--- /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="glViewportIndexed">
+ <refmeta>
+ <refmetainfo>
+ <copyright>
+ <year>2010</year>
+ <holder>Khronos Group</holder>
+ </copyright>
+ </refmetainfo>
+ <refentrytitle>glViewportIndexed</refentrytitle>
+ <manvolnum>3G</manvolnum>
+ </refmeta>
+ <refnamediv>
+ <refname>glViewportIndexed</refname>
+ <refpurpose>set a specified viewport</refpurpose>
+ </refnamediv>
+ <refsynopsisdiv><title>C Specification</title>
+ <funcsynopsis>
+ <funcprototype>
+ <funcdef>void <function>glViewportIndexedf</function></funcdef>
+ <paramdef>GLuint <parameter>index</parameter></paramdef>
+ <paramdef>GLfloat <parameter>x</parameter></paramdef>
+ <paramdef>GLfloat <parameter>y</parameter></paramdef>
+ <paramdef>GLfloat <parameter>w</parameter></paramdef>
+ <paramdef>GLfloat <parameter>h</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ <funcsynopsis>
+ <funcprototype>
+ <funcdef>void <function>glViewportIndexedfv</function></funcdef>
+ <paramdef>GLuint <parameter>index</parameter></paramdef>
+ <paramdef>const GLfloat *<parameter>v</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ </refsynopsisdiv>
+ <!-- eqn: ignoring delim $$ -->
+ <refsect1 id="parameters"><title>Parameters</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>index</parameter></term>
+ <listitem>
+ <para>
+ Specify the first viewport to set.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>x</parameter></term>
+ <term><parameter>y</parameter></term>
+ <listitem>
+ <para>
+ For <function>glViewportIndexedf</function>, specifies the lower left corner of
+ the viewport rectangle, in pixels. The initial value is (0,0).
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>width</parameter></term>
+ <term><parameter>height</parameter></term>
+ <listitem>
+ <para>
+ For <function>glViewportIndexedf</function>, specifies the width and height
+ of the viewport.
+ When a GL context is first attached to a window,
+ <parameter>width</parameter> and <parameter>height</parameter> are set to the dimensions of that
+ window.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>v</parameter></term>
+ <listitem>
+ <para>
+ For <function>glViewportIndexedfv</function>, specifies the address of an array containing the viewport parameters.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1 id="description"><title>Description</title>
+ <para>
+ <function>glViewportIndexedf</function> and <function>glViewportIndexedfv</function>
+ specify the parameters for a single viewport.
+ <parameter>index</parameter> specifies the index of the viewport
+ to modify.
+ <parameter>index</parameter> must be less than the value of <constant>GL_MAX_VIEWPORTS</constant>.
+ For <function>glViewportIndexedf</function>, <parameter>x</parameter>, <parameter>y</parameter>,
+ <parameter>w</parameter>, and <parameter>h</parameter> specify the left, bottom, width and height
+ of the viewport in pixels, respectively.
+ For <function>glViewportIndexedfv</function>, <parameter>v</parameter> contains the address of an array of floating
+ point values specifying the
+ left (<inlineequation><mml:math><mml:mi mathvariant="italic">x</mml:mi></mml:math></inlineequation>),
+ bottom (<inlineequation><mml:math><mml:mi mathvariant="italic">y</mml:mi></mml:math></inlineequation>),
+ width (<inlineequation><mml:math><mml:mi mathvariant="italic">w</mml:mi></mml:math></inlineequation>),
+ and height (<inlineequation><mml:math><mml:mi mathvariant="italic">h</mml:mi></mml:math></inlineequation>)
+ of each viewport, in that order. <inlineequation><mml:math><mml:mi mathvariant="italic">x</mml:mi></mml:math></inlineequation>
+ and <inlineequation><mml:math><mml:mi mathvariant="italic">y</mml:mi></mml:math></inlineequation> give
+ the location of the viewport's lower left corner, and
+ <inlineequation><mml:math><mml:mi mathvariant="italic">w</mml:mi></mml:math></inlineequation>
+ and <inlineequation><mml:math><mml:mi mathvariant="italic">h</mml:mi></mml:math></inlineequation>
+ give the width and height of the viewport, respectively.
+ The viewport specifies the affine transformation of
+ <inlineequation><mml:math><mml:mi mathvariant="italic">x</mml:mi></mml:math></inlineequation>
+ and
+ <inlineequation><mml:math><mml:mi mathvariant="italic">y</mml:mi></mml:math></inlineequation>
+ from
+ normalized device coordinates to window coordinates.
+ Let
+ <inlineequation><mml:math>
+ <!-- eqn: (x sub nd, y sub nd): -->
+ <mml:mfenced open="(" close=")">
+ <mml:msub><mml:mi mathvariant="italic">x</mml:mi>
+ <mml:mi mathvariant="italic">nd</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">y</mml:mi>
+ <mml:mi mathvariant="italic">nd</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:math></inlineequation>
+ be normalized device coordinates.
+ Then the window coordinates
+ <inlineequation><mml:math>
+ <!-- eqn: (x sub w, y sub w): -->
+ <mml:mfenced open="(" close=")">
+ <mml:msub><mml:mi mathvariant="italic">x</mml:mi>
+ <mml:mi mathvariant="italic">w</mml:mi>
+ </mml:msub>
+ <mml:msub><mml:mi mathvariant="italic">y</mml:mi>
+ <mml:mi mathvariant="italic">w</mml:mi>
+ </mml:msub>
+ </mml:mfenced>
+ </mml:math></inlineequation>
+ are computed as follows:
+ </para>
+ <para>
+ <informalequation><mml:math>
+ <!-- eqn: x sub w = ( x sub nd + 1 ) left ( width over 2 right ) + x: -->
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">x</mml:mi>
+ <mml:mi mathvariant="italic">w</mml:mi>
+ </mml:msub>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:mfenced open="(" close=")">
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">x</mml:mi>
+ <mml:mi mathvariant="italic">nd</mml:mi>
+ </mml:msub>
+ <mml:mo>+</mml:mo>
+ <mml:mn>1</mml:mn>
+ </mml:mrow>
+ </mml:mfenced>
+ <mml:mo>⁢</mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mfrac>
+ <mml:mi mathvariant="italic">width</mml:mi>
+ <mml:mn>2</mml:mn>
+ </mml:mfrac>
+ </mml:mfenced>
+ <mml:mo>+</mml:mo>
+ <mml:mi mathvariant="italic">x</mml:mi>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></informalequation>
+ </para>
+ <para>
+ <informalequation><mml:math>
+ <!-- eqn: y sub w = ( y sub nd + 1 ) left ( height over 2 right ) + y: -->
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">y</mml:mi>
+ <mml:mi mathvariant="italic">w</mml:mi>
+ </mml:msub>
+ <mml:mo>=</mml:mo>
+ <mml:mrow>
+ <mml:mfenced open="(" close=")">
+ <mml:mrow>
+ <mml:msub><mml:mi mathvariant="italic">y</mml:mi>
+ <mml:mi mathvariant="italic">nd</mml:mi>
+ </mml:msub>
+ <mml:mo>+</mml:mo>
+ <mml:mn>1</mml:mn>
+ </mml:mrow>
+ </mml:mfenced>
+ <mml:mo>⁢</mml:mo>
+ <mml:mfenced open="(" close=")">
+ <mml:mfrac>
+ <mml:mi mathvariant="italic">height</mml:mi>
+ <mml:mn>2</mml:mn>
+ </mml:mfrac>
+ </mml:mfenced>
+ <mml:mo>+</mml:mo>
+ <mml:mi mathvariant="italic">y</mml:mi>
+ </mml:mrow>
+ </mml:mrow>
+ </mml:math></informalequation>
+ </para>
+ <para>
+ The location of the viewport's bottom left corner, given by
+ (<inlineequation><mml:math><mml:mi mathvariant="italic">x</mml:mi></mml:math></inlineequation>, <inlineequation><mml:math><mml:mi mathvariant="italic">y</mml:mi></mml:math></inlineequation>)
+ is clamped to be within the implementaiton-dependent viewport bounds range.
+ The viewport bounds range [<inlineequation><mml:math><mml:mi mathvariant="italic">min</mml:mi></mml:math></inlineequation>, <inlineequation><mml:math><mml:mi mathvariant="italic">max</mml:mi></mml:math></inlineequation>]
+ can be determined by calling <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument
+ <constant>GL_VIEWPORT_BOUNDS_RANGE</constant>.
+ Viewport width and height are silently clamped
+ to a range that depends on the implementation.
+ To query this range, call <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument
+ <constant>GL_MAX_VIEWPORT_DIMS</constant>.
+ </para>
+ <para>
+ The precision with which the GL interprets the floating point viewport bounds is implementation-dependent
+ and may be determined by querying the impementation-defined constant <constant>GL_VIEWPORT_SUBPIXEL_BITS</constant>.
+ </para>
+ <para>
+ Calling <function>glViewportIndexedfv</function> is equivalent to calling <citerefentry><refentrytitle>glViewportArray</refentrytitle></citerefentry>
+ with <parameter>first</parameter> set to <parameter>index</parameter>, <parameter>count</parameter> set to
+ 1 and <parameter>v</parameter> passsed directly. <function>glViewportIndexedf</function> is equivalent
+ to:
+ </para>
+<programlisting><![CDATA[ void glViewportIndexedf(GLuint index, GLfloat x, GLfloat y, GLfloat w, GLfloat h)
+ {
+ const float v[4] = { x, y, w, h };
+ glViewportArrayv(index, 1, v);
+ }]]></programlisting>
+ </refsect1>
+ <refsect1 id="errors"><title>Errors</title>
+ <para>
+ <constant>GL_INVALID_VALUE</constant> is generated if <parameter>index</parameter> is greater than or equal to
+ the value of <constant>GL_MAX_VIEWPORTS</constant>.
+ </para>
+ <para>
+ <constant>GL_INVALID_VALUE</constant> is generated if either <parameter>width</parameter> or <parameter>height</parameter> is negative.
+ </para>
+ </refsect1>
+ <refsect1 id="associatedgets"><title>Associated Gets</title>
+ <para>
+ <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_VIEWPORT</constant>
+ </para>
+ <para>
+ <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_MAX_VIEWPORT_DIMS</constant>
+ </para>
+ <para>
+ <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_VIEWPORT_BOUNDS_RANGE</constant>
+ </para>
+ <para>
+ <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_VIEWPORT_SUBPIXEL_BITS</constant>
+ </para>
+ </refsect1>
+ <refsect1 id="seealso"><title>See Also</title>
+ <para>
+ <citerefentry><refentrytitle>glDepthRange</refentrytitle></citerefentry>,
+ <citerefentry><refentrytitle>glViewport</refentrytitle></citerefentry>,
+ <citerefentry><refentrytitle>glViewportArray</refentrytitle></citerefentry>
+ </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>
HCoop / clinton / guile-figl.git / blobdiff