--- /dev/null
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "xhtml1-transitional.dtd">
+<!-- saved from url=(0013)about:internet -->
+<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>glBlendEquation</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glBlendEquation"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glBlendEquation — specify the equation used for both the RGB blend equation and the Alpha blend equation</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glBlendEquation</b>(</code></td><td>GLenum </td><td><var class="pdparam">mode</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>mode</code></em></span></dt><dd><p>
+ specifies how source and destination colors are combined.
+ It must be <code class="constant">GL_FUNC_ADD</code>, <code class="constant">GL_FUNC_SUBTRACT</code>,
+ <code class="constant">GL_FUNC_REVERSE_SUBTRACT</code>, <code class="constant">GL_MIN</code>, <code class="constant">GL_MAX</code>.
+ </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
+ The blend equations determine how a new pixel (the ''source'' color)
+ is combined with a pixel already in the framebuffer (the ''destination''
+ color). This function sets both the RGB blend equation and the alpha
+ blend equation to a single equation.
+ </p><p>
+ These equations use the source and destination blend factors
+ specified by either <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>.
+ 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>
+ for a description of the various blend factors.
+ </p><p>
+ In the equations that follow, source and destination
+ color components are referred to as
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="(" close=")">
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:math>
+ and
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="(" close=")">
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:math>,
+ respectively.
+ The result color is referred to as
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="(" close=")">
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
+ <mml:mi mathvariant="italic">r</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:math>.
+ The source and destination blend factors are denoted
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="(" close=")">
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">R</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">G</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">B</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">A</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:math>
+ and
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="(" close=")">
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">R</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">G</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">B</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">A</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:math>,
+ respectively.
+ For these equations all color components are understood to have values
+ in the range
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close="]">
+ <mml:mn>0</mml:mn>
+ <mml:mn>1</mml:mn>
+ </mml:mfenced>
+ </mml:math>.
+
+ </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>
+ Mode
+ </strong></span></th><th align="left"><span class="bold"><strong>
+ RGB Components
+ </strong></span></th><th align="left"><span class="bold"><strong>
+ Alpha Component
+ </strong></span></th></tr></thead><tbody><tr><td align="left">
+ <code class="constant">GL_FUNC_ADD</code>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Rr</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">R</mml:mi>
+ </mml:msub>
+ <mml:mo>+</mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">R</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Gr</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">G</mml:mi>
+ </mml:msub>
+ <mml:mo>+</mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">G</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Br</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">B</mml:mi>
+ </mml:msub>
+ <mml:mo>+</mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">B</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Ar</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">A</mml:mi>
+ </mml:msub>
+ <mml:mo>+</mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">A</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_FUNC_SUBTRACT</code>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Rr</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">R</mml:mi>
+ </mml:msub>
+ <mml:mo>-</mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">R</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Gr</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">G</mml:mi>
+ </mml:msub>
+ <mml:mo>-</mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">G</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Br</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">B</mml:mi>
+ </mml:msub>
+ <mml:mo>-</mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">B</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Ar</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">A</mml:mi>
+ </mml:msub>
+ <mml:mo>-</mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">A</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_FUNC_REVERSE_SUBTRACT</code>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Rr</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">R</mml:mi>
+ </mml:msub>
+ <mml:mo>-</mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">R</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Gr</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">G</mml:mi>
+ </mml:msub>
+ <mml:mo>-</mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">G</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Br</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">B</mml:mi>
+ </mml:msub>
+ <mml:mo>-</mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">B</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Ar</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">d</mml:mi>
+ <mml:mi mathvariant="italic">A</mml:mi>
+ </mml:msub>
+ <mml:mo>-</mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ <mml:mo></mml:mo>
+ <mml:msub><mml:mi mathvariant="italic">s</mml:mi>
+ <mml:mi mathvariant="italic">A</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_MIN</code>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Rr</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">min</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Gr</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">min</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Br</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">min</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Ar</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">min</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_MAX</code>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Rr</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">max</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">R</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Gr</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">max</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">G</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Br</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">max</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">B</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ </td><td align="left">
+ <div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">Ar</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:mi mathvariant="italic">max</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">A</mml:mi>
+ <mml:mi mathvariant="italic">d</mml:mi>
+ </mml:msub>
+ </mml:mrow>
+ </mml:mfenced>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></div>
+ </td></tr></tbody></table></div><p>
+ </p><p>
+ The results of these equations are clamped to the range
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close="]">
+ <mml:mn>0</mml:mn>
+ <mml:mn>1</mml:mn>
+ </mml:mfenced>
+ </mml:math>.
+ </p><p>
+ The <code class="constant">GL_MIN</code> and <code class="constant">GL_MAX</code> equations are useful for applications
+ that analyze image data (image thresholding against a constant color,
+ for example).
+ The <code class="constant">GL_FUNC_ADD</code> equation is useful
+ for antialiasing and transparency, among other things.
+ </p><p>
+ Initially, both the RGB blend equation and the alpha blend equation are set to <code class="constant">GL_FUNC_ADD</code>.
+ </p><p>
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
+ The <code class="constant">GL_MIN</code>, and <code class="constant">GL_MAX</code> equations do not use
+ the source or destination factors, only the source and destination colors.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
+ <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>mode</code></em> is not one of
+ <code class="constant">GL_FUNC_ADD</code>, <code class="constant">GL_FUNC_SUBTRACT</code>, <code class="constant">GL_FUNC_REVERSE_SUBTRACT</code>,
+ <code class="constant">GL_MAX</code>, or <code class="constant">GL_MIN</code>.
+ </p><p>
+ <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glBlendEquation</code> is executed
+ between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a> and the corresponding
+ execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
+ <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>
+ </p><p>
+ <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>
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
+ <a class="citerefentry" href="glGetString.xml"><span class="citerefentry"><span class="refentrytitle">glGetString</span></span></a>,
+ <a class="citerefentry" href="glBlendColor.xml"><span class="citerefentry"><span class="refentrytitle">glBlendColor</span></span></a>,
+ <a class="citerefentry" href="glBlendFunc.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFunc</span></span></a>
+ <a class="citerefentry" href="glBlendFuncSeparate.xml"><span class="citerefentry"><span class="refentrytitle">glBlendFuncSeparate</span></span></a>
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
+ Copyright <span class="trademark"></span>© 1991-2006
+ Silicon Graphics, Inc. This document is licensed under the SGI
+ Free Software B License. For details, see
+ <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
+ </p></div></div></body></html>
HCoop / clinton / guile-figl.git / blobdiff