <parameter>v2</parameter></paramdef> | |
99 | <paramdef>GLubyte <parameter>v3</parameter></paramdef> | |
100 | </funcprototype> | |
101 | </funcsynopsis> | |
102 | </refsynopsisdiv> | |
103 | <refsect1 id="parameters"><title>Parameters</title> | |
104 | <variablelist> | |
105 | <varlistentry> | |
106 | <term><parameter>index</parameter></term> | |
107 | <listitem> | |
108 | <para>Specifies the index of the generic vertex | |
109 | attribute to be modified.</para> | |
110 | </listitem> | |
111 | </varlistentry> | |
112 | <varlistentry> | |
113 | <term> | |
114 | <parameter>v0</parameter>, | |
115 | <parameter>v1</parameter>, | |
116 | <parameter>v2</parameter>, | |
117 | <parameter>v3</parameter> | |
118 | </term> | |
119 | <listitem> | |
120 | <para>Specifies the new values to be used for the | |
121 | specified vertex attribute.</para> | |
122 | </listitem> | |
123 | </varlistentry> | |
124 | </variablelist> | |
125 | </refsect1> | |
126 | <refsynopsisdiv><title>C Specification</title> | |
127 | <funcsynopsis> | |
128 | <funcprototype> | |
129 | <funcdef>void <function>glVertexAttrib1fv</function></funcdef> | |
130 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
131 | <paramdef>const GLfloat *<parameter>v</parameter></paramdef> | |
132 | </funcprototype> | |
133 | <funcprototype> | |
134 | <funcdef>void <function>glVertexAttrib1sv</function></funcdef> | |
135 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
136 | <paramdef>const GLshort *<parameter>v</parameter></paramdef> | |
137 | </funcprototype> | |
138 | <funcprototype> | |
139 | <funcdef>void <function>glVertexAttrib1dv</function></funcdef> | |
140 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
141 | <paramdef>const GLdouble *<parameter>v</parameter></paramdef> | |
142 | </funcprototype> | |
143 | <funcprototype> | |
144 | <funcdef>void <function>glVertexAttrib2fv</function></funcdef> | |
145 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
146 | <paramdef>const GLfloat *<parameter>v</parameter></paramdef> | |
147 | </funcprototype> | |
148 | <funcprototype> | |
149 | <funcdef>void <function>glVertexAttrib2sv</function></funcdef> | |
150 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
151 | <paramdef>const GLshort *<parameter>v</parameter></paramdef> | |
152 | </funcprototype> | |
153 | <funcprototype> | |
154 | <funcdef>void <function>glVertexAttrib2dv</function></funcdef> | |
155 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
156 | <paramdef>const GLdouble *<parameter>v</parameter></paramdef> | |
157 | </funcprototype> | |
158 | <funcprototype> | |
159 | <funcdef>void <function>glVertexAttrib3fv</function></funcdef> | |
160 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
161 | <paramdef>const GLfloat *<parameter>v</parameter></paramdef> | |
162 | </funcprototype> | |
163 | <funcprototype> | |
164 | <funcdef>void <function>glVertexAttrib3sv</function></funcdef> | |
165 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
166 | <paramdef>const GLshort *<parameter>v</parameter></paramdef> | |
167 | </funcprototype> | |
168 | <funcprototype> | |
169 | <funcdef>void <function>glVertexAttrib3dv</function></funcdef> | |
170 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
171 | <paramdef>const GLdouble *<parameter>v</parameter></paramdef> | |
172 | </funcprototype> | |
173 | <funcprototype> | |
174 | <funcdef>void <function>glVertexAttrib4fv</function></funcdef> | |
175 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
176 | <paramdef>const GLfloat *<parameter>v</parameter></paramdef> | |
177 | </funcprototype> | |
178 | <funcprototype> | |
179 | <funcdef>void <function>glVertexAttrib4sv</function></funcdef> | |
180 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
181 | <paramdef>const GLshort *<parameter>v</parameter></paramdef> | |
182 | </funcprototype> | |
183 | <funcprototype> | |
184 | <funcdef>void <function>glVertexAttrib4dv</function></funcdef> | |
185 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
186 | <paramdef>const GLdouble *<parameter>v</parameter></paramdef> | |
187 | </funcprototype> | |
188 | <funcprototype> | |
189 | <funcdef>void <function>glVertexAttrib4iv</function></funcdef> | |
190 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
191 | <paramdef>const GLint *<parameter>v</parameter></paramdef> | |
192 | </funcprototype> | |
193 | <funcprototype> | |
194 | <funcdef>void <function>glVertexAttrib4bv</function></funcdef> | |
195 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
196 | <paramdef>const GLbyte *<parameter>v</parameter></paramdef> | |
197 | </funcprototype> | |
198 | <funcprototype> | |
199 | <funcdef>void <function>glVertexAttrib4ubv</function></funcdef> | |
200 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
201 | <paramdef>const GLubyte *<parameter>v</parameter></paramdef> | |
202 | </funcprototype> | |
203 | <funcprototype> | |
204 | <funcdef>void <function>glVertexAttrib4usv</function></funcdef> | |
205 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
206 | <paramdef>const GLushort *<parameter>v</parameter></paramdef> | |
207 | </funcprototype> | |
208 | <funcprototype> | |
209 | <funcdef>void <function>glVertexAttrib4uiv</function></funcdef> | |
210 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
211 | <paramdef>const GLuint *<parameter>v</parameter></paramdef> | |
212 | </funcprototype> | |
213 | <funcprototype> | |
214 | <funcdef>void <function>glVertexAttrib4Nbv</function></funcdef> | |
215 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
216 | <paramdef>const GLbyte *<parameter>v</parameter></paramdef> | |
217 | </funcprototype> | |
218 | <funcprototype> | |
219 | <funcdef>void <function>glVertexAttrib4Nsv</function></funcdef> | |
220 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
221 | <paramdef>const GLshort *<parameter>v</parameter></paramdef> | |
222 | </funcprototype> | |
223 | <funcprototype> | |
224 | <funcdef>void <function>glVertexAttrib4Niv</function></funcdef> | |
225 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
226 | <paramdef>const GLint *<parameter>v</parameter></paramdef> | |
227 | </funcprototype> | |
228 | <funcprototype> | |
229 | <funcdef>void <function>glVertexAttrib4Nubv</function></funcdef> | |
230 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
231 | <paramdef>const GLubyte *<parameter>v</parameter></paramdef> | |
232 | </funcprototype> | |
233 | <funcprototype> | |
234 | <funcdef>void <function>glVertexAttrib4Nusv</function></funcdef> | |
235 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
236 | <paramdef>const GLushort *<parameter>v</parameter></paramdef> | |
237 | </funcprototype> | |
238 | <funcprototype> | |
239 | <funcdef>void <function>glVertexAttrib4Nuiv</function></funcdef> | |
240 | <paramdef>GLuint <parameter>index</parameter></paramdef> | |
241 | <paramdef>const GLuint *<parameter>v</parameter></paramdef> | |
242 | </funcprototype> | |
243 | </funcsynopsis> | |
244 | </refsynopsisdiv> | |
245 | <refsect1 id="parameters2"><title>Parameters</title> | |
246 | <variablelist> | |
247 | <varlistentry> | |
248 | <term><parameter>index</parameter></term> | |
249 | <listitem> | |
250 | <para>Specifies the index of the generic vertex | |
251 | attribute to be modified.</para> | |
252 | </listitem> | |
253 | </varlistentry> | |
254 | <varlistentry> | |
255 | <term><parameter>v</parameter></term> | |
256 | <listitem> | |
257 | <para>Specifies a pointer to an array of values to | |
258 | be used for the generic vertex attribute.</para> | |
259 | </listitem> | |
260 | </varlistentry> | |
261 | </variablelist> | |
262 | </refsect1> | |
263 | <refsect1 id="description"><title>Description</title> | |
264 | <para>OpenGL defines a number of standard vertex attributes that | |
265 | applications can modify with standard API entry points (color, | |
266 | normal, texture coordinates, etc.). The | |
267 | <function>glVertexAttrib</function> family of entry points | |
268 | allows an application to pass generic vertex attributes in | |
269 | numbered locations.</para> | |
270 | ||
271 | <para>Generic attributes are defined as four-component values | |
272 | that are organized into an array. The first entry of this array | |
273 | is numbered 0, and the size of the array is specified by the | |
274 | implementation-dependent constant | |
275 | <constant>GL_MAX_VERTEX_ATTRIBS</constant>. Individual elements | |
276 | of this array can be modified with a | |
277 | <function>glVertexAttrib</function> call that specifies the | |
278 | index of the element to be modified and a value for that | |
279 | element.</para> | |
280 | ||
281 | <para>These commands can be used to specify one, two, three, or | |
282 | all four components of the generic vertex attribute specified by | |
283 | <parameter>index</parameter>. A <function>1</function> in the | |
284 | name of the command indicates that only one value is passed, and | |
285 | it will be used to modify the first component of the generic | |
286 | vertex attribute. The second and third components will be set to | |
287 | 0, and the fourth component will be set to 1. Similarly, a | |
288 | <function>2</function> in the name of the command indicates that | |
289 | values are provided for the first two components, the third | |
290 | component will be set to 0, and the fourth component will be set | |
291 | to 1. A <function>3</function> in the name of the command | |
292 | indicates that values are provided for the first three | |
293 | components and the fourth component will be set to 1, whereas a | |
294 | <function>4</function> in the name indicates that values are | |
295 | provided for all four components.</para> | |
296 | ||
297 | <para>The letters <function>s</function>, | |
298 | <function>f</function>, <function>i</function>, | |
299 | <function>d</function>, <function>ub</function>, | |
300 | <function>us</function>, and <function>ui</function> indicate | |
301 | whether the arguments are of type short, float, int, double, | |
302 | unsigned byte, unsigned short, or unsigned int. When | |
303 | <function>v</function> is appended to the name, the commands can | |
304 | take a pointer to an array of such values. The commands | |
305 | containing <function>N</function> indicate that the arguments | |
306 | will be passed as fixed-point values that are scaled to a | |
307 | normalized range according to the component conversion rules | |
308 | defined by the OpenGL specification. Signed values are | |
309 | understood to represent fixed-point values in the range [-1,1], | |
310 | and unsigned values are understood to represent fixed-point | |
311 | values in the range [0,1].</para> | |
312 | ||
313 | <para>OpenGL Shading Language attribute variables are allowed to | |
314 | be of type mat2, mat3, or mat4. Attributes of these types may be | |
315 | loaded using the <function>glVertexAttrib</function> entry | |
316 | points. Matrices must be loaded into successive generic | |
317 | attribute slots in column major order, with one column of the | |
318 | matrix in each generic attribute slot.</para> | |
319 | ||
320 | <para>A user-defined attribute variable declared in a vertex | |
321 | shader can be bound to a generic attribute index by calling | |
322 | <citerefentry><refentrytitle>glBindAttribLocation</refentrytitle></citerefentry>. | |
323 | This allows an application to use more descriptive variable | |
324 | names in a vertex shader. A subsequent change to the specified | |
325 | generic vertex attribute will be immediately reflected as a | |
326 | change to the corresponding attribute variable in the vertex | |
327 | shader.</para> | |
328 | ||
329 | <para>The binding between a generic vertex attribute index and a | |
330 | user-defined attribute variable in a vertex shader is part of | |
331 | the state of a program object, but the current value of the | |
332 | generic vertex attribute is not. The value of each generic | |
333 | vertex attribute is part of current state, just like standard | |
334 | vertex attributes, and it is maintained even if a different | |
335 | program object is used.</para> | |
336 | ||
337 | <para>An application may freely modify generic vertex attributes | |
338 | that are not bound to a named vertex shader attribute variable. | |
339 | These values are simply maintained as part of current state and | |
340 | will not be accessed by the vertex shader. If a generic vertex | |
341 | attribute bound to an attribute variable in a vertex shader is | |
342 | not updated while the vertex shader is executing, the vertex | |
343 | shader will repeatedly use the current value for the generic | |
344 | vertex attribute.</para> | |
345 | ||
346 | <para>The generic vertex attribute with index 0 is the same as | |
347 | the vertex position attribute previously defined by OpenGL. A | |
348 | <citerefentry><refentrytitle>glVertex2</refentrytitle></citerefentry>, | |
349 | <citerefentry><refentrytitle>glVertex3</refentrytitle></citerefentry>, | |
350 | or | |
351 | <citerefentry><refentrytitle>glVertex4</refentrytitle></citerefentry> | |
352 | command is completely equivalent to the corresponding | |
353 | <function>glVertexAttrib</function> command with an index | |
354 | argument of 0. A vertex shader can access generic vertex | |
355 | attribute 0 by using the built-in attribute variable | |
356 | <parameter>gl_Vertex</parameter>. There are no current values | |
357 | for generic vertex attribute 0. This is the only generic vertex | |
358 | attribute with this property; calls to set other standard vertex | |
359 | attributes can be freely mixed with calls to set any of the | |
360 | other generic vertex attributes.</para> | |
361 | </refsect1> | |
362 | <refsect1 id="notes"><title>Notes</title> | |
363 | <para><function>glVertexAttrib</function> is available only if | |
364 | the GL version is 2.0 or greater.</para> | |
365 | ||
366 | <para>Generic vertex attributes can be updated at any time. In | |
367 | particular, <function>glVertexAttrib</function> can be called | |
368 | between a call to | |
369 | <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> | |
370 | and the corresponding call to | |
371 | <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.</para> | |
372 | ||
373 | <para>It is possible for an application to bind more than one | |
374 | attribute name to the same generic vertex attribute index. This | |
375 | is referred to as aliasing, and it is allowed only if just one | |
376 | of the aliased attribute variables is active in the vertex | |
377 | shader, or if no path through the vertex shader consumes more | |
378 | than one of the attributes aliased to the same location. OpenGL | |
379 | implementations are not required to do error checking to detect | |
380 | aliasing, they are allowed to assume that aliasing will not | |
381 | occur, and they are allowed to employ optimizations that work | |
382 | only in the absence of aliasing.</para> | |
383 | ||
384 | <para>There is no provision for binding standard vertex | |
385 | attributes; therefore, it is not possible to alias generic | |
386 | attributes with standard attributes.</para> | |
387 | </refsect1> | |
388 | <refsect1 id="errors"><title>Errors</title> | |
389 | <para><constant>GL_INVALID_VALUE</constant> is generated if | |
390 | <parameter>index</parameter> is greater than or equal to | |
391 | <constant>GL_MAX_VERTEX_ATTRIBS</constant>.</para> | |
392 | </refsect1> | |
393 | <refsect1 id="associatedgets"><title>Associated Gets</title> | |
394 | <para><citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> | |
395 | with the argument <constant>GL_CURRENT_PROGRAM</constant></para> | |
396 | ||
397 | <para><citerefentry><refentrytitle>glGetActiveAttrib</refentrytitle></citerefentry> | |
398 | with argument <parameter>program</parameter> and the index of an active | |
399 | attribute variable</para> | |
400 | ||
401 | <para><citerefentry><refentrytitle>glGetAttribLocation</refentrytitle></citerefentry> | |
402 | with argument <parameter>program</parameter> and an attribute | |
403 | variable name</para> | |
404 | ||
405 | <para><citerefentry><refentrytitle>glGetVertexAttrib</refentrytitle></citerefentry> | |
406 | with arguments <constant>GL_CURRENT_VERTEX_ATTRIB</constant> and | |
407 | <parameter>index</parameter></para> | |
408 | </refsect1> | |
409 | <refsect1 id="seealso"><title>See Also</title> | |
410 | <para><citerefentry><refentrytitle>glBindAttribLocation</refentrytitle></citerefentry>, | |
411 | <citerefentry><refentrytitle>glVertex</refentrytitle></citerefentry>, | |
412 | <citerefentry><refentrytitle>glVertexAttribPointer</refentrytitle></citerefentry></para> | |
413 | </refsect1> | |
414 | <refsect1 id="Copyright"><title>Copyright</title> | |
415 | <para> | |
416 | Copyright <trademark class="copyright"></trademark> 2003-2005 3Dlabs Inc. Ltd. | |
417 | This material may be distributed subject to the terms and conditions set forth in | |
418 | the Open Publication License, v 1.0, 8 June 1999. | |
419 | <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>. | |
420 | </para> | |
421 | </refsect1> | |
422 | </refentry> |