Opentk/Source/Bind/Specifications/Docs/ES30/glBlendEquationSeparate.xml
2014-03-28 20:06:55 +01:00

792 lines
46 KiB
XML

<!DOCTYPE refentry [ <!ENTITY % mathent SYSTEM "math.ent"> %mathent; ]>
<!-- Converted by db4-upgrade version 1.1 -->
<refentry xmlns="http://docbook.org/ns/docbook" version="5.0" xml:id="glBlendEquationSeparate">
<info>
<copyright>
<year>1991-2006</year>
<holder>Silicon Graphics, Inc.</holder>
</copyright>
<copyright>
<year>2010-2014</year>
<holder>Khronos Group</holder>
</copyright>
</info>
<refmeta>
<refentrytitle>glBlendEquationSeparate</refentrytitle>
<manvolnum>3G</manvolnum>
</refmeta>
<refnamediv>
<refname>glBlendEquationSeparate</refname>
<refpurpose>set the RGB blend equation and the alpha blend equation separately</refpurpose>
</refnamediv>
<refsynopsisdiv><title>C Specification</title>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>glBlendEquationSeparate</function></funcdef>
<paramdef>GLenum <parameter>modeRGB</parameter></paramdef>
<paramdef>GLenum <parameter>modeAlpha</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1 xml:id="parameters"><title>Parameters</title>
<variablelist>
<varlistentry>
<term><parameter>modeRGB</parameter></term>
<listitem>
<para>
specifies the RGB blend equation, how the red, green, and blue components of the 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>
<varlistentry>
<term><parameter>modeAlpha</parameter></term>
<listitem>
<para>
specifies the alpha blend equation, how the alpha component of the 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 xml:id="description"><title>Description</title>
<para>
The blend equations determines how a new pixel (the ''source'' color)
is combined with a pixel already in the framebuffer (the ''destination''
color). This function specifies one blend equation for the RGB-color
components and one blend equation for the alpha component.
</para>
<para>
The blend 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 xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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 xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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 xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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 xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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 xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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 xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- eqn: [0,1]:-->
<mml:mfenced open="[" close="]">
<mml:mn>0</mml:mn>
<mml:mn>1</mml:mn>
</mml:mfenced>
</mml:math></inlineequation>.
<informaltable>
<tgroup cols="3" align="left">
<colspec colwidth="1.1*"/>
<colspec colwidth="1*"/>
<colspec colwidth="1*"/>
<thead>
<row>
<entry>
<emphasis role="bold"> Mode </emphasis>
</entry>
<entry>
<emphasis role="bold"> RGB Components </emphasis>
</entry>
<entry>
<emphasis role="bold"> Alpha Component </emphasis>
</entry>
</row>
</thead>
<tbody>
<row>
<entry>
<constant>GL_FUNC_ADD</constant>
</entry>
<entry>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&it;</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>&it;</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></inlineequation>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&it;</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>&it;</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></inlineequation>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&it;</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>&it;</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></inlineequation>
</entry>
<entry>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&it;</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>&it;</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></inlineequation>
</entry>
</row>
<row>
<entry>
<constant>GL_FUNC_SUBTRACT</constant>
</entry>
<entry>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&it;</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>&it;</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></inlineequation>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&it;</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>&it;</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></inlineequation>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&it;</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>&it;</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></inlineequation>
</entry>
<entry>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&it;</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>&it;</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></inlineequation>
</entry>
</row>
<row>
<entry>
<constant>GL_FUNC_REVERSE_SUBTRACT</constant>
</entry>
<entry>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&it;</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>&it;</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></inlineequation>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&it;</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>&it;</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></inlineequation>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&it;</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>&it;</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></inlineequation>
</entry>
<entry>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&it;</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>&it;</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></inlineequation>
</entry>
</row>
<row>
<entry>
<constant>GL_MIN</constant>
</entry>
<entry>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&af;</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></inlineequation>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&af;</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></inlineequation>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&af;</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></inlineequation>
</entry>
<entry>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&af;</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></inlineequation>
</entry>
</row>
<row>
<entry>
<constant>GL_MAX</constant>
</entry>
<entry>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&af;</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></inlineequation>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&af;</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></inlineequation>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&af;</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></inlineequation>
</entry>
<entry>
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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>&af;</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></inlineequation>
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</para>
<para>
The results of these equations are clamped to the range
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- 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 xml: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 xml:id="errors"><title>Errors</title>
<para>
<constant>GL_INVALID_ENUM</constant> is generated if either <parameter>modeRGB</parameter> or <parameter>modeAlpha</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>
</refsect1>
<refsect1 xml: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 xml:id="versions">
<title>API Version Support</title>
<informaltable>
<tgroup cols="3" align="left">
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apifunchead.xml" xpointer="xpointer(/*/*)"/>
<tbody>
<row>
<entry>glBlendEquationSeparate</entry>
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apiversion.xml" xpointer="xpointer(/*/*[@role='es20']/*)"/>
</row>
</tbody>
</tgroup>
</informaltable>
</refsect1>
<refsect1 xml:id="seealso"><title>See Also</title>
<para>
<citerefentry><refentrytitle>glGetString</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glBlendColor</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glBlendEquation</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glBlendFunc</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glBlendFuncSeparate</refentrytitle></citerefentry>
</para>
</refsect1>
<refsect1 xml:id="Copyright"><title>Copyright</title>
<para>
Copyright <trademark class="copyright"/> 1991-2006 Silicon Graphics, Inc.
Copyright <trademark class="copyright"/> 2010-2014 Khronos Group.
This document is licensed under the SGI Free Software B License.
For details, see
<link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/</link>.
</para>
</refsect1>
</refentry>