upstream-man-pages/man3/xhtml/glBlendEquationSeparate.xml

   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>