--- /dev/null
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+<?xml-stylesheet type="text/xsl" href="mathml.xsl"?><html xmlns="http://www.w3.org/1999/xhtml" xmlns:pref="http://www.w3.org/2002/Math/preference" pref:renderer="mathplayer-dl"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>glPixelStore</title><meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /></head><body><div class="refentry" lang="en" xml:lang="en"><a id="glPixelStore"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>glPixelStore — set pixel storage modes</p></div><div class="refsynopsisdiv"><h2>C Specification</h2><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glPixelStoref</b>(</code></td><td>GLenum </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLfloat </td><td><var class="pdparam">param</var><code>)</code>;</td></tr></table></div><div class="funcsynopsis"><table border="0" summary="Function synopsis" cellspacing="0" cellpadding="0"><tr><td><code class="funcdef">void <b class="fsfunc">glPixelStorei</b>(</code></td><td>GLenum </td><td><var class="pdparam">pname</var>, </td></tr><tr><td> </td><td>GLint </td><td><var class="pdparam">param</var><code>)</code>;</td></tr></table></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="parameters"></a><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><em class="parameter"><code>pname</code></em></span></dt><dd><p>
+ Specifies the symbolic name of the parameter to be set.
+ Six values affect the packing of pixel data into memory:
+ <code class="constant">GL_PACK_SWAP_BYTES</code>,
+ <code class="constant">GL_PACK_LSB_FIRST</code>,
+ <code class="constant">GL_PACK_ROW_LENGTH</code>,
+ <code class="constant">GL_PACK_IMAGE_HEIGHT</code>,
+ <code class="constant">GL_PACK_SKIP_PIXELS</code>,
+ <code class="constant">GL_PACK_SKIP_ROWS</code>,
+ <code class="constant">GL_PACK_SKIP_IMAGES</code>, and
+ <code class="constant">GL_PACK_ALIGNMENT</code>.
+ Six more affect the unpacking of pixel data <span class="emphasis"><em>from</em></span> memory:
+ <code class="constant">GL_UNPACK_SWAP_BYTES</code>,
+ <code class="constant">GL_UNPACK_LSB_FIRST</code>,
+ <code class="constant">GL_UNPACK_ROW_LENGTH</code>,
+ <code class="constant">GL_UNPACK_IMAGE_HEIGHT</code>,
+ <code class="constant">GL_UNPACK_SKIP_PIXELS</code>,
+ <code class="constant">GL_UNPACK_SKIP_ROWS</code>,
+ <code class="constant">GL_UNPACK_SKIP_IMAGES</code>, and
+ <code class="constant">GL_UNPACK_ALIGNMENT</code>.
+ </p></dd><dt><span class="term"><em class="parameter"><code>param</code></em></span></dt><dd><p>
+ Specifies the value that <em class="parameter"><code>pname</code></em> is set to.
+ </p></dd></dl></div></div><div class="refsect1" lang="en" xml:lang="en"><a id="description"></a><h2>Description</h2><p>
+ <code class="function">glPixelStore</code> sets pixel storage modes that affect the operation of subsequent
+ <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a> and <a class="citerefentry" href="glReadPixels.xml"><span class="citerefentry"><span class="refentrytitle">glReadPixels</span></span></a> as well as the unpacking of
+ polygon stipple patterns (see <a class="citerefentry" href="glPolygonStipple.xml"><span class="citerefentry"><span class="refentrytitle">glPolygonStipple</span></span></a>), bitmaps (see
+ <a class="citerefentry" href="glBitmap.xml"><span class="citerefentry"><span class="refentrytitle">glBitmap</span></span></a>), texture patterns (see <a class="citerefentry" href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>,
+ <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>, <a class="citerefentry" href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>, <a class="citerefentry" href="glTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage1D</span></span></a>,
+ <a class="citerefentry" href="glTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>, <a class="citerefentry" href="glTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage3D</span></span></a>).
+ Additionally, if the <code class="code">ARB_imaging</code> extension is supported, pixel
+ storage modes affect convolution filters
+ (see <a class="citerefentry" href="glConvolutionFilter1D.xml"><span class="citerefentry"><span class="refentrytitle">glConvolutionFilter1D</span></span></a>, <a class="citerefentry" href="glConvolutionFilter2D.xml"><span class="citerefentry"><span class="refentrytitle">glConvolutionFilter2D</span></span></a>, and
+ <a class="citerefentry" href="glSeparableFilter2D.xml"><span class="citerefentry"><span class="refentrytitle">glSeparableFilter2D</span></span></a>, color table (see <a class="citerefentry" href="glColorTable.xml"><span class="citerefentry"><span class="refentrytitle">glColorTable</span></span></a>, and
+ <a class="citerefentry" href="glColorSubTable.xml"><span class="citerefentry"><span class="refentrytitle">glColorSubTable</span></span></a>, and unpacking histogram (See <a class="citerefentry" href="glHistogram.xml"><span class="citerefentry"><span class="refentrytitle">glHistogram</span></span></a>),
+ and minmax (See <a class="citerefentry" href="glMinmax.xml"><span class="citerefentry"><span class="refentrytitle">glMinmax</span></span></a>) data.
+ </p><p>
+ <em class="parameter"><code>pname</code></em> is a symbolic constant indicating the parameter to be set, and
+ <em class="parameter"><code>param</code></em> is the new value. Six of the twelve storage parameters affect
+ how pixel data is returned to client memory.
+ They are as follows:
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_PACK_SWAP_BYTES</code></span></dt><dd><p>
+ If true,
+ byte ordering for multibyte color components,
+ depth components,
+ color indices,
+ or stencil indices
+ is reversed.
+ That is,
+ if a four-byte component consists of bytes
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>0</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>1</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>2</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>3</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ it is stored in memory as
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>3</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>2</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>1</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>0</mml:mn>
+ </mml:msub>
+ </mml:math>
+ if <code class="constant">GL_PACK_SWAP_BYTES</code> is true.
+ <code class="constant">GL_PACK_SWAP_BYTES</code> 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 <code class="constant">GL_RGB</code> format pixel are always stored with
+ red first,
+ green second,
+ and blue third,
+ regardless of the value of <code class="constant">GL_PACK_SWAP_BYTES</code>.
+ </p></dd><dt><span class="term"><code class="constant">GL_PACK_LSB_FIRST</code></span></dt><dd><p>
+ 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.
+ This parameter is significant for bitmap data only.
+ </p></dd><dt><span class="term"><code class="constant">GL_PACK_ROW_LENGTH</code></span></dt><dd><p>
+ If greater than 0,
+ <code class="constant">GL_PACK_ROW_LENGTH</code> defines the number of pixels in a row.
+ If the first pixel of a row is placed at location
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">p</mml:mi></mml:math>
+ in memory,
+ then the location of the first pixel of the next row is obtained by skipping
+ </p><p>
+ </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <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></div><p>
+ </p><p>
+ components or indices,
+ where
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">n</mml:mi></mml:math>
+ is the number of components or indices in a pixel,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">l</mml:mi></mml:math>
+ is the number of pixels in a row
+ (<code class="constant">GL_PACK_ROW_LENGTH</code> if it is greater than 0,
+ the
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">width</mml:mi></mml:math>
+ argument to the pixel routine otherwise),
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">a</mml:mi></mml:math>
+ is the value of <code class="constant">GL_PACK_ALIGNMENT</code>, and
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
+ is the size, in bytes, of a single component
+ (if
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">a</mml:mi>
+ <mml:mo><</mml:mo>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:mrow>
+ </mml:math>,
+ then it is as if
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">a</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:mrow>
+ </mml:math>).
+ In the case of 1-bit values,
+ the location of the next row is obtained by skipping
+ </p><p>
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <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>
+ </p><p>
+ components or indices.
+ </p><p>
+ The word <span class="emphasis"><em>component</em></span> in this description refers to the nonindex values
+ red,
+ green,
+ blue,
+ alpha,
+ and depth.
+ Storage format <code class="constant">GL_RGB</code>,
+ for example,
+ has three components per pixel:
+ first red,
+ then green,
+ and finally blue.
+ </p></dd><dt><span class="term"><code class="constant">GL_PACK_IMAGE_HEIGHT</code></span></dt><dd><p>
+ If greater than 0,
+ <code class="constant">GL_PACK_IMAGE_HEIGHT</code> 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
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">p</mml:mi></mml:math>
+ in memory,
+ then the location of the first pixel of the next row is obtained by skipping
+ </p><p>
+ </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <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></div><p>
+ </p><p>
+ components or indices, where
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">n</mml:mi></mml:math>
+ is the number of components or indices
+ in a pixel,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">l</mml:mi></mml:math>
+ is the number of pixels in a row
+ (<code class="constant">GL_PACK_ROW_LENGTH</code> if it is greater than 0, the
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">width</mml:mi></mml:math>
+ argument to <a class="citerefentry" href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a> otherwise),
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">h</mml:mi></mml:math>
+ is the number of
+ rows in a pixel image (<code class="constant">GL_PACK_IMAGE_HEIGHT</code> if it is greater than
+ 0, the
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">height</mml:mi></mml:math>
+ argument to the <a class="citerefentry" href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a> routine otherwise),
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">a</mml:mi></mml:math>
+ is the value of
+ <code class="constant">GL_PACK_ALIGNMENT</code>, and
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
+ is the size, in bytes, of a single
+ component (if
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">a</mml:mi>
+ <mml:mo><</mml:mo>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:mrow>
+ </mml:math>,
+ then it is as if
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">a</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:mrow>
+ </mml:math>).
+ </p><p>
+ The word <span class="emphasis"><em>component</em></span> in this description refers to the nonindex values
+ red,
+ green,
+ blue,
+ alpha,
+ and depth.
+ Storage format <code class="constant">GL_RGB</code>,
+ for example,
+ has three components per pixel:
+ first red,
+ then green,
+ and finally blue.
+ </p></dd><dt><span class="term"><code class="constant">GL_PACK_SKIP_PIXELS</code>, <code class="constant">GL_PACK_SKIP_ROWS</code>, and <code class="constant">GL_PACK_SKIP_IMAGES</code></span></dt><dd><p>
+ 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 <a class="citerefentry" href="glReadPixels.xml"><span class="citerefentry"><span class="refentrytitle">glReadPixels</span></span></a>.
+ Setting <code class="constant">GL_PACK_SKIP_PIXELS</code> to
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>
+ is equivalent to incrementing
+ the pointer by
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">i</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mi mathvariant="italic">n</mml:mi>
+ </mml:mrow>
+ </mml:math>
+ components or indices,
+ where
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">n</mml:mi></mml:math>
+ is the number of components or indices in each pixel.
+ Setting <code class="constant">GL_PACK_SKIP_ROWS</code> to
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">j</mml:mi></mml:math>
+ is equivalent to incrementing
+ the pointer by
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">j</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mi mathvariant="italic">m</mml:mi>
+ </mml:mrow>
+ </mml:math>
+ components or indices,
+ where
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">m</mml:mi></mml:math>
+ is the number of components or indices per row,
+ as just computed in the <code class="constant">GL_PACK_ROW_LENGTH</code> section.
+ Setting <code class="constant">GL_PACK_SKIP_IMAGES</code> to
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">k</mml:mi></mml:math>
+ is equivalent to incrementing
+ the pointer by
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">k</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mi mathvariant="italic">p</mml:mi>
+ </mml:mrow>
+ </mml:math>,
+ where
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">p</mml:mi></mml:math>
+ is the number of components or indices
+ per image, as computed in the <code class="constant">GL_PACK_IMAGE_HEIGHT</code> section.
+ </p></dd><dt><span class="term"><code class="constant">GL_PACK_ALIGNMENT</code></span></dt><dd><p>
+ 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).
+ </p></dd></dl></div><p>
+ The other six of the twelve storage parameters affect how pixel data is
+ read from client memory.
+ These values are significant for <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a>,
+ <a class="citerefentry" href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>,
+ <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>,
+ <a class="citerefentry" href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>,
+ <a class="citerefentry" href="glTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage1D</span></span></a>,
+ <a class="citerefentry" href="glTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>,
+ <a class="citerefentry" href="glTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage3D</span></span></a>,
+ <a class="citerefentry" href="glBitmap.xml"><span class="citerefentry"><span class="refentrytitle">glBitmap</span></span></a>, and
+ <a class="citerefentry" href="glPolygonStipple.xml"><span class="citerefentry"><span class="refentrytitle">glPolygonStipple</span></span></a>.
+ </p><p>
+ Additionally, if the <code class="code">ARB_imaging</code> extension is supported,
+ <a class="citerefentry" href="glColorTable.xml"><span class="citerefentry"><span class="refentrytitle">glColorTable</span></span></a>,
+ <a class="citerefentry" href="glColorSubTable.xml"><span class="citerefentry"><span class="refentrytitle">glColorSubTable</span></span></a>,
+ <a class="citerefentry" href="glConvolutionFilter1D.xml"><span class="citerefentry"><span class="refentrytitle">glConvolutionFilter1D</span></span></a>,
+ <a class="citerefentry" href="glConvolutionFilter2D.xml"><span class="citerefentry"><span class="refentrytitle">glConvolutionFilter2D</span></span></a>, and
+ <a class="citerefentry" href="glSeparableFilter2D.xml"><span class="citerefentry"><span class="refentrytitle">glSeparableFilter2D</span></span></a>.
+ They are as follows:
+ </p><div class="variablelist"><dl><dt><span class="term"><code class="constant">GL_UNPACK_SWAP_BYTES</code></span></dt><dd><p>
+ If true,
+ byte ordering for multibyte color components,
+ depth components,
+ color indices,
+ or stencil indices
+ is reversed.
+ That is,
+ if a four-byte component consists of bytes
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>0</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>1</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>2</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>3</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ it is taken from memory as
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>3</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>2</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>1</mml:mn>
+ </mml:msub>
+ </mml:math>,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:msub><mml:mi mathvariant="italic">b</mml:mi>
+ <mml:mn>0</mml:mn>
+ </mml:msub>
+ </mml:math>
+ if <code class="constant">GL_UNPACK_SWAP_BYTES</code> is true.
+ <code class="constant">GL_UNPACK_SWAP_BYTES</code> 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 <code class="constant">GL_RGB</code> format pixel are always stored with
+ red first,
+ green second,
+ and blue third,
+ regardless of the value of <code class="constant">GL_UNPACK_SWAP_BYTES</code>.
+ </p></dd><dt><span class="term"><code class="constant">GL_UNPACK_LSB_FIRST</code></span></dt><dd><p>
+ 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.
+ This is relevant only for bitmap data.
+ </p></dd><dt><span class="term"><code class="constant">GL_UNPACK_ROW_LENGTH</code></span></dt><dd><p>
+ If greater than 0,
+ <code class="constant">GL_UNPACK_ROW_LENGTH</code> defines the number of pixels in a row.
+ If the first pixel of a row is placed at location
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">p</mml:mi></mml:math>
+ in memory,
+ then the location of the first pixel of the next row is obtained by skipping
+ </p><p>
+ </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <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></div><p>
+ </p><p>
+ components or indices,
+ where
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">n</mml:mi></mml:math>
+ is the number of components or indices in a pixel,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">l</mml:mi></mml:math>
+ is the number of pixels in a row
+ (<code class="constant">GL_UNPACK_ROW_LENGTH</code> if it is greater than 0,
+ the
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">width</mml:mi></mml:math>
+ argument to the pixel routine otherwise),
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">a</mml:mi></mml:math>
+ is the value of <code class="constant">GL_UNPACK_ALIGNMENT</code>, and
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
+ is the size, in bytes, of a single component
+ (if
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">a</mml:mi>
+ <mml:mo><</mml:mo>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:mrow>
+ </mml:math>,
+ then it is as if
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">a</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:mrow>
+ </mml:math>).
+ In the case of 1-bit values,
+ the location of the next row is obtained by skipping
+ </p><p>
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <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>
+ </p><p>
+ components or indices.
+ </p><p>
+ The word <span class="emphasis"><em>component</em></span> in this description refers to the nonindex values
+ red,
+ green,
+ blue,
+ alpha,
+ and depth.
+ Storage format <code class="constant">GL_RGB</code>,
+ for example,
+ has three components per pixel:
+ first red,
+ then green,
+ and finally blue.
+ </p></dd><dt><span class="term"><code class="constant">GL_UNPACK_IMAGE_HEIGHT</code></span></dt><dd><p>
+ If greater than 0,
+ <code class="constant">GL_UNPACK_IMAGE_HEIGHT</code> 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
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">p</mml:mi></mml:math>
+ in memory,
+ then the location of the first pixel of the next row is obtained by skipping
+ </p><p>
+ </p><div class="informalequation"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <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></div><p>
+ </p><p>
+ components or indices,
+ where
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">n</mml:mi></mml:math>
+ is the number of components or indices in a pixel,
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">l</mml:mi></mml:math>
+ is the number of pixels in a row
+ (<code class="constant">GL_UNPACK_ROW_LENGTH</code> if it is greater than 0,
+ the
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">width</mml:mi></mml:math>
+ argument to <a class="citerefentry" href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a> otherwise),
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">h</mml:mi></mml:math>
+ is the number of rows in an image (<code class="constant">GL_UNPACK_IMAGE_HEIGHT</code> if
+ it is greater than 0, the
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">height</mml:mi></mml:math>
+ argument to <a class="citerefentry" href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a> otherwise),
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">a</mml:mi></mml:math>
+ is the value of <code class="constant">GL_UNPACK_ALIGNMENT</code>, and
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">s</mml:mi></mml:math>
+ is the size, in bytes, of a single component
+ (if
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">a</mml:mi>
+ <mml:mo><</mml:mo>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:mrow>
+ </mml:math>,
+ then it is as if
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">a</mml:mi>
+ <mml:mo>=</mml:mo>
+ <mml:mi mathvariant="italic">s</mml:mi>
+ </mml:mrow>
+ </mml:math>).
+ </p><p>
+ The word <span class="emphasis"><em>component</em></span> in this description refers to the nonindex values
+ red,
+ green,
+ blue,
+ alpha,
+ and depth.
+ Storage format <code class="constant">GL_RGB</code>,
+ for example,
+ has three components per pixel:
+ first red,
+ then green,
+ and finally blue.
+ </p></dd><dt><span class="term"><code class="constant">GL_UNPACK_SKIP_PIXELS</code> and <code class="constant">GL_UNPACK_SKIP_ROWS</code></span></dt><dd><p>
+ These values are provided as a convenience to the programmer;
+ they provide no functionality that cannot be duplicated by
+ incrementing the pointer passed to
+ <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a>,
+ <a class="citerefentry" href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>,
+ <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>,
+ <a class="citerefentry" href="glTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage1D</span></span></a>,
+ <a class="citerefentry" href="glTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>,
+ <a class="citerefentry" href="glBitmap.xml"><span class="citerefentry"><span class="refentrytitle">glBitmap</span></span></a>, or
+ <a class="citerefentry" href="glPolygonStipple.xml"><span class="citerefentry"><span class="refentrytitle">glPolygonStipple</span></span></a>.
+ Setting <code class="constant">GL_UNPACK_SKIP_PIXELS</code> to
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">i</mml:mi></mml:math>
+ is equivalent to incrementing
+ the pointer by
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">i</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mi mathvariant="italic">n</mml:mi>
+ </mml:mrow>
+ </mml:math>
+ components or indices,
+ where
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">n</mml:mi></mml:math>
+ is the number of components or indices in each pixel.
+ Setting <code class="constant">GL_UNPACK_SKIP_ROWS</code> to
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">j</mml:mi></mml:math>
+ is equivalent to incrementing
+ the pointer by
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mrow>
+ <mml:mi mathvariant="italic">j</mml:mi>
+ <mml:mo></mml:mo>
+ <mml:mi mathvariant="italic">k</mml:mi>
+ </mml:mrow>
+ </mml:math>
+ components or indices,
+ where
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"><mml:mi mathvariant="italic">k</mml:mi></mml:math>
+ is the number of components or indices per row,
+ as just computed in the <code class="constant">GL_UNPACK_ROW_LENGTH</code> section.
+ </p></dd><dt><span class="term"><code class="constant">GL_UNPACK_ALIGNMENT</code></span></dt><dd><p>
+ 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).
+ </p></dd></dl></div><p>
+ The following table gives the type,
+ initial value,
+ and range of valid values for each storage parameter
+ that can be set with <code class="function">glPixelStore</code>.
+ </p><p>
+ </p><div class="informaltable"><table border="1"><colgroup><col align="left" /><col align="center" /><col align="center" /><col align="center" /></colgroup><thead><tr><th align="left"><span class="bold"><strong>
+ <em class="parameter"><code>pname</code></em>
+ </strong></span></th><th align="center"><span class="bold"><strong>
+ Type
+ </strong></span></th><th align="center"><span class="bold"><strong>
+ Initial Value
+ </strong></span></th><th align="center"><span class="bold"><strong>
+ Valid Range
+ </strong></span></th></tr></thead><tbody><tr><td align="left">
+ <code class="constant">GL_PACK_SWAP_BYTES</code>
+ </td><td align="center">
+ boolean
+ </td><td align="center">
+ false
+ </td><td align="center">
+ true or false
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_PACK_LSB_FIRST</code>
+ </td><td align="center">
+ boolean
+ </td><td align="center">
+ false
+ </td><td align="center">
+ true or false
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_PACK_ROW_LENGTH</code>
+ </td><td align="center">
+ integer
+ </td><td align="center">
+ 0
+ </td><td align="center">
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close=")">
+ <mml:mn>0</mml:mn>
+ <mml:infinity definitionURL="" encoding=""></mml:infinity>
+ </mml:mfenced>
+ </mml:math>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_PACK_IMAGE_HEIGHT</code>
+ </td><td align="center">
+ integer
+ </td><td align="center">
+ 0
+ </td><td align="center">
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close=")">
+ <mml:mn>0</mml:mn>
+ <mml:infinity definitionURL="" encoding=""></mml:infinity>
+ </mml:mfenced>
+ </mml:math>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_PACK_SKIP_ROWS</code>
+ </td><td align="center">
+ integer
+ </td><td align="center">
+ 0
+ </td><td align="center">
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close=")">
+ <mml:mn>0</mml:mn>
+ <mml:infinity definitionURL="" encoding=""></mml:infinity>
+ </mml:mfenced>
+ </mml:math>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_PACK_SKIP_PIXELS</code>
+ </td><td align="center">
+ integer
+ </td><td align="center">
+ 0
+ </td><td align="center">
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close=")">
+ <mml:mn>0</mml:mn>
+ <mml:infinity definitionURL="" encoding=""></mml:infinity>
+ </mml:mfenced>
+ </mml:math>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_PACK_SKIP_IMAGES</code>
+ </td><td align="center">
+ integer
+ </td><td align="center">
+ 0
+ </td><td align="center">
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close=")">
+ <mml:mn>0</mml:mn>
+ <mml:infinity definitionURL="" encoding=""></mml:infinity>
+ </mml:mfenced>
+ </mml:math>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_PACK_ALIGNMENT</code>
+ </td><td align="center">
+ integer
+ </td><td align="center">
+ 4
+ </td><td align="center">
+ 1, 2, 4, or 8
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_UNPACK_SWAP_BYTES</code>
+ </td><td align="center">
+ boolean
+ </td><td align="center">
+ false
+ </td><td align="center">
+ true or false
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_UNPACK_LSB_FIRST</code>
+ </td><td align="center">
+ boolean
+ </td><td align="center">
+ false
+ </td><td align="center">
+ true or false
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_UNPACK_ROW_LENGTH</code>
+ </td><td align="center">
+ integer
+ </td><td align="center">
+ 0
+ </td><td align="center">
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close=")">
+ <mml:mn>0</mml:mn>
+ <mml:infinity definitionURL="" encoding=""></mml:infinity>
+ </mml:mfenced>
+ </mml:math>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_UNPACK_IMAGE_HEIGHT</code>
+ </td><td align="center">
+ integer
+ </td><td align="center">
+ 0
+ </td><td align="center">
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close=")">
+ <mml:mn>0</mml:mn>
+ <mml:infinity definitionURL="" encoding=""></mml:infinity>
+ </mml:mfenced>
+ </mml:math>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_UNPACK_SKIP_ROWS</code>
+ </td><td align="center">
+ integer
+ </td><td align="center">
+ 0
+ </td><td align="center">
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close=")">
+ <mml:mn>0</mml:mn>
+ <mml:infinity definitionURL="" encoding=""></mml:infinity>
+ </mml:mfenced>
+ </mml:math>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_UNPACK_SKIP_PIXELS</code>
+ </td><td align="center">
+ integer
+ </td><td align="center">
+ 0
+ </td><td align="center">
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close=")">
+ <mml:mn>0</mml:mn>
+ <mml:infinity definitionURL="" encoding=""></mml:infinity>
+ </mml:mfenced>
+ </mml:math>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_UNPACK_SKIP_IMAGES</code>
+ </td><td align="center">
+ integer
+ </td><td align="center">
+ 0
+ </td><td align="center">
+ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll">
+
+ <mml:mfenced open="[" close=")">
+ <mml:mn>0</mml:mn>
+ <mml:infinity definitionURL="" encoding=""></mml:infinity>
+ </mml:mfenced>
+ </mml:math>
+ </td></tr><tr><td align="left">
+ <code class="constant">GL_UNPACK_ALIGNMENT</code>
+ </td><td align="center">
+ integer
+ </td><td align="center">
+ 4
+ </td><td align="center">
+ 1, 2, 4, or 8
+ </td></tr></tbody></table></div><p>
+ <code class="function">glPixelStoref</code> can be used to set any pixel store parameter.
+ If the parameter type is boolean,
+ then if <em class="parameter"><code>param</code></em> is 0,
+ the parameter is false;
+ otherwise it is set to true.
+ If <em class="parameter"><code>pname</code></em> is a integer type parameter,
+ <em class="parameter"><code>param</code></em> is rounded to the nearest integer.
+ </p><p>
+ Likewise, <code class="function">glPixelStorei</code> can also be used to set any of the
+ pixel store parameters.
+ Boolean parameters are set to false if <em class="parameter"><code>param</code></em> is 0 and true otherwise.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="notes"></a><h2>Notes</h2><p>
+ The pixel storage modes in effect when
+ <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a>,
+ <a class="citerefentry" href="glReadPixels.xml"><span class="citerefentry"><span class="refentrytitle">glReadPixels</span></span></a>,
+ <a class="citerefentry" href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>,
+ <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>,
+ <a class="citerefentry" href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>,
+ <a class="citerefentry" href="glTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage1D</span></span></a>,
+ <a class="citerefentry" href="glTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>,
+ <a class="citerefentry" href="glTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage3D</span></span></a>,
+ <a class="citerefentry" href="glBitmap.xml"><span class="citerefentry"><span class="refentrytitle">glBitmap</span></span></a>,
+ or <a class="citerefentry" href="glPolygonStipple.xml"><span class="citerefentry"><span class="refentrytitle">glPolygonStipple</span></span></a> is placed in a display list control the interpretation
+ of memory data.
+ Likewise, if the <code class="code">ARB_imaging</code> extension is supported, the pixel
+ storage modes in effect when
+ <a class="citerefentry" href="glColorTable.xml"><span class="citerefentry"><span class="refentrytitle">glColorTable</span></span></a>,
+ <a class="citerefentry" href="glColorSubTable.xml"><span class="citerefentry"><span class="refentrytitle">glColorSubTable</span></span></a>,
+ <a class="citerefentry" href="glConvolutionFilter1D.xml"><span class="citerefentry"><span class="refentrytitle">glConvolutionFilter1D</span></span></a>,
+ <a class="citerefentry" href="glConvolutionFilter2D.xml"><span class="citerefentry"><span class="refentrytitle">glConvolutionFilter2D</span></span></a>, of
+ <a class="citerefentry" href="glSeparableFilter2D.xml"><span class="citerefentry"><span class="refentrytitle">glSeparableFilter2D</span></span></a> is placed in a display list control the
+ interpretation of memory data.
+ The pixel storage modes in effect when a display list is executed are
+ not significant.
+ </p><p>
+ Pixel storage modes are client state and must be pushed and restored
+ using
+ <a class="citerefentry" href="glPushClientAttrib.xml"><span class="citerefentry"><span class="refentrytitle">glPushClientAttrib</span></span></a> and <a class="citerefentry" href="glPopClientAttrib.xml"><span class="citerefentry"><span class="refentrytitle">glPopClientAttrib</span></span></a>.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="errors"></a><h2>Errors</h2><p>
+ <code class="constant">GL_INVALID_ENUM</code> is generated if <em class="parameter"><code>pname</code></em> is not an accepted value.
+ </p><p>
+ <code class="constant">GL_INVALID_VALUE</code> 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.
+ </p><p>
+ <code class="constant">GL_INVALID_OPERATION</code> is generated if <code class="function">glPixelStore</code>
+ is executed between the execution of <a class="citerefentry" href="glBegin.xml"><span class="citerefentry"><span class="refentrytitle">glBegin</span></span></a>
+ and the corresponding execution of <a class="citerefentry" href="glEnd.xml"><span class="citerefentry"><span class="refentrytitle">glEnd</span></span></a>.
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="associatedgets"></a><h2>Associated Gets</h2><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PACK_SWAP_BYTES</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PACK_LSB_FIRST</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PACK_ROW_LENGTH</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PACK_IMAGE_HEIGHT</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PACK_SKIP_ROWS</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PACK_SKIP_PIXELS</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PACK_SKIP_IMAGES</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_PACK_ALIGNMENT</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_UNPACK_SWAP_BYTES</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_UNPACK_LSB_FIRST</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_UNPACK_ROW_LENGTH</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_UNPACK_IMAGE_HEIGHT</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_UNPACK_SKIP_ROWS</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_UNPACK_SKIP_PIXELS</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_UNPACK_SKIP_IMAGES</code>
+ </p><p>
+ <a class="citerefentry" href="glGet.xml"><span class="citerefentry"><span class="refentrytitle">glGet</span></span></a> with argument <code class="constant">GL_UNPACK_ALIGNMENT</code>
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="seealso"></a><h2>See Also</h2><p>
+ <a class="citerefentry" href="glBitmap.xml"><span class="citerefentry"><span class="refentrytitle">glBitmap</span></span></a>,
+ <a class="citerefentry" href="glColorTable.xml"><span class="citerefentry"><span class="refentrytitle">glColorTable</span></span></a>,
+ <a class="citerefentry" href="glColorSubTable.xml"><span class="citerefentry"><span class="refentrytitle">glColorSubTable</span></span></a>,
+ <a class="citerefentry" href="glConvolutionFilter1D.xml"><span class="citerefentry"><span class="refentrytitle">glConvolutionFilter1D</span></span></a>,
+ <a class="citerefentry" href="glConvolutionFilter2D.xml"><span class="citerefentry"><span class="refentrytitle">glConvolutionFilter2D</span></span></a>,
+ <a class="citerefentry" href="glSeparableFilter2D.xml"><span class="citerefentry"><span class="refentrytitle">glSeparableFilter2D</span></span></a>,
+ <a class="citerefentry" href="glDrawPixels.xml"><span class="citerefentry"><span class="refentrytitle">glDrawPixels</span></span></a>,
+ <a class="citerefentry" href="glHistogram.xml"><span class="citerefentry"><span class="refentrytitle">glHistogram</span></span></a>,
+ <a class="citerefentry" href="glMinmax.xml"><span class="citerefentry"><span class="refentrytitle">glMinmax</span></span></a>,
+ <a class="citerefentry" href="glPixelMap.xml"><span class="citerefentry"><span class="refentrytitle">glPixelMap</span></span></a>,
+ <a class="citerefentry" href="glPixelTransfer.xml"><span class="citerefentry"><span class="refentrytitle">glPixelTransfer</span></span></a>,
+ <a class="citerefentry" href="glPixelZoom.xml"><span class="citerefentry"><span class="refentrytitle">glPixelZoom</span></span></a>,
+ <a class="citerefentry" href="glPolygonStipple.xml"><span class="citerefentry"><span class="refentrytitle">glPolygonStipple</span></span></a>,
+ <a class="citerefentry" href="glPushClientAttrib.xml"><span class="citerefentry"><span class="refentrytitle">glPushClientAttrib</span></span></a>,
+ <a class="citerefentry" href="glReadPixels.xml"><span class="citerefentry"><span class="refentrytitle">glReadPixels</span></span></a>,
+ <a class="citerefentry" href="glTexImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage1D</span></span></a>,
+ <a class="citerefentry" href="glTexImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage2D</span></span></a>,
+ <a class="citerefentry" href="glTexImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexImage3D</span></span></a>,
+ <a class="citerefentry" href="glTexSubImage1D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage1D</span></span></a>,
+ <a class="citerefentry" href="glTexSubImage2D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage2D</span></span></a>,
+ <a class="citerefentry" href="glTexSubImage3D.xml"><span class="citerefentry"><span class="refentrytitle">glTexSubImage3D</span></span></a>
+ </p></div><div class="refsect1" lang="en" xml:lang="en"><a id="Copyright"></a><h2>Copyright</h2><p>
+ Copyright <span class="trademark"></span>© 1991-2006
+ Silicon Graphics, Inc. This document is licensed under the SGI
+ Free Software B License. For details, see
+ <a class="ulink" href="http://oss.sgi.com/projects/FreeB/" target="_top">http://oss.sgi.com/projects/FreeB/</a>.
+ </p></div></div></body></html>
HCoop / clinton / guile-figl.git / blobdiff