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<?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="glPixelMap">
<refmeta>
<refmetainfo>
<copyright>
<year>1991-2006</year>
<holder>Silicon Graphics, Inc.</holder>
</copyright>
</refmetainfo>
<refentrytitle>glPixelMap</refentrytitle>
<manvolnum>3G</manvolnum>
</refmeta>
<refnamediv>
<refname>glPixelMap</refname>
<refpurpose>set up pixel transfer maps</refpurpose>
</refnamediv>
<refsynopsisdiv><title>C Specification</title>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>glPixelMapfv</function></funcdef>
<paramdef>GLenum <parameter>map</parameter></paramdef>
<paramdef>GLsizei <parameter>mapsize</parameter></paramdef>
<paramdef>const GLfloat * <parameter>values</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>glPixelMapuiv</function></funcdef>
<paramdef>GLenum <parameter>map</parameter></paramdef>
<paramdef>GLsizei <parameter>mapsize</parameter></paramdef>
<paramdef>const GLuint * <parameter>values</parameter></paramdef>
</funcprototype>
</funcsynopsis>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>glPixelMapusv</function></funcdef>
<paramdef>GLenum <parameter>map</parameter></paramdef>
<paramdef>GLsizei <parameter>mapsize</parameter></paramdef>
<paramdef>const GLushort * <parameter>values</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<!-- eqn: ignoring delim $$ -->
<refsect1 id="parameters"><title>Parameters</title>
<variablelist>
<varlistentry>
<term><parameter>map</parameter></term>
<listitem>
<para>
Specifies a symbolic map name.
Must be one of the following:
<constant>GL_PIXEL_MAP_I_TO_I</constant>,
<constant>GL_PIXEL_MAP_S_TO_S</constant>,
<constant>GL_PIXEL_MAP_I_TO_R</constant>,
<constant>GL_PIXEL_MAP_I_TO_G</constant>,
<constant>GL_PIXEL_MAP_I_TO_B</constant>,
<constant>GL_PIXEL_MAP_I_TO_A</constant>,
<constant>GL_PIXEL_MAP_R_TO_R</constant>,
<constant>GL_PIXEL_MAP_G_TO_G</constant>,
<constant>GL_PIXEL_MAP_B_TO_B</constant>, or
<constant>GL_PIXEL_MAP_A_TO_A</constant>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>mapsize</parameter></term>
<listitem>
<para>
Specifies the size of the map being defined.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>values</parameter></term>
<listitem>
<para>
Specifies an array of <parameter>mapsize</parameter> values.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id="description"><title>Description</title>
<para>
<function>glPixelMap</function> sets up translation tables,
or <emphasis>maps</emphasis>,
used by
<citerefentry><refentrytitle>glCopyPixels</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glCopyTexImage1D</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glCopyTexImage2D</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glCopyTexSubImage1D</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glCopyTexSubImage2D</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glCopyTexSubImage3D</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glDrawPixels</refentrytitle></citerefentry>,
<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>, and
<citerefentry><refentrytitle>glTexSubImage3D</refentrytitle></citerefentry>.
Additionally, if the <code>ARB_imaging</code> subset is supported, the
routines
<citerefentry><refentrytitle>glColorTable</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glColorSubTable</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glConvolutionFilter1D</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glConvolutionFilter2D</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glHistogram</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glMinmax</refentrytitle></citerefentry>, and
<citerefentry><refentrytitle>glSeparableFilter2D</refentrytitle></citerefentry>.
Use of these maps is described completely in the
<citerefentry><refentrytitle>glPixelTransfer</refentrytitle></citerefentry> reference page,
and partly in the reference pages for the pixel and texture image commands.
Only the specification of the maps is described in this reference page.
</para>
<para>
<parameter>map</parameter> is a symbolic map name,
indicating one of ten maps to set.
<parameter>mapsize</parameter> specifies the number of entries in the map,
and <parameter>values</parameter> is a pointer to an array of <parameter>mapsize</parameter> map values.
</para>
<para>
If a non-zero named buffer object is bound to the <constant>GL_PIXEL_UNPACK_BUFFER</constant> target
(see <citerefentry><refentrytitle>glBindBuffer</refentrytitle></citerefentry>) while a pixel transfer map is
specified, <parameter>values</parameter> is treated as a byte offset into the buffer object's data store.
</para>
<para>
The ten maps are as follows:
</para>
<variablelist>
<varlistentry>
<term><constant>GL_PIXEL_MAP_I_TO_I</constant></term>
<listitem>
<para>
Maps color indices to color indices.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>GL_PIXEL_MAP_S_TO_S</constant></term>
<listitem>
<para>
Maps stencil indices to stencil indices.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>GL_PIXEL_MAP_I_TO_R</constant></term>
<listitem>
<para>
Maps color indices to red components.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>GL_PIXEL_MAP_I_TO_G</constant></term>
<listitem>
<para>
Maps color indices to green components.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>GL_PIXEL_MAP_I_TO_B</constant></term>
<listitem>
<para>
Maps color indices to blue components.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>GL_PIXEL_MAP_I_TO_A</constant></term>
<listitem>
<para>
Maps color indices to alpha components.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>GL_PIXEL_MAP_R_TO_R</constant></term>
<listitem>
<para>
Maps red components to red components.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>GL_PIXEL_MAP_G_TO_G</constant></term>
<listitem>
<para>
Maps green components to green components.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>GL_PIXEL_MAP_B_TO_B</constant></term>
<listitem>
<para>
Maps blue components to blue components.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><constant>GL_PIXEL_MAP_A_TO_A</constant></term>
<listitem>
<para>
Maps alpha components to alpha components.
</para>
</listitem>
</varlistentry>
</variablelist>
<para>
The entries in a map can be specified as single-precision
floating-point numbers,
unsigned short integers,
or unsigned int integers.
Maps that store color component values
(all but <constant>GL_PIXEL_MAP_I_TO_I</constant> and <constant>GL_PIXEL_MAP_S_TO_S</constant>)
retain their values in floating-point format,
with unspecified mantissa and exponent sizes.
Floating-point values specified by <function>glPixelMapfv</function> are converted directly
to the internal floating-point format of these maps,
then clamped to the range [0,1].
Unsigned integer values specified by <function>glPixelMapusv</function> and
<function>glPixelMapuiv</function> are converted linearly such that
the largest representable integer maps to 1.0,
and 0 maps to 0.0.
</para>
<para>
Maps that store indices,
<constant>GL_PIXEL_MAP_I_TO_I</constant> and <constant>GL_PIXEL_MAP_S_TO_S</constant>,
retain their values in fixed-point format,
with an unspecified number of bits to the right of the binary point.
Floating-point values specified by <function>glPixelMapfv</function> are converted directly
to the internal fixed-point format of these maps.
Unsigned integer values specified by <function>glPixelMapusv</function> and
<function>glPixelMapuiv</function> specify integer values,
with all 0's to the right of the binary point.
</para>
<para>
The following table shows the initial sizes and values for each of the maps.
Maps that are indexed by either color or stencil indices must have
<parameter>mapsize</parameter> =
<inlineequation><mml:math>
<!-- eqn: 2 sup n:-->
<mml:msup><mml:mn>2</mml:mn>
<mml:mi mathvariant="italic">n</mml:mi>
</mml:msup>
</mml:math></inlineequation>
for some
<inlineequation><mml:math><mml:mi mathvariant="italic">n</mml:mi></mml:math></inlineequation>
or the results are undefined.
The maximum allowable size for each map depends on the implementation
and can be determined by calling <citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument
<constant>GL_MAX_PIXEL_MAP_TABLE</constant>.
The single maximum applies to all maps; it is at
least 32.
</para>
<informaltable frame="topbot">
<tgroup cols="5" align="left">
<colspec colwidth="4*" />
<colspec colwidth="2*" align="center"/>
<colspec colwidth="2*" align="center"/>
<colspec colwidth="1*" align="center"/>
<colspec colwidth="1*" align="center"/>
<thead>
<row>
<entry rowsep="1" align="left"><emphasis role="bold">
<parameter>map</parameter>
</emphasis></entry>
<entry rowsep="1" align="center"><emphasis role="bold">
Lookup Index
</emphasis></entry>
<entry rowsep="1" align="center"><emphasis role="bold">
Lookup Value
</emphasis></entry>
<entry rowsep="1" align="center"><emphasis role="bold">
Initial Size
</emphasis></entry>
<entry rowsep="1" align="center"><emphasis role="bold">
Initial Value
</emphasis></entry>
</row>
</thead>
<tbody>
<row>
<entry align="left">
<constant>GL_PIXEL_MAP_I_TO_I</constant>
</entry>
<entry align="center">
color index
</entry>
<entry align="center">
color index
</entry>
<entry align="center">
1
</entry>
<entry align="center">
0
</entry>
</row>
<row>
<entry align="left">
<constant>GL_PIXEL_MAP_S_TO_S</constant>
</entry>
<entry align="center">
stencil index
</entry>
<entry align="center">
stencil index
</entry>
<entry align="center">
1
</entry>
<entry align="center">
0
</entry>
</row>
<row>
<entry align="left">
<constant>GL_PIXEL_MAP_I_TO_R</constant>
</entry>
<entry align="center">
color index
</entry>
<entry align="center">
R
</entry>
<entry align="center">
1
</entry>
<entry align="center">
0
</entry>
</row>
<row>
<entry align="left">
<constant>GL_PIXEL_MAP_I_TO_G</constant>
</entry>
<entry align="center">
color index
</entry>
<entry align="center">
G
</entry>
<entry align="center">
1
</entry>
<entry align="center">
0
</entry>
</row>
<row>
<entry align="left">
<constant>GL_PIXEL_MAP_I_TO_B</constant>
</entry>
<entry align="center">
color index
</entry>
<entry align="center">
B
</entry>
<entry align="center">
1
</entry>
<entry align="center">
0
</entry>
</row>
<row>
<entry align="left">
<constant>GL_PIXEL_MAP_I_TO_A</constant>
</entry>
<entry align="center">
color index
</entry>
<entry align="center">
A
</entry>
<entry align="center">
1
</entry>
<entry align="center">
0
</entry>
</row>
<row>
<entry align="left">
<constant>GL_PIXEL_MAP_R_TO_R</constant>
</entry>
<entry align="center">
R
</entry>
<entry align="center">
R
</entry>
<entry align="center">
1
</entry>
<entry align="center">
0
</entry>
</row>
<row>
<entry align="left">
<constant>GL_PIXEL_MAP_G_TO_G</constant>
</entry>
<entry align="center">
G
</entry>
<entry align="center">
G
</entry>
<entry align="center">
1
</entry>
<entry align="center">
0
</entry>
</row>
<row>
<entry align="left">
<constant>GL_PIXEL_MAP_B_TO_B</constant>
</entry>
<entry align="center">
B
</entry>
<entry align="center">
B
</entry>
<entry align="center">
1
</entry>
<entry align="center">
0
</entry>
</row>
<row>
<entry align="left">
<constant>GL_PIXEL_MAP_A_TO_A</constant>
</entry>
<entry align="center">
A
</entry>
<entry align="center">
A
</entry>
<entry align="center">
1
</entry>
<entry align="center">
0
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</refsect1>
<refsect1 id="errors"><title>Errors</title>
<para>
<constant>GL_INVALID_ENUM</constant> is generated if <parameter>map</parameter> is not an accepted value.
</para>
<para>
<constant>GL_INVALID_VALUE</constant> is generated if <parameter>mapsize</parameter> is less than one
or larger than <constant>GL_MAX_PIXEL_MAP_TABLE</constant>.
</para>
<para>
<constant>GL_INVALID_VALUE</constant> is generated if <parameter>map</parameter> is
<constant>GL_PIXEL_MAP_I_TO_I</constant>,
<constant>GL_PIXEL_MAP_S_TO_S</constant>,
<constant>GL_PIXEL_MAP_I_TO_R</constant>,
<constant>GL_PIXEL_MAP_I_TO_G</constant>,
<constant>GL_PIXEL_MAP_I_TO_B</constant>, or
<constant>GL_PIXEL_MAP_I_TO_A</constant>,
and <parameter>mapsize</parameter> is not a power of two.
</para>
<para>
<constant>GL_INVALID_OPERATION</constant> is generated if a non-zero buffer object name is bound to the
<constant>GL_PIXEL_UNPACK_BUFFER</constant> target and the buffer object's data store is currently mapped.
</para>
<para>
<constant>GL_INVALID_OPERATION</constant> is generated if a non-zero buffer object name is bound to the
<constant>GL_PIXEL_UNPACK_BUFFER</constant> target and the data would be unpacked from the buffer
object such that the memory reads required would exceed the data store size.
</para>
<para>
<constant>GL_INVALID_OPERATION</constant> is generated by <function>glPixelMapfv</function> if a non-zero buffer object name is bound to the
<constant>GL_PIXEL_UNPACK_BUFFER</constant> target and <parameter>values</parameter> is not evenly divisible
into the number of bytes needed to store in memory a GLfloat datum.
</para>
<para>
<constant>GL_INVALID_OPERATION</constant> is generated by <function>glPixelMapuiv</function> if a non-zero buffer object name is bound to the
<constant>GL_PIXEL_UNPACK_BUFFER</constant> target and <parameter>values</parameter> is not evenly divisible
into the number of bytes needed to store in memory a GLuint datum.
</para>
<para>
<constant>GL_INVALID_OPERATION</constant> is generated by <function>glPixelMapusv</function> if a non-zero buffer object name is bound to the
<constant>GL_PIXEL_UNPACK_BUFFER</constant> target and <parameter>values</parameter> is not evenly divisible
into the number of bytes needed to store in memory a GLushort datum.
</para>
<para>
<constant>GL_INVALID_OPERATION</constant> is generated if <function>glPixelMap</function>
is executed between the execution of <citerefentry><refentrytitle>glBegin</refentrytitle></citerefentry>
and the corresponding execution of <citerefentry><refentrytitle>glEnd</refentrytitle></citerefentry>.
</para>
</refsect1>
<refsect1 id="associatedgets"><title>Associated Gets</title>
<para>
<citerefentry><refentrytitle>glGetPixelMap</refentrytitle></citerefentry>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PIXEL_MAP_I_TO_I_SIZE</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PIXEL_MAP_S_TO_S_SIZE</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PIXEL_MAP_I_TO_R_SIZE</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PIXEL_MAP_I_TO_G_SIZE</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PIXEL_MAP_I_TO_B_SIZE</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PIXEL_MAP_I_TO_A_SIZE</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PIXEL_MAP_R_TO_R_SIZE</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PIXEL_MAP_G_TO_G_SIZE</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PIXEL_MAP_B_TO_B_SIZE</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PIXEL_MAP_A_TO_A_SIZE</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_MAX_PIXEL_MAP_TABLE</constant>
</para>
<para>
<citerefentry><refentrytitle>glGet</refentrytitle></citerefentry> with argument <constant>GL_PIXEL_UNPACK_BUFFER_BINDING</constant>
</para>
</refsect1>
<refsect1 id="seealso"><title>See Also</title>
<para>
<citerefentry><refentrytitle>glColorTable</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glColorSubTable</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glConvolutionFilter1D</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glConvolutionFilter2D</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glCopyPixels</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glCopyTexImage1D</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glCopyTexImage2D</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glCopyTexSubImage1D</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glCopyTexSubImage2D</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glDrawPixels</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glHistogram</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glMinmax</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glPixelStore</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glPixelTransfer</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glReadPixels</refentrytitle></citerefentry>,
<citerefentry><refentrytitle>glSeparableFilter2D</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>