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=
"glTexGen">
9 <holder>Silicon Graphics, Inc.
</holder>
12 <refentrytitle>glTexGen
</refentrytitle>
13 <manvolnum>3G
</manvolnum>
16 <refname>glTexGen
</refname>
17 <refpurpose>control the generation of texture coordinates
</refpurpose>
19 <refsynopsisdiv><title>C Specification
</title>
22 <funcdef>void
<function>glTexGeni
</function></funcdef>
23 <paramdef>GLenum
<parameter>coord
</parameter></paramdef>
24 <paramdef>GLenum
<parameter>pname
</parameter></paramdef>
25 <paramdef>GLint
<parameter>param
</parameter></paramdef>
30 <funcdef>void
<function>glTexGenf
</function></funcdef>
31 <paramdef>GLenum
<parameter>coord
</parameter></paramdef>
32 <paramdef>GLenum
<parameter>pname
</parameter></paramdef>
33 <paramdef>GLfloat
<parameter>param
</parameter></paramdef>
38 <funcdef>void
<function>glTexGend
</function></funcdef>
39 <paramdef>GLenum
<parameter>coord
</parameter></paramdef>
40 <paramdef>GLenum
<parameter>pname
</parameter></paramdef>
41 <paramdef>GLdouble
<parameter>param
</parameter></paramdef>
45 <!-- eqn: ignoring delim $$ -->
46 <refsect1 id=
"parameters"><title>Parameters
</title>
49 <term><parameter>coord
</parameter></term>
52 Specifies a texture coordinate.
53 Must be one of
<constant>GL_S
</constant>,
<constant>GL_T
</constant>,
<constant>GL_R
</constant>, or
<constant>GL_Q
</constant>.
58 <term><parameter>pname
</parameter></term>
61 Specifies the symbolic name of the texture-coordinate generation function.
62 Must be
<constant>GL_TEXTURE_GEN_MODE
</constant>.
67 <term><parameter>param
</parameter></term>
70 Specifies a single-valued texture generation parameter,
71 one of
<constant>GL_OBJECT_LINEAR
</constant>,
<constant>GL_EYE_LINEAR
</constant>,
<constant>GL_SPHERE_MAP
</constant>,
72 <constant>GL_NORMAL_MAP
</constant>, or
<constant>GL_REFLECTION_MAP
</constant>.
78 <refsynopsisdiv><title>C Specification
</title>
81 <funcdef>void
<function>glTexGeniv
</function></funcdef>
82 <paramdef>GLenum
<parameter>coord
</parameter></paramdef>
83 <paramdef>GLenum
<parameter>pname
</parameter></paramdef>
84 <paramdef>const GLint *
<parameter>params
</parameter></paramdef>
89 <funcdef>void
<function>glTexGenfv
</function></funcdef>
90 <paramdef>GLenum
<parameter>coord
</parameter></paramdef>
91 <paramdef>GLenum
<parameter>pname
</parameter></paramdef>
92 <paramdef>const GLfloat *
<parameter>params
</parameter></paramdef>
97 <funcdef>void
<function>glTexGendv
</function></funcdef>
98 <paramdef>GLenum
<parameter>coord
</parameter></paramdef>
99 <paramdef>GLenum
<parameter>pname
</parameter></paramdef>
100 <paramdef>const GLdouble *
<parameter>params
</parameter></paramdef>
104 <refsect1 id=
"parameters2"><title>Parameters
</title>
107 <term><parameter>coord
</parameter></term>
110 Specifies a texture coordinate.
111 Must be one of
<constant>GL_S
</constant>,
<constant>GL_T
</constant>,
<constant>GL_R
</constant>, or
<constant>GL_Q
</constant>.
116 <term><parameter>pname
</parameter></term>
119 Specifies the symbolic name of the texture-coordinate generation function
120 or function parameters.
122 <constant>GL_TEXTURE_GEN_MODE
</constant>,
123 <constant>GL_OBJECT_PLANE
</constant>, or
124 <constant>GL_EYE_PLANE
</constant>.
129 <term><parameter>params
</parameter></term>
132 Specifies a pointer to an array of texture generation parameters.
133 If
<parameter>pname
</parameter> is
<constant>GL_TEXTURE_GEN_MODE
</constant>,
134 then the array must contain a single symbolic constant,
136 <constant>GL_OBJECT_LINEAR
</constant>,
137 <constant>GL_EYE_LINEAR
</constant>,
138 <constant>GL_SPHERE_MAP
</constant>,
139 <constant>GL_NORMAL_MAP
</constant>, or
140 <constant>GL_REFLECTION_MAP
</constant>.
142 <parameter>params
</parameter> holds the coefficients for the texture-coordinate generation function
143 specified by
<parameter>pname
</parameter>.
149 <refsect1 id=
"description"><title>Description
</title>
151 <function>glTexGen
</function> selects a texture-coordinate generation function
152 or supplies coefficients for one of the functions.
153 <parameter>coord
</parameter> names one of the (
<emphasis>s
</emphasis>,
<emphasis>t
</emphasis>,
<emphasis>r
</emphasis>,
<emphasis>q
</emphasis>) texture
154 coordinates; it must be one of the symbols
155 <constant>GL_S
</constant>,
156 <constant>GL_T
</constant>,
157 <constant>GL_R
</constant>, or
158 <constant>GL_Q
</constant>.
159 <parameter>pname
</parameter> must be one of three symbolic constants:
160 <constant>GL_TEXTURE_GEN_MODE
</constant>,
161 <constant>GL_OBJECT_PLANE
</constant>, or
162 <constant>GL_EYE_PLANE
</constant>.
163 If
<parameter>pname
</parameter> is
<constant>GL_TEXTURE_GEN_MODE
</constant>,
164 then
<parameter>params
</parameter> chooses a mode,
166 <constant>GL_OBJECT_LINEAR
</constant>,
167 <constant>GL_EYE_LINEAR
</constant>,
168 <constant>GL_SPHERE_MAP
</constant>,
169 <constant>GL_NORMAL_MAP
</constant>, or
170 <constant>GL_REFLECTION_MAP
</constant>.
171 If
<parameter>pname
</parameter> is either
<constant>GL_OBJECT_PLANE
</constant> or
<constant>GL_EYE_PLANE
</constant>,
172 <parameter>params
</parameter> contains coefficients for the corresponding
173 texture generation function.
176 If the texture generation function is
<constant>GL_OBJECT_LINEAR
</constant>,
180 <inlineequation><mml:math>
181 <!-- eqn: g = p sub 1 * x sub o + p sub 2 * y sub o + p sub 3 * z sub o + p sub 4 * w sub o:-->
183 <mml:mi mathvariant=
"italic">g
</mml:mi>
187 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
190 <mml:mo>×</mml:mo>
191 <mml:msub><mml:mi mathvariant=
"italic">x
</mml:mi>
192 <mml:mi mathvariant=
"italic">o
</mml:mi>
197 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
200 <mml:mo>×</mml:mo>
201 <mml:msub><mml:mi mathvariant=
"italic">y
</mml:mi>
202 <mml:mi mathvariant=
"italic">o
</mml:mi>
207 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
210 <mml:mo>×</mml:mo>
211 <mml:msub><mml:mi mathvariant=
"italic">z
</mml:mi>
212 <mml:mi mathvariant=
"italic">o
</mml:mi>
217 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
220 <mml:mo>×</mml:mo>
221 <mml:msub><mml:mi mathvariant=
"italic">w
</mml:mi>
222 <mml:mi mathvariant=
"italic">o
</mml:mi>
227 </mml:math></inlineequation>
231 <inlineequation><mml:math><mml:mi mathvariant=
"italic">g
</mml:mi></mml:math></inlineequation>
232 is the value computed for the coordinate named in
<parameter>coord
</parameter>,
233 <inlineequation><mml:math>
234 <!-- eqn: p sub 1:-->
235 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
238 </mml:math></inlineequation>,
239 <inlineequation><mml:math>
240 <!-- eqn: p sub 2:-->
241 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
244 </mml:math></inlineequation>,
245 <inlineequation><mml:math>
246 <!-- eqn: p sub 3:-->
247 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
250 </mml:math></inlineequation>,
252 <inlineequation><mml:math>
253 <!-- eqn: p sub 4:-->
254 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
257 </mml:math></inlineequation>
258 are the four values supplied in
<parameter>params
</parameter>, and
259 <inlineequation><mml:math>
260 <!-- eqn: x sub o:-->
261 <mml:msub><mml:mi mathvariant=
"italic">x
</mml:mi>
262 <mml:mi mathvariant=
"italic">o
</mml:mi>
264 </mml:math></inlineequation>,
265 <inlineequation><mml:math>
266 <!-- eqn: y sub o:-->
267 <mml:msub><mml:mi mathvariant=
"italic">y
</mml:mi>
268 <mml:mi mathvariant=
"italic">o
</mml:mi>
270 </mml:math></inlineequation>,
271 <inlineequation><mml:math>
272 <!-- eqn: z sub o:-->
273 <mml:msub><mml:mi mathvariant=
"italic">z
</mml:mi>
274 <mml:mi mathvariant=
"italic">o
</mml:mi>
276 </mml:math></inlineequation>,
278 <inlineequation><mml:math>
279 <!-- eqn: w sub o:-->
280 <mml:msub><mml:mi mathvariant=
"italic">w
</mml:mi>
281 <mml:mi mathvariant=
"italic">o
</mml:mi>
283 </mml:math></inlineequation>
284 are the object coordinates of the vertex.
285 This function can be used, for example, to texture-map terrain using sea level
288 <inlineequation><mml:math>
289 <!-- eqn: p sub 1:-->
290 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
293 </mml:math></inlineequation>,
294 <inlineequation><mml:math>
295 <!-- eqn: p sub 2:-->
296 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
299 </mml:math></inlineequation>,
300 <inlineequation><mml:math>
301 <!-- eqn: p sub 3:-->
302 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
305 </mml:math></inlineequation>,
307 <inlineequation><mml:math>
308 <!-- eqn: p sub 4:-->
309 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
312 </mml:math></inlineequation>).
313 The altitude of a terrain vertex is computed by the
<constant>GL_OBJECT_LINEAR
</constant>
314 coordinate generation function as its distance from sea level;
315 that altitude can then be used to index the texture image to map white snow
316 onto peaks and green grass onto foothills.
319 If the texture generation function is
<constant>GL_EYE_LINEAR
</constant>, the function
322 <informalequation><mml:math>
323 <!-- eqn: g = {p sub 1} sup prime * x sub e + {p sub 2} sup prime * y sub e + {p sub 3} sup prime * z sub e + {p sub 4} sup prime * w sub e:-->
325 <mml:mi mathvariant=
"italic">g
</mml:mi>
329 <mml:msup><mml:mfenced open=
"" close=
"">
330 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
334 <mml:mo>″</mml:mo>
336 <mml:mo>×</mml:mo>
337 <mml:msub><mml:mi mathvariant=
"italic">x
</mml:mi>
338 <mml:mi mathvariant=
"italic">e
</mml:mi>
343 <mml:msup><mml:mfenced open=
"" close=
"">
344 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
348 <mml:mo>″</mml:mo>
350 <mml:mo>×</mml:mo>
351 <mml:msub><mml:mi mathvariant=
"italic">y
</mml:mi>
352 <mml:mi mathvariant=
"italic">e
</mml:mi>
357 <mml:msup><mml:mfenced open=
"" close=
"">
358 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
362 <mml:mo>″</mml:mo>
364 <mml:mo>×</mml:mo>
365 <mml:msub><mml:mi mathvariant=
"italic">z
</mml:mi>
366 <mml:mi mathvariant=
"italic">e
</mml:mi>
371 <mml:msup><mml:mfenced open=
"" close=
"">
372 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
376 <mml:mo>″</mml:mo>
378 <mml:mo>×</mml:mo>
379 <mml:msub><mml:mi mathvariant=
"italic">w
</mml:mi>
380 <mml:mi mathvariant=
"italic">e
</mml:mi>
385 </mml:math></informalequation>
391 <informalequation><mml:math>
392 <!-- eqn: left ( {p sub 1} sup prime {p sub 2} sup prime {p sub 3} sup prime {p sub 4} sup prime right ) = left ( p sub 1 p sub 2 p sub 3 p sub 4 right ) M sup -1:-->
394 <mml:mfenced open=
"(" close=
")">
396 <mml:msup><mml:mfenced open=
"" close=
"">
397 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
401 <mml:mo>″</mml:mo>
403 <mml:mo>⁢</mml:mo>
404 <mml:msup><mml:mfenced open=
"" close=
"">
405 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
409 <mml:mo>″</mml:mo>
411 <mml:mo>⁢</mml:mo>
412 <mml:msup><mml:mfenced open=
"" close=
"">
413 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
417 <mml:mo>″</mml:mo>
419 <mml:mo>⁢</mml:mo>
420 <mml:msup><mml:mfenced open=
"" close=
"">
421 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
425 <mml:mo>″</mml:mo>
431 <mml:mfenced open=
"(" close=
")">
433 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
436 <mml:mo>⁢</mml:mo>
437 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
440 <mml:mo>⁢</mml:mo>
441 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
444 <mml:mo>⁢</mml:mo>
445 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
450 <mml:mo>⁢</mml:mo>
451 <mml:msup><mml:mi mathvariant=
"italic">M
</mml:mi>
456 </mml:math></informalequation>
460 <inlineequation><mml:math>
461 <!-- eqn: x sub e:-->
462 <mml:msub><mml:mi mathvariant=
"italic">x
</mml:mi>
463 <mml:mi mathvariant=
"italic">e
</mml:mi>
465 </mml:math></inlineequation>,
466 <inlineequation><mml:math>
467 <!-- eqn: y sub e:-->
468 <mml:msub><mml:mi mathvariant=
"italic">y
</mml:mi>
469 <mml:mi mathvariant=
"italic">e
</mml:mi>
471 </mml:math></inlineequation>,
472 <inlineequation><mml:math>
473 <!-- eqn: z sub e:-->
474 <mml:msub><mml:mi mathvariant=
"italic">z
</mml:mi>
475 <mml:mi mathvariant=
"italic">e
</mml:mi>
477 </mml:math></inlineequation>,
479 <inlineequation><mml:math>
480 <!-- eqn: w sub e:-->
481 <mml:msub><mml:mi mathvariant=
"italic">w
</mml:mi>
482 <mml:mi mathvariant=
"italic">e
</mml:mi>
484 </mml:math></inlineequation>
485 are the eye coordinates of the vertex,
486 <inlineequation><mml:math>
487 <!-- eqn: p sub 1:-->
488 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
491 </mml:math></inlineequation>,
492 <inlineequation><mml:math>
493 <!-- eqn: p sub 2:-->
494 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
497 </mml:math></inlineequation>,
498 <inlineequation><mml:math>
499 <!-- eqn: p sub 3:-->
500 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
503 </mml:math></inlineequation>,
505 <inlineequation><mml:math>
506 <!-- eqn: p sub 4:-->
507 <mml:msub><mml:mi mathvariant=
"italic">p
</mml:mi>
510 </mml:math></inlineequation>
511 are the values supplied in
<parameter>params
</parameter>, and
512 <inlineequation><mml:math><mml:mi mathvariant=
"italic">M
</mml:mi></mml:math></inlineequation>
513 is the modelview matrix when
<function>glTexGen
</function> is invoked.
515 <inlineequation><mml:math><mml:mi mathvariant=
"italic">M
</mml:mi></mml:math></inlineequation>
516 is poorly conditioned or singular,
517 texture coordinates generated by the resulting function may be inaccurate
521 Note that the values in
<parameter>params
</parameter> define a reference plane in eye coordinates.
522 The modelview matrix that is applied to them may not be the same one
523 in effect when the polygon vertices are transformed.
524 This function establishes a field of texture coordinates
525 that can produce dynamic contour lines on moving objects.
528 If the texture generation function is
<constant>GL_SPHERE_MAP
</constant> and
<parameter>coord
</parameter> is either
529 <constant>GL_S
</constant> or
530 <constant>GL_T
</constant>,
531 <inlineequation><mml:math><mml:mi mathvariant=
"italic">s
</mml:mi></mml:math></inlineequation>
533 <inlineequation><mml:math><mml:mi mathvariant=
"italic">t
</mml:mi></mml:math></inlineequation>
534 texture coordinates are generated as follows.
535 Let
<emphasis>u
</emphasis> be the unit vector pointing from the origin to the polygon vertex
536 (in eye coordinates).
537 Let
<emphasis>n
</emphasis> sup prime be the current normal,
538 after transformation to eye coordinates.
542 <inlineequation><mml:math>
543 <!-- eqn: f = ( f sub x f sub y f sub z ) sup T:-->
545 <mml:mi mathvariant=
"italic">f
</mml:mi>
547 <mml:msup><mml:mfenced open=
"(" close=
")">
549 <mml:msub><mml:mi mathvariant=
"italic">f
</mml:mi>
550 <mml:mi mathvariant=
"italic">x
</mml:mi>
552 <mml:mo>⁢</mml:mo>
553 <mml:msub><mml:mi mathvariant=
"italic">f
</mml:mi>
554 <mml:mi mathvariant=
"italic">y
</mml:mi>
556 <mml:mo>⁢</mml:mo>
557 <mml:msub><mml:mi mathvariant=
"italic">f
</mml:mi>
558 <mml:mi mathvariant=
"italic">z
</mml:mi>
562 <mml:mi mathvariant=
"italic">T
</mml:mi>
565 </mml:math></inlineequation>
566 be the reflection vector such that
569 <inlineequation><mml:math>
570 <!-- eqn: f = u - 2 n sup prime {n sup prime} sup T u:-->
572 <mml:mi mathvariant=
"italic">f
</mml:mi>
575 <mml:mi mathvariant=
"italic">u
</mml:mi>
578 <mml:mo>⁢</mml:mo>
579 <mml:msup><mml:mi mathvariant=
"italic">n
</mml:mi>
580 <mml:mo>″</mml:mo>
582 <mml:mo>⁢</mml:mo>
583 <mml:msup><mml:mfenced open=
"" close=
"">
584 <mml:msup><mml:mi mathvariant=
"italic">n
</mml:mi>
585 <mml:mo>″</mml:mo>
588 <mml:mi mathvariant=
"italic">T
</mml:mi>
590 <mml:mo>⁢</mml:mo>
591 <mml:mi mathvariant=
"italic">u
</mml:mi>
594 </mml:math></inlineequation>
598 <inlineequation><mml:math>
599 <!-- eqn: m = 2 sqrt ({f sub x} sup 2 + {f sub y} sup 2 + (f sub z + 1) sup 2):-->
601 <mml:mi mathvariant=
"italic">m
</mml:mi>
605 <mml:mo>⁢</mml:mo>
607 <mml:mfenced open=
"(" close=
")">
609 <mml:msup><mml:mfenced open=
"" close=
"">
610 <mml:msub><mml:mi mathvariant=
"italic">f
</mml:mi>
611 <mml:mi mathvariant=
"italic">x
</mml:mi>
617 <mml:msup><mml:mfenced open=
"" close=
"">
618 <mml:msub><mml:mi mathvariant=
"italic">f
</mml:mi>
619 <mml:mi mathvariant=
"italic">y
</mml:mi>
625 <mml:msup><mml:mfenced open=
"(" close=
")">
627 <mml:msub><mml:mi mathvariant=
"italic">f
</mml:mi>
628 <mml:mi mathvariant=
"italic">z
</mml:mi>
641 </mml:math></inlineequation>.
642 Then the values assigned to the
643 <inlineequation><mml:math><mml:mi mathvariant=
"italic">s
</mml:mi></mml:math></inlineequation>
645 <inlineequation><mml:math><mml:mi mathvariant=
"italic">t
</mml:mi></mml:math></inlineequation>
646 texture coordinates are
649 <inlineequation><mml:math>
650 <!-- eqn: s = f sub x over m + 1 over 2:-->
652 <mml:mi mathvariant=
"italic">s
</mml:mi>
656 <mml:msub><mml:mi mathvariant=
"italic">f
</mml:mi>
657 <mml:mi mathvariant=
"italic">x
</mml:mi>
659 <mml:mi mathvariant=
"italic">m
</mml:mi>
668 </mml:math></inlineequation>
671 <inlineequation><mml:math>
672 <!-- eqn: t = f sub y over m + 1 over 2:-->
674 <mml:mi mathvariant=
"italic">t
</mml:mi>
678 <mml:msub><mml:mi mathvariant=
"italic">f
</mml:mi>
679 <mml:mi mathvariant=
"italic">y
</mml:mi>
681 <mml:mi mathvariant=
"italic">m
</mml:mi>
690 </mml:math></inlineequation>
693 To enable or disable a texture-coordinate generation function, call
694 <citerefentry><refentrytitle>glEnable
</refentrytitle></citerefentry> or
<citerefentry><refentrytitle>glDisable
</refentrytitle></citerefentry>
695 with one of the symbolic texture-coordinate names
696 (
<constant>GL_TEXTURE_GEN_S
</constant>,
697 <constant>GL_TEXTURE_GEN_T
</constant>,
698 <constant>GL_TEXTURE_GEN_R
</constant>, or
699 <constant>GL_TEXTURE_GEN_Q
</constant>) as the argument.
701 the specified texture coordinate is computed
702 according to the generating function associated with that coordinate.
704 subsequent vertices take the specified texture coordinate
705 from the current set of texture coordinates. Initially, all texture
706 generation functions are set to
<constant>GL_EYE_LINEAR
</constant> and are disabled.
708 <inlineequation><mml:math><mml:mi mathvariant=
"italic">s
</mml:mi></mml:math></inlineequation>
709 plane equations are (
1,
0,
0,
0),
711 <inlineequation><mml:math><mml:mi mathvariant=
"italic">t
</mml:mi></mml:math></inlineequation>
712 plane equations are (
0,
1,
0,
0),
714 <inlineequation><mml:math><mml:mi mathvariant=
"italic">r
</mml:mi></mml:math></inlineequation>
716 <inlineequation><mml:math><mml:mi mathvariant=
"italic">q
</mml:mi></mml:math></inlineequation>
717 plane equations are (
0,
0,
0,
0).
720 When the
<code>ARB_multitexture
</code> extension is supported,
<function>glTexGen
</function> sets the
721 texture generation parameters for the currently active texture unit,
722 selected with
<citerefentry><refentrytitle>glActiveTexture
</refentrytitle></citerefentry>.
725 <refsect1 id=
"errors"><title>Errors
</title>
727 <constant>GL_INVALID_ENUM
</constant> is generated when
<parameter>coord
</parameter> or
<parameter>pname
</parameter> is not an
728 accepted defined value,
729 or when
<parameter>pname
</parameter> is
<constant>GL_TEXTURE_GEN_MODE
</constant> and
<parameter>params
</parameter> is not an
730 accepted defined value.
733 <constant>GL_INVALID_ENUM
</constant> is generated when
<parameter>pname
</parameter> is
<constant>GL_TEXTURE_GEN_MODE
</constant>,
734 <parameter>params
</parameter> is
<constant>GL_SPHERE_MAP
</constant>,
735 and
<parameter>coord
</parameter> is either
<constant>GL_R
</constant> or
<constant>GL_Q
</constant>.
738 <constant>GL_INVALID_OPERATION
</constant> is generated if
<function>glTexGen
</function>
739 is executed between the execution of
<citerefentry><refentrytitle>glBegin
</refentrytitle></citerefentry>
740 and the corresponding execution of
<citerefentry><refentrytitle>glEnd
</refentrytitle></citerefentry>.
743 <refsect1 id=
"associatedgets"><title>Associated Gets
</title>
745 <citerefentry><refentrytitle>glGetTexGen
</refentrytitle></citerefentry>
748 <citerefentry><refentrytitle>glIsEnabled
</refentrytitle></citerefentry> with argument
<constant>GL_TEXTURE_GEN_S
</constant>
751 <citerefentry><refentrytitle>glIsEnabled
</refentrytitle></citerefentry> with argument
<constant>GL_TEXTURE_GEN_T
</constant>
754 <citerefentry><refentrytitle>glIsEnabled
</refentrytitle></citerefentry> with argument
<constant>GL_TEXTURE_GEN_R
</constant>
757 <citerefentry><refentrytitle>glIsEnabled
</refentrytitle></citerefentry> with argument
<constant>GL_TEXTURE_GEN_Q
</constant>
760 <refsect1 id=
"seealso"><title>See Also
</title>
762 <citerefentry><refentrytitle>glActiveTexture
</refentrytitle></citerefentry>,
763 <citerefentry><refentrytitle>glCopyPixels
</refentrytitle></citerefentry>,
764 <citerefentry><refentrytitle>glCopyTexImage2D
</refentrytitle></citerefentry>,
765 <citerefentry><refentrytitle>glCopyTexSubImage1D
</refentrytitle></citerefentry>,
766 <citerefentry><refentrytitle>glCopyTexSubImage2D
</refentrytitle></citerefentry>,
767 <citerefentry><refentrytitle>glCopyTexSubImage3D
</refentrytitle></citerefentry>,
768 <citerefentry><refentrytitle>glTexEnv
</refentrytitle></citerefentry>,
769 <citerefentry><refentrytitle>glTexImage1D
</refentrytitle></citerefentry>,
770 <citerefentry><refentrytitle>glTexImage2D
</refentrytitle></citerefentry>,
771 <citerefentry><refentrytitle>glTexImage3D
</refentrytitle></citerefentry>,
772 <citerefentry><refentrytitle>glTexParameter
</refentrytitle></citerefentry>,
773 <citerefentry><refentrytitle>glTexSubImage1D
</refentrytitle></citerefentry>,
774 <citerefentry><refentrytitle>glTexSubImage2D
</refentrytitle></citerefentry>,
775 <citerefentry><refentrytitle>glTexSubImage3D
</refentrytitle></citerefentry>
778 <refsect1 id=
"Copyright"><title>Copyright
</title>
780 Copyright
<trademark class=
"copyright"></trademark> 1991-
2006
781 Silicon Graphics, Inc. This document is licensed under the SGI
782 Free Software B License. For details, see
783 <ulink url=
"http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/
</ulink>.