upstream-doc/man2/xhtml/glBlendEquationSeparate.xml

   1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
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   3 <?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" /><title>glBlendEquationSeparate</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><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"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glBlendEquationSeparate</b>(</code></td><td>GLenum  </td><td><var class="pdparam">modeRGB</var>, </td></tr><tr><td> </td><td>GLenum  </td><td><var class="pdparam">modeAlpha</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><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>
   4                     specifies the RGB blend equation, how the red, green, and blue components of the source and destination colors are combined.
   5                     It must be <code class="constant">GL_FUNC_ADD</code>, <code class="constant">GL_FUNC_SUBTRACT</code>,
   6                     <code class="constant">GL_FUNC_REVERSE_SUBTRACT</code>, <code class="constant">GL_MIN</code>, <code class="constant">GL_MAX</code>.
   7                 </p></dd><dt><span class="term"><em class="parameter"><code>modeAlpha</code></em></span></dt><dd><p>
   8                     specifies the alpha blend equation, how the alpha component of the source and destination colors are combined.
   9                     It must be <code class="constant">GL_FUNC_ADD</code>, <code class="constant">GL_FUNC_SUBTRACT</code>,
  10                     <code class="constant">GL_FUNC_REVERSE_SUBTRACT</code>, <code class="constant">GL_MIN</code>, <code class="constant">GL_MAX</code>.
  11                 </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
  12             The blend equations determines how a new pixel (the ''source'' color)
  13             is combined with a pixel already in the framebuffer (the ''destination''
  14             color).  This function specifies one blend equation for the RGB-color
  15             components and one blend equation for the alpha component.
  16         </p><p>
  17             The blend equations use the source and destination blend factors
  18             specified by either <a class="citerefentry" href="glBlendFunc.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a> or
  19             <a class="citerefentry" href="glBlendFuncSeparate.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFuncSeparate</span></span></a>.
  20             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>
  21             for a description of the various blend factors.
  22         </p><p>
  23             In the equations that follow, source and destination
  24             color components are referred to as
  25             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  26
  27                 <mml:mfenced open="(" close=")">
  28                     <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
  29                     <mml:mi mathvariant="italic">s</mml:mi>
  30                     </mml:msub>
  31                     <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
  32                     <mml:mi mathvariant="italic">s</mml:mi>
  33                     </mml:msub>
  34                     <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
  35                     <mml:mi mathvariant="italic">s</mml:mi>
  36                     </mml:msub>
  37                     <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
  38                     <mml:mi mathvariant="italic">s</mml:mi>
  39                     </mml:msub>
  40                 </mml:mfenced>
  41             </mml:math>
  42             and
  43             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  44
  45                 <mml:mfenced open="(" close=")">
  46                     <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
  47                     <mml:mi mathvariant="italic">d</mml:mi>
  48                     </mml:msub>
  49                     <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
  50                     <mml:mi mathvariant="italic">d</mml:mi>
  51                     </mml:msub>
  52                     <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
  53                     <mml:mi mathvariant="italic">d</mml:mi>
  54                     </mml:msub>
  55                     <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
  56                     <mml:mi mathvariant="italic">d</mml:mi>
  57                     </mml:msub>
  58                 </mml:mfenced>
  59             </mml:math>,
  60             respectively.
  61             The result color is referred to as
  62             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  63
  64                 <mml:mfenced open="(" close=")">
  65                     <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
  66                     <mml:mi mathvariant="italic">r</mml:mi>
  67                     </mml:msub>
  68                     <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
  69                     <mml:mi mathvariant="italic">r</mml:mi>
  70                     </mml:msub>
  71                     <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
  72                     <mml:mi mathvariant="italic">r</mml:mi>
  73                     </mml:msub>
  74                     <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
  75                     <mml:mi mathvariant="italic">r</mml:mi>
  76                     </mml:msub>
  77                 </mml:mfenced>
  78             </mml:math>.
  79             The source and destination blend factors are denoted
  80             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  81
  82                 <mml:mfenced open="(" close=")">
  83                     <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
  84                     <mml:mi mathvariant="italic">R</mml:mi>
  85                     </mml:msub>
  86                     <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
  87                     <mml:mi mathvariant="italic">G</mml:mi>
  88                     </mml:msub>
  89                     <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
  90                     <mml:mi mathvariant="italic">B</mml:mi>
  91                     </mml:msub>
  92                     <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
  93                     <mml:mi mathvariant="italic">A</mml:mi>
  94                     </mml:msub>
  95                 </mml:mfenced>
  96             </mml:math>
  97             and
  98             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
  99
 100                 <mml:mfenced open="(" close=")">
 101                     <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 102                     <mml:mi mathvariant="italic">R</mml:mi>
 103                     </mml:msub>
 104                     <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 105                     <mml:mi mathvariant="italic">G</mml:mi>
 106                     </mml:msub>
 107                     <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 108                     <mml:mi mathvariant="italic">B</mml:mi>
 109                     </mml:msub>
 110                     <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 111                     <mml:mi mathvariant="italic">A</mml:mi>
 112                     </mml:msub>
 113                 </mml:mfenced>
 114             </mml:math>,
 115             respectively.
 116             For these equations all color components are understood to have values
 117             in the range
 118             <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 119
 120                 <mml:mfenced open="[" close="]">
 121                     <mml:mn>0</mml:mn>
 122                     <mml:mn>1</mml:mn>
 123                 </mml:mfenced>
 124             </mml:math>.
 125
 126         </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>
 127                         Mode
 128                         </strong></span></th><th align="left"><span class="bold"><strong>
 129                         RGB Components
 130                         </strong></span></th><th align="left"><span class="bold"><strong>
 131                         Alpha Component
 132                         </strong></span></th></tr></thead><tbody><tr><td align="left">
 133                         <code class="constant">GL_FUNC_ADD</code>
 134                         </td><td align="left">
 135                         <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 136
 137                             <mml:mrow>
 138                                 <mml:mi mathvariant="italic">Rr</mml:mi>
 139                                 <mml:mo>=</mml:mo>
 140                                 <mml:mrow>
 141                                                                         <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
 142                                                                         <mml:mi mathvariant="italic">s</mml:mi>
 143                                                                         </mml:msub>
 144                                                                         <mml:mo>⁢</mml:mo>
 145                                                                         <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
 146                                                                         <mml:mi mathvariant="italic">R</mml:mi>
 147                                                                         </mml:msub>
 148                                                                         <mml:mo>+</mml:mo>
 149                                                                         <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
 150                                                                         <mml:mi mathvariant="italic">d</mml:mi>
 151                                                                         </mml:msub>
 152                                                                         <mml:mo>⁢</mml:mo>
 153                                                                         <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 154                                                                         <mml:mi mathvariant="italic">R</mml:mi>
 155                                                                         </mml:msub>
 156                                 </mml:mrow>
 157                             </mml:mrow>
 158                         </mml:math></div>
 159                         <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 160
 161                             <mml:mrow>
 162                                 <mml:mi mathvariant="italic">Gr</mml:mi>
 163                                 <mml:mo>=</mml:mo>
 164                                 <mml:mrow>
 165                                                                         <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
 166                                                                         <mml:mi mathvariant="italic">s</mml:mi>
 167                                                                         </mml:msub>
 168                                                                         <mml:mo>⁢</mml:mo>
 169                                                                         <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
 170                                                                         <mml:mi mathvariant="italic">G</mml:mi>
 171                                                                         </mml:msub>
 172                                                                         <mml:mo>+</mml:mo>
 173                                                                         <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
 174                                                                         <mml:mi mathvariant="italic">d</mml:mi>
 175                                                                         </mml:msub>
 176                                                                         <mml:mo>⁢</mml:mo>
 177                                                                         <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 178                                                                         <mml:mi mathvariant="italic">G</mml:mi>
 179                                                                         </mml:msub>
 180                                 </mml:mrow>
 181                             </mml:mrow>
 182                         </mml:math></div>
 183                         <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 184
 185                             <mml:mrow>
 186                                 <mml:mi mathvariant="italic">Br</mml:mi>
 187                                 <mml:mo>=</mml:mo>
 188                                 <mml:mrow>
 189                                                                         <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
 190                                                                         <mml:mi mathvariant="italic">s</mml:mi>
 191                                                                         </mml:msub>
 192                                                                         <mml:mo>⁢</mml:mo>
 193                                                                         <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
 194                                                                         <mml:mi mathvariant="italic">B</mml:mi>
 195                                                                         </mml:msub>
 196                                                                         <mml:mo>+</mml:mo>
 197                                                                         <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
 198                                                                         <mml:mi mathvariant="italic">d</mml:mi>
 199                                                                         </mml:msub>
 200                                                                         <mml:mo>⁢</mml:mo>
 201                                                                         <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 202                                                                         <mml:mi mathvariant="italic">B</mml:mi>
 203                                                                         </mml:msub>
 204                                 </mml:mrow>
 205                             </mml:mrow>
 206                         </mml:math></div>
 207                         </td><td align="left">
 208                         <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 209
 210                             <mml:mrow>
 211                                 <mml:mi mathvariant="italic">Ar</mml:mi>
 212                                 <mml:mo>=</mml:mo>
 213                                 <mml:mrow>
 214                                                                         <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
 215                                                                         <mml:mi mathvariant="italic">s</mml:mi>
 216                                                                         </mml:msub>
 217                                                                         <mml:mo>⁢</mml:mo>
 218                                                                         <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
 219                                                                         <mml:mi mathvariant="italic">A</mml:mi>
 220                                                                         </mml:msub>
 221                                                                         <mml:mo>+</mml:mo>
 222                                                                         <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
 223                                                                         <mml:mi mathvariant="italic">d</mml:mi>
 224                                                                         </mml:msub>
 225                                                                         <mml:mo>⁢</mml:mo>
 226                                                                         <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 227                                                                         <mml:mi mathvariant="italic">A</mml:mi>
 228                                                                         </mml:msub>
 229                                 </mml:mrow>
 230                             </mml:mrow>
 231                         </mml:math></div>
 232                         </td></tr><tr><td align="left">
 233                         <code class="constant">GL_FUNC_SUBTRACT</code>
 234                         </td><td align="left">
 235                         <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 236
 237                             <mml:mrow>
 238                                 <mml:mi mathvariant="italic">Rr</mml:mi>
 239                                 <mml:mo>=</mml:mo>
 240                                 <mml:mrow>
 241                                                                         <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
 242                                                                         <mml:mi mathvariant="italic">s</mml:mi>
 243                                                                         </mml:msub>
 244                                                                         <mml:mo>⁢</mml:mo>
 245                                                                         <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
 246                                                                         <mml:mi mathvariant="italic">R</mml:mi>
 247                                                                         </mml:msub>
 248                                                                         <mml:mo>-</mml:mo>
 249                                                                         <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
 250                                                                         <mml:mi mathvariant="italic">d</mml:mi>
 251                                                                         </mml:msub>
 252                                                                         <mml:mo>⁢</mml:mo>
 253                                                                         <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 254                                                                         <mml:mi mathvariant="italic">R</mml:mi>
 255                                                                         </mml:msub>
 256                                 </mml:mrow>
 257                             </mml:mrow>
 258                         </mml:math></div>
 259                         <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 260
 261                             <mml:mrow>
 262                                 <mml:mi mathvariant="italic">Gr</mml:mi>
 263                                 <mml:mo>=</mml:mo>
 264                                 <mml:mrow>
 265                                                                         <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
 266                                                                         <mml:mi mathvariant="italic">s</mml:mi>
 267                                                                         </mml:msub>
 268                                                                         <mml:mo>⁢</mml:mo>
 269                                                                         <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
 270                                                                         <mml:mi mathvariant="italic">G</mml:mi>
 271                                                                         </mml:msub>
 272                                                                         <mml:mo>-</mml:mo>
 273                                                                         <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
 274                                                                         <mml:mi mathvariant="italic">d</mml:mi>
 275                                                                         </mml:msub>
 276                                                                         <mml:mo>⁢</mml:mo>
 277                                                                         <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 278                                                                         <mml:mi mathvariant="italic">G</mml:mi>
 279                                                                         </mml:msub>
 280                                 </mml:mrow>
 281                             </mml:mrow>
 282                         </mml:math></div>
 283                         <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 284
 285                             <mml:mrow>
 286                                 <mml:mi mathvariant="italic">Br</mml:mi>
 287                                 <mml:mo>=</mml:mo>
 288                                 <mml:mrow>
 289                                                                         <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
 290                                                                         <mml:mi mathvariant="italic">s</mml:mi>
 291                                                                         </mml:msub>
 292                                                                         <mml:mo>⁢</mml:mo>
 293                                                                         <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
 294                                                                         <mml:mi mathvariant="italic">B</mml:mi>
 295                                                                         </mml:msub>
 296                                                                         <mml:mo>-</mml:mo>
 297                                                                         <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
 298                                                                         <mml:mi mathvariant="italic">d</mml:mi>
 299                                                                         </mml:msub>
 300                                                                         <mml:mo>⁢</mml:mo>
 301                                                                         <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 302                                                                         <mml:mi mathvariant="italic">B</mml:mi>
 303                                                                         </mml:msub>
 304                                 </mml:mrow>
 305                             </mml:mrow>
 306                         </mml:math></div>
 307                         </td><td align="left">
 308                         <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 309
 310                             <mml:mrow>
 311                                 <mml:mi mathvariant="italic">Ar</mml:mi>
 312                                 <mml:mo>=</mml:mo>
 313                                 <mml:mrow>
 314                                                                         <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
 315                                                                         <mml:mi mathvariant="italic">s</mml:mi>
 316                                                                         </mml:msub>
 317                                                                         <mml:mo>⁢</mml:mo>
 318                                                                         <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
 319                                                                         <mml:mi mathvariant="italic">A</mml:mi>
 320                                                                         </mml:msub>
 321                                                                         <mml:mo>-</mml:mo>
 322                                                                         <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
 323                                                                         <mml:mi mathvariant="italic">d</mml:mi>
 324                                                                         </mml:msub>
 325                                                                         <mml:mo>⁢</mml:mo>
 326                                                                         <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 327                                                                         <mml:mi mathvariant="italic">A</mml:mi>
 328                                                                         </mml:msub>
 329                                 </mml:mrow>
 330                             </mml:mrow>
 331                         </mml:math></div>
 332                         </td></tr><tr><td align="left">
 333                         <code class="constant">GL_FUNC_REVERSE_SUBTRACT</code>
 334                         </td><td align="left">
 335                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 336
 337                                 <mml:mrow>
 338                                     <mml:mi mathvariant="italic">Rr</mml:mi>
 339                                     <mml:mo>=</mml:mo>
 340                                     <mml:mrow>
 341                                                                                 <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
 342                                                                                 <mml:mi mathvariant="italic">d</mml:mi>
 343                                                                                 </mml:msub>
 344                                                                                 <mml:mo>⁢</mml:mo>
 345                                                                                 <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 346                                                                                 <mml:mi mathvariant="italic">R</mml:mi>
 347                                                                                 </mml:msub>
 348                                                                                 <mml:mo>-</mml:mo>
 349                                                                                 <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
 350                                                                                 <mml:mi mathvariant="italic">s</mml:mi>
 351                                                                                 </mml:msub>
 352                                                                                 <mml:mo>⁢</mml:mo>
 353                                                                                 <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
 354                                                                                 <mml:mi mathvariant="italic">R</mml:mi>
 355                                                                                 </mml:msub>
 356                                     </mml:mrow>
 357                                 </mml:mrow>
 358                             </mml:math></div>
 359                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 360
 361                                 <mml:mrow>
 362                                     <mml:mi mathvariant="italic">Gr</mml:mi>
 363                                     <mml:mo>=</mml:mo>
 364                                     <mml:mrow>
 365                                                                                 <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
 366                                                                                 <mml:mi mathvariant="italic">d</mml:mi>
 367                                                                                 </mml:msub>
 368                                                                                 <mml:mo>⁢</mml:mo>
 369                                                                                 <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 370                                                                                 <mml:mi mathvariant="italic">G</mml:mi>
 371                                                                                 </mml:msub>
 372                                                                                 <mml:mo>-</mml:mo>
 373                                                                                 <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
 374                                                                                 <mml:mi mathvariant="italic">s</mml:mi>
 375                                                                                 </mml:msub>
 376                                                                                 <mml:mo>⁢</mml:mo>
 377                                                                                 <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
 378                                                                                 <mml:mi mathvariant="italic">G</mml:mi>
 379                                                                                 </mml:msub>
 380                                     </mml:mrow>
 381                                 </mml:mrow>
 382                             </mml:math></div>
 383                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 384
 385                                 <mml:mrow>
 386                                     <mml:mi mathvariant="italic">Br</mml:mi>
 387                                     <mml:mo>=</mml:mo>
 388                                     <mml:mrow>
 389                                                                                 <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
 390                                                                                 <mml:mi mathvariant="italic">d</mml:mi>
 391                                                                                 </mml:msub>
 392                                                                                 <mml:mo>⁢</mml:mo>
 393                                                                                 <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 394                                                                                 <mml:mi mathvariant="italic">B</mml:mi>
 395                                                                                 </mml:msub>
 396                                                                                 <mml:mo>-</mml:mo>
 397                                                                                 <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
 398                                                                                 <mml:mi mathvariant="italic">s</mml:mi>
 399                                                                                 </mml:msub>
 400                                                                                 <mml:mo>⁢</mml:mo>
 401                                                                                 <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
 402                                                                                 <mml:mi mathvariant="italic">B</mml:mi>
 403                                                                                 </mml:msub>
 404                                     </mml:mrow>
 405                                 </mml:mrow>
 406                             </mml:math></div>
 407                         </td><td align="left">
 408                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 409
 410                                 <mml:mrow>
 411                                     <mml:mi mathvariant="italic">Ar</mml:mi>
 412                                     <mml:mo>=</mml:mo>
 413                                     <mml:mrow>
 414                                                                                 <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
 415                                                                                 <mml:mi mathvariant="italic">d</mml:mi>
 416                                                                                 </mml:msub>
 417                                                                                 <mml:mo>⁢</mml:mo>
 418                                                                                 <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
 419                                                                                 <mml:mi mathvariant="italic">A</mml:mi>
 420                                                                                 </mml:msub>
 421                                                                                 <mml:mo>-</mml:mo>
 422                                                                                 <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
 423                                                                                 <mml:mi mathvariant="italic">s</mml:mi>
 424                                                                                 </mml:msub>
 425                                                                                 <mml:mo>⁢</mml:mo>
 426                                                                                 <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
 427                                                                                 <mml:mi mathvariant="italic">A</mml:mi>
 428                                                                                 </mml:msub>
 429                                     </mml:mrow>
 430                                 </mml:mrow>
 431                             </mml:math></div>
 432                         </td></tr><tr><td align="left">
 433                         <code class="constant">GL_MIN</code>
 434                         </td><td align="left">
 435                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 436
 437                                 <mml:mrow>
 438                                     <mml:mi mathvariant="italic">Rr</mml:mi>
 439                                     <mml:mo>=</mml:mo>
 440                                     <mml:mrow>
 441                                         <mml:mi mathvariant="italic">min</mml:mi>
 442                                         <mml:mo>⁡</mml:mo>
 443                                         <mml:mfenced open="(" close=")">
 444                                             <mml:mrow>
 445                                                 <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
 446                                                 <mml:mi mathvariant="italic">s</mml:mi>
 447                                                 </mml:msub>
 448                                             </mml:mrow>
 449                                             <mml:mrow>
 450                                                 <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
 451                                                 <mml:mi mathvariant="italic">d</mml:mi>
 452                                                 </mml:msub>
 453                                             </mml:mrow>
 454                                         </mml:mfenced>
 455                                     </mml:mrow>
 456                                 </mml:mrow>
 457                             </mml:math></div>
 458                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 459
 460                                 <mml:mrow>
 461                                     <mml:mi mathvariant="italic">Gr</mml:mi>
 462                                     <mml:mo>=</mml:mo>
 463                                     <mml:mrow>
 464                                         <mml:mi mathvariant="italic">min</mml:mi>
 465                                         <mml:mo>⁡</mml:mo>
 466                                         <mml:mfenced open="(" close=")">
 467                                             <mml:mrow>
 468                                                 <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
 469                                                 <mml:mi mathvariant="italic">s</mml:mi>
 470                                                 </mml:msub>
 471                                             </mml:mrow>
 472                                             <mml:mrow>
 473                                                 <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
 474                                                 <mml:mi mathvariant="italic">d</mml:mi>
 475                                                 </mml:msub>
 476                                             </mml:mrow>
 477                                         </mml:mfenced>
 478                                     </mml:mrow>
 479                                 </mml:mrow>
 480                             </mml:math></div>
 481                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 482
 483                                 <mml:mrow>
 484                                     <mml:mi mathvariant="italic">Br</mml:mi>
 485                                     <mml:mo>=</mml:mo>
 486                                     <mml:mrow>
 487                                         <mml:mi mathvariant="italic">min</mml:mi>
 488                                         <mml:mo>⁡</mml:mo>
 489                                         <mml:mfenced open="(" close=")">
 490                                             <mml:mrow>
 491                                                 <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
 492                                                 <mml:mi mathvariant="italic">s</mml:mi>
 493                                                 </mml:msub>
 494                                             </mml:mrow>
 495                                             <mml:mrow>
 496                                                 <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
 497                                                 <mml:mi mathvariant="italic">d</mml:mi>
 498                                                 </mml:msub>
 499                                             </mml:mrow>
 500                                         </mml:mfenced>
 501                                     </mml:mrow>
 502                                 </mml:mrow>
 503                             </mml:math></div>
 504                         </td><td align="left">
 505                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 506
 507                                 <mml:mrow>
 508                                     <mml:mi mathvariant="italic">Ar</mml:mi>
 509                                     <mml:mo>=</mml:mo>
 510                                     <mml:mrow>
 511                                         <mml:mi mathvariant="italic">min</mml:mi>
 512                                         <mml:mo>⁡</mml:mo>
 513                                         <mml:mfenced open="(" close=")">
 514                                             <mml:mrow>
 515                                                 <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
 516                                                 <mml:mi mathvariant="italic">s</mml:mi>
 517                                                 </mml:msub>
 518                                             </mml:mrow>
 519                                             <mml:mrow>
 520                                                 <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
 521                                                 <mml:mi mathvariant="italic">d</mml:mi>
 522                                                 </mml:msub>
 523                                             </mml:mrow>
 524                                         </mml:mfenced>
 525                                     </mml:mrow>
 526                                 </mml:mrow>
 527                             </mml:math></div>
 528                         </td></tr><tr><td align="left">
 529                         <code class="constant">GL_MAX</code>
 530                         </td><td align="left">
 531                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 532
 533                                 <mml:mrow>
 534                                     <mml:mi mathvariant="italic">Rr</mml:mi>
 535                                     <mml:mo>=</mml:mo>
 536                                     <mml:mrow>
 537                                         <mml:mi mathvariant="italic">max</mml:mi>
 538                                         <mml:mo>⁡</mml:mo>
 539                                         <mml:mfenced open="(" close=")">
 540                                             <mml:mrow>
 541                                                 <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
 542                                                 <mml:mi mathvariant="italic">s</mml:mi>
 543                                                 </mml:msub>
 544                                             </mml:mrow>
 545                                             <mml:mrow>
 546                                                 <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
 547                                                 <mml:mi mathvariant="italic">d</mml:mi>
 548                                                 </mml:msub>
 549                                             </mml:mrow>
 550                                         </mml:mfenced>
 551                                     </mml:mrow>
 552                                 </mml:mrow>
 553                             </mml:math></div>
 554                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 555
 556                                 <mml:mrow>
 557                                     <mml:mi mathvariant="italic">Gr</mml:mi>
 558                                     <mml:mo>=</mml:mo>
 559                                     <mml:mrow>
 560                                         <mml:mi mathvariant="italic">max</mml:mi>
 561                                         <mml:mo>⁡</mml:mo>
 562                                         <mml:mfenced open="(" close=")">
 563                                             <mml:mrow>
 564                                                 <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
 565                                                 <mml:mi mathvariant="italic">s</mml:mi>
 566                                                 </mml:msub>
 567                                             </mml:mrow>
 568                                             <mml:mrow>
 569                                                 <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
 570                                                 <mml:mi mathvariant="italic">d</mml:mi>
 571                                                 </mml:msub>
 572                                             </mml:mrow>
 573                                         </mml:mfenced>
 574                                     </mml:mrow>
 575                                 </mml:mrow>
 576                             </mml:math></div>
 577                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 578
 579                                 <mml:mrow>
 580                                     <mml:mi mathvariant="italic">Br</mml:mi>
 581                                     <mml:mo>=</mml:mo>
 582                                     <mml:mrow>
 583                                         <mml:mi mathvariant="italic">max</mml:mi>
 584                                         <mml:mo>⁡</mml:mo>
 585                                         <mml:mfenced open="(" close=")">
 586                                             <mml:mrow>
 587                                                 <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
 588                                                 <mml:mi mathvariant="italic">s</mml:mi>
 589                                                 </mml:msub>
 590                                             </mml:mrow>
 591                                             <mml:mrow>
 592                                                 <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
 593                                                 <mml:mi mathvariant="italic">d</mml:mi>
 594                                                 </mml:msub>
 595                                             </mml:mrow>
 596                                         </mml:mfenced>
 597                                     </mml:mrow>
 598                                 </mml:mrow>
 599                             </mml:math></div>
 600                         </td><td align="left">
 601                             <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 602
 603                                 <mml:mrow>
 604                                     <mml:mi mathvariant="italic">Ar</mml:mi>
 605                                     <mml:mo>=</mml:mo>
 606                                     <mml:mrow>
 607                                         <mml:mi mathvariant="italic">max</mml:mi>
 608                                         <mml:mo>⁡</mml:mo>
 609                                         <mml:mfenced open="(" close=")">
 610                                             <mml:mrow>
 611                                                 <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
 612                                                 <mml:mi mathvariant="italic">s</mml:mi>
 613                                                 </mml:msub>
 614                                             </mml:mrow>
 615                                             <mml:mrow>
 616                                                 <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
 617                                                 <mml:mi mathvariant="italic">d</mml:mi>
 618                                                 </mml:msub>
 619                                             </mml:mrow>
 620                                         </mml:mfenced>
 621                                     </mml:mrow>
 622                                 </mml:mrow>
 623                             </mml:math></div>
 624                         </td></tr></tbody></table></div><p>
 625         </p><p>
 626             The results of these equations are clamped to the range
 627                         <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
 628
 629                             <mml:mfenced open="[" close="]">
 630                                 <mml:mn>0</mml:mn>
 631                                 <mml:mn>1</mml:mn>
 632                             </mml:mfenced>
 633                         </mml:math>.
 634         </p><p>
 635             The <code class="constant">GL_MIN</code> and <code class="constant">GL_MAX</code> equations are useful for applications
 636             that analyze image data (image thresholding against a constant color,
 637             for example).
 638             The <code class="constant">GL_FUNC_ADD</code> equation is useful
 639             for antialiasing and transparency, among other things.
 640         </p><p>
 641             Initially, both the RGB blend equation and the alpha blend equation are set to <code class="constant">GL_FUNC_ADD</code>.
 642         </p><p>
 643         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
 644             <code class="function">glBlendEquationSeparate</code> is available only if the GL version is 2.0 or greater.
 645         </p><p>
 646             The <code class="constant">GL_MIN</code>, and <code class="constant">GL_MAX</code> equations do not use
 647             the source or destination factors, only the source and destination colors.
 648         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
 649             <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
 650             <code class="constant">GL_FUNC_ADD</code>, <code class="constant">GL_FUNC_SUBTRACT</code>, <code class="constant">GL_FUNC_REVERSE_SUBTRACT</code>,
 651             <code class="constant">GL_MAX</code>, or <code class="constant">GL_MIN</code>.
 652         </p><p>
 653             <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glBlendEquationSeparate</code> is executed
 654             between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> and the corresponding
 655             execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
 656         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
 657                     <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>
 658                 </p><p>
 659                     <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>
 660                 </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
 661             <a class="citerefentry" href="glGetString.xml"><span class="citerefentry"><span class="refentrytitle">glGetString</span></span></a>,
 662             <a class="citerefentry" href="glBlendColor.xml"><span class="citerefentry"><span class="refentrytitle">glBlendColor</span></span></a>,
 663             <a class="citerefentry" href="glBlendFunc.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a>,
 664             <a class="citerefentry" href="glBlendFuncSeparate.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFuncSeparate</span></span></a>
 665         </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
 666             Copyright <span class="trademark"></span>© 2006 Khronos Group.
 667             This material may be distributed subject to the terms and conditions set forth in
 668             the Open Publication License, v 1.0, 8 June 1999.
 669             <a class="ulink" href="http://opencontent.org/openpub/" target="_top">http://opencontent.org/openpub/</a>.
 670         </p></div></div></body></html>