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=
"glBlendEquation">
9 <holder>Silicon Graphics, Inc.
</holder>
12 <refentrytitle>glBlendEquation
</refentrytitle>
13 <manvolnum>3G
</manvolnum>
16 <refname>glBlendEquation
</refname>
17 <refpurpose>specify the equation used for both the RGB blend equation and the Alpha blend equation
</refpurpose>
19 <refsynopsisdiv><title>C Specification
</title>
22 <funcdef>void
<function>glBlendEquation
</function></funcdef>
23 <paramdef>GLenum
<parameter>mode
</parameter></paramdef>
27 <!-- eqn: ignoring delim $$ -->
28 <refsect1 id=
"parameters"><title>Parameters
</title>
31 <term><parameter>mode
</parameter></term>
34 specifies how source and destination colors are combined.
35 It must be
<constant>GL_FUNC_ADD
</constant>,
<constant>GL_FUNC_SUBTRACT
</constant>,
36 <constant>GL_FUNC_REVERSE_SUBTRACT
</constant>,
<constant>GL_MIN
</constant>,
<constant>GL_MAX
</constant>.
42 <refsect1 id=
"description"><title>Description
</title>
44 The blend equations determine how a new pixel (the ''source'' color)
45 is combined with a pixel already in the framebuffer (the ''destination''
46 color). This function sets both the RGB blend equation and the alpha
47 blend equation to a single equation.
50 These equations use the source and destination blend factors
51 specified by either
<citerefentry><refentrytitle>glBlendFunc
</refentrytitle></citerefentry> or
52 <citerefentry><refentrytitle>glBlendFuncSeparate
</refentrytitle></citerefentry>.
53 See
<citerefentry><refentrytitle>glBlendFunc
</refentrytitle></citerefentry> or
<citerefentry><refentrytitle>glBlendFuncSeparate
</refentrytitle></citerefentry>
54 for a description of the various blend factors.
57 In the equations that follow, source and destination
58 color components are referred to as
59 <inlineequation><mml:math>
60 <!-- eqn: ( R sub s, G sub s, B sub s, A sub s ): -->
61 <mml:mfenced open=
"(" close=
")">
62 <mml:msub><mml:mi mathvariant=
"italic">R
</mml:mi>
63 <mml:mi mathvariant=
"italic">s
</mml:mi>
65 <mml:msub><mml:mi mathvariant=
"italic">G
</mml:mi>
66 <mml:mi mathvariant=
"italic">s
</mml:mi>
68 <mml:msub><mml:mi mathvariant=
"italic">B
</mml:mi>
69 <mml:mi mathvariant=
"italic">s
</mml:mi>
71 <mml:msub><mml:mi mathvariant=
"italic">A
</mml:mi>
72 <mml:mi mathvariant=
"italic">s
</mml:mi>
75 </mml:math></inlineequation>
77 <inlineequation><mml:math>
78 <!-- eqn: ( R sub d, G sub d, B sub d, A sub d ): -->
79 <mml:mfenced open=
"(" close=
")">
80 <mml:msub><mml:mi mathvariant=
"italic">R
</mml:mi>
81 <mml:mi mathvariant=
"italic">d
</mml:mi>
83 <mml:msub><mml:mi mathvariant=
"italic">G
</mml:mi>
84 <mml:mi mathvariant=
"italic">d
</mml:mi>
86 <mml:msub><mml:mi mathvariant=
"italic">B
</mml:mi>
87 <mml:mi mathvariant=
"italic">d
</mml:mi>
89 <mml:msub><mml:mi mathvariant=
"italic">A
</mml:mi>
90 <mml:mi mathvariant=
"italic">d
</mml:mi>
93 </mml:math></inlineequation>,
95 The result color is referred to as
96 <inlineequation><mml:math>
97 <!-- eqn: ( R sub r, G sub r, B sub r, A sub r ): -->
98 <mml:mfenced open=
"(" close=
")">
99 <mml:msub><mml:mi mathvariant=
"italic">R
</mml:mi>
100 <mml:mi mathvariant=
"italic">r
</mml:mi>
102 <mml:msub><mml:mi mathvariant=
"italic">G
</mml:mi>
103 <mml:mi mathvariant=
"italic">r
</mml:mi>
105 <mml:msub><mml:mi mathvariant=
"italic">B
</mml:mi>
106 <mml:mi mathvariant=
"italic">r
</mml:mi>
108 <mml:msub><mml:mi mathvariant=
"italic">A
</mml:mi>
109 <mml:mi mathvariant=
"italic">r
</mml:mi>
112 </mml:math></inlineequation>.
113 The source and destination blend factors are denoted
114 <inlineequation><mml:math>
115 <!-- eqn: ( s sub R, s sub G, s sub B, s sub A ): -->
116 <mml:mfenced open=
"(" close=
")">
117 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
118 <mml:mi mathvariant=
"italic">R
</mml:mi>
120 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
121 <mml:mi mathvariant=
"italic">G
</mml:mi>
123 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
124 <mml:mi mathvariant=
"italic">B
</mml:mi>
126 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
127 <mml:mi mathvariant=
"italic">A
</mml:mi>
130 </mml:math></inlineequation>
132 <inlineequation><mml:math>
133 <!-- eqn: ( d sub R, d sub G, d sub B, d sub A ): -->
134 <mml:mfenced open=
"(" close=
")">
135 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
136 <mml:mi mathvariant=
"italic">R
</mml:mi>
138 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
139 <mml:mi mathvariant=
"italic">G
</mml:mi>
141 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
142 <mml:mi mathvariant=
"italic">B
</mml:mi>
144 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
145 <mml:mi mathvariant=
"italic">A
</mml:mi>
148 </mml:math></inlineequation>,
150 For these equations all color components are understood to have values
152 <inlineequation><mml:math>
154 <mml:mfenced open=
"[" close=
"]">
158 </mml:math></inlineequation>.
160 <informaltable frame=
"topbot">
161 <tgroup cols=
"3" align=
"left">
162 <colspec colwidth=
"1.1*" />
163 <colspec colwidth=
"1*" />
164 <colspec colwidth=
"1*" />
167 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
170 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
173 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
181 <constant>GL_FUNC_ADD
</constant>
184 <informalequation><mml:math>
185 <!-- eqn: Rr = R sub s s sub R + R sub d d sub R : -->
187 <mml:mi mathvariant=
"italic">Rr
</mml:mi>
190 <mml:msub><mml:mi mathvariant=
"italic">R
</mml:mi>
191 <mml:mi mathvariant=
"italic">s
</mml:mi>
193 <mml:mo>⁢</mml:mo>
194 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
195 <mml:mi mathvariant=
"italic">R
</mml:mi>
198 <mml:msub><mml:mi mathvariant=
"italic">R
</mml:mi>
199 <mml:mi mathvariant=
"italic">d
</mml:mi>
201 <mml:mo>⁢</mml:mo>
202 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
203 <mml:mi mathvariant=
"italic">R
</mml:mi>
207 </mml:math></informalequation>
208 <informalequation><mml:math>
209 <!-- eqn: Gr = G sub s s sub G + G sub d d sub G : -->
211 <mml:mi mathvariant=
"italic">Gr
</mml:mi>
214 <mml:msub><mml:mi mathvariant=
"italic">G
</mml:mi>
215 <mml:mi mathvariant=
"italic">s
</mml:mi>
217 <mml:mo>⁢</mml:mo>
218 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
219 <mml:mi mathvariant=
"italic">G
</mml:mi>
222 <mml:msub><mml:mi mathvariant=
"italic">G
</mml:mi>
223 <mml:mi mathvariant=
"italic">d
</mml:mi>
225 <mml:mo>⁢</mml:mo>
226 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
227 <mml:mi mathvariant=
"italic">G
</mml:mi>
231 </mml:math></informalequation>
232 <informalequation><mml:math>
233 <!-- eqn: Br = B sub s s sub B + B sub d d sub B : -->
235 <mml:mi mathvariant=
"italic">Br
</mml:mi>
238 <mml:msub><mml:mi mathvariant=
"italic">B
</mml:mi>
239 <mml:mi mathvariant=
"italic">s
</mml:mi>
241 <mml:mo>⁢</mml:mo>
242 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
243 <mml:mi mathvariant=
"italic">B
</mml:mi>
246 <mml:msub><mml:mi mathvariant=
"italic">B
</mml:mi>
247 <mml:mi mathvariant=
"italic">d
</mml:mi>
249 <mml:mo>⁢</mml:mo>
250 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
251 <mml:mi mathvariant=
"italic">B
</mml:mi>
255 </mml:math></informalequation>
258 <informalequation><mml:math>
259 <!-- eqn: Ar = A sub s s sub A + A sub d d sub A : -->
261 <mml:mi mathvariant=
"italic">Ar
</mml:mi>
264 <mml:msub><mml:mi mathvariant=
"italic">A
</mml:mi>
265 <mml:mi mathvariant=
"italic">s
</mml:mi>
267 <mml:mo>⁢</mml:mo>
268 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
269 <mml:mi mathvariant=
"italic">A
</mml:mi>
272 <mml:msub><mml:mi mathvariant=
"italic">A
</mml:mi>
273 <mml:mi mathvariant=
"italic">d
</mml:mi>
275 <mml:mo>⁢</mml:mo>
276 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
277 <mml:mi mathvariant=
"italic">A
</mml:mi>
281 </mml:math></informalequation>
286 <constant>GL_FUNC_SUBTRACT
</constant>
289 <informalequation><mml:math>
290 <!-- eqn: Rr = R sub s s sub R - R sub d d sub R : -->
292 <mml:mi mathvariant=
"italic">Rr
</mml:mi>
295 <mml:msub><mml:mi mathvariant=
"italic">R
</mml:mi>
296 <mml:mi mathvariant=
"italic">s
</mml:mi>
298 <mml:mo>⁢</mml:mo>
299 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
300 <mml:mi mathvariant=
"italic">R
</mml:mi>
303 <mml:msub><mml:mi mathvariant=
"italic">R
</mml:mi>
304 <mml:mi mathvariant=
"italic">d
</mml:mi>
306 <mml:mo>⁢</mml:mo>
307 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
308 <mml:mi mathvariant=
"italic">R
</mml:mi>
312 </mml:math></informalequation>
313 <informalequation><mml:math>
314 <!-- eqn: Gr = G sub s s sub G - G sub d d sub G : -->
316 <mml:mi mathvariant=
"italic">Gr
</mml:mi>
319 <mml:msub><mml:mi mathvariant=
"italic">G
</mml:mi>
320 <mml:mi mathvariant=
"italic">s
</mml:mi>
322 <mml:mo>⁢</mml:mo>
323 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
324 <mml:mi mathvariant=
"italic">G
</mml:mi>
327 <mml:msub><mml:mi mathvariant=
"italic">G
</mml:mi>
328 <mml:mi mathvariant=
"italic">d
</mml:mi>
330 <mml:mo>⁢</mml:mo>
331 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
332 <mml:mi mathvariant=
"italic">G
</mml:mi>
336 </mml:math></informalequation>
337 <informalequation><mml:math>
338 <!-- eqn: Br = B sub s s sub B - B sub d d sub B : -->
340 <mml:mi mathvariant=
"italic">Br
</mml:mi>
343 <mml:msub><mml:mi mathvariant=
"italic">B
</mml:mi>
344 <mml:mi mathvariant=
"italic">s
</mml:mi>
346 <mml:mo>⁢</mml:mo>
347 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
348 <mml:mi mathvariant=
"italic">B
</mml:mi>
351 <mml:msub><mml:mi mathvariant=
"italic">B
</mml:mi>
352 <mml:mi mathvariant=
"italic">d
</mml:mi>
354 <mml:mo>⁢</mml:mo>
355 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
356 <mml:mi mathvariant=
"italic">B
</mml:mi>
360 </mml:math></informalequation>
363 <informalequation><mml:math>
364 <!-- eqn: Ar = A sub s s sub A - A sub d d sub A : -->
366 <mml:mi mathvariant=
"italic">Ar
</mml:mi>
369 <mml:msub><mml:mi mathvariant=
"italic">A
</mml:mi>
370 <mml:mi mathvariant=
"italic">s
</mml:mi>
372 <mml:mo>⁢</mml:mo>
373 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
374 <mml:mi mathvariant=
"italic">A
</mml:mi>
377 <mml:msub><mml:mi mathvariant=
"italic">A
</mml:mi>
378 <mml:mi mathvariant=
"italic">d
</mml:mi>
380 <mml:mo>⁢</mml:mo>
381 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
382 <mml:mi mathvariant=
"italic">A
</mml:mi>
386 </mml:math></informalequation>
391 <constant>GL_FUNC_REVERSE_SUBTRACT
</constant>
394 <informalequation><mml:math>
395 <!-- eqn: Rr = R sub d d sub R - R sub s s sub R : -->
397 <mml:mi mathvariant=
"italic">Rr
</mml:mi>
400 <mml:msub><mml:mi mathvariant=
"italic">R
</mml:mi>
401 <mml:mi mathvariant=
"italic">d
</mml:mi>
403 <mml:mo>⁢</mml:mo>
404 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
405 <mml:mi mathvariant=
"italic">R
</mml:mi>
408 <mml:msub><mml:mi mathvariant=
"italic">R
</mml:mi>
409 <mml:mi mathvariant=
"italic">s
</mml:mi>
411 <mml:mo>⁢</mml:mo>
412 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
413 <mml:mi mathvariant=
"italic">R
</mml:mi>
417 </mml:math></informalequation>
418 <informalequation><mml:math>
419 <!-- eqn: Gr = G sub d d sub G - G sub s s sub G : -->
421 <mml:mi mathvariant=
"italic">Gr
</mml:mi>
424 <mml:msub><mml:mi mathvariant=
"italic">G
</mml:mi>
425 <mml:mi mathvariant=
"italic">d
</mml:mi>
427 <mml:mo>⁢</mml:mo>
428 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
429 <mml:mi mathvariant=
"italic">G
</mml:mi>
432 <mml:msub><mml:mi mathvariant=
"italic">G
</mml:mi>
433 <mml:mi mathvariant=
"italic">s
</mml:mi>
435 <mml:mo>⁢</mml:mo>
436 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
437 <mml:mi mathvariant=
"italic">G
</mml:mi>
441 </mml:math></informalequation>
442 <informalequation><mml:math>
443 <!-- eqn: Br = B sub d d sub B - B sub s s sub B : -->
445 <mml:mi mathvariant=
"italic">Br
</mml:mi>
448 <mml:msub><mml:mi mathvariant=
"italic">B
</mml:mi>
449 <mml:mi mathvariant=
"italic">d
</mml:mi>
451 <mml:mo>⁢</mml:mo>
452 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
453 <mml:mi mathvariant=
"italic">B
</mml:mi>
456 <mml:msub><mml:mi mathvariant=
"italic">B
</mml:mi>
457 <mml:mi mathvariant=
"italic">s
</mml:mi>
459 <mml:mo>⁢</mml:mo>
460 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
461 <mml:mi mathvariant=
"italic">B
</mml:mi>
465 </mml:math></informalequation>
468 <informalequation><mml:math>
469 <!-- eqn: Ar = A sub d d sub A - A sub s s sub A : -->
471 <mml:mi mathvariant=
"italic">Ar
</mml:mi>
474 <mml:msub><mml:mi mathvariant=
"italic">A
</mml:mi>
475 <mml:mi mathvariant=
"italic">d
</mml:mi>
477 <mml:mo>⁢</mml:mo>
478 <mml:msub><mml:mi mathvariant=
"italic">d
</mml:mi>
479 <mml:mi mathvariant=
"italic">A
</mml:mi>
482 <mml:msub><mml:mi mathvariant=
"italic">A
</mml:mi>
483 <mml:mi mathvariant=
"italic">s
</mml:mi>
485 <mml:mo>⁢</mml:mo>
486 <mml:msub><mml:mi mathvariant=
"italic">s
</mml:mi>
487 <mml:mi mathvariant=
"italic">A
</mml:mi>
491 </mml:math></informalequation>
496 <constant>GL_MIN
</constant>
499 <informalequation><mml:math>
500 <!-- eqn: Rr = min ( R sub s, R sub d): -->
502 <mml:mi mathvariant=
"italic">Rr
</mml:mi>
505 <mml:mi mathvariant=
"italic">min
</mml:mi>
506 <mml:mo>⁡</mml:mo>
507 <mml:mfenced open=
"(" close=
")">
509 <mml:msub><mml:mi mathvariant=
"italic">R
</mml:mi>
510 <mml:mi mathvariant=
"italic">s
</mml:mi>
514 <mml:msub><mml:mi mathvariant=
"italic">R
</mml:mi>
515 <mml:mi mathvariant=
"italic">d
</mml:mi>
521 </mml:math></informalequation>
522 <informalequation><mml:math>
523 <!-- eqn: Gr = min ( G sub s, G sub d): -->
525 <mml:mi mathvariant=
"italic">Gr
</mml:mi>
528 <mml:mi mathvariant=
"italic">min
</mml:mi>
529 <mml:mo>⁡</mml:mo>
530 <mml:mfenced open=
"(" close=
")">
532 <mml:msub><mml:mi mathvariant=
"italic">G
</mml:mi>
533 <mml:mi mathvariant=
"italic">s
</mml:mi>
537 <mml:msub><mml:mi mathvariant=
"italic">G
</mml:mi>
538 <mml:mi mathvariant=
"italic">d
</mml:mi>
544 </mml:math></informalequation>
545 <informalequation><mml:math>
546 <!-- eqn: Br = min ( B sub s, B sub d): -->
548 <mml:mi mathvariant=
"italic">Br
</mml:mi>
551 <mml:mi mathvariant=
"italic">min
</mml:mi>
552 <mml:mo>⁡</mml:mo>
553 <mml:mfenced open=
"(" close=
")">
555 <mml:msub><mml:mi mathvariant=
"italic">B
</mml:mi>
556 <mml:mi mathvariant=
"italic">s
</mml:mi>
560 <mml:msub><mml:mi mathvariant=
"italic">B
</mml:mi>
561 <mml:mi mathvariant=
"italic">d
</mml:mi>
567 </mml:math></informalequation>
570 <informalequation><mml:math>
571 <!-- eqn: Ar = min ( A sub s, A sub d): -->
573 <mml:mi mathvariant=
"italic">Ar
</mml:mi>
576 <mml:mi mathvariant=
"italic">min
</mml:mi>
577 <mml:mo>⁡</mml:mo>
578 <mml:mfenced open=
"(" close=
")">
580 <mml:msub><mml:mi mathvariant=
"italic">A
</mml:mi>
581 <mml:mi mathvariant=
"italic">s
</mml:mi>
585 <mml:msub><mml:mi mathvariant=
"italic">A
</mml:mi>
586 <mml:mi mathvariant=
"italic">d
</mml:mi>
592 </mml:math></informalequation>
597 <constant>GL_MAX
</constant>
600 <informalequation><mml:math>
601 <!-- eqn: Rr = max ( R sub s, R sub d): -->
603 <mml:mi mathvariant=
"italic">Rr
</mml:mi>
606 <mml:mi mathvariant=
"italic">max
</mml:mi>
607 <mml:mo>⁡</mml:mo>
608 <mml:mfenced open=
"(" close=
")">
610 <mml:msub><mml:mi mathvariant=
"italic">R
</mml:mi>
611 <mml:mi mathvariant=
"italic">s
</mml:mi>
615 <mml:msub><mml:mi mathvariant=
"italic">R
</mml:mi>
616 <mml:mi mathvariant=
"italic">d
</mml:mi>
622 </mml:math></informalequation>
623 <informalequation><mml:math>
624 <!-- eqn: Gr = max ( G sub s, G sub d): -->
626 <mml:mi mathvariant=
"italic">Gr
</mml:mi>
629 <mml:mi mathvariant=
"italic">max
</mml:mi>
630 <mml:mo>⁡</mml:mo>
631 <mml:mfenced open=
"(" close=
")">
633 <mml:msub><mml:mi mathvariant=
"italic">G
</mml:mi>
634 <mml:mi mathvariant=
"italic">s
</mml:mi>
638 <mml:msub><mml:mi mathvariant=
"italic">G
</mml:mi>
639 <mml:mi mathvariant=
"italic">d
</mml:mi>
645 </mml:math></informalequation>
646 <informalequation><mml:math>
647 <!-- eqn: Br = max ( B sub s, B sub d): -->
649 <mml:mi mathvariant=
"italic">Br
</mml:mi>
652 <mml:mi mathvariant=
"italic">max
</mml:mi>
653 <mml:mo>⁡</mml:mo>
654 <mml:mfenced open=
"(" close=
")">
656 <mml:msub><mml:mi mathvariant=
"italic">B
</mml:mi>
657 <mml:mi mathvariant=
"italic">s
</mml:mi>
661 <mml:msub><mml:mi mathvariant=
"italic">B
</mml:mi>
662 <mml:mi mathvariant=
"italic">d
</mml:mi>
668 </mml:math></informalequation>
671 <informalequation><mml:math>
672 <!-- eqn: Ar = max ( A sub s, A sub d): -->
674 <mml:mi mathvariant=
"italic">Ar
</mml:mi>
677 <mml:mi mathvariant=
"italic">max
</mml:mi>
678 <mml:mo>⁡</mml:mo>
679 <mml:mfenced open=
"(" close=
")">
681 <mml:msub><mml:mi mathvariant=
"italic">A
</mml:mi>
682 <mml:mi mathvariant=
"italic">s
</mml:mi>
686 <mml:msub><mml:mi mathvariant=
"italic">A
</mml:mi>
687 <mml:mi mathvariant=
"italic">d
</mml:mi>
693 </mml:math></informalequation>
701 The results of these equations are clamped to the range
702 <inlineequation><mml:math>
704 <mml:mfenced open=
"[" close=
"]">
708 </mml:math></inlineequation>.
711 The
<constant>GL_MIN
</constant> and
<constant>GL_MAX
</constant> equations are useful for applications
712 that analyze image data (image thresholding against a constant color,
714 The
<constant>GL_FUNC_ADD
</constant> equation is useful
715 for antialiasing and transparency, among other things.
718 Initially, both the RGB blend equation and the alpha blend equation are set to
<constant>GL_FUNC_ADD
</constant>.
723 <refsect1 id=
"notes"><title>Notes
</title>
725 The
<constant>GL_MIN
</constant>, and
<constant>GL_MAX
</constant> equations do not use
726 the source or destination factors, only the source and destination colors.
729 <refsect1 id=
"errors"><title>Errors
</title>
731 <constant>GL_INVALID_ENUM
</constant> is generated if
<parameter>mode
</parameter> is not one of
732 <constant>GL_FUNC_ADD
</constant>,
<constant>GL_FUNC_SUBTRACT
</constant>,
<constant>GL_FUNC_REVERSE_SUBTRACT
</constant>,
733 <constant>GL_MAX
</constant>, or
<constant>GL_MIN
</constant>.
736 <refsect1 id=
"associatedgets"><title>Associated Gets
</title>
738 <citerefentry><refentrytitle>glGet
</refentrytitle></citerefentry> with an argument of
<constant>GL_BLEND_EQUATION_RGB
</constant>
741 <citerefentry><refentrytitle>glGet
</refentrytitle></citerefentry> with an argument of
<constant>GL_BLEND_EQUATION_ALPHA
</constant>
744 <refsect1 id=
"seealso"><title>See Also
</title>
746 <citerefentry><refentrytitle>glBlendColor
</refentrytitle></citerefentry>,
747 <citerefentry><refentrytitle>glBlendFunc
</refentrytitle></citerefentry>
748 <citerefentry><refentrytitle>glBlendFuncSeparate
</refentrytitle></citerefentry>
751 <refsect1 id=
"Copyright"><title>Copyright
</title>
753 Copyright
<trademark class=
"copyright"></trademark> 1991-
2006
754 Silicon Graphics, Inc. This document is licensed under the SGI
755 Free Software B License. For details, see
756 <ulink url=
"http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/
</ulink>.