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1 | <?xml version="1.0" encoding="UTF-8"?> |
2 | <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd"> | |
3 | <!-- saved from url=(0013)about:internet --> | |
4 | <?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><link rel="stylesheet" type="text/css" href="opengl-man.css" /><title>glBlendEquationSeparate</title><meta name="generator" content="DocBook XSL Stylesheets V1.75.2" /></head><body><div class="refentry" title="glBlendEquationSeparate"><a id="glBlendEquationSeparate"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glBlendEquationSeparate — set the RGB blend equation and the alpha blend equation separately</p></div><div class="refsynopsisdiv" title="C Specification"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" class="funcprototype-table"><tr><td><code class="funcdef">void <b class="fsfunc">glBlendEquationSeparate</b>(</code></td><td>GLenum <var class="pdparam">modeRGB</var>, </td></tr><tr><td> </td><td>GLenum <var class="pdparam">modeAlpha</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1" title="Parameters"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>modeRGB</code></em></span></dt><dd><p> | |
5 | specifies the RGB blend equation, how the red, green, and blue components of the source and destination colors are combined. | |
6 | It must be <code class="constant">GL_FUNC_ADD</code>, <code class="constant">GL_FUNC_SUBTRACT</code>, | |
7 | <code class="constant">GL_FUNC_REVERSE_SUBTRACT</code>, <code class="constant">GL_MIN</code>, <code class="constant">GL_MAX</code>. | |
8 | </p></dd><dt><span class="term"><em class="parameter"><code>modeAlpha</code></em></span></dt><dd><p> | |
9 | specifies the alpha blend equation, how the alpha component of the source and destination colors are combined. | |
10 | It must be <code class="constant">GL_FUNC_ADD</code>, <code class="constant">GL_FUNC_SUBTRACT</code>, | |
11 | <code class="constant">GL_FUNC_REVERSE_SUBTRACT</code>, <code class="constant">GL_MIN</code>, <code class="constant">GL_MAX</code>. | |
12 | </p></dd></dl></div></div><div class="refsect1" title="Description"><a id="description"></a><h2>Description</h2><p> | |
13 | The blend equations determines how a new pixel (the ''source'' color) | |
14 | is combined with a pixel already in the framebuffer (the ''destination'' | |
15 | color). This function specifies one blend equation for the RGB-color | |
16 | components and one blend equation for the alpha component. | |
17 | </p><p> | |
18 | The blend equations use the source and destination blend factors | |
19 | specified by either <a class="citerefentry" href="glBlendFunc.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a> or | |
20 | <a class="citerefentry" href="glBlendFuncSeparate.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFuncSeparate</span></span></a>. | |
21 | See <a class="citerefentry" href="glBlendFunc.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a> or <a class="citerefentry" href="glBlendFuncSeparate.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFuncSeparate</span></span></a> | |
22 | for a description of the various blend factors. | |
23 | </p><p> | |
24 | In the equations that follow, source and destination | |
25 | color components are referred to as | |
26 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
27 | ||
28 | <mml:mfenced open="(" close=")"> | |
29 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> | |
30 | <mml:mi mathvariant="italic">s</mml:mi> | |
31 | </mml:msub> | |
32 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> | |
33 | <mml:mi mathvariant="italic">s</mml:mi> | |
34 | </mml:msub> | |
35 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> | |
36 | <mml:mi mathvariant="italic">s</mml:mi> | |
37 | </mml:msub> | |
38 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> | |
39 | <mml:mi mathvariant="italic">s</mml:mi> | |
40 | </mml:msub> | |
41 | </mml:mfenced> | |
42 | </mml:math> | |
43 | and | |
44 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
45 | ||
46 | <mml:mfenced open="(" close=")"> | |
47 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> | |
48 | <mml:mi mathvariant="italic">d</mml:mi> | |
49 | </mml:msub> | |
50 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> | |
51 | <mml:mi mathvariant="italic">d</mml:mi> | |
52 | </mml:msub> | |
53 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> | |
54 | <mml:mi mathvariant="italic">d</mml:mi> | |
55 | </mml:msub> | |
56 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> | |
57 | <mml:mi mathvariant="italic">d</mml:mi> | |
58 | </mml:msub> | |
59 | </mml:mfenced> | |
60 | </mml:math>, | |
61 | respectively. | |
62 | The result color is referred to as | |
63 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
64 | ||
65 | <mml:mfenced open="(" close=")"> | |
66 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> | |
67 | <mml:mi mathvariant="italic">r</mml:mi> | |
68 | </mml:msub> | |
69 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> | |
70 | <mml:mi mathvariant="italic">r</mml:mi> | |
71 | </mml:msub> | |
72 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> | |
73 | <mml:mi mathvariant="italic">r</mml:mi> | |
74 | </mml:msub> | |
75 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> | |
76 | <mml:mi mathvariant="italic">r</mml:mi> | |
77 | </mml:msub> | |
78 | </mml:mfenced> | |
79 | </mml:math>. | |
80 | The source and destination blend factors are denoted | |
81 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
82 | ||
83 | <mml:mfenced open="(" close=")"> | |
84 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
85 | <mml:mi mathvariant="italic">R</mml:mi> | |
86 | </mml:msub> | |
87 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
88 | <mml:mi mathvariant="italic">G</mml:mi> | |
89 | </mml:msub> | |
90 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
91 | <mml:mi mathvariant="italic">B</mml:mi> | |
92 | </mml:msub> | |
93 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
94 | <mml:mi mathvariant="italic">A</mml:mi> | |
95 | </mml:msub> | |
96 | </mml:mfenced> | |
97 | </mml:math> | |
98 | and | |
99 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
100 | ||
101 | <mml:mfenced open="(" close=")"> | |
102 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
103 | <mml:mi mathvariant="italic">R</mml:mi> | |
104 | </mml:msub> | |
105 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
106 | <mml:mi mathvariant="italic">G</mml:mi> | |
107 | </mml:msub> | |
108 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
109 | <mml:mi mathvariant="italic">B</mml:mi> | |
110 | </mml:msub> | |
111 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
112 | <mml:mi mathvariant="italic">A</mml:mi> | |
113 | </mml:msub> | |
114 | </mml:mfenced> | |
115 | </mml:math>, | |
116 | respectively. | |
117 | For these equations all color components are understood to have values | |
118 | in the range | |
119 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
120 | ||
121 | <mml:mfenced open="[" close="]"> | |
122 | <mml:mn>0</mml:mn> | |
123 | <mml:mn>1</mml:mn> | |
124 | </mml:mfenced> | |
125 | </mml:math>. | |
126 | ||
127 | </p><div class="informaltable"><table border="1"><colgroup><col align="left" /><col align="left" /><col align="left" /></colgroup><thead><tr><th align="left"><span class="bold"><strong> | |
128 | Mode | |
129 | </strong></span></th><th align="left"><span class="bold"><strong> | |
130 | RGB Components | |
131 | </strong></span></th><th align="left"><span class="bold"><strong> | |
132 | Alpha Component | |
133 | </strong></span></th></tr></thead><tbody><tr><td align="left"> | |
134 | <code class="constant">GL_FUNC_ADD</code> | |
135 | </td><td align="left"> | |
136 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
137 | ||
138 | <mml:mrow> | |
139 | <mml:mi mathvariant="italic">Rr</mml:mi> | |
140 | <mml:mo>=</mml:mo> | |
141 | <mml:mrow> | |
142 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> | |
143 | <mml:mi mathvariant="italic">s</mml:mi> | |
144 | </mml:msub> | |
145 | <mml:mo></mml:mo> | |
146 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
147 | <mml:mi mathvariant="italic">R</mml:mi> | |
148 | </mml:msub> | |
149 | <mml:mo>+</mml:mo> | |
150 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> | |
151 | <mml:mi mathvariant="italic">d</mml:mi> | |
152 | </mml:msub> | |
153 | <mml:mo></mml:mo> | |
154 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
155 | <mml:mi mathvariant="italic">R</mml:mi> | |
156 | </mml:msub> | |
157 | </mml:mrow> | |
158 | </mml:mrow> | |
159 | </mml:math></div> | |
160 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
161 | ||
162 | <mml:mrow> | |
163 | <mml:mi mathvariant="italic">Gr</mml:mi> | |
164 | <mml:mo>=</mml:mo> | |
165 | <mml:mrow> | |
166 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> | |
167 | <mml:mi mathvariant="italic">s</mml:mi> | |
168 | </mml:msub> | |
169 | <mml:mo></mml:mo> | |
170 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
171 | <mml:mi mathvariant="italic">G</mml:mi> | |
172 | </mml:msub> | |
173 | <mml:mo>+</mml:mo> | |
174 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> | |
175 | <mml:mi mathvariant="italic">d</mml:mi> | |
176 | </mml:msub> | |
177 | <mml:mo></mml:mo> | |
178 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
179 | <mml:mi mathvariant="italic">G</mml:mi> | |
180 | </mml:msub> | |
181 | </mml:mrow> | |
182 | </mml:mrow> | |
183 | </mml:math></div> | |
184 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
185 | ||
186 | <mml:mrow> | |
187 | <mml:mi mathvariant="italic">Br</mml:mi> | |
188 | <mml:mo>=</mml:mo> | |
189 | <mml:mrow> | |
190 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> | |
191 | <mml:mi mathvariant="italic">s</mml:mi> | |
192 | </mml:msub> | |
193 | <mml:mo></mml:mo> | |
194 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
195 | <mml:mi mathvariant="italic">B</mml:mi> | |
196 | </mml:msub> | |
197 | <mml:mo>+</mml:mo> | |
198 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> | |
199 | <mml:mi mathvariant="italic">d</mml:mi> | |
200 | </mml:msub> | |
201 | <mml:mo></mml:mo> | |
202 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
203 | <mml:mi mathvariant="italic">B</mml:mi> | |
204 | </mml:msub> | |
205 | </mml:mrow> | |
206 | </mml:mrow> | |
207 | </mml:math></div> | |
208 | </td><td align="left"> | |
209 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
210 | ||
211 | <mml:mrow> | |
212 | <mml:mi mathvariant="italic">Ar</mml:mi> | |
213 | <mml:mo>=</mml:mo> | |
214 | <mml:mrow> | |
215 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> | |
216 | <mml:mi mathvariant="italic">s</mml:mi> | |
217 | </mml:msub> | |
218 | <mml:mo></mml:mo> | |
219 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
220 | <mml:mi mathvariant="italic">A</mml:mi> | |
221 | </mml:msub> | |
222 | <mml:mo>+</mml:mo> | |
223 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> | |
224 | <mml:mi mathvariant="italic">d</mml:mi> | |
225 | </mml:msub> | |
226 | <mml:mo></mml:mo> | |
227 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
228 | <mml:mi mathvariant="italic">A</mml:mi> | |
229 | </mml:msub> | |
230 | </mml:mrow> | |
231 | </mml:mrow> | |
232 | </mml:math></div> | |
233 | </td></tr><tr><td align="left"> | |
234 | <code class="constant">GL_FUNC_SUBTRACT</code> | |
235 | </td><td align="left"> | |
236 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
237 | ||
238 | <mml:mrow> | |
239 | <mml:mi mathvariant="italic">Rr</mml:mi> | |
240 | <mml:mo>=</mml:mo> | |
241 | <mml:mrow> | |
242 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> | |
243 | <mml:mi mathvariant="italic">s</mml:mi> | |
244 | </mml:msub> | |
245 | <mml:mo></mml:mo> | |
246 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
247 | <mml:mi mathvariant="italic">R</mml:mi> | |
248 | </mml:msub> | |
249 | <mml:mo>-</mml:mo> | |
250 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> | |
251 | <mml:mi mathvariant="italic">d</mml:mi> | |
252 | </mml:msub> | |
253 | <mml:mo></mml:mo> | |
254 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
255 | <mml:mi mathvariant="italic">R</mml:mi> | |
256 | </mml:msub> | |
257 | </mml:mrow> | |
258 | </mml:mrow> | |
259 | </mml:math></div> | |
260 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
261 | ||
262 | <mml:mrow> | |
263 | <mml:mi mathvariant="italic">Gr</mml:mi> | |
264 | <mml:mo>=</mml:mo> | |
265 | <mml:mrow> | |
266 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> | |
267 | <mml:mi mathvariant="italic">s</mml:mi> | |
268 | </mml:msub> | |
269 | <mml:mo></mml:mo> | |
270 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
271 | <mml:mi mathvariant="italic">G</mml:mi> | |
272 | </mml:msub> | |
273 | <mml:mo>-</mml:mo> | |
274 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> | |
275 | <mml:mi mathvariant="italic">d</mml:mi> | |
276 | </mml:msub> | |
277 | <mml:mo></mml:mo> | |
278 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
279 | <mml:mi mathvariant="italic">G</mml:mi> | |
280 | </mml:msub> | |
281 | </mml:mrow> | |
282 | </mml:mrow> | |
283 | </mml:math></div> | |
284 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
285 | ||
286 | <mml:mrow> | |
287 | <mml:mi mathvariant="italic">Br</mml:mi> | |
288 | <mml:mo>=</mml:mo> | |
289 | <mml:mrow> | |
290 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> | |
291 | <mml:mi mathvariant="italic">s</mml:mi> | |
292 | </mml:msub> | |
293 | <mml:mo></mml:mo> | |
294 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
295 | <mml:mi mathvariant="italic">B</mml:mi> | |
296 | </mml:msub> | |
297 | <mml:mo>-</mml:mo> | |
298 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> | |
299 | <mml:mi mathvariant="italic">d</mml:mi> | |
300 | </mml:msub> | |
301 | <mml:mo></mml:mo> | |
302 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
303 | <mml:mi mathvariant="italic">B</mml:mi> | |
304 | </mml:msub> | |
305 | </mml:mrow> | |
306 | </mml:mrow> | |
307 | </mml:math></div> | |
308 | </td><td align="left"> | |
309 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
310 | ||
311 | <mml:mrow> | |
312 | <mml:mi mathvariant="italic">Ar</mml:mi> | |
313 | <mml:mo>=</mml:mo> | |
314 | <mml:mrow> | |
315 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> | |
316 | <mml:mi mathvariant="italic">s</mml:mi> | |
317 | </mml:msub> | |
318 | <mml:mo></mml:mo> | |
319 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
320 | <mml:mi mathvariant="italic">A</mml:mi> | |
321 | </mml:msub> | |
322 | <mml:mo>-</mml:mo> | |
323 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> | |
324 | <mml:mi mathvariant="italic">d</mml:mi> | |
325 | </mml:msub> | |
326 | <mml:mo></mml:mo> | |
327 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
328 | <mml:mi mathvariant="italic">A</mml:mi> | |
329 | </mml:msub> | |
330 | </mml:mrow> | |
331 | </mml:mrow> | |
332 | </mml:math></div> | |
333 | </td></tr><tr><td align="left"> | |
334 | <code class="constant">GL_FUNC_REVERSE_SUBTRACT</code> | |
335 | </td><td align="left"> | |
336 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
337 | ||
338 | <mml:mrow> | |
339 | <mml:mi mathvariant="italic">Rr</mml:mi> | |
340 | <mml:mo>=</mml:mo> | |
341 | <mml:mrow> | |
342 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> | |
343 | <mml:mi mathvariant="italic">d</mml:mi> | |
344 | </mml:msub> | |
345 | <mml:mo></mml:mo> | |
346 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
347 | <mml:mi mathvariant="italic">R</mml:mi> | |
348 | </mml:msub> | |
349 | <mml:mo>-</mml:mo> | |
350 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> | |
351 | <mml:mi mathvariant="italic">s</mml:mi> | |
352 | </mml:msub> | |
353 | <mml:mo></mml:mo> | |
354 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
355 | <mml:mi mathvariant="italic">R</mml:mi> | |
356 | </mml:msub> | |
357 | </mml:mrow> | |
358 | </mml:mrow> | |
359 | </mml:math></div> | |
360 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
361 | ||
362 | <mml:mrow> | |
363 | <mml:mi mathvariant="italic">Gr</mml:mi> | |
364 | <mml:mo>=</mml:mo> | |
365 | <mml:mrow> | |
366 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> | |
367 | <mml:mi mathvariant="italic">d</mml:mi> | |
368 | </mml:msub> | |
369 | <mml:mo></mml:mo> | |
370 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
371 | <mml:mi mathvariant="italic">G</mml:mi> | |
372 | </mml:msub> | |
373 | <mml:mo>-</mml:mo> | |
374 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> | |
375 | <mml:mi mathvariant="italic">s</mml:mi> | |
376 | </mml:msub> | |
377 | <mml:mo></mml:mo> | |
378 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
379 | <mml:mi mathvariant="italic">G</mml:mi> | |
380 | </mml:msub> | |
381 | </mml:mrow> | |
382 | </mml:mrow> | |
383 | </mml:math></div> | |
384 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
385 | ||
386 | <mml:mrow> | |
387 | <mml:mi mathvariant="italic">Br</mml:mi> | |
388 | <mml:mo>=</mml:mo> | |
389 | <mml:mrow> | |
390 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> | |
391 | <mml:mi mathvariant="italic">d</mml:mi> | |
392 | </mml:msub> | |
393 | <mml:mo></mml:mo> | |
394 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
395 | <mml:mi mathvariant="italic">B</mml:mi> | |
396 | </mml:msub> | |
397 | <mml:mo>-</mml:mo> | |
398 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> | |
399 | <mml:mi mathvariant="italic">s</mml:mi> | |
400 | </mml:msub> | |
401 | <mml:mo></mml:mo> | |
402 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
403 | <mml:mi mathvariant="italic">B</mml:mi> | |
404 | </mml:msub> | |
405 | </mml:mrow> | |
406 | </mml:mrow> | |
407 | </mml:math></div> | |
408 | </td><td align="left"> | |
409 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
410 | ||
411 | <mml:mrow> | |
412 | <mml:mi mathvariant="italic">Ar</mml:mi> | |
413 | <mml:mo>=</mml:mo> | |
414 | <mml:mrow> | |
415 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> | |
416 | <mml:mi mathvariant="italic">d</mml:mi> | |
417 | </mml:msub> | |
418 | <mml:mo></mml:mo> | |
419 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> | |
420 | <mml:mi mathvariant="italic">A</mml:mi> | |
421 | </mml:msub> | |
422 | <mml:mo>-</mml:mo> | |
423 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> | |
424 | <mml:mi mathvariant="italic">s</mml:mi> | |
425 | </mml:msub> | |
426 | <mml:mo></mml:mo> | |
427 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> | |
428 | <mml:mi mathvariant="italic">A</mml:mi> | |
429 | </mml:msub> | |
430 | </mml:mrow> | |
431 | </mml:mrow> | |
432 | </mml:math></div> | |
433 | </td></tr><tr><td align="left"> | |
434 | <code class="constant">GL_MIN</code> | |
435 | </td><td align="left"> | |
436 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
437 | ||
438 | <mml:mrow> | |
439 | <mml:mi mathvariant="italic">Rr</mml:mi> | |
440 | <mml:mo>=</mml:mo> | |
441 | <mml:mrow> | |
442 | <mml:mi mathvariant="italic">min</mml:mi> | |
443 | <mml:mo></mml:mo> | |
444 | <mml:mfenced open="(" close=")"> | |
445 | <mml:mrow> | |
446 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> | |
447 | <mml:mi mathvariant="italic">s</mml:mi> | |
448 | </mml:msub> | |
449 | </mml:mrow> | |
450 | <mml:mrow> | |
451 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> | |
452 | <mml:mi mathvariant="italic">d</mml:mi> | |
453 | </mml:msub> | |
454 | </mml:mrow> | |
455 | </mml:mfenced> | |
456 | </mml:mrow> | |
457 | </mml:mrow> | |
458 | </mml:math></div> | |
459 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
460 | ||
461 | <mml:mrow> | |
462 | <mml:mi mathvariant="italic">Gr</mml:mi> | |
463 | <mml:mo>=</mml:mo> | |
464 | <mml:mrow> | |
465 | <mml:mi mathvariant="italic">min</mml:mi> | |
466 | <mml:mo></mml:mo> | |
467 | <mml:mfenced open="(" close=")"> | |
468 | <mml:mrow> | |
469 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> | |
470 | <mml:mi mathvariant="italic">s</mml:mi> | |
471 | </mml:msub> | |
472 | </mml:mrow> | |
473 | <mml:mrow> | |
474 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> | |
475 | <mml:mi mathvariant="italic">d</mml:mi> | |
476 | </mml:msub> | |
477 | </mml:mrow> | |
478 | </mml:mfenced> | |
479 | </mml:mrow> | |
480 | </mml:mrow> | |
481 | </mml:math></div> | |
482 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
483 | ||
484 | <mml:mrow> | |
485 | <mml:mi mathvariant="italic">Br</mml:mi> | |
486 | <mml:mo>=</mml:mo> | |
487 | <mml:mrow> | |
488 | <mml:mi mathvariant="italic">min</mml:mi> | |
489 | <mml:mo></mml:mo> | |
490 | <mml:mfenced open="(" close=")"> | |
491 | <mml:mrow> | |
492 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> | |
493 | <mml:mi mathvariant="italic">s</mml:mi> | |
494 | </mml:msub> | |
495 | </mml:mrow> | |
496 | <mml:mrow> | |
497 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> | |
498 | <mml:mi mathvariant="italic">d</mml:mi> | |
499 | </mml:msub> | |
500 | </mml:mrow> | |
501 | </mml:mfenced> | |
502 | </mml:mrow> | |
503 | </mml:mrow> | |
504 | </mml:math></div> | |
505 | </td><td align="left"> | |
506 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
507 | ||
508 | <mml:mrow> | |
509 | <mml:mi mathvariant="italic">Ar</mml:mi> | |
510 | <mml:mo>=</mml:mo> | |
511 | <mml:mrow> | |
512 | <mml:mi mathvariant="italic">min</mml:mi> | |
513 | <mml:mo></mml:mo> | |
514 | <mml:mfenced open="(" close=")"> | |
515 | <mml:mrow> | |
516 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> | |
517 | <mml:mi mathvariant="italic">s</mml:mi> | |
518 | </mml:msub> | |
519 | </mml:mrow> | |
520 | <mml:mrow> | |
521 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> | |
522 | <mml:mi mathvariant="italic">d</mml:mi> | |
523 | </mml:msub> | |
524 | </mml:mrow> | |
525 | </mml:mfenced> | |
526 | </mml:mrow> | |
527 | </mml:mrow> | |
528 | </mml:math></div> | |
529 | </td></tr><tr><td align="left"> | |
530 | <code class="constant">GL_MAX</code> | |
531 | </td><td align="left"> | |
532 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
533 | ||
534 | <mml:mrow> | |
535 | <mml:mi mathvariant="italic">Rr</mml:mi> | |
536 | <mml:mo>=</mml:mo> | |
537 | <mml:mrow> | |
538 | <mml:mi mathvariant="italic">max</mml:mi> | |
539 | <mml:mo></mml:mo> | |
540 | <mml:mfenced open="(" close=")"> | |
541 | <mml:mrow> | |
542 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> | |
543 | <mml:mi mathvariant="italic">s</mml:mi> | |
544 | </mml:msub> | |
545 | </mml:mrow> | |
546 | <mml:mrow> | |
547 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> | |
548 | <mml:mi mathvariant="italic">d</mml:mi> | |
549 | </mml:msub> | |
550 | </mml:mrow> | |
551 | </mml:mfenced> | |
552 | </mml:mrow> | |
553 | </mml:mrow> | |
554 | </mml:math></div> | |
555 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
556 | ||
557 | <mml:mrow> | |
558 | <mml:mi mathvariant="italic">Gr</mml:mi> | |
559 | <mml:mo>=</mml:mo> | |
560 | <mml:mrow> | |
561 | <mml:mi mathvariant="italic">max</mml:mi> | |
562 | <mml:mo></mml:mo> | |
563 | <mml:mfenced open="(" close=")"> | |
564 | <mml:mrow> | |
565 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> | |
566 | <mml:mi mathvariant="italic">s</mml:mi> | |
567 | </mml:msub> | |
568 | </mml:mrow> | |
569 | <mml:mrow> | |
570 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> | |
571 | <mml:mi mathvariant="italic">d</mml:mi> | |
572 | </mml:msub> | |
573 | </mml:mrow> | |
574 | </mml:mfenced> | |
575 | </mml:mrow> | |
576 | </mml:mrow> | |
577 | </mml:math></div> | |
578 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
579 | ||
580 | <mml:mrow> | |
581 | <mml:mi mathvariant="italic">Br</mml:mi> | |
582 | <mml:mo>=</mml:mo> | |
583 | <mml:mrow> | |
584 | <mml:mi mathvariant="italic">max</mml:mi> | |
585 | <mml:mo></mml:mo> | |
586 | <mml:mfenced open="(" close=")"> | |
587 | <mml:mrow> | |
588 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> | |
589 | <mml:mi mathvariant="italic">s</mml:mi> | |
590 | </mml:msub> | |
591 | </mml:mrow> | |
592 | <mml:mrow> | |
593 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> | |
594 | <mml:mi mathvariant="italic">d</mml:mi> | |
595 | </mml:msub> | |
596 | </mml:mrow> | |
597 | </mml:mfenced> | |
598 | </mml:mrow> | |
599 | </mml:mrow> | |
600 | </mml:math></div> | |
601 | </td><td align="left"> | |
602 | <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
603 | ||
604 | <mml:mrow> | |
605 | <mml:mi mathvariant="italic">Ar</mml:mi> | |
606 | <mml:mo>=</mml:mo> | |
607 | <mml:mrow> | |
608 | <mml:mi mathvariant="italic">max</mml:mi> | |
609 | <mml:mo></mml:mo> | |
610 | <mml:mfenced open="(" close=")"> | |
611 | <mml:mrow> | |
612 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> | |
613 | <mml:mi mathvariant="italic">s</mml:mi> | |
614 | </mml:msub> | |
615 | </mml:mrow> | |
616 | <mml:mrow> | |
617 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> | |
618 | <mml:mi mathvariant="italic">d</mml:mi> | |
619 | </mml:msub> | |
620 | </mml:mrow> | |
621 | </mml:mfenced> | |
622 | </mml:mrow> | |
623 | </mml:mrow> | |
624 | </mml:math></div> | |
625 | </td></tr></tbody></table></div><p> | |
626 | </p><p> | |
627 | The results of these equations are clamped to the range | |
628 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> | |
629 | ||
630 | <mml:mfenced open="[" close="]"> | |
631 | <mml:mn>0</mml:mn> | |
632 | <mml:mn>1</mml:mn> | |
633 | </mml:mfenced> | |
634 | </mml:math>. | |
635 | </p><p> | |
636 | The <code class="constant">GL_MIN</code> and <code class="constant">GL_MAX</code> equations are useful for applications | |
637 | that analyze image data (image thresholding against a constant color, | |
638 | for example). | |
639 | The <code class="constant">GL_FUNC_ADD</code> equation is useful | |
640 | for antialiasing and transparency, among other things. | |
641 | </p><p> | |
642 | Initially, both the RGB blend equation and the alpha blend equation are set to <code class="constant">GL_FUNC_ADD</code>. | |
643 | </p><p> | |
644 | </p></div><div class="refsect1" title="Notes"><a id="notes"></a><h2>Notes</h2><p> | |
645 | The <code class="constant">GL_MIN</code>, and <code class="constant">GL_MAX</code> equations do not use | |
646 | the source or destination factors, only the source and destination colors. | |
647 | </p></div><div class="refsect1" title="Errors"><a id="errors"></a><h2>Errors</h2><p> | |
648 | <code class="constant">GL_INVALID_ENUM</code> is generated if either <em class="parameter"><code>modeRGB</code></em> or <em class="parameter"><code>modeAlpha</code></em> is not one of | |
649 | <code class="constant">GL_FUNC_ADD</code>, <code class="constant">GL_FUNC_SUBTRACT</code>, <code class="constant">GL_FUNC_REVERSE_SUBTRACT</code>, | |
650 | <code class="constant">GL_MAX</code>, or <code class="constant">GL_MIN</code>. | |
651 | </p></div><div class="refsect1" title="Associated Gets"><a id="associatedgets"></a><h2>Associated Gets</h2><p> | |
652 | <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with an argument of <code class="constant">GL_BLEND_EQUATION_RGB</code> | |
653 | </p><p> | |
654 | <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with an argument of <code class="constant">GL_BLEND_EQUATION_ALPHA</code> | |
655 | </p></div><div class="refsect1" title="See Also"><a id="seealso"></a><h2>See Also</h2><p> | |
656 | <a class="citerefentry" href="glGetString.xml"><span class="citerefentry"><span class="refentrytitle">glGetString</span></span></a>, | |
657 | <a class="citerefentry" href="glBlendColor.xml"><span class="citerefentry"><span class="refentrytitle">glBlendColor</span></span></a>, | |
658 | <a class="citerefentry" href="glBlendFunc.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a>, | |
659 | <a class="citerefentry" href="glBlendFuncSeparate.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFuncSeparate</span></span></a> | |
660 | </p></div><div class="refsect1" title="Copyright"><a id="Copyright"></a><h2>Copyright</h2><p> | |
661 | Copyright <span class="trademark"></span>© 2006 Khronos Group. | |
662 | This material may be distributed subject to the terms and conditions set forth in | |
663 | the Open Publication License, v 1.0, 8 June 1999. | |
664 | <a class="ulink" href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>. | |
665 | </p></div></div></body></html> |