--- /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="glPixelStore">
+ <refmeta>
+ <refmetainfo>
+ <copyright>
+ <year>1991-2006</year>
+ <holder>Silicon Graphics, Inc.</holder>
+ </copyright>
+ </refmetainfo>
+ <refentrytitle>glPixelStore</refentrytitle>
+ <manvolnum>3G</manvolnum>
+ </refmeta>
+ <refnamediv>
+ <refname>glPixelStore</refname>
+ <refpurpose>set pixel storage modes</refpurpose>
+ </refnamediv>
+ <refsynopsisdiv><title>C Specification</title>
+ <funcsynopsis>
+ <funcprototype>
+ <funcdef>void <function>glPixelStoref</function></funcdef>
+ <paramdef>GLenum <parameter>pname</parameter></paramdef>
+ <paramdef>GLfloat <parameter>param</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ <funcsynopsis>
+ <funcprototype>
+ <funcdef>void <function>glPixelStorei</function></funcdef>
+ <paramdef>GLenum <parameter>pname</parameter></paramdef>
+ <paramdef>GLint <parameter>param</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ </refsynopsisdiv>
+ <!-- eqn: ignoring delim $$ -->
+ <refsect1 id="parameters"><title>Parameters</title>
+ <variablelist>
+ <varlistentry>
+ <term><parameter>pname</parameter></term>
+ <listitem>
+ <para>
+ Specifies the symbolic name of the parameter to be set.
+ Six values affect the packing of pixel data into memory:
+ <constant>GL_PACK_SWAP_BYTES</constant>,
+ <constant>GL_PACK_LSB_FIRST</constant>,
+ <constant>GL_PACK_ROW_LENGTH</constant>,
+ <constant>GL_PACK_IMAGE_HEIGHT</constant>,
+ <constant>GL_PACK_SKIP_PIXELS</constant>,
+ <constant>GL_PACK_SKIP_ROWS</constant>,
+ <constant>GL_PACK_SKIP_IMAGES</constant>, and
+ <constant>GL_PACK_ALIGNMENT</constant>.
+ Six more affect the unpacking of pixel data <emphasis>from</emphasis> memory:
+ <constant>GL_UNPACK_SWAP_BYTES</constant>,
+ <constant>GL_UNPACK_LSB_FIRST</constant>,
+ <constant>GL_UNPACK_ROW_LENGTH</constant>,
+ <constant>GL_UNPACK_IMAGE_HEIGHT</constant>,
+ <constant>GL_UNPACK_SKIP_PIXELS</constant>,
+ <constant>GL_UNPACK_SKIP_ROWS</constant>,
+ <constant>GL_UNPACK_SKIP_IMAGES</constant>, and
+ <constant>GL_UNPACK_ALIGNMENT</constant>.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><parameter>param</parameter></term>
+ <listitem>
+ <para>
+ Specifies the value that <parameter>pname</parameter> is set to.
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+ <refsect1 id="description"><title>Description</title>
+ <para>
+ <function>glPixelStore</function> sets pixel storage modes that affect the operation of subsequent
+ <citerefentry><refentrytitle>glReadPixels</refentrytitle></citerefentry> as well as the unpacking of
+ texture patterns (see <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>).
+ </para>
+ <para>
+ <parameter>pname</parameter> is a symbolic constant indicating the parameter to be set, and
+ <parameter>param</parameter> is the new value. Six of the twelve storage parameters affect
+ how pixel data is returned to client memory.
+ They are as follows:
+ </para>
+ <variablelist>
+ <varlistentry>
+ <term><constant>GL_PACK_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 stored in 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_PACK_SWAP_BYTES</constant> is true.
+ <constant>GL_PACK_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_PACK_SWAP_BYTES</constant>.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><constant>GL_PACK_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_PACK_ROW_LENGTH</constant></term>
+ <listitem>
+ <para>
+ If greater than 0,
+ <constant>GL_PACK_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_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 the pixel 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>).
+ 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_PACK_IMAGE_HEIGHT</constant></term>
+ <listitem>
+ <para>
+ If greater than 0,
+ <constant>GL_PACK_IMAGE_HEIGHT</constant> defines the number of pixels in an image
+ three-dimensional texture volume, where ``image'' is defined by all pixels
+ 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_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>
+ </para>
+ <para>
+ <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PACK_LSB_FIRST</constant>
+ </para>
+ <para>
+ <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PACK_ROW_LENGTH</constant>
+ </para>
+ <para>
+ <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PACK_IMAGE_HEIGHT</constant>
+ </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>
+ </para>
+ </refsect1>
+ <refsect1 id="Copyright"><title>Copyright</title>
+ <para>
+ Copyright <trademark class="copyright"></trademark> 1991-2006
+ Silicon Graphics, Inc. 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>
HCoop / clinton / guile-figl.git / blobdiff