1 <?xml version=
"1.0" encoding=
"UTF-8"?>
2 <!DOCTYPE book PUBLIC
"-//OASIS//DTD DocBook MathML Module V1.1b1//EN"
3 "http://www.oasis-open.org/docbook/xml/mathml/1.1CR1/dbmathml.dtd">
4 <refentry id=
"glGetHistogramParameter">
9 <holder>Silicon Graphics, Inc.
</holder>
12 <refentrytitle>glGetHistogramParameter
</refentrytitle>
13 <manvolnum>3G
</manvolnum>
16 <refname>glGetHistogramParameter
</refname>
17 <refpurpose>get histogram parameters
</refpurpose>
19 <refsynopsisdiv><title>C Specification
</title>
22 <funcdef>void
<function>glGetHistogramParameterfv
</function></funcdef>
23 <paramdef>GLenum
<parameter>target
</parameter></paramdef>
24 <paramdef>GLenum
<parameter>pname
</parameter></paramdef>
25 <paramdef>GLfloat *
<parameter>params
</parameter></paramdef>
30 <funcdef>void
<function>glGetHistogramParameteriv
</function></funcdef>
31 <paramdef>GLenum
<parameter>target
</parameter></paramdef>
32 <paramdef>GLenum
<parameter>pname
</parameter></paramdef>
33 <paramdef>GLint *
<parameter>params
</parameter></paramdef>
37 <refsect1 id=
"parameters"><title>Parameters
</title>
40 <term><parameter>target
</parameter></term>
44 <constant>GL_HISTOGRAM
</constant> or
45 <constant>GL_PROXY_HISTOGRAM
</constant>.
50 <term><parameter>pname
</parameter></term>
53 The name of the parameter to be retrieved.
55 <constant>GL_HISTOGRAM_WIDTH
</constant>,
56 <constant>GL_HISTOGRAM_FORMAT
</constant>,
57 <constant>GL_HISTOGRAM_RED_SIZE
</constant>,
58 <constant>GL_HISTOGRAM_GREEN_SIZE
</constant>,
59 <constant>GL_HISTOGRAM_BLUE_SIZE
</constant>,
60 <constant>GL_HISTOGRAM_ALPHA_SIZE
</constant>,
61 <constant>GL_HISTOGRAM_LUMINANCE_SIZE
</constant>, or
62 <constant>GL_HISTOGRAM_SINK
</constant>.
67 <term><parameter>params
</parameter></term>
70 Pointer to storage for the returned values.
76 <refsect1 id=
"description"><title>Description
</title>
78 <function>glGetHistogramParameter
</function> is used to query parameter values for the current histogram or for
79 a proxy. The histogram state information may be queried by calling
80 <function>glGetHistogramParameter
</function> with a
<parameter>target
</parameter> of
<constant>GL_HISTOGRAM
</constant> (to
81 obtain information for the current histogram table) or
82 <constant>GL_PROXY_HISTOGRAM
</constant> (to obtain information from the most recent
83 proxy request) and one of the following values for the
<parameter>pname
</parameter> argument:
87 <informaltable frame=
"topbot">
88 <tgroup cols=
"2" align=
"left">
93 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
96 <entry rowsep=
"1" align=
"left"><emphasis role=
"bold">
104 <constant>GL_HISTOGRAM_WIDTH
</constant>
107 Histogram table width
112 <constant>GL_HISTOGRAM_FORMAT
</constant>
120 <constant>GL_HISTOGRAM_RED_SIZE
</constant>
123 Red component counter size, in bits
128 <constant>GL_HISTOGRAM_GREEN_SIZE
</constant>
131 Green component counter size, in bits
136 <constant>GL_HISTOGRAM_BLUE_SIZE
</constant>
139 Blue component counter size, in bits
144 <constant>GL_HISTOGRAM_ALPHA_SIZE
</constant>
147 Alpha component counter size, in bits
152 <constant>GL_HISTOGRAM_LUMINANCE_SIZE
</constant>
155 Luminance component counter size, in bits
160 <constant>GL_HISTOGRAM_SINK
</constant>
163 Value of the
<emphasis>sink
</emphasis> parameter
172 <refsect1 id=
"notes"><title>Notes
</title>
174 <function>glGetHistogramParameter
</function> is present only if
<code>ARB_imaging
</code> is returned when
<citerefentry><refentrytitle>glGetString
</refentrytitle></citerefentry>
175 is called with an argument of
<constant>GL_EXTENSIONS
</constant>.
178 <refsect1 id=
"errors"><title>Errors
</title>
180 <constant>GL_INVALID_ENUM
</constant> is generated if
<parameter>target
</parameter> is not one of the allowable
184 <constant>GL_INVALID_ENUM
</constant> is generated if
<parameter>pname
</parameter> is not one of the allowable
188 <constant>GL_INVALID_OPERATION
</constant> is generated if
<function>glGetHistogramParameter
</function> is executed
189 between the execution of
<citerefentry><refentrytitle>glBegin
</refentrytitle></citerefentry> and the corresponding
190 execution of
<citerefentry><refentrytitle>glEnd
</refentrytitle></citerefentry>.
193 <refsect1 id=
"seealso"><title>See Also
</title>
195 <citerefentry><refentrytitle>glGetHistogram
</refentrytitle></citerefentry>,
196 <citerefentry><refentrytitle>glHistogram
</refentrytitle></citerefentry>
199 <refsect1 id=
"Copyright"><title>Copyright
</title>
201 Copyright
<trademark class=
"copyright"></trademark> 1991-
2006
202 Silicon Graphics, Inc. This document is licensed under the SGI
203 Free Software B License. For details, see
204 <ulink url=
"http://oss.sgi.com/projects/FreeB/">http://oss.sgi.com/projects/FreeB/
</ulink>.