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1432 lines
78 KiB
XML
1432 lines
78 KiB
XML
<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
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"http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
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<refentry id="glPixelStore">
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<refentryinfo>
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<copyright>
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<year>1991-2006</year>
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<holder>Silicon Graphics, Inc.</holder>
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</copyright>
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<copyright>
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<year>2010-2013</year>
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<holder>Khronos Group</holder>
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</copyright>
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</refentryinfo>
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<refmeta>
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<refentrytitle>glPixelStore</refentrytitle>
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<manvolnum>3G</manvolnum>
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</refmeta>
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<refnamediv>
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<refname>glPixelStore</refname>
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<refpurpose>set pixel storage modes</refpurpose>
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</refnamediv>
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<refsynopsisdiv><title>C Specification</title>
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<funcsynopsis>
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<funcprototype>
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<funcdef>void <function>glPixelStoref</function></funcdef>
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<paramdef>GLenum <parameter>pname</parameter></paramdef>
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<paramdef>GLfloat <parameter>param</parameter></paramdef>
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</funcprototype>
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</funcsynopsis>
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<funcsynopsis>
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<funcprototype>
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<funcdef>void <function>glPixelStorei</function></funcdef>
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<paramdef>GLenum <parameter>pname</parameter></paramdef>
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<paramdef>GLint <parameter>param</parameter></paramdef>
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</funcprototype>
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</funcsynopsis>
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</refsynopsisdiv>
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<refsect1 id="parameters"><title>Parameters</title>
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<variablelist>
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<varlistentry>
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<term><parameter>pname</parameter></term>
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<listitem>
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<para>
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Specifies the symbolic name of the parameter to be set.
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Six values affect the packing of pixel data into memory:
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<constant>GL_PACK_SWAP_BYTES</constant>,
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<constant>GL_PACK_LSB_FIRST</constant>,
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<constant>GL_PACK_ROW_LENGTH</constant>,
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<constant>GL_PACK_IMAGE_HEIGHT</constant>,
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<constant>GL_PACK_SKIP_PIXELS</constant>,
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<constant>GL_PACK_SKIP_ROWS</constant>,
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<constant>GL_PACK_SKIP_IMAGES</constant>, and
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<constant>GL_PACK_ALIGNMENT</constant>.
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Six more affect the unpacking of pixel data <emphasis>from</emphasis> memory:
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<constant>GL_UNPACK_SWAP_BYTES</constant>,
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<constant>GL_UNPACK_LSB_FIRST</constant>,
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<constant>GL_UNPACK_ROW_LENGTH</constant>,
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<constant>GL_UNPACK_IMAGE_HEIGHT</constant>,
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<constant>GL_UNPACK_SKIP_PIXELS</constant>,
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<constant>GL_UNPACK_SKIP_ROWS</constant>,
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<constant>GL_UNPACK_SKIP_IMAGES</constant>, and
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<constant>GL_UNPACK_ALIGNMENT</constant>.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>param</parameter></term>
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<listitem>
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<para>
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Specifies the value that <parameter>pname</parameter> is set to.
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</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</refsect1>
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<refsect1 id="description"><title>Description</title>
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<para>
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<function>glPixelStore</function> sets pixel storage modes that affect the operation of subsequent
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<citerefentry><refentrytitle>glReadPixels</refentrytitle></citerefentry> as well as the unpacking of
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texture patterns (see <citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
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<citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glTexSubImage1D</refentrytitle></citerefentry>,
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<citerefentry><refentrytitle>glTexSubImage2D</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glTexSubImage3D</refentrytitle></citerefentry>),
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<citerefentry><refentrytitle>glCompressedTexImage1D</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glCompressedTexImage2D</refentrytitle></citerefentry>,
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<citerefentry><refentrytitle>glCompressedTexImage3D</refentrytitle></citerefentry>, <citerefentry><refentrytitle>glCompressedTexSubImage1D</refentrytitle></citerefentry>,
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<citerefentry><refentrytitle>glCompressedTexSubImage2D</refentrytitle></citerefentry> or <citerefentry><refentrytitle>glCompressedTexSubImage1D</refentrytitle></citerefentry>.
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</para>
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<para>
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<parameter>pname</parameter> is a symbolic constant indicating the parameter to be set, and
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<parameter>param</parameter> is the new value. Six of the twelve storage parameters affect
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how pixel data is returned to client memory.
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They are as follows:
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</para>
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<variablelist>
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<varlistentry>
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<term><constant>GL_PACK_SWAP_BYTES</constant></term>
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<listitem>
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<para>
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If true,
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byte ordering for multibyte color components,
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depth components,
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or stencil indices
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is reversed.
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That is,
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if a four-byte component consists of bytes
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<inlineequation><mml:math>
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<!-- eqn: b sub 0: -->
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<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
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<mml:mn>0</mml:mn>
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</mml:msub>
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</mml:math></inlineequation>,
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<inlineequation><mml:math>
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<!-- eqn: b sub 1: -->
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<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
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<mml:mn>1</mml:mn>
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</mml:msub>
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</mml:math></inlineequation>,
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<inlineequation><mml:math>
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<!-- eqn: b sub 2: -->
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<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
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<mml:mn>2</mml:mn>
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</mml:msub>
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</mml:math></inlineequation>,
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<inlineequation><mml:math>
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<!-- eqn: b sub 3: -->
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<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
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<mml:mn>3</mml:mn>
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</mml:msub>
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</mml:math></inlineequation>,
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it is stored in memory as
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<inlineequation><mml:math>
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<!-- eqn: b sub 3: -->
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<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
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<mml:mn>3</mml:mn>
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</mml:msub>
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</mml:math></inlineequation>,
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<inlineequation><mml:math>
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<!-- eqn: b sub 2: -->
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<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
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<mml:mn>2</mml:mn>
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</mml:msub>
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</mml:math></inlineequation>,
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<inlineequation><mml:math>
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<!-- eqn: b sub 1: -->
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<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
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<mml:mn>1</mml:mn>
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</mml:msub>
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</mml:math></inlineequation>,
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<inlineequation><mml:math>
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<!-- eqn: b sub 0: -->
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<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
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<mml:mn>0</mml:mn>
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</mml:msub>
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</mml:math></inlineequation>
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if <constant>GL_PACK_SWAP_BYTES</constant> is true.
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<constant>GL_PACK_SWAP_BYTES</constant> has no effect on the memory order of components
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within a pixel,
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only on the order of bytes within components or indices.
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For example,
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the three components of a <constant>GL_RGB</constant> format pixel are always stored with
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red first,
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green second,
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and blue third,
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regardless of the value of <constant>GL_PACK_SWAP_BYTES</constant>.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>GL_PACK_LSB_FIRST</constant></term>
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<listitem>
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<para>
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If true,
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bits are ordered within a byte from least significant to most significant;
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otherwise,
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the first bit in each byte is the most significant one.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>GL_PACK_ROW_LENGTH</constant></term>
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<listitem>
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<para>
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If greater than 0,
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<constant>GL_PACK_ROW_LENGTH</constant> defines the number of pixels in a row.
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If the first pixel of a row is placed at location
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<inlineequation><mml:math><mml:mi mathvariant="italic">p</mml:mi></mml:math></inlineequation>
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in memory,
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then the location of the first pixel of the next row is obtained by skipping
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</para>
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<para>
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<informalequation><mml:math>
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<!-- eqn: k = left { lpile { n l above {a over s} left ceiling { s n l } over a right ceiling} lpile {s >= a above s < a }: -->
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<mml:mrow>
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<mml:mi mathvariant="italic">k</mml:mi>
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<mml:mo>=</mml:mo>
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<mml:mfenced open="{" close="">
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<mml:mrow>
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<mml:mtable>
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<mml:mtr><mml:mtd>
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<mml:mrow>
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<mml:mi mathvariant="italic">n</mml:mi>
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<mml:mo>⁢</mml:mo>
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<mml:mi mathvariant="italic">l</mml:mi>
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</mml:mrow>
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</mml:mtd></mml:mtr>
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<mml:mtr><mml:mtd>
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<mml:mrow>
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<mml:mfenced open="" close="">
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<mml:mfrac>
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<mml:mi mathvariant="italic">a</mml:mi>
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<mml:mi mathvariant="italic">s</mml:mi>
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</mml:mfrac>
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</mml:mfenced>
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<mml:mo>⁢</mml:mo>
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<mml:mfenced open="⌈" close="⌉">
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<mml:mfrac>
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<mml:mfenced open="" close="">
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<mml:mrow>
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<mml:mi mathvariant="italic">s</mml:mi>
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<mml:mo>⁢</mml:mo>
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<mml:mi mathvariant="italic">n</mml:mi>
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<mml:mo>⁢</mml:mo>
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<mml:mi mathvariant="italic">l</mml:mi>
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</mml:mrow>
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</mml:mfenced>
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<mml:mi mathvariant="italic">a</mml:mi>
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</mml:mfrac>
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</mml:mfenced>
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</mml:mrow>
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</mml:mtd></mml:mtr>
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</mml:mtable>
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<mml:mo>⁢</mml:mo>
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<mml:mtable>
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<mml:mtr><mml:mtd>
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<mml:mrow>
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<mml:mi mathvariant="italic">s</mml:mi>
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<mml:mo>>=</mml:mo>
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<mml:mi mathvariant="italic">a</mml:mi>
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</mml:mrow>
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</mml:mtd></mml:mtr>
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<mml:mtr><mml:mtd>
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<mml:mrow>
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<mml:mi mathvariant="italic">s</mml:mi>
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<mml:mo><</mml:mo>
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<mml:mi mathvariant="italic">a</mml:mi>
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</mml:mrow>
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</mml:mtd></mml:mtr>
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</mml:mtable>
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</mml:mrow>
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</mml:mfenced>
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</mml:mrow>
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</mml:math></informalequation>
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</para>
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<para>
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components or indices,
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where
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<inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>
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is the number of components or indices in a pixel,
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<inlineequation><mml:math><mml:mi mathvariant="italic">l</mml:mi></mml:math></inlineequation>
|
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is the number of pixels in a row
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(<constant>GL_PACK_ROW_LENGTH</constant> if it is greater than 0,
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the
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<inlineequation><mml:math><mml:mi mathvariant="italic">width</mml:mi></mml:math></inlineequation>
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argument to the pixel routine otherwise),
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<inlineequation><mml:math><mml:mi mathvariant="italic">a</mml:mi></mml:math></inlineequation>
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is the value of <constant>GL_PACK_ALIGNMENT</constant>, and
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<inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>
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is the size, in bytes, of a single component
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(if
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<inlineequation><mml:math>
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<!-- eqn: a < s: -->
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<mml:mrow>
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<mml:mi mathvariant="italic">a</mml:mi>
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<mml:mo><</mml:mo>
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<mml:mi mathvariant="italic">s</mml:mi>
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</mml:mrow>
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</mml:math></inlineequation>,
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then it is as if
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<inlineequation><mml:math>
|
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<!-- eqn: a = s: -->
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<mml:mrow>
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<mml:mi mathvariant="italic">a</mml:mi>
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<mml:mo>=</mml:mo>
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<mml:mi mathvariant="italic">s</mml:mi>
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</mml:mrow>
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</mml:math></inlineequation>).
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In the case of 1-bit values,
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the location of the next row is obtained by skipping
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</para>
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<para>
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<inlineequation><mml:math>
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<!-- eqn: k = 8 a left ceiling { n l } over { 8 a } right ceiling: -->
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<mml:mrow>
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<mml:mi mathvariant="italic">k</mml:mi>
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<mml:mo>=</mml:mo>
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<mml:mrow>
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<mml:mn>8</mml:mn>
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<mml:mo>⁢</mml:mo>
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<mml:mi mathvariant="italic">a</mml:mi>
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<mml:mo>⁢</mml:mo>
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<mml:mfenced open="⌈" close="⌉">
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<mml:mfrac>
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<mml:mfenced open="" close="">
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<mml:mrow>
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<mml:mi mathvariant="italic">n</mml:mi>
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<mml:mo>⁢</mml:mo>
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<mml:mi mathvariant="italic">l</mml:mi>
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</mml:mrow>
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</mml:mfenced>
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<mml:mfenced open="" close="">
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<mml:mrow>
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<mml:mn>8</mml:mn>
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<mml:mo>⁢</mml:mo>
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<mml:mi mathvariant="italic">a</mml:mi>
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</mml:mrow>
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</mml:mfenced>
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</mml:mfrac>
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</mml:mfenced>
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</mml:mrow>
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</mml:mrow>
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</mml:math></inlineequation>
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</para>
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<para>
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components or indices.
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</para>
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<para>
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The word <emphasis>component</emphasis> in this description refers to the nonindex values
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red,
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green,
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blue,
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alpha,
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and depth.
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Storage format <constant>GL_RGB</constant>,
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for example,
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has three components per pixel:
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first red,
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then green,
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and finally blue.
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</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>GL_PACK_IMAGE_HEIGHT</constant></term>
|
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<listitem>
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<para>
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If greater than 0,
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<constant>GL_PACK_IMAGE_HEIGHT</constant> defines the number of pixels in an image
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three-dimensional texture volume, where ``image'' is defined by all pixels
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sharing the same third dimension index.
|
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If the first pixel of a row is placed at location
|
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<inlineequation><mml:math><mml:mi mathvariant="italic">p</mml:mi></mml:math></inlineequation>
|
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in memory,
|
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then the location of the first pixel of the next row is obtained by skipping
|
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</para>
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<para>
|
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<informalequation><mml:math>
|
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<!-- eqn: k = left { lpile { n l h above {a over s} left ceiling { s n l h } over a right ceiling} lpile {s >= a above s < a }: -->
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<mml:mrow>
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<mml:mi mathvariant="italic">k</mml:mi>
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<mml:mo>=</mml:mo>
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<mml:mfenced open="{" close="">
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<mml:mrow>
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<mml:mtable>
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<mml:mtr><mml:mtd>
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<mml:mrow>
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<mml:mi mathvariant="italic">n</mml:mi>
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<mml:mo>⁢</mml:mo>
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<mml:mi mathvariant="italic">l</mml:mi>
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<mml:mo>⁢</mml:mo>
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<mml:mi mathvariant="italic">h</mml:mi>
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</mml:mrow>
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</mml:mtd></mml:mtr>
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<mml:mtr><mml:mtd>
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<mml:mrow>
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<mml:mfenced open="" close="">
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<mml:mfrac>
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<mml:mi mathvariant="italic">a</mml:mi>
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<mml:mi mathvariant="italic">s</mml:mi>
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</mml:mfrac>
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</mml:mfenced>
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<mml:mo>⁢</mml:mo>
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<mml:mfenced open="⌈" close="⌉">
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<mml:mfrac>
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<mml:mfenced open="" close="">
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<mml:mrow>
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<mml:mi mathvariant="italic">s</mml:mi>
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<mml:mo>⁢</mml:mo>
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<mml:mi mathvariant="italic">n</mml:mi>
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<mml:mo>⁢</mml:mo>
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<mml:mi mathvariant="italic">l</mml:mi>
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<mml:mo>⁢</mml:mo>
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<mml:mi mathvariant="italic">h</mml:mi>
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</mml:mrow>
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</mml:mfenced>
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<mml:mi mathvariant="italic">a</mml:mi>
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</mml:mfrac>
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</mml:mfenced>
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</mml:mrow>
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</mml:mtd></mml:mtr>
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</mml:mtable>
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<mml:mo>⁢</mml:mo>
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<mml:mtable>
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<mml:mtr><mml:mtd>
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<mml:mrow>
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<mml:mi mathvariant="italic">s</mml:mi>
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<mml:mo>>=</mml:mo>
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<mml:mi mathvariant="italic">a</mml:mi>
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</mml:mrow>
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</mml:mtd></mml:mtr>
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<mml:mtr><mml:mtd>
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<mml:mrow>
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<mml:mi mathvariant="italic">s</mml:mi>
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<mml:mo><</mml:mo>
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<mml:mi mathvariant="italic">a</mml:mi>
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</mml:mrow>
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</mml:mtd></mml:mtr>
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</mml:mtable>
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</mml:mrow>
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</mml:mfenced>
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</mml:mrow>
|
|
</mml:math></informalequation>
|
|
</para>
|
|
<para>
|
|
components or indices, where
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>
|
|
is the number of components or indices
|
|
in a pixel,
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">l</mml:mi></mml:math></inlineequation>
|
|
is the number of pixels in a row
|
|
(<constant>GL_PACK_ROW_LENGTH</constant> if it is greater than 0, the
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">width</mml:mi></mml:math></inlineequation>
|
|
argument to <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry> otherwise),
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">h</mml:mi></mml:math></inlineequation>
|
|
is the number of
|
|
rows in a pixel image (<constant>GL_PACK_IMAGE_HEIGHT</constant> if it is greater than
|
|
0, the
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">height</mml:mi></mml:math></inlineequation>
|
|
argument to the <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry> routine otherwise),
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">a</mml:mi></mml:math></inlineequation>
|
|
is the value of
|
|
<constant>GL_PACK_ALIGNMENT</constant>, and
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>
|
|
is the size, in bytes, of a single
|
|
component (if
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: a < s: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
<mml:mo><</mml:mo>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
</mml:mrow>
|
|
</mml:math></inlineequation>,
|
|
then it is as if
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: a = s: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
<mml:mo>=</mml:mo>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
</mml:mrow>
|
|
</mml:math></inlineequation>).
|
|
</para>
|
|
<para>
|
|
The word <emphasis>component</emphasis> in this description refers to the nonindex values
|
|
red,
|
|
green,
|
|
blue,
|
|
alpha,
|
|
and depth.
|
|
Storage format <constant>GL_RGB</constant>,
|
|
for example,
|
|
has three components per pixel:
|
|
first red,
|
|
then green,
|
|
and finally blue.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><constant>GL_PACK_SKIP_PIXELS</constant>, <constant>GL_PACK_SKIP_ROWS</constant>, and <constant>GL_PACK_SKIP_IMAGES</constant></term>
|
|
<listitem>
|
|
<para>
|
|
These values are provided as a convenience to the programmer;
|
|
they provide no functionality that cannot be duplicated simply by
|
|
incrementing the pointer passed to <citerefentry><refentrytitle>glReadPixels</refentrytitle></citerefentry>.
|
|
Setting <constant>GL_PACK_SKIP_PIXELS</constant> to
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">i</mml:mi></mml:math></inlineequation>
|
|
is equivalent to incrementing
|
|
the pointer by
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: i n: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">i</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">n</mml:mi>
|
|
</mml:mrow>
|
|
</mml:math></inlineequation>
|
|
components or indices,
|
|
where
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>
|
|
is the number of components or indices in each pixel.
|
|
Setting <constant>GL_PACK_SKIP_ROWS</constant> to
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">j</mml:mi></mml:math></inlineequation>
|
|
is equivalent to incrementing
|
|
the pointer by
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: j m: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">j</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">m</mml:mi>
|
|
</mml:mrow>
|
|
</mml:math></inlineequation>
|
|
components or indices,
|
|
where
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">m</mml:mi></mml:math></inlineequation>
|
|
is the number of components or indices per row,
|
|
as just computed in the <constant>GL_PACK_ROW_LENGTH</constant> section.
|
|
Setting <constant>GL_PACK_SKIP_IMAGES</constant> to
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">k</mml:mi></mml:math></inlineequation>
|
|
is equivalent to incrementing
|
|
the pointer by
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: k p: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">k</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">p</mml:mi>
|
|
</mml:mrow>
|
|
</mml:math></inlineequation>,
|
|
where
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">p</mml:mi></mml:math></inlineequation>
|
|
is the number of components or indices
|
|
per image, as computed in the <constant>GL_PACK_IMAGE_HEIGHT</constant> section.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><constant>GL_PACK_ALIGNMENT</constant></term>
|
|
<listitem>
|
|
<para>
|
|
Specifies the alignment requirements for the start of each pixel row in memory.
|
|
The allowable values are
|
|
1 (byte-alignment),
|
|
2 (rows aligned to even-numbered bytes),
|
|
4 (word-alignment), and
|
|
8 (rows start on double-word boundaries).
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
<para>
|
|
The other six of the twelve storage parameters affect how pixel data is
|
|
read from client memory.
|
|
These values are significant for
|
|
<citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glTexSubImage1D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glTexSubImage2D</refentrytitle></citerefentry>, and
|
|
<citerefentry><refentrytitle>glTexSubImage3D</refentrytitle></citerefentry>
|
|
</para>
|
|
<para>
|
|
They are as follows:
|
|
</para>
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><constant>GL_UNPACK_SWAP_BYTES</constant></term>
|
|
<listitem>
|
|
<para>
|
|
If true,
|
|
byte ordering for multibyte color components,
|
|
depth components,
|
|
or stencil indices
|
|
is reversed.
|
|
That is,
|
|
if a four-byte component consists of bytes
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: b sub 0: -->
|
|
<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
|
|
<mml:mn>0</mml:mn>
|
|
</mml:msub>
|
|
</mml:math></inlineequation>,
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: b sub 1: -->
|
|
<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
|
|
<mml:mn>1</mml:mn>
|
|
</mml:msub>
|
|
</mml:math></inlineequation>,
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: b sub 2: -->
|
|
<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
|
|
<mml:mn>2</mml:mn>
|
|
</mml:msub>
|
|
</mml:math></inlineequation>,
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: b sub 3: -->
|
|
<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
|
|
<mml:mn>3</mml:mn>
|
|
</mml:msub>
|
|
</mml:math></inlineequation>,
|
|
it is taken from memory as
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: b sub 3: -->
|
|
<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
|
|
<mml:mn>3</mml:mn>
|
|
</mml:msub>
|
|
</mml:math></inlineequation>,
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: b sub 2: -->
|
|
<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
|
|
<mml:mn>2</mml:mn>
|
|
</mml:msub>
|
|
</mml:math></inlineequation>,
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: b sub 1: -->
|
|
<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
|
|
<mml:mn>1</mml:mn>
|
|
</mml:msub>
|
|
</mml:math></inlineequation>,
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: b sub 0: -->
|
|
<mml:msub><mml:mi mathvariant="italic">b</mml:mi>
|
|
<mml:mn>0</mml:mn>
|
|
</mml:msub>
|
|
</mml:math></inlineequation>
|
|
if <constant>GL_UNPACK_SWAP_BYTES</constant> is true.
|
|
<constant>GL_UNPACK_SWAP_BYTES</constant> has no effect on the memory order of components
|
|
within a pixel,
|
|
only on the order of bytes within components or indices.
|
|
For example,
|
|
the three components of a <constant>GL_RGB</constant> format pixel are always stored with
|
|
red first,
|
|
green second,
|
|
and blue third,
|
|
regardless of the value of <constant>GL_UNPACK_SWAP_BYTES</constant>.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><constant>GL_UNPACK_LSB_FIRST</constant></term>
|
|
<listitem>
|
|
<para>
|
|
If true,
|
|
bits are ordered within a byte from least significant to most significant;
|
|
otherwise,
|
|
the first bit in each byte is the most significant one.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><constant>GL_UNPACK_ROW_LENGTH</constant></term>
|
|
<listitem>
|
|
<para>
|
|
If greater than 0,
|
|
<constant>GL_UNPACK_ROW_LENGTH</constant> defines the number of pixels in a row.
|
|
If the first pixel of a row is placed at location
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">p</mml:mi></mml:math></inlineequation>
|
|
in memory,
|
|
then the location of the first pixel of the next row is obtained by skipping
|
|
</para>
|
|
<para>
|
|
<informalequation><mml:math>
|
|
<!-- eqn: k = left { lpile { n l above {a over s} left ceiling { s n l } over a right ceiling } lpile { s >= a above s < a }: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">k</mml:mi>
|
|
<mml:mo>=</mml:mo>
|
|
<mml:mfenced open="{" close="">
|
|
<mml:mrow>
|
|
<mml:mtable>
|
|
<mml:mtr><mml:mtd>
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">n</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">l</mml:mi>
|
|
</mml:mrow>
|
|
</mml:mtd></mml:mtr>
|
|
<mml:mtr><mml:mtd>
|
|
<mml:mrow>
|
|
<mml:mfenced open="" close="">
|
|
<mml:mfrac>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
</mml:mfrac>
|
|
</mml:mfenced>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mfenced open="⌈" close="⌉">
|
|
<mml:mfrac>
|
|
<mml:mfenced open="" close="">
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">n</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">l</mml:mi>
|
|
</mml:mrow>
|
|
</mml:mfenced>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
</mml:mfrac>
|
|
</mml:mfenced>
|
|
</mml:mrow>
|
|
</mml:mtd></mml:mtr>
|
|
</mml:mtable>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mtable>
|
|
<mml:mtr><mml:mtd>
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
<mml:mo>>=</mml:mo>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
</mml:mrow>
|
|
</mml:mtd></mml:mtr>
|
|
<mml:mtr><mml:mtd>
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
<mml:mo><</mml:mo>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
</mml:mrow>
|
|
</mml:mtd></mml:mtr>
|
|
</mml:mtable>
|
|
</mml:mrow>
|
|
</mml:mfenced>
|
|
</mml:mrow>
|
|
</mml:math></informalequation>
|
|
</para>
|
|
<para>
|
|
components or indices,
|
|
where
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>
|
|
is the number of components or indices in a pixel,
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">l</mml:mi></mml:math></inlineequation>
|
|
is the number of pixels in a row
|
|
(<constant>GL_UNPACK_ROW_LENGTH</constant> if it is greater than 0,
|
|
the
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">width</mml:mi></mml:math></inlineequation>
|
|
argument to the pixel routine otherwise),
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">a</mml:mi></mml:math></inlineequation>
|
|
is the value of <constant>GL_UNPACK_ALIGNMENT</constant>, and
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>
|
|
is the size, in bytes, of a single component
|
|
(if
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: a < s: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
<mml:mo><</mml:mo>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
</mml:mrow>
|
|
</mml:math></inlineequation>,
|
|
then it is as if
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: a = s: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
<mml:mo>=</mml:mo>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
</mml:mrow>
|
|
</mml:math></inlineequation>).
|
|
In the case of 1-bit values,
|
|
the location of the next row is obtained by skipping
|
|
</para>
|
|
<para>
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: k = 8 a left ceiling { n l } over { 8 a } right ceiling: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">k</mml:mi>
|
|
<mml:mo>=</mml:mo>
|
|
<mml:mrow>
|
|
<mml:mn>8</mml:mn>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mfenced open="⌈" close="⌉">
|
|
<mml:mfrac>
|
|
<mml:mfenced open="" close="">
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">n</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">l</mml:mi>
|
|
</mml:mrow>
|
|
</mml:mfenced>
|
|
<mml:mfenced open="" close="">
|
|
<mml:mrow>
|
|
<mml:mn>8</mml:mn>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
</mml:mrow>
|
|
</mml:mfenced>
|
|
</mml:mfrac>
|
|
</mml:mfenced>
|
|
</mml:mrow>
|
|
</mml:mrow>
|
|
</mml:math></inlineequation>
|
|
</para>
|
|
<para>
|
|
components or indices.
|
|
</para>
|
|
<para>
|
|
The word <emphasis>component</emphasis> in this description refers to the nonindex values
|
|
red,
|
|
green,
|
|
blue,
|
|
alpha,
|
|
and depth.
|
|
Storage format <constant>GL_RGB</constant>,
|
|
for example,
|
|
has three components per pixel:
|
|
first red,
|
|
then green,
|
|
and finally blue.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><constant>GL_UNPACK_IMAGE_HEIGHT</constant></term>
|
|
<listitem>
|
|
<para>
|
|
If greater than 0,
|
|
<constant>GL_UNPACK_IMAGE_HEIGHT</constant> defines the number of pixels in an image of
|
|
a three-dimensional texture volume. Where ``image'' is defined by all
|
|
pixel sharing the same third dimension index.
|
|
If the first pixel of a row is placed at location
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">p</mml:mi></mml:math></inlineequation>
|
|
in memory,
|
|
then the location of the first pixel of the next row is obtained by skipping
|
|
</para>
|
|
<para>
|
|
<informalequation><mml:math>
|
|
<!-- eqn: k = left { lpile { n l h above {a over s} left ceiling { s n l h } over a right ceiling } lpile { s >= a above s < a }: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">k</mml:mi>
|
|
<mml:mo>=</mml:mo>
|
|
<mml:mfenced open="{" close="">
|
|
<mml:mrow>
|
|
<mml:mtable>
|
|
<mml:mtr><mml:mtd>
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">n</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">l</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">h</mml:mi>
|
|
</mml:mrow>
|
|
</mml:mtd></mml:mtr>
|
|
<mml:mtr><mml:mtd>
|
|
<mml:mrow>
|
|
<mml:mfenced open="" close="">
|
|
<mml:mfrac>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
</mml:mfrac>
|
|
</mml:mfenced>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mfenced open="⌈" close="⌉">
|
|
<mml:mfrac>
|
|
<mml:mfenced open="" close="">
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">n</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">l</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">h</mml:mi>
|
|
</mml:mrow>
|
|
</mml:mfenced>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
</mml:mfrac>
|
|
</mml:mfenced>
|
|
</mml:mrow>
|
|
</mml:mtd></mml:mtr>
|
|
</mml:mtable>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mtable>
|
|
<mml:mtr><mml:mtd>
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
<mml:mo>>=</mml:mo>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
</mml:mrow>
|
|
</mml:mtd></mml:mtr>
|
|
<mml:mtr><mml:mtd>
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
<mml:mo><</mml:mo>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
</mml:mrow>
|
|
</mml:mtd></mml:mtr>
|
|
</mml:mtable>
|
|
</mml:mrow>
|
|
</mml:mfenced>
|
|
</mml:mrow>
|
|
</mml:math></informalequation>
|
|
</para>
|
|
<para>
|
|
components or indices,
|
|
where
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>
|
|
is the number of components or indices in a pixel,
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">l</mml:mi></mml:math></inlineequation>
|
|
is the number of pixels in a row
|
|
(<constant>GL_UNPACK_ROW_LENGTH</constant> if it is greater than 0,
|
|
the
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">width</mml:mi></mml:math></inlineequation>
|
|
argument to <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry> otherwise),
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">h</mml:mi></mml:math></inlineequation>
|
|
is the number of rows in an image (<constant>GL_UNPACK_IMAGE_HEIGHT</constant> if
|
|
it is greater than 0, the
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">height</mml:mi></mml:math></inlineequation>
|
|
argument to <citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry> otherwise),
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">a</mml:mi></mml:math></inlineequation>
|
|
is the value of <constant>GL_UNPACK_ALIGNMENT</constant>, and
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">s</mml:mi></mml:math></inlineequation>
|
|
is the size, in bytes, of a single component
|
|
(if
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: a < s: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
<mml:mo><</mml:mo>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
</mml:mrow>
|
|
</mml:math></inlineequation>,
|
|
then it is as if
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: a = s: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">a</mml:mi>
|
|
<mml:mo>=</mml:mo>
|
|
<mml:mi mathvariant="italic">s</mml:mi>
|
|
</mml:mrow>
|
|
</mml:math></inlineequation>).
|
|
</para>
|
|
<para>
|
|
The word <emphasis>component</emphasis> in this description refers to the nonindex values
|
|
red,
|
|
green,
|
|
blue,
|
|
alpha,
|
|
and depth.
|
|
Storage format <constant>GL_RGB</constant>,
|
|
for example,
|
|
has three components per pixel:
|
|
first red,
|
|
then green,
|
|
and finally blue.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><constant>GL_UNPACK_SKIP_PIXELS</constant> and <constant>GL_UNPACK_SKIP_ROWS</constant></term>
|
|
<listitem>
|
|
<para>
|
|
These values are provided as a convenience to the programmer;
|
|
they provide no functionality that cannot be duplicated by
|
|
incrementing the pointer passed to
|
|
<citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glTexSubImage1D</refentrytitle></citerefentry> or
|
|
<citerefentry><refentrytitle>glTexSubImage2D</refentrytitle></citerefentry>.
|
|
Setting <constant>GL_UNPACK_SKIP_PIXELS</constant> to
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">i</mml:mi></mml:math></inlineequation>
|
|
is equivalent to incrementing
|
|
the pointer by
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: i n: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">i</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">n</mml:mi>
|
|
</mml:mrow>
|
|
</mml:math></inlineequation>
|
|
components or indices,
|
|
where
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>
|
|
is the number of components or indices in each pixel.
|
|
Setting <constant>GL_UNPACK_SKIP_ROWS</constant> to
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">j</mml:mi></mml:math></inlineequation>
|
|
is equivalent to incrementing
|
|
the pointer by
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: j k: -->
|
|
<mml:mrow>
|
|
<mml:mi mathvariant="italic">j</mml:mi>
|
|
<mml:mo>⁢</mml:mo>
|
|
<mml:mi mathvariant="italic">k</mml:mi>
|
|
</mml:mrow>
|
|
</mml:math></inlineequation>
|
|
components or indices,
|
|
where
|
|
<inlineequation><mml:math><mml:mi mathvariant="italic">k</mml:mi></mml:math></inlineequation>
|
|
is the number of components or indices per row,
|
|
as just computed in the <constant>GL_UNPACK_ROW_LENGTH</constant> section.
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
<varlistentry>
|
|
<term><constant>GL_UNPACK_ALIGNMENT</constant></term>
|
|
<listitem>
|
|
<para>
|
|
Specifies the alignment requirements for the start of each pixel row in memory.
|
|
The allowable values are
|
|
1 (byte-alignment),
|
|
2 (rows aligned to even-numbered bytes),
|
|
4 (word-alignment), and
|
|
8 (rows start on double-word boundaries).
|
|
</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
<para>
|
|
The following table gives the type,
|
|
initial value,
|
|
and range of valid values for each storage parameter
|
|
that can be set with <function>glPixelStore</function>.
|
|
</para>
|
|
<para>
|
|
</para>
|
|
<informaltable frame="topbot">
|
|
<tgroup cols="4" align="left">
|
|
<colspec colwidth="2.5*" />
|
|
<colspec colwidth="1*" align="center"/>
|
|
<colspec colwidth="1*" align="center"/>
|
|
<colspec colwidth="2*" align="center"/>
|
|
<thead>
|
|
<row>
|
|
<entry rowsep="1" align="left"><emphasis role="bold">
|
|
<parameter>pname</parameter>
|
|
</emphasis></entry>
|
|
<entry rowsep="1" align="center"><emphasis role="bold">
|
|
Type
|
|
</emphasis></entry>
|
|
<entry rowsep="1" align="center"><emphasis role="bold">
|
|
Initial Value
|
|
</emphasis></entry>
|
|
<entry rowsep="1" align="center"><emphasis role="bold">
|
|
Valid Range
|
|
</emphasis></entry>
|
|
</row>
|
|
</thead>
|
|
<tbody>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_PACK_SWAP_BYTES</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
boolean
|
|
</entry>
|
|
<entry align="center">
|
|
false
|
|
</entry>
|
|
<entry align="center">
|
|
true or false
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_PACK_LSB_FIRST</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
boolean
|
|
</entry>
|
|
<entry align="center">
|
|
false
|
|
</entry>
|
|
<entry align="center">
|
|
true or false
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_PACK_ROW_LENGTH</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
integer
|
|
</entry>
|
|
<entry align="center">
|
|
0
|
|
</entry>
|
|
<entry align="center">
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: left [ 0,\(if right ): -->
|
|
<mml:mfenced open="[" close=")">
|
|
<mml:mn>0</mml:mn>
|
|
<mml:infinity/>
|
|
</mml:mfenced>
|
|
</mml:math></inlineequation>
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_PACK_IMAGE_HEIGHT</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
integer
|
|
</entry>
|
|
<entry align="center">
|
|
0
|
|
</entry>
|
|
<entry align="center">
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: left [ 0, \(if right ): -->
|
|
<mml:mfenced open="[" close=")">
|
|
<mml:mn>0</mml:mn>
|
|
<mml:infinity/>
|
|
</mml:mfenced>
|
|
</mml:math></inlineequation>
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_PACK_SKIP_ROWS</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
integer
|
|
</entry>
|
|
<entry align="center">
|
|
0
|
|
</entry>
|
|
<entry align="center">
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: left [ 0,\(if right ): -->
|
|
<mml:mfenced open="[" close=")">
|
|
<mml:mn>0</mml:mn>
|
|
<mml:infinity/>
|
|
</mml:mfenced>
|
|
</mml:math></inlineequation>
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_PACK_SKIP_PIXELS</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
integer
|
|
</entry>
|
|
<entry align="center">
|
|
0
|
|
</entry>
|
|
<entry align="center">
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: left [ 0,\(if right ): -->
|
|
<mml:mfenced open="[" close=")">
|
|
<mml:mn>0</mml:mn>
|
|
<mml:infinity/>
|
|
</mml:mfenced>
|
|
</mml:math></inlineequation>
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_PACK_SKIP_IMAGES</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
integer
|
|
</entry>
|
|
<entry align="center">
|
|
0
|
|
</entry>
|
|
<entry align="center">
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: left [ 0,\(if right ): -->
|
|
<mml:mfenced open="[" close=")">
|
|
<mml:mn>0</mml:mn>
|
|
<mml:infinity/>
|
|
</mml:mfenced>
|
|
</mml:math></inlineequation>
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_PACK_ALIGNMENT</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
integer
|
|
</entry>
|
|
<entry align="center">
|
|
4
|
|
</entry>
|
|
<entry align="center">
|
|
1, 2, 4, or 8
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_UNPACK_SWAP_BYTES</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
boolean
|
|
</entry>
|
|
<entry align="center">
|
|
false
|
|
</entry>
|
|
<entry align="center">
|
|
true or false
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_UNPACK_LSB_FIRST</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
boolean
|
|
</entry>
|
|
<entry align="center">
|
|
false
|
|
</entry>
|
|
<entry align="center">
|
|
true or false
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_UNPACK_ROW_LENGTH</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
integer
|
|
</entry>
|
|
<entry align="center">
|
|
0
|
|
</entry>
|
|
<entry align="center">
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: left [ 0,\(if right ): -->
|
|
<mml:mfenced open="[" close=")">
|
|
<mml:mn>0</mml:mn>
|
|
<mml:infinity/>
|
|
</mml:mfenced>
|
|
</mml:math></inlineequation>
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_UNPACK_IMAGE_HEIGHT</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
integer
|
|
</entry>
|
|
<entry align="center">
|
|
0
|
|
</entry>
|
|
<entry align="center">
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: left [ 0,\(if right ): -->
|
|
<mml:mfenced open="[" close=")">
|
|
<mml:mn>0</mml:mn>
|
|
<mml:infinity/>
|
|
</mml:mfenced>
|
|
</mml:math></inlineequation>
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_UNPACK_SKIP_ROWS</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
integer
|
|
</entry>
|
|
<entry align="center">
|
|
0
|
|
</entry>
|
|
<entry align="center">
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: left [ 0,\(if right ): -->
|
|
<mml:mfenced open="[" close=")">
|
|
<mml:mn>0</mml:mn>
|
|
<mml:infinity/>
|
|
</mml:mfenced>
|
|
</mml:math></inlineequation>
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_UNPACK_SKIP_PIXELS</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
integer
|
|
</entry>
|
|
<entry align="center">
|
|
0
|
|
</entry>
|
|
<entry align="center">
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: left [ 0,\(if right ): -->
|
|
<mml:mfenced open="[" close=")">
|
|
<mml:mn>0</mml:mn>
|
|
<mml:infinity/>
|
|
</mml:mfenced>
|
|
</mml:math></inlineequation>
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_UNPACK_SKIP_IMAGES</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
integer
|
|
</entry>
|
|
<entry align="center">
|
|
0
|
|
</entry>
|
|
<entry align="center">
|
|
<inlineequation><mml:math>
|
|
<!-- eqn: left [ 0,\(if right ): -->
|
|
<mml:mfenced open="[" close=")">
|
|
<mml:mn>0</mml:mn>
|
|
<mml:infinity/>
|
|
</mml:mfenced>
|
|
</mml:math></inlineequation>
|
|
</entry>
|
|
</row>
|
|
<row>
|
|
<entry align="left">
|
|
<constant>GL_UNPACK_ALIGNMENT</constant>
|
|
</entry>
|
|
<entry align="center">
|
|
integer
|
|
</entry>
|
|
<entry align="center">
|
|
4
|
|
</entry>
|
|
<entry align="center">
|
|
1, 2, 4, or 8
|
|
</entry>
|
|
</row>
|
|
</tbody>
|
|
</tgroup>
|
|
</informaltable>
|
|
<para>
|
|
<function>glPixelStoref</function> can be used to set any pixel store parameter.
|
|
If the parameter type is boolean,
|
|
then if <parameter>param</parameter> is 0,
|
|
the parameter is false;
|
|
otherwise it is set to true.
|
|
If <parameter>pname</parameter> is a integer type parameter,
|
|
<parameter>param</parameter> is rounded to the nearest integer.
|
|
</para>
|
|
<para>
|
|
Likewise, <function>glPixelStorei</function> can also be used to set any of the
|
|
pixel store parameters.
|
|
Boolean parameters are set to false if <parameter>param</parameter> is 0 and true otherwise.
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 id="errors"><title>Errors</title>
|
|
<para>
|
|
<constant>GL_INVALID_ENUM</constant> is generated if <parameter>pname</parameter> is not an accepted value.
|
|
</para>
|
|
<para>
|
|
<constant>GL_INVALID_VALUE</constant> is generated if a negative row length,
|
|
pixel skip,
|
|
or row skip value is specified,
|
|
or if alignment is specified as other than 1, 2, 4, or 8.
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 id="associatedgets"><title>Associated Gets</title>
|
|
<para>
|
|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PACK_SWAP_BYTES</constant>
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|
</para>
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|
<para>
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|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PACK_LSB_FIRST</constant>
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</para>
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|
<para>
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|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PACK_ROW_LENGTH</constant>
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|
</para>
|
|
<para>
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|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PACK_IMAGE_HEIGHT</constant>
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|
</para>
|
|
<para>
|
|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PACK_SKIP_ROWS</constant>
|
|
</para>
|
|
<para>
|
|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PACK_SKIP_PIXELS</constant>
|
|
</para>
|
|
<para>
|
|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PACK_SKIP_IMAGES</constant>
|
|
</para>
|
|
<para>
|
|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PACK_ALIGNMENT</constant>
|
|
</para>
|
|
<para>
|
|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_UNPACK_SWAP_BYTES</constant>
|
|
</para>
|
|
<para>
|
|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_UNPACK_LSB_FIRST</constant>
|
|
</para>
|
|
<para>
|
|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_UNPACK_ROW_LENGTH</constant>
|
|
</para>
|
|
<para>
|
|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_UNPACK_IMAGE_HEIGHT</constant>
|
|
</para>
|
|
<para>
|
|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_UNPACK_SKIP_ROWS</constant>
|
|
</para>
|
|
<para>
|
|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_UNPACK_SKIP_PIXELS</constant>
|
|
</para>
|
|
<para>
|
|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_UNPACK_SKIP_IMAGES</constant>
|
|
</para>
|
|
<para>
|
|
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_UNPACK_ALIGNMENT</constant>
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 id="seealso"><title>See Also</title>
|
|
<para>
|
|
<citerefentry><refentrytitle>glReadPixels</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glTexImage1D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glTexImage2D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glTexImage3D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glTexSubImage1D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glTexSubImage2D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glTexSubImage3D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glCompressedTexImage1D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glCompressedTexImage2D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glCompressedTexImage3D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glCompressedTexSubImage1D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glCompressedTexSubImage2D</refentrytitle></citerefentry>,
|
|
<citerefentry><refentrytitle>glCompressedTexSubImage1D</refentrytitle></citerefentry>.
|
|
</para>
|
|
</refsect1>
|
|
<refsect1 id="Copyright"><title>Copyright</title>
|
|
<para>
|
|
Copyright <trademark class="copyright"></trademark> 1991-2006 Silicon Graphics, Inc.
|
|
Copyright <trademark class="copyright"></trademark> 2010-2013 Khronos Group.
|
|
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>
|