--- /dev/null
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
+ "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
+<refentry id="glBlendEquation">
+ <refmeta>
+ <refmetainfo>
+ <copyright>
+ <year>1991-2006</year>
+ <holder>Silicon Graphics, Inc.</holder>
+ </copyright>
+ </refmetainfo>
+ <refentrytitle>glBlendEquation</refentrytitle>
+ <manvolnum>3G</manvolnum>
+ </refmeta>
+ <refnamediv>
+ <refname>glBlendEquation</refname>
+ <refpurpose>specify the equation used for both the RGB blend equation and the Alpha blend equation</refpurpose>
+ </refnamediv>
+ <refsynopsisdiv><title>C Specification</title>
+ <funcsynopsis>
+ <funcprototype>
+ <funcdef>void <function>glBlendEquation</function></funcdef>
+ <paramdef>GLenum <parameter>mode</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ </refsynopsisdiv>
+ <!-- eqn: ignoring delim $$ -->
+ <refsect1 id="parameters"><title>Parameters</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>mode</parameter></term>
+ <listitem>
+ <para>
+ specifies how source and destination colors are combined.
+ It must be <constant>GL_FUNC_ADD</constant>, <constant>GL_FUNC_SUBTRACT</constant>,
+ <constant>GL_FUNC_REVERSE_SUBTRACT</constant>, <constant>GL_MIN</constant>, <constant>GL_MAX</constant>.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1 id="description"><title>Description</title>
+ <para>
+ 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.
+ </para>
+ <para>
+ These equations use the source and destination blend factors
+ specified by either <citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry> or
+ <citerefentry><refentrytitle>glBlendFuncSeparate</refentrytitle></citerefentry>.
+ See <citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry> or <citerefentry><refentrytitle>glBlendFuncSeparate</refentrytitle></citerefentry>
+ for a description of the various blend factors.
+ </para>
+ <para>
+ In the equations that follow, source and destination
+ color components are referred to as
+ <inlineequation><mml:math>
+ <!-- eqn: ( R sub s, G sub s, B sub s, A sub s ):-->
+ <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></inlineequation>
+ and
+ <inlineequation><mml:math>
+ <!-- eqn: ( R sub d, G sub d, B sub d, A sub d ):-->
+ <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></inlineequation>,
+ respectively.
+ The result color is referred to as
+ <inlineequation><mml:math>
+ <!-- eqn: ( R sub r, G sub r, B sub r, A sub r ):-->
+ <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></inlineequation>.
+ The source and destination blend factors are denoted
+ <inlineequation><mml:math>
+ <!-- eqn: ( s sub R, s sub G, s sub B, s sub A ):-->
+ <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></inlineequation>
+ and
+ <inlineequation><mml:math>
+ <!-- eqn: ( d sub R, d sub G, d sub B, d sub A ):-->
+ <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></inlineequation>,
+ respectively.
+ For these equations all color components are understood to have values
+ in the range
+ <inlineequation><mml:math>
+ <!-- eqn: [0,1]:-->
+ <mml:mfenced open="[" close="]">
+ <mml:mn>0</mml:mn>
+ <mml:mn>1</mml:mn>
+ </mml:mfenced>
+ </mml:math></inlineequation>.
+
+ <informaltable frame="topbot">
+ <tgroup cols="3" align="left">
+ <colspec colwidth="1.1*" />
+ <colspec colwidth="1*" />
+ <colspec colwidth="1*" />
+ <thead>
+ <row>
+ <entry rowsep="1" align="left"><emphasis role="bold">
+ Mode
+ </emphasis></entry>
+ <entry rowsep="1" align="left"><emphasis role="bold">
+ RGB Components
+ </emphasis></entry>
+ <entry rowsep="1" align="left"><emphasis role="bold">
+ Alpha Component
+ </emphasis></entry>
+ </row>
+ </thead>
+ <tbody>
+ <row>
+ <entry align="left">
+ <constant>GL_FUNC_ADD</constant>
+ </entry>
+ <entry align="left">
+ <informalequation><mml:math>
+ <!-- eqn: Rr = R sub s s sub R + R sub d d sub R :-->
+ <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></informalequation>
+ <informalequation><mml:math>
+ <!-- eqn: Gr = G sub s s sub G + G sub d d sub G :-->
+ <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></informalequation>
+ <informalequation><mml:math>
+ <!-- eqn: Br = B sub s s sub B + B sub d d sub B :-->
+ <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></informalequation>
+ </entry>
+ <entry align="left">
+ <informalequation><mml:math>
+ <!-- eqn: Ar = A sub s s sub A + A sub d d sub A :-->
+ <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></informalequation>
+ </entry>
+ </row>
+ <row>
+ <entry align="left">
+ <constant>GL_FUNC_SUBTRACT</constant>
+ </entry>
+ <entry align="left">
+ <informalequation><mml:math>
+ <!-- eqn: Rr = R sub s s sub R - R sub d d sub R :-->
+ <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></informalequation>
+ <informalequation><mml:math>
+ <!-- eqn: Gr = G sub s s sub G - G sub d d sub G :-->
+ <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></informalequation>
+ <informalequation><mml:math>
+ <!-- eqn: Br = B sub s s sub B - B sub d d sub B :-->
+ <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></informalequation>
+ </entry>
+ <entry align="left">
+ <informalequation><mml:math>
+ <!-- eqn: Ar = A sub s s sub A - A sub d d sub A :-->
+ <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></informalequation>
+ </entry>
+ </row>
+ <row>
+ <entry align="left">
+ <constant>GL_FUNC_REVERSE_SUBTRACT</constant>
+ </entry>
+ <entry align="left">
+ <informalequation><mml:math>
+ <!-- eqn: Rr = R sub d d sub R - R sub s s sub R :-->
+ <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></informalequation>
+ <informalequation><mml:math>
+ <!-- eqn: Gr = G sub d d sub G - G sub s s sub G :-->
+ <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></informalequation>
+ <informalequation><mml:math>
+ <!-- eqn: Br = B sub d d sub B - B sub s s sub B :-->
+ <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></informalequation>
+ </entry>
+ <entry align="left">
+ <informalequation><mml:math>
+ <!-- eqn: Ar = A sub d d sub A - A sub s s sub A :-->
+ <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></informalequation>
+ </entry>
+ </row>
+ <row>
+ <entry align="left">
+ <constant>GL_MIN</constant>
+ </entry>
+ <entry align="left">
+ <informalequation><mml:math>
+ <!-- eqn: Rr = min ( R sub s, R sub d):-->
+ <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></informalequation>
+ <informalequation><mml:math>
+ <!-- eqn: Gr = min ( G sub s, G sub d):-->
+ <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></informalequation>
+ <informalequation><mml:math>
+ <!-- eqn: Br = min ( B sub s, B sub d):-->
+ <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></informalequation>
+ </entry>
+ <entry align="left">
+ <informalequation><mml:math>
+ <!-- eqn: Ar = min ( A sub s, A sub d):-->
+ <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></informalequation>
+ </entry>
+ </row>
+ <row>
+ <entry align="left">
+ <constant>GL_MAX</constant>
+ </entry>
+ <entry align="left">
+ <informalequation><mml:math>
+ <!-- eqn: Rr = max ( R sub s, R sub d):-->
+ <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></informalequation>
+ <informalequation><mml:math>
+ <!-- eqn: Gr = max ( G sub s, G sub d):-->
+ <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></informalequation>
+ <informalequation><mml:math>
+ <!-- eqn: Br = max ( B sub s, B sub d):-->
+ <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></informalequation>
+ </entry>
+ <entry align="left">
+ <informalequation><mml:math>
+ <!-- eqn: Ar = max ( A sub s, A sub d):-->
+ <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></informalequation>
+ </entry>
+ </row>
+ </tbody>
+ </tgroup>
+ </informaltable>
+ </para>
+ <para>
+ The results of these equations are clamped to the range
+ <inlineequation><mml:math>
+ <!-- eqn: [0,1]:-->
+ <mml:mfenced open="[" close="]">
+ <mml:mn>0</mml:mn>
+ <mml:mn>1</mml:mn>
+ </mml:mfenced>
+ </mml:math></inlineequation>.
+ </para>
+ <para>
+ The <constant>GL_MIN</constant> and <constant>GL_MAX</constant> equations are useful for applications
+ that analyze image data (image thresholding against a constant color,
+ for example).
+ The <constant>GL_FUNC_ADD</constant> equation is useful
+ for antialiasing and transparency, among other things.
+ </para>
+ <para>
+ Initially, both the RGB blend equation and the alpha blend equation are set to <constant>GL_FUNC_ADD</constant>.
+ </para>
+ <para>
+ </para>
+ </refsect1>
+ <refsect1 id="notes"><title>Notes</title>
+ <para>
+ The <constant>GL_MIN</constant>, and <constant>GL_MAX</constant> equations do not use
+ the source or destination factors, only the source and destination colors.
+ </para>
+ </refsect1>
+ <refsect1 id="errors"><title>Errors</title>
+ <para>
+ <constant>GL_INVALID_ENUM</constant> is generated if <parameter>mode</parameter> is not one of
+ <constant>GL_FUNC_ADD</constant>, <constant>GL_FUNC_SUBTRACT</constant>, <constant>GL_FUNC_REVERSE_SUBTRACT</constant>,
+ <constant>GL_MAX</constant>, or <constant>GL_MIN</constant>.
+ </para>
+ <para>
+ <constant>GL_INVALID_OPERATION</constant> is generated if <function>glBlendEquation</function> is executed
+ between the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry> and the corresponding
+ execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
+ </para>
+ </refsect1>
+ <refsect1 id="associatedgets"><title>Associated Gets</title>
+ <para>
+ <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with an argument of <constant>GL_BLEND_EQUATION_RGB</constant>
+ </para>
+ <para>
+ <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with an argument of <constant>GL_BLEND_EQUATION_ALPHA</constant>
+ </para>
+ </refsect1>
+ <refsect1 id="seealso"><title>See Also</title>
+ <para>
+ <citerefentry><refentrytitle>glGetString</refentrytitle></citerefentry>,
+ <citerefentry><refentrytitle>glBlendColor</refentrytitle></citerefentry>,
+ <citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry>
+ <citerefentry><refentrytitle>glBlendFuncSeparate</refentrytitle></citerefentry>
+ </para>
+ </refsect1>
+ <refsect1 id="Copyright"><title>Copyright</title>
+ <para>
+ Copyright <trademark class="copyright"></trademark> 1991-2006
+ Silicon Graphics, Inc. This document is licensed under the SGI
+ Free Software B License. For details, see
+ <ulink url="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</ulink>.
+ </para>
+ </refsect1>
+</refentry>
HCoop / clinton / guile-figl.git / blobdiff