rename upstream-man-pages to upstream-doc

[clinton/guile-figl.git] / upstream-doc / man4 / glGetShaderPrecisionFormat.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
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<refentry id="glGetShaderPrecisionFormat">
    <refmeta>
        <refmetainfo>
            <copyright>
                <year>2010</year>
                <holder>Khronos Group</holder>
            </copyright>
        </refmetainfo>
        <refentrytitle>glGetShaderPrecisionFormat</refentrytitle>
        <manvolnum>3G</manvolnum>
    </refmeta>
    <refnamediv>
        <refname>glGetShaderPrecisionFormat</refname>
        <refpurpose>retrieve the range and precision for numeric formats supported by the shader compiler</refpurpose>
    </refnamediv>
    <refsynopsisdiv><title>C Specification</title>
        <funcsynopsis>
            <funcprototype>
                <funcdef>void <function>glGetShaderPrecisionFormat</function></funcdef>
                <paramdef>GLenum <parameter>shaderType</parameter></paramdef>
                <paramdef>GLenum <parameter>precisionType</parameter></paramdef>
                <paramdef>GLint *<parameter>range</parameter></paramdef>
                <paramdef>GLint *<parameter>precision</parameter></paramdef>
            </funcprototype>
        </funcsynopsis>
    </refsynopsisdiv>
    <refsect1 id="parameters"><title>Parameters</title>
        <variablelist>
        <varlistentry>
            <term><parameter>shaderType</parameter></term>
            <listitem>
            <para>
                Specifies the type of shader whose precision to query. <parameter>shaderType</parameter>
                must be <constant>GL_VERTEX_SHADER</constant> or <constant>GL_FRAGMENT_SHADER</constant>.
            </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>precisionType</parameter></term>
            <listitem>
            <para>
                Specifies the numeric format whose precision and range to query.
            </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>range</parameter></term>
            <listitem>
            <para>
                Specifies the address of array of two integers into which encodings of the implementation's
                numeric range are returned.
            </para>
            </listitem>
        </varlistentry>
        <varlistentry>
            <term><parameter>precision</parameter></term>
            <listitem>
            <para>
                Specifies the address of an integer into which the numeric precision of the implementation
                is written.
            </para>
            </listitem>
        </varlistentry>
        </variablelist>
    </refsect1>
    <refsect1 id="description"><title>Description</title>
        <para>
            <function>glGetShaderPrecisionFormat</function> retrieves the numeric range and precision for
            the implementation's representation of quantities in different numeric formats in specified
            shader type. <parameter>shaderType</parameter> specifies the type of shader for which the numeric
            precision and range is to be retrieved and must be one of <constant>GL_VERTEX_SHADER</constant>
            or <constant>GL_FRAGMENT_SHADER</constant>. <parameter>precisionType</parameter> specifies the
            numeric format to query and must be one of <constant>GL_LOW_FLOAT</constant>, <constant>GL_MEDIUM_FLOAT</constant>
            <constant>GL_HIGH_FLOAT</constant>, <constant>GL_LOW_INT</constant>, <constant>GL_MEDIUM_INT</constant>,
            or <constant>GL_HIGH_INT</constant>.
        </para>
        <para>
            <parameter>range</parameter> points to an array of two integers into which the format's numeric range
            will be returned. If min and max are the smallest values representable in the format, then the values
            returned are defined to be: <parameter>range</parameter>[0] = floor(log2(|min|)) and
            <parameter>range</parameter>[1] = floor(log2(|max|)).
        </para>
        <para>
            <parameter>precision</parameter> specifies the address of an integer into which will be written
            the log2 value of the number of bits of precision of the format. If the smallest representable
            value greater than 1 is 1 + <emphasis>eps</emphasis>, then the integer addressed by <parameter>precision</parameter>
            will contain floor(-log2(eps)).
        </para>
    </refsect1>
    <refsect1 id="errors"><title>Errors</title>
        <para>
            <constant>GL_INVALID_ENUM</constant> is generated if <parameter>shaderType</parameter> or
            <parameter>precisionType</parameter> is not an accepted value.
        </para>
    </refsect1>
    <refsect1 id="Copyright"><title>Copyright</title>
        <para>
            Copyright <trademark class="copyright"></trademark> 2010 Khronos Group. 
            This material may be distributed subject to the terms and conditions set forth in 
            the Open Publication License, v 1.0, 8 June 1999.
            <ulink url="http://opencontent.org/openpub/">http://opencontent.org/openpub/</ulink>.
        </para>
    </refsect1>
</refentry>