| 1 | <?xml version="1.0" encoding="UTF-8"?> |
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| 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>glBlendFunc - OpenGL 4 Reference Pages</title><meta name="generator" content="DocBook XSL Stylesheets V1.69.1" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glBlendFunc"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glBlendFunc — specify pixel arithmetic</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0" style="padding-bottom: 1em"><tr><td><code class="funcdef">void <b class="fsfunc">glBlendFunc</b>(</code></td><td>GLenum </td><td><var class="pdparam">sfactor</var>, </td></tr><tr><td> </td><td>GLenum </td><td><var class="pdparam">dfactor</var><code>)</code>;</td></tr></table><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glBlendFunci</b>(</code></td><td>GLuint </td><td><var class="pdparam">buf</var>, </td></tr><tr><td> </td><td>GLenum </td><td><var class="pdparam">sfactor</var>, </td></tr><tr><td> </td><td>GLenum </td><td><var class="pdparam">dfactor</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>buf</code></em></span></dt><dd><p> |
| 5 | For <code class="function">glBlendFunci</code>, specifies the index of the draw |
| 6 | buffer for which to set the blend function. |
| 7 | </p></dd><dt><span class="term"><em class="parameter"><code>sfactor</code></em></span></dt><dd><p> |
| 8 | Specifies how the red, green, blue, |
| 9 | and alpha source blending factors are computed. |
| 10 | The initial value is <code class="constant">GL_ONE</code>. |
| 11 | </p></dd><dt><span class="term"><em class="parameter"><code>dfactor</code></em></span></dt><dd><p> |
| 12 | Specifies how the red, green, blue, |
| 13 | and alpha destination blending factors are computed. |
| 14 | The following symbolic constants are accepted: |
| 15 | <code class="constant">GL_ZERO</code>, |
| 16 | <code class="constant">GL_ONE</code>, |
| 17 | <code class="constant">GL_SRC_COLOR</code>, |
| 18 | <code class="constant">GL_ONE_MINUS_SRC_COLOR</code>, |
| 19 | <code class="constant">GL_DST_COLOR</code>, |
| 20 | <code class="constant">GL_ONE_MINUS_DST_COLOR</code>, |
| 21 | <code class="constant">GL_SRC_ALPHA</code>, |
| 22 | <code class="constant">GL_ONE_MINUS_SRC_ALPHA</code>, |
| 23 | <code class="constant">GL_DST_ALPHA</code>, |
| 24 | <code class="constant">GL_ONE_MINUS_DST_ALPHA</code>. |
| 25 | <code class="constant">GL_CONSTANT_COLOR</code>, |
| 26 | <code class="constant">GL_ONE_MINUS_CONSTANT_COLOR</code>, |
| 27 | <code class="constant">GL_CONSTANT_ALPHA</code>, and |
| 28 | <code class="constant">GL_ONE_MINUS_CONSTANT_ALPHA</code>. |
| 29 | The initial value is <code class="constant">GL_ZERO</code>. |
| 30 | </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p> |
| 31 | Pixels can be drawn using a function that blends |
| 32 | the incoming (source) RGBA values with the RGBA values |
| 33 | that are already in the frame buffer (the destination values). |
| 34 | Blending is initially disabled. |
| 35 | Use <a href="glEnable.xml"><span class="citerefentry"><span class="refentrytitle">glEnable</span></span></a> and <a href="glDisable.xml"><span class="citerefentry"><span class="refentrytitle">glDisable</span></span></a> with argument <code class="constant">GL_BLEND</code> |
| 36 | to enable and disable blending. |
| 37 | </p><p> |
| 38 | <code class="function">glBlendFunc</code> defines the operation of blending for all draw buffers when it is enabled. |
| 39 | <code class="function">glBlendFunci</code> defines the operation of blending for a single draw buffer |
| 40 | specified by <em class="parameter"><code>buf</code></em> when enabled for that draw buffer. |
| 41 | <em class="parameter"><code>sfactor</code></em> specifies which method is used to scale the |
| 42 | source color components. |
| 43 | <em class="parameter"><code>dfactor</code></em> specifies which method is used to scale the |
| 44 | destination color components. |
| 45 | Both parameters must be one of the following symbolic constants: |
| 46 | <code class="constant">GL_ZERO</code>, |
| 47 | <code class="constant">GL_ONE</code>, |
| 48 | <code class="constant">GL_SRC_COLOR</code>, |
| 49 | <code class="constant">GL_ONE_MINUS_SRC_COLOR</code>, |
| 50 | <code class="constant">GL_DST_COLOR</code>, |
| 51 | <code class="constant">GL_ONE_MINUS_DST_COLOR</code>, |
| 52 | <code class="constant">GL_SRC_ALPHA</code>, |
| 53 | <code class="constant">GL_ONE_MINUS_SRC_ALPHA</code>, |
| 54 | <code class="constant">GL_DST_ALPHA</code>, |
| 55 | <code class="constant">GL_ONE_MINUS_DST_ALPHA</code>, |
| 56 | <code class="constant">GL_CONSTANT_COLOR</code>, |
| 57 | <code class="constant">GL_ONE_MINUS_CONSTANT_COLOR</code>, |
| 58 | <code class="constant">GL_CONSTANT_ALPHA</code>, |
| 59 | <code class="constant">GL_ONE_MINUS_CONSTANT_ALPHA</code>, |
| 60 | <code class="constant">GL_SRC_ALPHA_SATURATE</code>, |
| 61 | <code class="constant">GL_SRC1_COLOR</code>, |
| 62 | <code class="constant">GL_ONE_MINUS_SRC1_COLOR</code>, |
| 63 | <code class="constant">GL_SRC1_ALPHA</code>, and |
| 64 | <code class="constant">GL_ONE_MINUS_SRC1_ALPHA</code>. |
| 65 | The possible methods are described in the following table. |
| 66 | Each method defines four scale factors, |
| 67 | one each for red, green, blue, and alpha. |
| 68 | In the table and in subsequent equations, first source, second source |
| 69 | and destination color components are referred to as |
| 70 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 71 | |
| 72 | <mml:mfenced open="(" close=")"> |
| 73 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 74 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 75 | </mml:msub> |
| 76 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 77 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 78 | </mml:msub> |
| 79 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 80 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 81 | </mml:msub> |
| 82 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 83 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 84 | </mml:msub> |
| 85 | </mml:mfenced> |
| 86 | </mml:math>, |
| 87 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 88 | |
| 89 | <mml:mfenced open="(" close=")"> |
| 90 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 91 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 92 | </mml:msub> |
| 93 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 94 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 95 | </mml:msub> |
| 96 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 97 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 98 | </mml:msub> |
| 99 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 100 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 101 | </mml:msub> |
| 102 | </mml:mfenced> |
| 103 | </mml:math> |
| 104 | and |
| 105 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 106 | |
| 107 | <mml:mfenced open="(" close=")"> |
| 108 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 109 | <mml:mi mathvariant="italic">d</mml:mi> |
| 110 | </mml:msub> |
| 111 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 112 | <mml:mi mathvariant="italic">d</mml:mi> |
| 113 | </mml:msub> |
| 114 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 115 | <mml:mi mathvariant="italic">d</mml:mi> |
| 116 | </mml:msub> |
| 117 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 118 | <mml:mi mathvariant="italic">d</mml:mi> |
| 119 | </mml:msub> |
| 120 | </mml:mfenced> |
| 121 | </mml:math>, respectively. |
| 122 | The color specified by <a href="glBlendColor.xml"><span class="citerefentry"><span class="refentrytitle">glBlendColor</span></span></a> is referred to as |
| 123 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 124 | |
| 125 | <mml:mfenced open="(" close=")"> |
| 126 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 127 | <mml:mi mathvariant="italic">c</mml:mi> |
| 128 | </mml:msub> |
| 129 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 130 | <mml:mi mathvariant="italic">c</mml:mi> |
| 131 | </mml:msub> |
| 132 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 133 | <mml:mi mathvariant="italic">c</mml:mi> |
| 134 | </mml:msub> |
| 135 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 136 | <mml:mi mathvariant="italic">c</mml:mi> |
| 137 | </mml:msub> |
| 138 | </mml:mfenced> |
| 139 | </mml:math>. |
| 140 | They are understood to have integer values between 0 and |
| 141 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 142 | |
| 143 | <mml:mfenced open="(" close=")"> |
| 144 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 145 | <mml:mi mathvariant="italic">R</mml:mi> |
| 146 | </mml:msub> |
| 147 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 148 | <mml:mi mathvariant="italic">G</mml:mi> |
| 149 | </mml:msub> |
| 150 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 151 | <mml:mi mathvariant="italic">B</mml:mi> |
| 152 | </mml:msub> |
| 153 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 154 | <mml:mi mathvariant="italic">A</mml:mi> |
| 155 | </mml:msub> |
| 156 | </mml:mfenced> |
| 157 | </mml:math>, |
| 158 | where |
| 159 | </p><p> |
| 160 | </p><p> |
| 161 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 162 | |
| 163 | <mml:mrow> |
| 164 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 165 | <mml:mi mathvariant="italic">c</mml:mi> |
| 166 | </mml:msub> |
| 167 | <mml:mo>=</mml:mo> |
| 168 | <mml:mrow> |
| 169 | <mml:msup><mml:mn>2</mml:mn> |
| 170 | <mml:mfenced open="" close=""> |
| 171 | <mml:msub><mml:mi mathvariant="italic">m</mml:mi> |
| 172 | <mml:mi mathvariant="italic">c</mml:mi> |
| 173 | </mml:msub> |
| 174 | </mml:mfenced> |
| 175 | </mml:msup> |
| 176 | <mml:mo>-</mml:mo> |
| 177 | <mml:mn>1</mml:mn> |
| 178 | </mml:mrow> |
| 179 | </mml:mrow> |
| 180 | </mml:math> |
| 181 | </p><p> |
| 182 | </p><p> |
| 183 | and |
| 184 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 185 | |
| 186 | <mml:mfenced open="(" close=")"> |
| 187 | <mml:msub><mml:mi mathvariant="italic">m</mml:mi> |
| 188 | <mml:mi mathvariant="italic">R</mml:mi> |
| 189 | </mml:msub> |
| 190 | <mml:msub><mml:mi mathvariant="italic">m</mml:mi> |
| 191 | <mml:mi mathvariant="italic">G</mml:mi> |
| 192 | </mml:msub> |
| 193 | <mml:msub><mml:mi mathvariant="italic">m</mml:mi> |
| 194 | <mml:mi mathvariant="italic">B</mml:mi> |
| 195 | </mml:msub> |
| 196 | <mml:msub><mml:mi mathvariant="italic">m</mml:mi> |
| 197 | <mml:mi mathvariant="italic">A</mml:mi> |
| 198 | </mml:msub> |
| 199 | </mml:mfenced> |
| 200 | </mml:math> |
| 201 | is the number of red, |
| 202 | green, |
| 203 | blue, |
| 204 | and alpha bitplanes. |
| 205 | </p><p> |
| 206 | Source and destination scale factors are referred to as |
| 207 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 208 | |
| 209 | <mml:mfenced open="(" close=")"> |
| 210 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> |
| 211 | <mml:mi mathvariant="italic">R</mml:mi> |
| 212 | </mml:msub> |
| 213 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> |
| 214 | <mml:mi mathvariant="italic">G</mml:mi> |
| 215 | </mml:msub> |
| 216 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> |
| 217 | <mml:mi mathvariant="italic">B</mml:mi> |
| 218 | </mml:msub> |
| 219 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> |
| 220 | <mml:mi mathvariant="italic">A</mml:mi> |
| 221 | </mml:msub> |
| 222 | </mml:mfenced> |
| 223 | </mml:math> |
| 224 | and |
| 225 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 226 | |
| 227 | <mml:mfenced open="(" close=")"> |
| 228 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> |
| 229 | <mml:mi mathvariant="italic">R</mml:mi> |
| 230 | </mml:msub> |
| 231 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> |
| 232 | <mml:mi mathvariant="italic">G</mml:mi> |
| 233 | </mml:msub> |
| 234 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> |
| 235 | <mml:mi mathvariant="italic">B</mml:mi> |
| 236 | </mml:msub> |
| 237 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> |
| 238 | <mml:mi mathvariant="italic">A</mml:mi> |
| 239 | </mml:msub> |
| 240 | </mml:mfenced> |
| 241 | </mml:math>. |
| 242 | The scale factors described in the table, |
| 243 | denoted |
| 244 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 245 | |
| 246 | <mml:mfenced open="(" close=")"> |
| 247 | <mml:msub><mml:mi mathvariant="italic">f</mml:mi> |
| 248 | <mml:mi mathvariant="italic">R</mml:mi> |
| 249 | </mml:msub> |
| 250 | <mml:msub><mml:mi mathvariant="italic">f</mml:mi> |
| 251 | <mml:mi mathvariant="italic">G</mml:mi> |
| 252 | </mml:msub> |
| 253 | <mml:msub><mml:mi mathvariant="italic">f</mml:mi> |
| 254 | <mml:mi mathvariant="italic">B</mml:mi> |
| 255 | </mml:msub> |
| 256 | <mml:msub><mml:mi mathvariant="italic">f</mml:mi> |
| 257 | <mml:mi mathvariant="italic">A</mml:mi> |
| 258 | </mml:msub> |
| 259 | </mml:mfenced> |
| 260 | </mml:math>, |
| 261 | represent either source or destination factors. |
| 262 | All scale factors have range |
| 263 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 264 | |
| 265 | <mml:mfenced open="[" close="]"> |
| 266 | <mml:mn>0</mml:mn> |
| 267 | <mml:mn>1</mml:mn> |
| 268 | </mml:mfenced> |
| 269 | </mml:math>. |
| 270 | </p><p> |
| 271 | </p><div class="informaltable"><table border="1"><colgroup><col align="left" /><col align="left" /></colgroup><thead><tr><th align="left"><span class="bold"><strong> |
| 272 | Parameter |
| 273 | </strong></span></th><th align="left"><span class="bold"><strong> |
| 274 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 275 | |
| 276 | <mml:mfenced open="(" close=")"> |
| 277 | <mml:msub><mml:mi mathvariant="italic">f</mml:mi> |
| 278 | <mml:mi mathvariant="italic">R</mml:mi> |
| 279 | </mml:msub> |
| 280 | <mml:msub><mml:mi mathvariant="italic">f</mml:mi> |
| 281 | <mml:mi mathvariant="italic">G</mml:mi> |
| 282 | </mml:msub> |
| 283 | <mml:msub><mml:mi mathvariant="italic">f</mml:mi> |
| 284 | <mml:mi mathvariant="italic">B</mml:mi> |
| 285 | </mml:msub> |
| 286 | <mml:msub><mml:mi mathvariant="italic">f</mml:mi> |
| 287 | <mml:mi mathvariant="italic">A</mml:mi> |
| 288 | </mml:msub> |
| 289 | </mml:mfenced> |
| 290 | </mml:math> |
| 291 | </strong></span></th></tr></thead><tbody><tr><td align="left"> |
| 292 | <code class="constant">GL_ZERO</code> |
| 293 | </td><td align="left"> |
| 294 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 295 | |
| 296 | <mml:mfenced open="(" close=")"> |
| 297 | <mml:mn>0</mml:mn> |
| 298 | <mml:mn>0</mml:mn> |
| 299 | <mml:mn>0</mml:mn> |
| 300 | <mml:mn>0</mml:mn> |
| 301 | </mml:mfenced> |
| 302 | </mml:math> |
| 303 | </td></tr><tr><td align="left"> |
| 304 | <code class="constant">GL_ONE</code> |
| 305 | </td><td align="left"> |
| 306 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 307 | |
| 308 | <mml:mfenced open="(" close=")"> |
| 309 | <mml:mn>1</mml:mn> |
| 310 | <mml:mn>1</mml:mn> |
| 311 | <mml:mn>1</mml:mn> |
| 312 | <mml:mn>1</mml:mn> |
| 313 | </mml:mfenced> |
| 314 | </mml:math> |
| 315 | </td></tr><tr><td align="left"> |
| 316 | <code class="constant">GL_SRC_COLOR</code> |
| 317 | </td><td align="left"> |
| 318 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 319 | |
| 320 | <mml:mfenced open="(" close=")"> |
| 321 | <mml:mfrac> |
| 322 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 323 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 324 | </mml:msub> |
| 325 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 326 | <mml:mi mathvariant="italic">R</mml:mi> |
| 327 | </mml:msub> |
| 328 | </mml:mfrac> |
| 329 | <mml:mfrac> |
| 330 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 331 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 332 | </mml:msub> |
| 333 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 334 | <mml:mi mathvariant="italic">G</mml:mi> |
| 335 | </mml:msub> |
| 336 | </mml:mfrac> |
| 337 | <mml:mfrac> |
| 338 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 339 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 340 | </mml:msub> |
| 341 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 342 | <mml:mi mathvariant="italic">B</mml:mi> |
| 343 | </mml:msub> |
| 344 | </mml:mfrac> |
| 345 | <mml:mfrac> |
| 346 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 347 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 348 | </mml:msub> |
| 349 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 350 | <mml:mi mathvariant="italic">A</mml:mi> |
| 351 | </mml:msub> |
| 352 | </mml:mfrac> |
| 353 | </mml:mfenced> |
| 354 | </mml:math> |
| 355 | </td></tr><tr><td align="left"> |
| 356 | <code class="constant">GL_ONE_MINUS_SRC_COLOR</code> |
| 357 | </td><td align="left"> |
| 358 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 359 | |
| 360 | <mml:mrow> |
| 361 | <mml:mfenced open="(" close=")"> |
| 362 | <mml:mn>1</mml:mn> |
| 363 | <mml:mn>1</mml:mn> |
| 364 | <mml:mn>1</mml:mn> |
| 365 | <mml:mn>1</mml:mn> |
| 366 | </mml:mfenced> |
| 367 | <mml:mo>-</mml:mo> |
| 368 | <mml:mfenced open="(" close=")"> |
| 369 | <mml:mfrac> |
| 370 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 371 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 372 | </mml:msub> |
| 373 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 374 | <mml:mi mathvariant="italic">R</mml:mi> |
| 375 | </mml:msub> |
| 376 | </mml:mfrac> |
| 377 | <mml:mfrac> |
| 378 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 379 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 380 | </mml:msub> |
| 381 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 382 | <mml:mi mathvariant="italic">G</mml:mi> |
| 383 | </mml:msub> |
| 384 | </mml:mfrac> |
| 385 | <mml:mfrac> |
| 386 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 387 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 388 | </mml:msub> |
| 389 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 390 | <mml:mi mathvariant="italic">B</mml:mi> |
| 391 | </mml:msub> |
| 392 | </mml:mfrac> |
| 393 | <mml:mfrac> |
| 394 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 395 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 396 | </mml:msub> |
| 397 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 398 | <mml:mi mathvariant="italic">A</mml:mi> |
| 399 | </mml:msub> |
| 400 | </mml:mfrac> |
| 401 | </mml:mfenced> |
| 402 | </mml:mrow> |
| 403 | </mml:math> |
| 404 | </td></tr><tr><td align="left"> |
| 405 | <code class="constant">GL_DST_COLOR</code> |
| 406 | </td><td align="left"> |
| 407 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 408 | |
| 409 | <mml:mfenced open="(" close=")"> |
| 410 | <mml:mfrac> |
| 411 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 412 | <mml:mi mathvariant="italic">d</mml:mi> |
| 413 | </mml:msub> |
| 414 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 415 | <mml:mi mathvariant="italic">R</mml:mi> |
| 416 | </mml:msub> |
| 417 | </mml:mfrac> |
| 418 | <mml:mfrac> |
| 419 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 420 | <mml:mi mathvariant="italic">d</mml:mi> |
| 421 | </mml:msub> |
| 422 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 423 | <mml:mi mathvariant="italic">G</mml:mi> |
| 424 | </mml:msub> |
| 425 | </mml:mfrac> |
| 426 | <mml:mfrac> |
| 427 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 428 | <mml:mi mathvariant="italic">d</mml:mi> |
| 429 | </mml:msub> |
| 430 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 431 | <mml:mi mathvariant="italic">B</mml:mi> |
| 432 | </mml:msub> |
| 433 | </mml:mfrac> |
| 434 | <mml:mfrac> |
| 435 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 436 | <mml:mi mathvariant="italic">d</mml:mi> |
| 437 | </mml:msub> |
| 438 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 439 | <mml:mi mathvariant="italic">A</mml:mi> |
| 440 | </mml:msub> |
| 441 | </mml:mfrac> |
| 442 | </mml:mfenced> |
| 443 | </mml:math> |
| 444 | </td></tr><tr><td align="left"> |
| 445 | <code class="constant">GL_ONE_MINUS_DST_COLOR</code> |
| 446 | </td><td align="left"> |
| 447 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 448 | |
| 449 | <mml:mrow> |
| 450 | <mml:mfenced open="(" close=")"> |
| 451 | <mml:mn>1</mml:mn> |
| 452 | <mml:mn>1</mml:mn> |
| 453 | <mml:mn>1</mml:mn> |
| 454 | <mml:mn>1</mml:mn> |
| 455 | </mml:mfenced> |
| 456 | <mml:mo>-</mml:mo> |
| 457 | <mml:mfenced open="(" close=")"> |
| 458 | <mml:mfrac> |
| 459 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 460 | <mml:mi mathvariant="italic">d</mml:mi> |
| 461 | </mml:msub> |
| 462 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 463 | <mml:mi mathvariant="italic">R</mml:mi> |
| 464 | </mml:msub> |
| 465 | </mml:mfrac> |
| 466 | <mml:mfrac> |
| 467 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 468 | <mml:mi mathvariant="italic">d</mml:mi> |
| 469 | </mml:msub> |
| 470 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 471 | <mml:mi mathvariant="italic">G</mml:mi> |
| 472 | </mml:msub> |
| 473 | </mml:mfrac> |
| 474 | <mml:mfrac> |
| 475 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 476 | <mml:mi mathvariant="italic">d</mml:mi> |
| 477 | </mml:msub> |
| 478 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 479 | <mml:mi mathvariant="italic">B</mml:mi> |
| 480 | </mml:msub> |
| 481 | </mml:mfrac> |
| 482 | <mml:mfrac> |
| 483 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 484 | <mml:mi mathvariant="italic">d</mml:mi> |
| 485 | </mml:msub> |
| 486 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 487 | <mml:mi mathvariant="italic">A</mml:mi> |
| 488 | </mml:msub> |
| 489 | </mml:mfrac> |
| 490 | </mml:mfenced> |
| 491 | </mml:mrow> |
| 492 | </mml:math> |
| 493 | </td></tr><tr><td align="left"> |
| 494 | <code class="constant">GL_SRC_ALPHA</code> |
| 495 | </td><td align="left"> |
| 496 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 497 | |
| 498 | <mml:mfenced open="(" close=")"> |
| 499 | <mml:mfrac> |
| 500 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 501 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 502 | </mml:msub> |
| 503 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 504 | <mml:mi mathvariant="italic">A</mml:mi> |
| 505 | </mml:msub> |
| 506 | </mml:mfrac> |
| 507 | <mml:mfrac> |
| 508 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 509 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 510 | </mml:msub> |
| 511 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 512 | <mml:mi mathvariant="italic">A</mml:mi> |
| 513 | </mml:msub> |
| 514 | </mml:mfrac> |
| 515 | <mml:mfrac> |
| 516 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 517 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 518 | </mml:msub> |
| 519 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 520 | <mml:mi mathvariant="italic">A</mml:mi> |
| 521 | </mml:msub> |
| 522 | </mml:mfrac> |
| 523 | <mml:mfrac> |
| 524 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 525 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 526 | </mml:msub> |
| 527 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 528 | <mml:mi mathvariant="italic">A</mml:mi> |
| 529 | </mml:msub> |
| 530 | </mml:mfrac> |
| 531 | </mml:mfenced> |
| 532 | </mml:math> |
| 533 | </td></tr><tr><td align="left"> |
| 534 | <code class="constant">GL_ONE_MINUS_SRC_ALPHA</code> |
| 535 | </td><td align="left"> |
| 536 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 537 | |
| 538 | <mml:mrow> |
| 539 | <mml:mfenced open="(" close=")"> |
| 540 | <mml:mn>1</mml:mn> |
| 541 | <mml:mn>1</mml:mn> |
| 542 | <mml:mn>1</mml:mn> |
| 543 | <mml:mn>1</mml:mn> |
| 544 | </mml:mfenced> |
| 545 | <mml:mo>-</mml:mo> |
| 546 | <mml:mfenced open="(" close=")"> |
| 547 | <mml:mfrac> |
| 548 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 549 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 550 | </mml:msub> |
| 551 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 552 | <mml:mi mathvariant="italic">A</mml:mi> |
| 553 | </mml:msub> |
| 554 | </mml:mfrac> |
| 555 | <mml:mfrac> |
| 556 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 557 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 558 | </mml:msub> |
| 559 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 560 | <mml:mi mathvariant="italic">A</mml:mi> |
| 561 | </mml:msub> |
| 562 | </mml:mfrac> |
| 563 | <mml:mfrac> |
| 564 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 565 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 566 | </mml:msub> |
| 567 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 568 | <mml:mi mathvariant="italic">A</mml:mi> |
| 569 | </mml:msub> |
| 570 | </mml:mfrac> |
| 571 | <mml:mfrac> |
| 572 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 573 | <mml:mi mathvariant="italic">s0</mml:mi> |
| 574 | </mml:msub> |
| 575 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 576 | <mml:mi mathvariant="italic">A</mml:mi> |
| 577 | </mml:msub> |
| 578 | </mml:mfrac> |
| 579 | </mml:mfenced> |
| 580 | </mml:mrow> |
| 581 | </mml:math> |
| 582 | </td></tr><tr><td align="left"> |
| 583 | <code class="constant">GL_DST_ALPHA</code> |
| 584 | </td><td align="left"> |
| 585 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 586 | |
| 587 | <mml:mfenced open="(" close=")"> |
| 588 | <mml:mfrac> |
| 589 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 590 | <mml:mi mathvariant="italic">d</mml:mi> |
| 591 | </mml:msub> |
| 592 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 593 | <mml:mi mathvariant="italic">A</mml:mi> |
| 594 | </mml:msub> |
| 595 | </mml:mfrac> |
| 596 | <mml:mfrac> |
| 597 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 598 | <mml:mi mathvariant="italic">d</mml:mi> |
| 599 | </mml:msub> |
| 600 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 601 | <mml:mi mathvariant="italic">A</mml:mi> |
| 602 | </mml:msub> |
| 603 | </mml:mfrac> |
| 604 | <mml:mfrac> |
| 605 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 606 | <mml:mi mathvariant="italic">d</mml:mi> |
| 607 | </mml:msub> |
| 608 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 609 | <mml:mi mathvariant="italic">A</mml:mi> |
| 610 | </mml:msub> |
| 611 | </mml:mfrac> |
| 612 | <mml:mfrac> |
| 613 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 614 | <mml:mi mathvariant="italic">d</mml:mi> |
| 615 | </mml:msub> |
| 616 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 617 | <mml:mi mathvariant="italic">A</mml:mi> |
| 618 | </mml:msub> |
| 619 | </mml:mfrac> |
| 620 | </mml:mfenced> |
| 621 | </mml:math> |
| 622 | </td></tr><tr><td align="left"> |
| 623 | <code class="constant">GL_ONE_MINUS_DST_ALPHA</code> |
| 624 | </td><td align="left"> |
| 625 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 626 | |
| 627 | <mml:mrow> |
| 628 | <mml:mfenced open="(" close=")"> |
| 629 | <mml:mn>1</mml:mn> |
| 630 | <mml:mn>1</mml:mn> |
| 631 | <mml:mn>1</mml:mn> |
| 632 | <mml:mn>1</mml:mn> |
| 633 | </mml:mfenced> |
| 634 | <mml:mo>-</mml:mo> |
| 635 | <mml:mfenced open="(" close=")"> |
| 636 | <mml:mfrac> |
| 637 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 638 | <mml:mi mathvariant="italic">d</mml:mi> |
| 639 | </mml:msub> |
| 640 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 641 | <mml:mi mathvariant="italic">A</mml:mi> |
| 642 | </mml:msub> |
| 643 | </mml:mfrac> |
| 644 | <mml:mfrac> |
| 645 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 646 | <mml:mi mathvariant="italic">d</mml:mi> |
| 647 | </mml:msub> |
| 648 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 649 | <mml:mi mathvariant="italic">A</mml:mi> |
| 650 | </mml:msub> |
| 651 | </mml:mfrac> |
| 652 | <mml:mfrac> |
| 653 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 654 | <mml:mi mathvariant="italic">d</mml:mi> |
| 655 | </mml:msub> |
| 656 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 657 | <mml:mi mathvariant="italic">A</mml:mi> |
| 658 | </mml:msub> |
| 659 | </mml:mfrac> |
| 660 | <mml:mfrac> |
| 661 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 662 | <mml:mi mathvariant="italic">d</mml:mi> |
| 663 | </mml:msub> |
| 664 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 665 | <mml:mi mathvariant="italic">A</mml:mi> |
| 666 | </mml:msub> |
| 667 | </mml:mfrac> |
| 668 | </mml:mfenced> |
| 669 | </mml:mrow> |
| 670 | </mml:math> |
| 671 | </td></tr><tr><td align="left"> |
| 672 | <code class="constant">GL_CONSTANT_COLOR</code> |
| 673 | </td><td align="left"> |
| 674 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 675 | |
| 676 | <mml:mfenced open="(" close=")"> |
| 677 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 678 | <mml:mi mathvariant="italic">c</mml:mi> |
| 679 | </mml:msub> |
| 680 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 681 | <mml:mi mathvariant="italic">c</mml:mi> |
| 682 | </mml:msub> |
| 683 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 684 | <mml:mi mathvariant="italic">c</mml:mi> |
| 685 | </mml:msub> |
| 686 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 687 | <mml:mi mathvariant="italic">c</mml:mi> |
| 688 | </mml:msub> |
| 689 | </mml:mfenced> |
| 690 | </mml:math> |
| 691 | </td></tr><tr><td align="left"> |
| 692 | <code class="constant">GL_ONE_MINUS_CONSTANT_COLOR</code> |
| 693 | </td><td align="left"> |
| 694 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 695 | |
| 696 | <mml:mrow> |
| 697 | <mml:mfenced open="(" close=")"> |
| 698 | <mml:mn>1</mml:mn> |
| 699 | <mml:mn>1</mml:mn> |
| 700 | <mml:mn>1</mml:mn> |
| 701 | <mml:mn>1</mml:mn> |
| 702 | </mml:mfenced> |
| 703 | <mml:mo>-</mml:mo> |
| 704 | <mml:mfenced open="(" close=")"> |
| 705 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 706 | <mml:mi mathvariant="italic">c</mml:mi> |
| 707 | </mml:msub> |
| 708 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 709 | <mml:mi mathvariant="italic">c</mml:mi> |
| 710 | </mml:msub> |
| 711 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 712 | <mml:mi mathvariant="italic">c</mml:mi> |
| 713 | </mml:msub> |
| 714 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 715 | <mml:mi mathvariant="italic">c</mml:mi> |
| 716 | </mml:msub> |
| 717 | </mml:mfenced> |
| 718 | </mml:mrow> |
| 719 | </mml:math> |
| 720 | </td></tr><tr><td align="left"> |
| 721 | <code class="constant">GL_CONSTANT_ALPHA</code> |
| 722 | </td><td align="left"> |
| 723 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 724 | |
| 725 | <mml:mfenced open="(" close=")"> |
| 726 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 727 | <mml:mi mathvariant="italic">c</mml:mi> |
| 728 | </mml:msub> |
| 729 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 730 | <mml:mi mathvariant="italic">c</mml:mi> |
| 731 | </mml:msub> |
| 732 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 733 | <mml:mi mathvariant="italic">c</mml:mi> |
| 734 | </mml:msub> |
| 735 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 736 | <mml:mi mathvariant="italic">c</mml:mi> |
| 737 | </mml:msub> |
| 738 | </mml:mfenced> |
| 739 | </mml:math> |
| 740 | </td></tr><tr><td align="left"> |
| 741 | <code class="constant">GL_ONE_MINUS_CONSTANT_ALPHA</code> |
| 742 | </td><td align="left"> |
| 743 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 744 | |
| 745 | <mml:mrow> |
| 746 | <mml:mfenced open="(" close=")"> |
| 747 | <mml:mn>1</mml:mn> |
| 748 | <mml:mn>1</mml:mn> |
| 749 | <mml:mn>1</mml:mn> |
| 750 | <mml:mn>1</mml:mn> |
| 751 | </mml:mfenced> |
| 752 | <mml:mo>-</mml:mo> |
| 753 | <mml:mfenced open="(" close=")"> |
| 754 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 755 | <mml:mi mathvariant="italic">c</mml:mi> |
| 756 | </mml:msub> |
| 757 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 758 | <mml:mi mathvariant="italic">c</mml:mi> |
| 759 | </mml:msub> |
| 760 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 761 | <mml:mi mathvariant="italic">c</mml:mi> |
| 762 | </mml:msub> |
| 763 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 764 | <mml:mi mathvariant="italic">c</mml:mi> |
| 765 | </mml:msub> |
| 766 | </mml:mfenced> |
| 767 | </mml:mrow> |
| 768 | </mml:math> |
| 769 | </td></tr><tr><td align="left"> |
| 770 | <code class="constant">GL_SRC_ALPHA_SATURATE</code> |
| 771 | </td><td align="left"> |
| 772 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 773 | |
| 774 | <mml:mfenced open="(" close=")"> |
| 775 | <mml:mi mathvariant="italic">i</mml:mi> |
| 776 | <mml:mi mathvariant="italic">i</mml:mi> |
| 777 | <mml:mi mathvariant="italic">i</mml:mi> |
| 778 | <mml:mn>1</mml:mn> |
| 779 | </mml:mfenced> |
| 780 | </mml:math> |
| 781 | </td></tr><tr><td align="left"> |
| 782 | <code class="constant">GL_SRC1_COLOR</code> |
| 783 | </td><td align="left"> |
| 784 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 785 | |
| 786 | <mml:mfenced open="(" close=")"> |
| 787 | <mml:mfrac> |
| 788 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 789 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 790 | </mml:msub> |
| 791 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 792 | <mml:mi mathvariant="italic">R</mml:mi> |
| 793 | </mml:msub> |
| 794 | </mml:mfrac> |
| 795 | <mml:mfrac> |
| 796 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 797 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 798 | </mml:msub> |
| 799 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 800 | <mml:mi mathvariant="italic">G</mml:mi> |
| 801 | </mml:msub> |
| 802 | </mml:mfrac> |
| 803 | <mml:mfrac> |
| 804 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 805 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 806 | </mml:msub> |
| 807 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 808 | <mml:mi mathvariant="italic">B</mml:mi> |
| 809 | </mml:msub> |
| 810 | </mml:mfrac> |
| 811 | <mml:mfrac> |
| 812 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 813 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 814 | </mml:msub> |
| 815 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 816 | <mml:mi mathvariant="italic">A</mml:mi> |
| 817 | </mml:msub> |
| 818 | </mml:mfrac> |
| 819 | </mml:mfenced> |
| 820 | </mml:math> |
| 821 | </td></tr><tr><td align="left"> |
| 822 | <code class="constant">GL_ONE_MINUS_SRC1_COLOR</code> |
| 823 | </td><td align="left"> |
| 824 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 825 | |
| 826 | <mml:mrow> |
| 827 | <mml:mfenced open="(" close=")"> |
| 828 | <mml:mn>1</mml:mn> |
| 829 | <mml:mn>1</mml:mn> |
| 830 | <mml:mn>1</mml:mn> |
| 831 | <mml:mn>1</mml:mn> |
| 832 | </mml:mfenced> |
| 833 | <mml:mo>-</mml:mo> |
| 834 | <mml:mfenced open="(" close=")"> |
| 835 | <mml:mfrac> |
| 836 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 837 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 838 | </mml:msub> |
| 839 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 840 | <mml:mi mathvariant="italic">R</mml:mi> |
| 841 | </mml:msub> |
| 842 | </mml:mfrac> |
| 843 | <mml:mfrac> |
| 844 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 845 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 846 | </mml:msub> |
| 847 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 848 | <mml:mi mathvariant="italic">G</mml:mi> |
| 849 | </mml:msub> |
| 850 | </mml:mfrac> |
| 851 | <mml:mfrac> |
| 852 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 853 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 854 | </mml:msub> |
| 855 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 856 | <mml:mi mathvariant="italic">B</mml:mi> |
| 857 | </mml:msub> |
| 858 | </mml:mfrac> |
| 859 | <mml:mfrac> |
| 860 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 861 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 862 | </mml:msub> |
| 863 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 864 | <mml:mi mathvariant="italic">A</mml:mi> |
| 865 | </mml:msub> |
| 866 | </mml:mfrac> |
| 867 | </mml:mfenced> |
| 868 | </mml:mrow> |
| 869 | </mml:math> |
| 870 | </td></tr><tr><td align="left"> |
| 871 | <code class="constant">GL_SRC1_ALPHA</code> |
| 872 | </td><td align="left"> |
| 873 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 874 | |
| 875 | <mml:mfenced open="(" close=")"> |
| 876 | <mml:mfrac> |
| 877 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 878 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 879 | </mml:msub> |
| 880 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 881 | <mml:mi mathvariant="italic">A</mml:mi> |
| 882 | </mml:msub> |
| 883 | </mml:mfrac> |
| 884 | <mml:mfrac> |
| 885 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 886 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 887 | </mml:msub> |
| 888 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 889 | <mml:mi mathvariant="italic">A</mml:mi> |
| 890 | </mml:msub> |
| 891 | </mml:mfrac> |
| 892 | <mml:mfrac> |
| 893 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 894 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 895 | </mml:msub> |
| 896 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 897 | <mml:mi mathvariant="italic">A</mml:mi> |
| 898 | </mml:msub> |
| 899 | </mml:mfrac> |
| 900 | <mml:mfrac> |
| 901 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 902 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 903 | </mml:msub> |
| 904 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 905 | <mml:mi mathvariant="italic">A</mml:mi> |
| 906 | </mml:msub> |
| 907 | </mml:mfrac> |
| 908 | </mml:mfenced> |
| 909 | </mml:math> |
| 910 | </td></tr><tr><td align="left"> |
| 911 | <code class="constant">GL_ONE_MINUS_SRC1_ALPHA</code> |
| 912 | </td><td align="left"> |
| 913 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 914 | |
| 915 | <mml:mrow> |
| 916 | <mml:mfenced open="(" close=")"> |
| 917 | <mml:mn>1</mml:mn> |
| 918 | <mml:mn>1</mml:mn> |
| 919 | <mml:mn>1</mml:mn> |
| 920 | <mml:mn>1</mml:mn> |
| 921 | </mml:mfenced> |
| 922 | <mml:mo>-</mml:mo> |
| 923 | <mml:mfenced open="(" close=")"> |
| 924 | <mml:mfrac> |
| 925 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 926 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 927 | </mml:msub> |
| 928 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 929 | <mml:mi mathvariant="italic">A</mml:mi> |
| 930 | </mml:msub> |
| 931 | </mml:mfrac> |
| 932 | <mml:mfrac> |
| 933 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 934 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 935 | </mml:msub> |
| 936 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 937 | <mml:mi mathvariant="italic">A</mml:mi> |
| 938 | </mml:msub> |
| 939 | </mml:mfrac> |
| 940 | <mml:mfrac> |
| 941 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 942 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 943 | </mml:msub> |
| 944 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 945 | <mml:mi mathvariant="italic">A</mml:mi> |
| 946 | </mml:msub> |
| 947 | </mml:mfrac> |
| 948 | <mml:mfrac> |
| 949 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 950 | <mml:mi mathvariant="italic">s1</mml:mi> |
| 951 | </mml:msub> |
| 952 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 953 | <mml:mi mathvariant="italic">A</mml:mi> |
| 954 | </mml:msub> |
| 955 | </mml:mfrac> |
| 956 | </mml:mfenced> |
| 957 | </mml:mrow> |
| 958 | </mml:math> |
| 959 | </td></tr></tbody></table></div><p> |
| 960 | In the table, |
| 961 | </p><p> |
| 962 | </p><p> |
| 963 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 964 | |
| 965 | <mml:mrow> |
| 966 | <mml:mi mathvariant="italic">i</mml:mi> |
| 967 | <mml:mo>=</mml:mo> |
| 968 | <mml:mfrac> |
| 969 | <mml:mrow> |
| 970 | <mml:mi mathvariant="italic">min</mml:mi> |
| 971 | <mml:mo></mml:mo> |
| 972 | <mml:mfenced open="(" close=")"> |
| 973 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 974 | <mml:mi mathvariant="italic">s</mml:mi> |
| 975 | </mml:msub> |
| 976 | <mml:mrow> |
| 977 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 978 | <mml:mi mathvariant="italic">A</mml:mi> |
| 979 | </mml:msub> |
| 980 | <mml:mo>-</mml:mo> |
| 981 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 982 | <mml:mi mathvariant="italic">d</mml:mi> |
| 983 | </mml:msub> |
| 984 | </mml:mrow> |
| 985 | </mml:mfenced> |
| 986 | </mml:mrow> |
| 987 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 988 | <mml:mi mathvariant="italic">A</mml:mi> |
| 989 | </mml:msub> |
| 990 | </mml:mfrac> |
| 991 | </mml:mrow> |
| 992 | </mml:math> |
| 993 | </p><p> |
| 994 | </p><p> |
| 995 | To determine the blended RGBA values of a pixel, |
| 996 | the system uses the following equations: |
| 997 | </p><p> |
| 998 | </p><p> |
| 999 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 1000 | |
| 1001 | <mml:mrow> |
| 1002 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 1003 | <mml:mi mathvariant="italic">d</mml:mi> |
| 1004 | </mml:msub> |
| 1005 | <mml:mo>=</mml:mo> |
| 1006 | <mml:mrow> |
| 1007 | <mml:mi mathvariant="italic">min</mml:mi> |
| 1008 | <mml:mo></mml:mo> |
| 1009 | <mml:mfenced open="(" close=")"> |
| 1010 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 1011 | <mml:mi mathvariant="italic">R</mml:mi> |
| 1012 | </mml:msub> |
| 1013 | <mml:mrow> |
| 1014 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 1015 | <mml:mi mathvariant="italic">s</mml:mi> |
| 1016 | </mml:msub> |
| 1017 | <mml:mo></mml:mo> |
| 1018 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> |
| 1019 | <mml:mi mathvariant="italic">R</mml:mi> |
| 1020 | </mml:msub> |
| 1021 | <mml:mo>+</mml:mo> |
| 1022 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 1023 | <mml:mi mathvariant="italic">d</mml:mi> |
| 1024 | </mml:msub> |
| 1025 | <mml:mo></mml:mo> |
| 1026 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> |
| 1027 | <mml:mi mathvariant="italic">R</mml:mi> |
| 1028 | </mml:msub> |
| 1029 | </mml:mrow> |
| 1030 | </mml:mfenced> |
| 1031 | </mml:mrow> |
| 1032 | </mml:mrow> |
| 1033 | </mml:math> |
| 1034 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 1035 | |
| 1036 | <mml:mrow> |
| 1037 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 1038 | <mml:mi mathvariant="italic">d</mml:mi> |
| 1039 | </mml:msub> |
| 1040 | <mml:mo>=</mml:mo> |
| 1041 | <mml:mrow> |
| 1042 | <mml:mi mathvariant="italic">min</mml:mi> |
| 1043 | <mml:mo></mml:mo> |
| 1044 | <mml:mfenced open="(" close=")"> |
| 1045 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 1046 | <mml:mi mathvariant="italic">G</mml:mi> |
| 1047 | </mml:msub> |
| 1048 | <mml:mrow> |
| 1049 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 1050 | <mml:mi mathvariant="italic">s</mml:mi> |
| 1051 | </mml:msub> |
| 1052 | <mml:mo></mml:mo> |
| 1053 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> |
| 1054 | <mml:mi mathvariant="italic">G</mml:mi> |
| 1055 | </mml:msub> |
| 1056 | <mml:mo>+</mml:mo> |
| 1057 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 1058 | <mml:mi mathvariant="italic">d</mml:mi> |
| 1059 | </mml:msub> |
| 1060 | <mml:mo></mml:mo> |
| 1061 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> |
| 1062 | <mml:mi mathvariant="italic">G</mml:mi> |
| 1063 | </mml:msub> |
| 1064 | </mml:mrow> |
| 1065 | </mml:mfenced> |
| 1066 | </mml:mrow> |
| 1067 | </mml:mrow> |
| 1068 | </mml:math> |
| 1069 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 1070 | |
| 1071 | <mml:mrow> |
| 1072 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 1073 | <mml:mi mathvariant="italic">d</mml:mi> |
| 1074 | </mml:msub> |
| 1075 | <mml:mo>=</mml:mo> |
| 1076 | <mml:mrow> |
| 1077 | <mml:mi mathvariant="italic">min</mml:mi> |
| 1078 | <mml:mo></mml:mo> |
| 1079 | <mml:mfenced open="(" close=")"> |
| 1080 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 1081 | <mml:mi mathvariant="italic">B</mml:mi> |
| 1082 | </mml:msub> |
| 1083 | <mml:mrow> |
| 1084 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 1085 | <mml:mi mathvariant="italic">s</mml:mi> |
| 1086 | </mml:msub> |
| 1087 | <mml:mo></mml:mo> |
| 1088 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> |
| 1089 | <mml:mi mathvariant="italic">B</mml:mi> |
| 1090 | </mml:msub> |
| 1091 | <mml:mo>+</mml:mo> |
| 1092 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 1093 | <mml:mi mathvariant="italic">d</mml:mi> |
| 1094 | </mml:msub> |
| 1095 | <mml:mo></mml:mo> |
| 1096 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> |
| 1097 | <mml:mi mathvariant="italic">B</mml:mi> |
| 1098 | </mml:msub> |
| 1099 | </mml:mrow> |
| 1100 | </mml:mfenced> |
| 1101 | </mml:mrow> |
| 1102 | </mml:mrow> |
| 1103 | </mml:math> |
| 1104 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 1105 | |
| 1106 | <mml:mrow> |
| 1107 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 1108 | <mml:mi mathvariant="italic">d</mml:mi> |
| 1109 | </mml:msub> |
| 1110 | <mml:mo>=</mml:mo> |
| 1111 | <mml:mrow> |
| 1112 | <mml:mi mathvariant="italic">min</mml:mi> |
| 1113 | <mml:mo></mml:mo> |
| 1114 | <mml:mfenced open="(" close=")"> |
| 1115 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 1116 | <mml:mi mathvariant="italic">A</mml:mi> |
| 1117 | </mml:msub> |
| 1118 | <mml:mrow> |
| 1119 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 1120 | <mml:mi mathvariant="italic">s</mml:mi> |
| 1121 | </mml:msub> |
| 1122 | <mml:mo></mml:mo> |
| 1123 | <mml:msub><mml:mi mathvariant="italic">s</mml:mi> |
| 1124 | <mml:mi mathvariant="italic">A</mml:mi> |
| 1125 | </mml:msub> |
| 1126 | <mml:mo>+</mml:mo> |
| 1127 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 1128 | <mml:mi mathvariant="italic">d</mml:mi> |
| 1129 | </mml:msub> |
| 1130 | <mml:mo></mml:mo> |
| 1131 | <mml:msub><mml:mi mathvariant="italic">d</mml:mi> |
| 1132 | <mml:mi mathvariant="italic">A</mml:mi> |
| 1133 | </mml:msub> |
| 1134 | </mml:mrow> |
| 1135 | </mml:mfenced> |
| 1136 | </mml:mrow> |
| 1137 | </mml:mrow> |
| 1138 | </mml:math> |
| 1139 | </p><p> |
| 1140 | </p><p> |
| 1141 | Despite the apparent precision of the above equations, |
| 1142 | blending arithmetic is not exactly specified, |
| 1143 | because blending operates with imprecise integer color values. |
| 1144 | However, |
| 1145 | a blend factor that should be equal to 1 |
| 1146 | is guaranteed not to modify its multiplicand, |
| 1147 | and a blend factor equal to 0 reduces its multiplicand to 0. |
| 1148 | For example, |
| 1149 | when <em class="parameter"><code>sfactor</code></em> is <code class="constant">GL_SRC_ALPHA</code>, |
| 1150 | <em class="parameter"><code>dfactor</code></em> is <code class="constant">GL_ONE_MINUS_SRC_ALPHA</code>, |
| 1151 | and |
| 1152 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 1153 | |
| 1154 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 1155 | <mml:mi mathvariant="italic">s</mml:mi> |
| 1156 | </mml:msub> |
| 1157 | </mml:math> |
| 1158 | is equal to |
| 1159 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 1160 | |
| 1161 | <mml:msub><mml:mi mathvariant="italic">k</mml:mi> |
| 1162 | <mml:mi mathvariant="italic">A</mml:mi> |
| 1163 | </mml:msub> |
| 1164 | </mml:math>, |
| 1165 | the equations reduce to simple replacement: |
| 1166 | </p><p> |
| 1167 | </p><p> |
| 1168 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 1169 | |
| 1170 | <mml:mrow> |
| 1171 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 1172 | <mml:mi mathvariant="italic">d</mml:mi> |
| 1173 | </mml:msub> |
| 1174 | <mml:mo>=</mml:mo> |
| 1175 | <mml:msub><mml:mi mathvariant="italic">R</mml:mi> |
| 1176 | <mml:mi mathvariant="italic">s</mml:mi> |
| 1177 | </mml:msub> |
| 1178 | </mml:mrow> |
| 1179 | </mml:math> |
| 1180 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 1181 | |
| 1182 | <mml:mrow> |
| 1183 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 1184 | <mml:mi mathvariant="italic">d</mml:mi> |
| 1185 | </mml:msub> |
| 1186 | <mml:mo>=</mml:mo> |
| 1187 | <mml:msub><mml:mi mathvariant="italic">G</mml:mi> |
| 1188 | <mml:mi mathvariant="italic">s</mml:mi> |
| 1189 | </mml:msub> |
| 1190 | </mml:mrow> |
| 1191 | </mml:math> |
| 1192 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 1193 | |
| 1194 | <mml:mrow> |
| 1195 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 1196 | <mml:mi mathvariant="italic">d</mml:mi> |
| 1197 | </mml:msub> |
| 1198 | <mml:mo>=</mml:mo> |
| 1199 | <mml:msub><mml:mi mathvariant="italic">B</mml:mi> |
| 1200 | <mml:mi mathvariant="italic">s</mml:mi> |
| 1201 | </mml:msub> |
| 1202 | </mml:mrow> |
| 1203 | </mml:math> |
| 1204 | <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 1205 | |
| 1206 | <mml:mrow> |
| 1207 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 1208 | <mml:mi mathvariant="italic">d</mml:mi> |
| 1209 | </mml:msub> |
| 1210 | <mml:mo>=</mml:mo> |
| 1211 | <mml:msub><mml:mi mathvariant="italic">A</mml:mi> |
| 1212 | <mml:mi mathvariant="italic">s</mml:mi> |
| 1213 | </mml:msub> |
| 1214 | </mml:mrow> |
| 1215 | </mml:math> |
| 1216 | </p><p> |
| 1217 | </p><p> |
| 1218 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="examples"></a><h2>Examples</h2><p> |
| 1219 | </p><p> |
| 1220 | Transparency is best implemented using blend function |
| 1221 | (<code class="constant">GL_SRC_ALPHA</code>, <code class="constant">GL_ONE_MINUS_SRC_ALPHA</code>) |
| 1222 | with primitives sorted from farthest to nearest. |
| 1223 | Note that this transparency calculation does not require |
| 1224 | the presence of alpha bitplanes in the frame buffer. |
| 1225 | </p><p> |
| 1226 | Blend function |
| 1227 | (<code class="constant">GL_SRC_ALPHA</code>, <code class="constant">GL_ONE_MINUS_SRC_ALPHA</code>) |
| 1228 | is also useful for rendering antialiased points and lines |
| 1229 | in arbitrary order. |
| 1230 | </p><p> |
| 1231 | Polygon antialiasing is optimized using blend function |
| 1232 | (<code class="constant">GL_SRC_ALPHA_SATURATE</code>, <code class="constant">GL_ONE</code>) |
| 1233 | with polygons sorted from nearest to farthest. |
| 1234 | (See the <a href="glEnable.xml"><span class="citerefentry"><span class="refentrytitle">glEnable</span></span></a>, <a href="glDisable.xml"><span class="citerefentry"><span class="refentrytitle">glDisable</span></span></a> reference page and the |
| 1235 | <code class="constant">GL_POLYGON_SMOOTH</code> argument for information on polygon antialiasing.) |
| 1236 | Destination alpha bitplanes, |
| 1237 | which must be present for this blend function to operate correctly, |
| 1238 | store the accumulated coverage. |
| 1239 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p> |
| 1240 | Incoming (source) alpha is correctly thought of as a material opacity, |
| 1241 | ranging from 1.0 |
| 1242 | (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> |
| 1243 | |
| 1244 | <mml:msub><mml:mi mathvariant="italic">K</mml:mi> |
| 1245 | <mml:mi mathvariant="italic">A</mml:mi> |
| 1246 | </mml:msub> |
| 1247 | </mml:math>), |
| 1248 | representing complete opacity, |
| 1249 | to 0.0 (0), representing complete |
| 1250 | transparency. |
| 1251 | </p><p> |
| 1252 | When more than one color buffer is enabled for drawing, |
| 1253 | the GL performs blending separately for each enabled buffer, |
| 1254 | using the contents of that buffer for destination color. |
| 1255 | (See <a href="glDrawBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glDrawBuffer</span></span></a>.) |
| 1256 | </p><p> |
| 1257 | When dual source blending is enabled (i.e., one of the blend factors requiring |
| 1258 | the second color input is used), the maximum number of enabled draw buffers |
| 1259 | is given by <code class="constant">GL_MAX_DUAL_SOURCE_DRAW_BUFFERS</code>, which may |
| 1260 | be lower than <code class="constant">GL_MAX_DRAW_BUFFERS</code>. |
| 1261 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p> |
| 1262 | <code class="constant">GL_INVALID_ENUM</code> is generated if either <em class="parameter"><code>sfactor</code></em> |
| 1263 | or <em class="parameter"><code>dfactor</code></em> is not an accepted value. |
| 1264 | </p><p> |
| 1265 | <code class="constant">GL_INVALID_VALUE</code> is generated by <code class="function">glBlendFunci</code> if <em class="parameter"><code>buf</code></em> is greater |
| 1266 | than or equal to the value of <code class="constant">GL_MAX_DRAW_BUFFERS</code>. |
| 1267 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p> |
| 1268 | <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_BLEND_SRC</code> |
| 1269 | </p><p> |
| 1270 | <a href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_BLEND_DST</code> |
| 1271 | </p><p> |
| 1272 | <a href="glIsEnabled.xml"><span class="citerefentry"><span class="refentrytitle">glIsEnabled</span></span></a> with argument <code class="constant">GL_BLEND</code> |
| 1273 | </p><p> |
| 1274 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p> |
| 1275 | <a href="glBlendColor.xml"><span class="citerefentry"><span class="refentrytitle">glBlendColor</span></span></a>, |
| 1276 | <a href="glBlendEquation.xml"><span class="citerefentry"><span class="refentrytitle">glBlendEquation</span></span></a>, |
| 1277 | <a href="glBlendFuncSeparate.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFuncSeparate</span></span></a>, |
| 1278 | <a href="glClear.xml"><span class="citerefentry"><span class="refentrytitle">glClear</span></span></a>, |
| 1279 | <a href="glDrawBuffer.xml"><span class="citerefentry"><span class="refentrytitle">glDrawBuffer</span></span></a>, |
| 1280 | <a href="glEnable.xml"><span class="citerefentry"><span class="refentrytitle">glEnable</span></span></a>, |
| 1281 | <a href="glLogicOp.xml"><span class="citerefentry"><span class="refentrytitle">glLogicOp</span></span></a>, |
| 1282 | <a href="glStencilFunc.xml"><span class="citerefentry"><span class="refentrytitle">glStencilFunc</span></span></a> |
| 1283 | </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p> |
| 1284 | Copyright <span class="trademark"></span>© 1991-2006 |
| 1285 | Silicon Graphics, Inc. This document is licensed under the SGI |
| 1286 | Free Software B License. For details, see |
| 1287 | <a href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>. |
| 1288 | </p></div></div></body></html> |