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1 | <?xml version="1.0" encoding="UTF-8"?>\r |
2 | <!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"\r | |
3 | "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">\r | |
4 | <refentry id="glBlendEquationSeparate">\r | |
5 | <refmeta>\r | |
6 | <refmetainfo>\r | |
7 | <copyright>\r | |
8 | <year>1991-2006</year>\r | |
9 | <holder>Silicon Graphics, Inc.</holder>\r | |
10 | </copyright>\r | |
11 | </refmetainfo>\r | |
12 | <refentrytitle>glBlendEquationSeparate</refentrytitle>\r | |
13 | <manvolnum>3G</manvolnum>\r | |
14 | </refmeta>\r | |
15 | <refnamediv>\r | |
16 | <refname>glBlendEquationSeparate</refname>\r | |
17 | <refpurpose>set the RGB blend equation and the alpha blend equation separately</refpurpose>\r | |
18 | </refnamediv>\r | |
19 | <refsynopsisdiv><title>C Specification</title>\r | |
20 | <funcsynopsis>\r | |
21 | <funcprototype>\r | |
22 | <funcdef>void <function>glBlendEquationSeparate</function></funcdef>\r | |
23 | <paramdef>GLenum <parameter>modeRGB</parameter></paramdef>\r | |
24 | <paramdef>GLenum <parameter>modeAlpha</parameter></paramdef>\r | |
25 | </funcprototype>\r | |
26 | </funcsynopsis>\r | |
27 | </refsynopsisdiv>\r | |
28 | <!-- eqn: ignoring delim $$ -->\r | |
29 | <refsect1 id="parameters"><title>Parameters</title>\r | |
30 | <variablelist>\r | |
31 | <varlistentry>\r | |
32 | <term><parameter>modeRGB</parameter></term>\r | |
33 | <listitem>\r | |
34 | <para>\r | |
35 | specifies the RGB blend equation, how the red, green, and blue components of the source and destination colors are combined.\r | |
36 | It must be <constant>GL_FUNC_ADD</constant>, <constant>GL_FUNC_SUBTRACT</constant>,\r | |
37 | <constant>GL_FUNC_REVERSE_SUBTRACT</constant>, <constant>GL_MIN</constant>, <constant>GL_MAX</constant>.\r | |
38 | </para>\r | |
39 | </listitem>\r | |
40 | </varlistentry>\r | |
41 | <varlistentry>\r | |
42 | <term><parameter>modeAlpha</parameter></term>\r | |
43 | <listitem>\r | |
44 | <para>\r | |
45 | specifies the alpha blend equation, how the alpha component of the source and destination colors are combined.\r | |
46 | It must be <constant>GL_FUNC_ADD</constant>, <constant>GL_FUNC_SUBTRACT</constant>,\r | |
47 | <constant>GL_FUNC_REVERSE_SUBTRACT</constant>, <constant>GL_MIN</constant>, <constant>GL_MAX</constant>.\r | |
48 | </para>\r | |
49 | </listitem>\r | |
50 | </varlistentry>\r | |
51 | </variablelist>\r | |
52 | </refsect1>\r | |
53 | <refsect1 id="description"><title>Description</title>\r | |
54 | <para>\r | |
55 | The blend equations determines how a new pixel (the ''source'' color)\r | |
56 | is combined with a pixel already in the framebuffer (the ''destination''\r | |
57 | color). This function specifies one blend equation for the RGB-color \r | |
58 | components and one blend equation for the alpha component.\r | |
59 | </para>\r | |
60 | <para>\r | |
61 | The blend equations use the source and destination blend factors\r | |
62 | specified by either <citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry> or\r | |
63 | <citerefentry><refentrytitle>glBlendFuncSeparate</refentrytitle></citerefentry>.\r | |
64 | See <citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry> or <citerefentry><refentrytitle>glBlendFuncSeparate</refentrytitle></citerefentry>\r | |
65 | for a description of the various blend factors.\r | |
66 | </para>\r | |
67 | <para>\r | |
68 | In the equations that follow, source and destination\r | |
69 | color components are referred to as\r | |
70 | <inlineequation><mml:math>\r | |
71 | <!-- eqn: ( R sub s, G sub s, B sub s, A sub s ):-->\r | |
72 | <mml:mfenced open="(" close=")">\r | |
73 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
74 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
75 | </mml:msub>\r | |
76 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi>\r | |
77 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
78 | </mml:msub>\r | |
79 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi>\r | |
80 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
81 | </mml:msub>\r | |
82 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi>\r | |
83 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
84 | </mml:msub>\r | |
85 | </mml:mfenced>\r | |
86 | </mml:math></inlineequation>\r | |
87 | and\r | |
88 | <inlineequation><mml:math>\r | |
89 | <!-- eqn: ( R sub d, G sub d, B sub d, A sub d ):-->\r | |
90 | <mml:mfenced open="(" close=")">\r | |
91 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
92 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
93 | </mml:msub>\r | |
94 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi>\r | |
95 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
96 | </mml:msub>\r | |
97 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi>\r | |
98 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
99 | </mml:msub>\r | |
100 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi>\r | |
101 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
102 | </mml:msub>\r | |
103 | </mml:mfenced>\r | |
104 | </mml:math></inlineequation>,\r | |
105 | respectively.\r | |
106 | The result color is referred to as\r | |
107 | <inlineequation><mml:math>\r | |
108 | <!-- eqn: ( R sub r, G sub r, B sub r, A sub r ):-->\r | |
109 | <mml:mfenced open="(" close=")">\r | |
110 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
111 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
112 | </mml:msub>\r | |
113 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi>\r | |
114 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
115 | </mml:msub>\r | |
116 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi>\r | |
117 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
118 | </mml:msub>\r | |
119 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi>\r | |
120 | <mml:mi mathvariant="italic">r</mml:mi>\r | |
121 | </mml:msub>\r | |
122 | </mml:mfenced>\r | |
123 | </mml:math></inlineequation>.\r | |
124 | The source and destination blend factors are denoted\r | |
125 | <inlineequation><mml:math>\r | |
126 | <!-- eqn: ( s sub R, s sub G, s sub B, s sub A ):-->\r | |
127 | <mml:mfenced open="(" close=")">\r | |
128 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
129 | <mml:mi mathvariant="italic">R</mml:mi>\r | |
130 | </mml:msub>\r | |
131 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
132 | <mml:mi mathvariant="italic">G</mml:mi>\r | |
133 | </mml:msub>\r | |
134 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
135 | <mml:mi mathvariant="italic">B</mml:mi>\r | |
136 | </mml:msub>\r | |
137 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
138 | <mml:mi mathvariant="italic">A</mml:mi>\r | |
139 | </mml:msub>\r | |
140 | </mml:mfenced>\r | |
141 | </mml:math></inlineequation>\r | |
142 | and\r | |
143 | <inlineequation><mml:math>\r | |
144 | <!-- eqn: ( d sub R, d sub G, d sub B, d sub A ):-->\r | |
145 | <mml:mfenced open="(" close=")">\r | |
146 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
147 | <mml:mi mathvariant="italic">R</mml:mi>\r | |
148 | </mml:msub>\r | |
149 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
150 | <mml:mi mathvariant="italic">G</mml:mi>\r | |
151 | </mml:msub>\r | |
152 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
153 | <mml:mi mathvariant="italic">B</mml:mi>\r | |
154 | </mml:msub>\r | |
155 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
156 | <mml:mi mathvariant="italic">A</mml:mi>\r | |
157 | </mml:msub>\r | |
158 | </mml:mfenced>\r | |
159 | </mml:math></inlineequation>,\r | |
160 | respectively.\r | |
161 | For these equations all color components are understood to have values\r | |
162 | in the range \r | |
163 | <inlineequation><mml:math>\r | |
164 | <!-- eqn: [0,1]:-->\r | |
165 | <mml:mfenced open="[" close="]">\r | |
166 | <mml:mn>0</mml:mn>\r | |
167 | <mml:mn>1</mml:mn>\r | |
168 | </mml:mfenced>\r | |
169 | </mml:math></inlineequation>.\r | |
170 | \r | |
171 | <informaltable frame="topbot">\r | |
172 | <tgroup cols="3" align="left">\r | |
173 | <colspec colwidth="1.1*" />\r | |
174 | <colspec colwidth="1*" />\r | |
175 | <colspec colwidth="1*" />\r | |
176 | <thead>\r | |
177 | <row>\r | |
178 | <entry rowsep="1" align="left"><emphasis role="bold">\r | |
179 | Mode\r | |
180 | </emphasis></entry>\r | |
181 | <entry rowsep="1" align="left"><emphasis role="bold">\r | |
182 | RGB Components\r | |
183 | </emphasis></entry>\r | |
184 | <entry rowsep="1" align="left"><emphasis role="bold">\r | |
185 | Alpha Component\r | |
186 | </emphasis></entry>\r | |
187 | </row>\r | |
188 | </thead>\r | |
189 | <tbody>\r | |
190 | <row>\r | |
191 | <entry align="left">\r | |
192 | <constant>GL_FUNC_ADD</constant>\r | |
193 | </entry>\r | |
194 | <entry align="left">\r | |
195 | <informalequation><mml:math>\r | |
196 | <!-- eqn: Rr = R sub s s sub R + R sub d d sub R :-->\r | |
197 | <mml:mrow>\r | |
198 | <mml:mi mathvariant="italic">Rr</mml:mi>\r | |
199 | <mml:mo>=</mml:mo>\r | |
200 | <mml:mrow>\r | |
201 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
202 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
203 | </mml:msub>\r | |
204 | <mml:mo>⁢</mml:mo>\r | |
205 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
206 | <mml:mi mathvariant="italic">R</mml:mi>\r | |
207 | </mml:msub>\r | |
208 | <mml:mo>+</mml:mo>\r | |
209 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
210 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
211 | </mml:msub>\r | |
212 | <mml:mo>⁢</mml:mo>\r | |
213 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
214 | <mml:mi mathvariant="italic">R</mml:mi>\r | |
215 | </mml:msub>\r | |
216 | </mml:mrow>\r | |
217 | </mml:mrow>\r | |
218 | </mml:math></informalequation>\r | |
219 | <informalequation><mml:math>\r | |
220 | <!-- eqn: Gr = G sub s s sub G + G sub d d sub G :-->\r | |
221 | <mml:mrow>\r | |
222 | <mml:mi mathvariant="italic">Gr</mml:mi>\r | |
223 | <mml:mo>=</mml:mo>\r | |
224 | <mml:mrow>\r | |
225 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi>\r | |
226 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
227 | </mml:msub>\r | |
228 | <mml:mo>⁢</mml:mo>\r | |
229 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
230 | <mml:mi mathvariant="italic">G</mml:mi>\r | |
231 | </mml:msub>\r | |
232 | <mml:mo>+</mml:mo>\r | |
233 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi>\r | |
234 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
235 | </mml:msub>\r | |
236 | <mml:mo>⁢</mml:mo>\r | |
237 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
238 | <mml:mi mathvariant="italic">G</mml:mi>\r | |
239 | </mml:msub>\r | |
240 | </mml:mrow>\r | |
241 | </mml:mrow>\r | |
242 | </mml:math></informalequation>\r | |
243 | <informalequation><mml:math>\r | |
244 | <!-- eqn: Br = B sub s s sub B + B sub d d sub B :-->\r | |
245 | <mml:mrow>\r | |
246 | <mml:mi mathvariant="italic">Br</mml:mi>\r | |
247 | <mml:mo>=</mml:mo>\r | |
248 | <mml:mrow>\r | |
249 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi>\r | |
250 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
251 | </mml:msub>\r | |
252 | <mml:mo>⁢</mml:mo>\r | |
253 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
254 | <mml:mi mathvariant="italic">B</mml:mi>\r | |
255 | </mml:msub>\r | |
256 | <mml:mo>+</mml:mo>\r | |
257 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi>\r | |
258 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
259 | </mml:msub>\r | |
260 | <mml:mo>⁢</mml:mo>\r | |
261 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
262 | <mml:mi mathvariant="italic">B</mml:mi>\r | |
263 | </mml:msub>\r | |
264 | </mml:mrow>\r | |
265 | </mml:mrow>\r | |
266 | </mml:math></informalequation>\r | |
267 | </entry>\r | |
268 | <entry align="left">\r | |
269 | <informalequation><mml:math>\r | |
270 | <!-- eqn: Ar = A sub s s sub A + A sub d d sub A :-->\r | |
271 | <mml:mrow>\r | |
272 | <mml:mi mathvariant="italic">Ar</mml:mi>\r | |
273 | <mml:mo>=</mml:mo>\r | |
274 | <mml:mrow>\r | |
275 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi>\r | |
276 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
277 | </mml:msub>\r | |
278 | <mml:mo>⁢</mml:mo>\r | |
279 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
280 | <mml:mi mathvariant="italic">A</mml:mi>\r | |
281 | </mml:msub>\r | |
282 | <mml:mo>+</mml:mo>\r | |
283 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi>\r | |
284 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
285 | </mml:msub>\r | |
286 | <mml:mo>⁢</mml:mo>\r | |
287 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
288 | <mml:mi mathvariant="italic">A</mml:mi>\r | |
289 | </mml:msub>\r | |
290 | </mml:mrow>\r | |
291 | </mml:mrow>\r | |
292 | </mml:math></informalequation>\r | |
293 | </entry>\r | |
294 | </row>\r | |
295 | <row>\r | |
296 | <entry align="left">\r | |
297 | <constant>GL_FUNC_SUBTRACT</constant>\r | |
298 | </entry>\r | |
299 | <entry align="left">\r | |
300 | <informalequation><mml:math>\r | |
301 | <!-- eqn: Rr = R sub s s sub R - R sub d d sub R :-->\r | |
302 | <mml:mrow>\r | |
303 | <mml:mi mathvariant="italic">Rr</mml:mi>\r | |
304 | <mml:mo>=</mml:mo>\r | |
305 | <mml:mrow>\r | |
306 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
307 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
308 | </mml:msub>\r | |
309 | <mml:mo>⁢</mml:mo>\r | |
310 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
311 | <mml:mi mathvariant="italic">R</mml:mi>\r | |
312 | </mml:msub>\r | |
313 | <mml:mo>-</mml:mo>\r | |
314 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
315 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
316 | </mml:msub>\r | |
317 | <mml:mo>⁢</mml:mo>\r | |
318 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
319 | <mml:mi mathvariant="italic">R</mml:mi>\r | |
320 | </mml:msub>\r | |
321 | </mml:mrow>\r | |
322 | </mml:mrow>\r | |
323 | </mml:math></informalequation>\r | |
324 | <informalequation><mml:math>\r | |
325 | <!-- eqn: Gr = G sub s s sub G - G sub d d sub G :-->\r | |
326 | <mml:mrow>\r | |
327 | <mml:mi mathvariant="italic">Gr</mml:mi>\r | |
328 | <mml:mo>=</mml:mo>\r | |
329 | <mml:mrow>\r | |
330 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi>\r | |
331 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
332 | </mml:msub>\r | |
333 | <mml:mo>⁢</mml:mo>\r | |
334 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
335 | <mml:mi mathvariant="italic">G</mml:mi>\r | |
336 | </mml:msub>\r | |
337 | <mml:mo>-</mml:mo>\r | |
338 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi>\r | |
339 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
340 | </mml:msub>\r | |
341 | <mml:mo>⁢</mml:mo>\r | |
342 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
343 | <mml:mi mathvariant="italic">G</mml:mi>\r | |
344 | </mml:msub>\r | |
345 | </mml:mrow>\r | |
346 | </mml:mrow>\r | |
347 | </mml:math></informalequation>\r | |
348 | <informalequation><mml:math>\r | |
349 | <!-- eqn: Br = B sub s s sub B - B sub d d sub B :-->\r | |
350 | <mml:mrow>\r | |
351 | <mml:mi mathvariant="italic">Br</mml:mi>\r | |
352 | <mml:mo>=</mml:mo>\r | |
353 | <mml:mrow>\r | |
354 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi>\r | |
355 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
356 | </mml:msub>\r | |
357 | <mml:mo>⁢</mml:mo>\r | |
358 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
359 | <mml:mi mathvariant="italic">B</mml:mi>\r | |
360 | </mml:msub>\r | |
361 | <mml:mo>-</mml:mo>\r | |
362 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi>\r | |
363 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
364 | </mml:msub>\r | |
365 | <mml:mo>⁢</mml:mo>\r | |
366 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
367 | <mml:mi mathvariant="italic">B</mml:mi>\r | |
368 | </mml:msub>\r | |
369 | </mml:mrow>\r | |
370 | </mml:mrow>\r | |
371 | </mml:math></informalequation>\r | |
372 | </entry>\r | |
373 | <entry align="left">\r | |
374 | <informalequation><mml:math>\r | |
375 | <!-- eqn: Ar = A sub s s sub A - A sub d d sub A :-->\r | |
376 | <mml:mrow>\r | |
377 | <mml:mi mathvariant="italic">Ar</mml:mi>\r | |
378 | <mml:mo>=</mml:mo>\r | |
379 | <mml:mrow>\r | |
380 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi>\r | |
381 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
382 | </mml:msub>\r | |
383 | <mml:mo>⁢</mml:mo>\r | |
384 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
385 | <mml:mi mathvariant="italic">A</mml:mi>\r | |
386 | </mml:msub>\r | |
387 | <mml:mo>-</mml:mo>\r | |
388 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi>\r | |
389 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
390 | </mml:msub>\r | |
391 | <mml:mo>⁢</mml:mo>\r | |
392 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
393 | <mml:mi mathvariant="italic">A</mml:mi>\r | |
394 | </mml:msub>\r | |
395 | </mml:mrow>\r | |
396 | </mml:mrow>\r | |
397 | </mml:math></informalequation>\r | |
398 | </entry>\r | |
399 | </row>\r | |
400 | <row>\r | |
401 | <entry align="left">\r | |
402 | <constant>GL_FUNC_REVERSE_SUBTRACT</constant>\r | |
403 | </entry>\r | |
404 | <entry align="left">\r | |
405 | <informalequation><mml:math>\r | |
406 | <!-- eqn: Rr = R sub d d sub R - R sub s s sub R :-->\r | |
407 | <mml:mrow>\r | |
408 | <mml:mi mathvariant="italic">Rr</mml:mi>\r | |
409 | <mml:mo>=</mml:mo>\r | |
410 | <mml:mrow>\r | |
411 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
412 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
413 | </mml:msub>\r | |
414 | <mml:mo>⁢</mml:mo>\r | |
415 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
416 | <mml:mi mathvariant="italic">R</mml:mi>\r | |
417 | </mml:msub>\r | |
418 | <mml:mo>-</mml:mo>\r | |
419 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
420 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
421 | </mml:msub>\r | |
422 | <mml:mo>⁢</mml:mo>\r | |
423 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
424 | <mml:mi mathvariant="italic">R</mml:mi>\r | |
425 | </mml:msub>\r | |
426 | </mml:mrow>\r | |
427 | </mml:mrow>\r | |
428 | </mml:math></informalequation>\r | |
429 | <informalequation><mml:math>\r | |
430 | <!-- eqn: Gr = G sub d d sub G - G sub s s sub G :-->\r | |
431 | <mml:mrow>\r | |
432 | <mml:mi mathvariant="italic">Gr</mml:mi>\r | |
433 | <mml:mo>=</mml:mo>\r | |
434 | <mml:mrow>\r | |
435 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi>\r | |
436 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
437 | </mml:msub>\r | |
438 | <mml:mo>⁢</mml:mo>\r | |
439 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
440 | <mml:mi mathvariant="italic">G</mml:mi>\r | |
441 | </mml:msub>\r | |
442 | <mml:mo>-</mml:mo>\r | |
443 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi>\r | |
444 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
445 | </mml:msub>\r | |
446 | <mml:mo>⁢</mml:mo>\r | |
447 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
448 | <mml:mi mathvariant="italic">G</mml:mi>\r | |
449 | </mml:msub>\r | |
450 | </mml:mrow>\r | |
451 | </mml:mrow>\r | |
452 | </mml:math></informalequation>\r | |
453 | <informalequation><mml:math>\r | |
454 | <!-- eqn: Br = B sub d d sub B - B sub s s sub B :-->\r | |
455 | <mml:mrow>\r | |
456 | <mml:mi mathvariant="italic">Br</mml:mi>\r | |
457 | <mml:mo>=</mml:mo>\r | |
458 | <mml:mrow>\r | |
459 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi>\r | |
460 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
461 | </mml:msub>\r | |
462 | <mml:mo>⁢</mml:mo>\r | |
463 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
464 | <mml:mi mathvariant="italic">B</mml:mi>\r | |
465 | </mml:msub>\r | |
466 | <mml:mo>-</mml:mo>\r | |
467 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi>\r | |
468 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
469 | </mml:msub>\r | |
470 | <mml:mo>⁢</mml:mo>\r | |
471 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
472 | <mml:mi mathvariant="italic">B</mml:mi>\r | |
473 | </mml:msub>\r | |
474 | </mml:mrow>\r | |
475 | </mml:mrow>\r | |
476 | </mml:math></informalequation>\r | |
477 | </entry>\r | |
478 | <entry align="left">\r | |
479 | <informalequation><mml:math>\r | |
480 | <!-- eqn: Ar = A sub d d sub A - A sub s s sub A :-->\r | |
481 | <mml:mrow>\r | |
482 | <mml:mi mathvariant="italic">Ar</mml:mi>\r | |
483 | <mml:mo>=</mml:mo>\r | |
484 | <mml:mrow>\r | |
485 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi>\r | |
486 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
487 | </mml:msub>\r | |
488 | <mml:mo>⁢</mml:mo>\r | |
489 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi>\r | |
490 | <mml:mi mathvariant="italic">A</mml:mi>\r | |
491 | </mml:msub>\r | |
492 | <mml:mo>-</mml:mo>\r | |
493 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi>\r | |
494 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
495 | </mml:msub>\r | |
496 | <mml:mo>⁢</mml:mo>\r | |
497 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi>\r | |
498 | <mml:mi mathvariant="italic">A</mml:mi>\r | |
499 | </mml:msub>\r | |
500 | </mml:mrow>\r | |
501 | </mml:mrow>\r | |
502 | </mml:math></informalequation>\r | |
503 | </entry>\r | |
504 | </row>\r | |
505 | <row>\r | |
506 | <entry align="left">\r | |
507 | <constant>GL_MIN</constant>\r | |
508 | </entry>\r | |
509 | <entry align="left">\r | |
510 | <informalequation><mml:math>\r | |
511 | <!-- eqn: Rr = min ( R sub s, R sub d):-->\r | |
512 | <mml:mrow>\r | |
513 | <mml:mi mathvariant="italic">Rr</mml:mi>\r | |
514 | <mml:mo>=</mml:mo>\r | |
515 | <mml:mrow>\r | |
516 | <mml:mi mathvariant="italic">min</mml:mi>\r | |
517 | <mml:mo>⁡</mml:mo>\r | |
518 | <mml:mfenced open="(" close=")">\r | |
519 | <mml:mrow>\r | |
520 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
521 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
522 | </mml:msub>\r | |
523 | </mml:mrow>\r | |
524 | <mml:mrow>\r | |
525 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
526 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
527 | </mml:msub>\r | |
528 | </mml:mrow>\r | |
529 | </mml:mfenced>\r | |
530 | </mml:mrow>\r | |
531 | </mml:mrow>\r | |
532 | </mml:math></informalequation>\r | |
533 | <informalequation><mml:math>\r | |
534 | <!-- eqn: Gr = min ( G sub s, G sub d):-->\r | |
535 | <mml:mrow>\r | |
536 | <mml:mi mathvariant="italic">Gr</mml:mi>\r | |
537 | <mml:mo>=</mml:mo>\r | |
538 | <mml:mrow>\r | |
539 | <mml:mi mathvariant="italic">min</mml:mi>\r | |
540 | <mml:mo>⁡</mml:mo>\r | |
541 | <mml:mfenced open="(" close=")">\r | |
542 | <mml:mrow>\r | |
543 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi>\r | |
544 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
545 | </mml:msub>\r | |
546 | </mml:mrow>\r | |
547 | <mml:mrow>\r | |
548 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi>\r | |
549 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
550 | </mml:msub>\r | |
551 | </mml:mrow>\r | |
552 | </mml:mfenced>\r | |
553 | </mml:mrow>\r | |
554 | </mml:mrow>\r | |
555 | </mml:math></informalequation>\r | |
556 | <informalequation><mml:math>\r | |
557 | <!-- eqn: Br = min ( B sub s, B sub d):-->\r | |
558 | <mml:mrow>\r | |
559 | <mml:mi mathvariant="italic">Br</mml:mi>\r | |
560 | <mml:mo>=</mml:mo>\r | |
561 | <mml:mrow>\r | |
562 | <mml:mi mathvariant="italic">min</mml:mi>\r | |
563 | <mml:mo>⁡</mml:mo>\r | |
564 | <mml:mfenced open="(" close=")">\r | |
565 | <mml:mrow>\r | |
566 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi>\r | |
567 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
568 | </mml:msub>\r | |
569 | </mml:mrow>\r | |
570 | <mml:mrow>\r | |
571 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi>\r | |
572 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
573 | </mml:msub>\r | |
574 | </mml:mrow>\r | |
575 | </mml:mfenced>\r | |
576 | </mml:mrow>\r | |
577 | </mml:mrow>\r | |
578 | </mml:math></informalequation>\r | |
579 | </entry>\r | |
580 | <entry align="left">\r | |
581 | <informalequation><mml:math>\r | |
582 | <!-- eqn: Ar = min ( A sub s, A sub d):-->\r | |
583 | <mml:mrow>\r | |
584 | <mml:mi mathvariant="italic">Ar</mml:mi>\r | |
585 | <mml:mo>=</mml:mo>\r | |
586 | <mml:mrow>\r | |
587 | <mml:mi mathvariant="italic">min</mml:mi>\r | |
588 | <mml:mo>⁡</mml:mo>\r | |
589 | <mml:mfenced open="(" close=")">\r | |
590 | <mml:mrow>\r | |
591 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi>\r | |
592 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
593 | </mml:msub>\r | |
594 | </mml:mrow>\r | |
595 | <mml:mrow>\r | |
596 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi>\r | |
597 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
598 | </mml:msub>\r | |
599 | </mml:mrow>\r | |
600 | </mml:mfenced>\r | |
601 | </mml:mrow>\r | |
602 | </mml:mrow>\r | |
603 | </mml:math></informalequation>\r | |
604 | </entry>\r | |
605 | </row>\r | |
606 | <row>\r | |
607 | <entry align="left">\r | |
608 | <constant>GL_MAX</constant>\r | |
609 | </entry>\r | |
610 | <entry align="left">\r | |
611 | <informalequation><mml:math>\r | |
612 | <!-- eqn: Rr = max ( R sub s, R sub d):-->\r | |
613 | <mml:mrow>\r | |
614 | <mml:mi mathvariant="italic">Rr</mml:mi>\r | |
615 | <mml:mo>=</mml:mo>\r | |
616 | <mml:mrow>\r | |
617 | <mml:mi mathvariant="italic">max</mml:mi>\r | |
618 | <mml:mo>⁡</mml:mo>\r | |
619 | <mml:mfenced open="(" close=")">\r | |
620 | <mml:mrow>\r | |
621 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
622 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
623 | </mml:msub>\r | |
624 | </mml:mrow>\r | |
625 | <mml:mrow>\r | |
626 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi>\r | |
627 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
628 | </mml:msub>\r | |
629 | </mml:mrow>\r | |
630 | </mml:mfenced>\r | |
631 | </mml:mrow>\r | |
632 | </mml:mrow>\r | |
633 | </mml:math></informalequation>\r | |
634 | <informalequation><mml:math>\r | |
635 | <!-- eqn: Gr = max ( G sub s, G sub d):-->\r | |
636 | <mml:mrow>\r | |
637 | <mml:mi mathvariant="italic">Gr</mml:mi>\r | |
638 | <mml:mo>=</mml:mo>\r | |
639 | <mml:mrow>\r | |
640 | <mml:mi mathvariant="italic">max</mml:mi>\r | |
641 | <mml:mo>⁡</mml:mo>\r | |
642 | <mml:mfenced open="(" close=")">\r | |
643 | <mml:mrow>\r | |
644 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi>\r | |
645 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
646 | </mml:msub>\r | |
647 | </mml:mrow>\r | |
648 | <mml:mrow>\r | |
649 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi>\r | |
650 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
651 | </mml:msub>\r | |
652 | </mml:mrow>\r | |
653 | </mml:mfenced>\r | |
654 | </mml:mrow>\r | |
655 | </mml:mrow>\r | |
656 | </mml:math></informalequation>\r | |
657 | <informalequation><mml:math>\r | |
658 | <!-- eqn: Br = max ( B sub s, B sub d):-->\r | |
659 | <mml:mrow>\r | |
660 | <mml:mi mathvariant="italic">Br</mml:mi>\r | |
661 | <mml:mo>=</mml:mo>\r | |
662 | <mml:mrow>\r | |
663 | <mml:mi mathvariant="italic">max</mml:mi>\r | |
664 | <mml:mo>⁡</mml:mo>\r | |
665 | <mml:mfenced open="(" close=")">\r | |
666 | <mml:mrow>\r | |
667 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi>\r | |
668 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
669 | </mml:msub>\r | |
670 | </mml:mrow>\r | |
671 | <mml:mrow>\r | |
672 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi>\r | |
673 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
674 | </mml:msub>\r | |
675 | </mml:mrow>\r | |
676 | </mml:mfenced>\r | |
677 | </mml:mrow>\r | |
678 | </mml:mrow>\r | |
679 | </mml:math></informalequation>\r | |
680 | </entry>\r | |
681 | <entry align="left">\r | |
682 | <informalequation><mml:math>\r | |
683 | <!-- eqn: Ar = max ( A sub s, A sub d):-->\r | |
684 | <mml:mrow>\r | |
685 | <mml:mi mathvariant="italic">Ar</mml:mi>\r | |
686 | <mml:mo>=</mml:mo>\r | |
687 | <mml:mrow>\r | |
688 | <mml:mi mathvariant="italic">max</mml:mi>\r | |
689 | <mml:mo>⁡</mml:mo>\r | |
690 | <mml:mfenced open="(" close=")">\r | |
691 | <mml:mrow>\r | |
692 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi>\r | |
693 | <mml:mi mathvariant="italic">s</mml:mi>\r | |
694 | </mml:msub>\r | |
695 | </mml:mrow>\r | |
696 | <mml:mrow>\r | |
697 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi>\r | |
698 | <mml:mi mathvariant="italic">d</mml:mi>\r | |
699 | </mml:msub>\r | |
700 | </mml:mrow>\r | |
701 | </mml:mfenced>\r | |
702 | </mml:mrow>\r | |
703 | </mml:mrow>\r | |
704 | </mml:math></informalequation>\r | |
705 | </entry>\r | |
706 | </row>\r | |
707 | </tbody>\r | |
708 | </tgroup>\r | |
709 | </informaltable>\r | |
710 | </para>\r | |
711 | <para>\r | |
712 | The results of these equations are clamped to the range \r | |
713 | <inlineequation><mml:math>\r | |
714 | <!-- eqn: [0,1]:-->\r | |
715 | <mml:mfenced open="[" close="]">\r | |
716 | <mml:mn>0</mml:mn>\r | |
717 | <mml:mn>1</mml:mn>\r | |
718 | </mml:mfenced>\r | |
719 | </mml:math></inlineequation>.\r | |
720 | </para>\r | |
721 | <para>\r | |
722 | The <constant>GL_MIN</constant> and <constant>GL_MAX</constant> equations are useful for applications\r | |
723 | that analyze image data (image thresholding against a constant color,\r | |
724 | for example).\r | |
725 | The <constant>GL_FUNC_ADD</constant> equation is useful\r | |
726 | for antialiasing and transparency, among other things.\r | |
727 | </para>\r | |
728 | <para>\r | |
729 | Initially, both the RGB blend equation and the alpha blend equation are set to <constant>GL_FUNC_ADD</constant>.\r | |
730 | </para>\r | |
731 | <para>\r | |
732 | </para>\r | |
733 | </refsect1>\r | |
734 | <refsect1 id="notes"><title>Notes</title>\r | |
735 | <para>\r | |
736 | <function>glBlendEquationSeparate</function> is available only if the GL version is 2.0 or greater.\r | |
737 | </para>\r | |
738 | <para>\r | |
739 | The <constant>GL_MIN</constant>, and <constant>GL_MAX</constant> equations do not use\r | |
740 | the source or destination factors, only the source and destination colors.\r | |
741 | </para>\r | |
742 | </refsect1>\r | |
743 | <refsect1 id="errors"><title>Errors</title>\r | |
744 | <para>\r | |
745 | <constant>GL_INVALID_ENUM</constant> is generated if either <parameter>modeRGB</parameter> or <parameter>modeAlpha</parameter> is not one of\r | |
746 | <constant>GL_FUNC_ADD</constant>, <constant>GL_FUNC_SUBTRACT</constant>, <constant>GL_FUNC_REVERSE_SUBTRACT</constant>,\r | |
747 | <constant>GL_MAX</constant>, or <constant>GL_MIN</constant>.\r | |
748 | </para>\r | |
749 | <para>\r | |
750 | <constant>GL_INVALID_OPERATION</constant> is generated if <function>glBlendEquationSeparate</function> is executed\r | |
751 | between the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> and the corresponding\r | |
752 | execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.\r | |
753 | </para>\r | |
754 | </refsect1>\r | |
755 | <refsect1 id="associatedgets"><title>Associated Gets</title>\r | |
756 | <para>\r | |
757 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with an argument of <constant>GL_BLEND_EQUATION_RGB</constant>\r | |
758 | </para>\r | |
759 | <para>\r | |
760 | <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with an argument of <constant>GL_BLEND_EQUATION_ALPHA</constant>\r | |
761 | </para>\r | |
762 | </refsect1>\r | |
763 | <refsect1 id="seealso"><title>See Also</title>\r | |
764 | <para>\r | |
765 | <citerefentry><refentrytitle>glGetString</refentrytitle></citerefentry>,\r | |
766 | <citerefentry><refentrytitle>glBlendColor</refentrytitle></citerefentry>,\r | |
767 | <citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry>,\r | |
768 | <citerefentry><refentrytitle>glBlendFuncSeparate</refentrytitle></citerefentry>\r | |
769 | </para>\r | |
770 | </refsect1>\r | |
771 | <refsect1 id="Copyright"><title>Copyright</title>\r | |
772 | <para>\r | |
773 | Copyright <trademark class="copyright"></trademark> 2006 Khronos Group. \r | |
774 | This material may be distributed subject to the terms and conditions set forth in \r | |
775 | the Open Publication License, v 1.0, 8 June 1999.\r | |
776 | <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.\r | |
777 | </para>\r | |
778 | </refsect1>\r | |
779 | </refentry>\r |