Opentk/Source/Bind/Specifications/Docs/ES31/glDepthRangef.xml
2014-03-28 20:06:55 +01:00

138 lines
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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="glDepthRangef">
<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>glDepthRangef</refentrytitle>
<manvolnum>3G</manvolnum>
</refmeta>
<refnamediv>
<refname>glDepthRangef</refname>
<refpurpose>specify mapping of depth values from normalized device coordinates to window coordinates</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>C Specification</title>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>glDepthRangef</function></funcdef>
<paramdef>GLfloat <parameter>n</parameter></paramdef>
<paramdef>GLfloat <parameter>f</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1 xml:id="parameters"><title>Parameters</title>
<variablelist>
<varlistentry>
<term><parameter>n</parameter></term>
<listitem>
<para>
Specifies the mapping of the near clipping plane to window coordinates.
The initial value is 0.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>f</parameter></term>
<listitem>
<para>
Specifies the mapping of the far clipping plane to window coordinates.
The initial value is 1.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 xml:id="description"><title>Description</title>
<para>
After clipping and division by <emphasis>w</emphasis>,
depth coordinates range from
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- eqn: -1: -->
<mml:mn>-1</mml:mn>
</mml:math></inlineequation>
to 1,
corresponding to the near and far clipping planes.
<function>glDepthRangef</function> specifies a linear mapping of the normalized depth coordinates
in this range to window depth coordinates.
If a fixed-point depth representation is used, the parameters <parameter>n</parameter> and <parameter>f</parameter>
are clamped to the range [0 to 1] when computing window z.
</para>
<para>
The setting of (0,1) maps the near plane to 0 and
the far plane to 1.
With this mapping,
the depth buffer range is fully utilized.
</para>
</refsect1>
<refsect1 xml:id="notes"><title>Notes</title>
<para>
It is not necessary that <parameter>n</parameter> be less than <parameter>f</parameter>.
Reverse mappings such as
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- eqn: n = 1: -->
<mml:mrow>
<mml:mi mathvariant="italic">n</mml:mi>
<mml:mo>=</mml:mo>
<mml:mn>1</mml:mn>
</mml:mrow>
</mml:math></inlineequation>,
and
<inlineequation><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
<!-- eqn: f = 0: -->
<mml:mrow>
<mml:mi mathvariant="italic">f</mml:mi>
<mml:mo>=</mml:mo>
<mml:mn>0</mml:mn>
</mml:mrow>
</mml:math></inlineequation>
are acceptable.
</para>
</refsect1>
<refsect1 xml:id="associatedgets"><title>Associated Gets</title>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_DEPTH_RANGE</constant>
</para>
</refsect1>
<refsect1 xml:id="versions">
<title>API Version Support</title>
<informaltable>
<tgroup cols="4" align="left">
<xi:include xmlns:xi="http://www.w3.org/2001/XInclude" href="apifunchead.xml" xpointer="xpointer(/*/*)"/>
<tbody>
<row>
<entry>glDepthRangef</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>glDepthFunc</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glPolygonOffset</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glViewport</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>