1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE html
PUBLIC "-//W3C//DTD XHTML 1.1 plus MathML 2.0//EN" "http://www.w3.org/TR/MathML2/dtd/xhtml-math11-f.dtd">
<html
xmlns="http://www.w3.org/1999/xhtml"
xmlns:mml="http://www.w3.org/1998/Math/MathML"
><head><title>glGetHistogram</title><link rel="stylesheet" href="style.css" type="text/css"/><meta name="generator" content="DocBook XSL Stylesheets V1.59.1"/><link rel="home" href="index.xml" title="PyOpenGL 2.0.1.07 Man Pages"/><link rel="up" href="reference-GL.xml" title="GL"/><link rel="previous" href="glGetError.3G.xml" title="glGetError"/><link rel="next" href="glGetHistogramParameter.3G.xml" title="glGetHistogramParameter"/></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">glGetHistogram</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="glGetError.3G.xml">Prev</a></td><th width="60%" align="center">GL</th><td width="20%" align="right"><a accesskey="n" href="glGetHistogramParameter.3G.xml">Next</a></td></tr></table><hr/></div><div class="refentry" lang="en"><a name="glGetHistogram.3G"/><div class="titlepage"/><div class="refnamediv"><a name="glGetHistogram.3G-name"/><h2>Name</h2><p>glGetHistogram — get histogram table</p></div><div class="refsynopsisdiv"><a name="glGetHistogram.3G-c_spec"/><h2>C Specification</h2><table class="funcprototype" border="0" cellpadding="0" cellspacing="0"><tr><td valign="top"><code>void<tt>glGetHistogram</tt></code></td><td valign="top"><code>(</code></td><td valign="top"><code>GLenum<i><tt>target</tt></i>, GLboolean<i><tt>reset</tt></i>, GLenum<i><tt>format</tt></i>, GLenum<i><tt>type</tt></i>, GLvoid*<i><tt>values</tt></i>);</code></td></tr></table></div><div class="refsynopsisdiv"><a name="glGetHistogram.3G-python_spec"/><h2>Python Specification</h2><table class="funcprototype" border="0" cellpadding="0" cellspacing="0"><tr><td valign="top"><code><tt>glGetHistogram</tt></code></td><td valign="top"><code>(</code></td><td valign="top"><code><i><tt>target</tt></i>, <i><tt>reset</tt></i>, <i><tt>format</tt></i>, <i><tt>type</tt></i>, <i><tt>values</tt></i>) →<tt>None</tt></code></td></tr></table></div><div class="refsect1" lang="en"><a name="glGetHistogram.3G-parameters"/><h2>Parameters</h2><div class="variablelist"><dl><dt><span class="term"><i><tt>target</tt></i></span></dt><dd>
Must be <tt>GL_HISTOGRAM</tt>.
</dd><dt><span class="term"><i><tt>reset</tt></i></span></dt><dd>
If <tt>GL_TRUE</tt>, each component counter that is actually returned is reset to zero. (Other
counters are unaffected.) If <tt>GL_FALSE</tt>, none of the counters in the histogram table is
modified.
</dd><dt><span class="term"><i><tt>format</tt></i></span></dt><dd>
The of values to be returned in <i><tt>values</tt></i>. Must be one of <tt>GL_RED</tt>,
<tt>GL_GREEN</tt>, <tt>GL_BLUE</tt>, <tt>GL_ALPHA</tt>,
<tt>GL_RGB</tt>, <tt>GL_BGR</tt>, <tt>GL_RGBA</tt>,
<tt>GL_BGRA</tt>, <tt>GL_LUMINANCE</tt>, or
<tt>GL_LUMINANCE_ALPHA</tt>.
</dd><dt><span class="term"><i><tt>type</tt></i></span></dt><dd>
The type of values to be returned in <i><tt>values</tt></i>. Symbolic constants
<tt>GL_UNSIGNED_BYTE</tt>, <tt>GL_BYTE</tt>, <tt>GL_BITMAP</tt>,
<tt>GL_UNSIGNED_SHORT</tt>, <tt>GL_SHORT</tt>,
<tt>GL_UNSIGNED_INT</tt>, <tt>GL_INT</tt>, <tt>GL_FLOAT</tt>,
<tt>GL_UNSIGNED_BYTE_3_3_2</tt>, <tt>GL_UNSIGNED_BYTE_2_3_3_REV</tt>,
<tt>GL_UNSIGNED_SHORT_5_6_5</tt>, <tt>GL_UNSIGNED_SHORT_5_6_5_REV</tt>,
<tt>GL_UNSIGNED_SHORT_4_4_4_4</tt>, <tt>GL_UNSIGNED_SHORT_4_4_4_4_REV</tt>,
<tt>GL_UNSIGNED_SHORT_5_5_5_1</tt>, <tt>GL_UNSIGNED_SHORT_1_5_5_5_REV</tt>,
<tt>GL_UNSIGNED_INT_8_8_8_8</tt>, <tt>GL_UNSIGNED_INT_8_8_8_8_REV</tt>,
<tt>GL_UNSIGNED_INT_10_10_10_2</tt>, and <tt>GL_UNSIGNED_INT_2_10_10_10_REV</tt>
are accepted.
</dd><dt><span class="term"><i><tt>values</tt></i></span></dt><dd>
A pointer to storage for the returned histogram table.
</dd></dl></div></div><div class="refsect1" lang="en"><a name="glGetHistogram.3G-description"/><h2>Description</h2><p>
<tt>glGetHistogram</tt> returns the current histogram table as a one-dimensional image with the same width
as the histogram. No pixel transfer operations are performed on this image, but pixel storage modes that are applicable
to 1D images are honored.
</p><p>
Color components that are requested in the specified <i><tt>format</tt></i>, but which are not included in the
internal of the histogram, are returned as zero. The assignments of internal color components to the components
requested by <i><tt>format</tt></i> are:
</p><div class="informaltable"><table border="1"><colgroup><col/><col/></colgroup><tbody><tr><td><span class="bold"><b>Internal Component</b></span></td><td><span class="bold"><b>Resulting Component</b></span></td></tr><tr><td>Red</td><td>Red</td></tr><tr><td>Green</td><td>Green</td></tr><tr><td>Blue</td><td>Blue</td></tr><tr><td>Alpha</td><td>Alpha</td></tr><tr><td>Luminance</td><td>Red</td></tr></tbody></table></div></div><div class="refsect1" lang="en"><a name="glGetHistogram.3G-notes"/><h2>Notes</h2><p>
<tt>glGetHistogram</tt> is present only if <tt>GL_ARB_imaging</tt> is returned when <a href="glGetString.3G.xml"><tt>glGetString</tt></a> is called with an argument of <tt>GL_EXTENSIONS</tt>.
</p></div><div class="refsect1" lang="en"><a name="glGetHistogram.3G-errors"/><h2>Errors</h2><p>
<tt>GL_INVALID_ENUM</tt> is generated if <i><tt>target</tt></i> is not
<tt>GL_HISTOGRAM</tt>.
</p><p>
<tt>GL_INVALID_ENUM</tt> is generated if <i><tt>format</tt></i> is not one of the allowable values.
</p><p>
<tt>GL_INVALID_ENUM</tt> is generated if <i><tt>type</tt></i> is not one of the allowable values.
</p><p>
<tt>GL_INVALID_OPERATION</tt> is generated if <tt>glGetHistogram</tt> is executed between the
execution of <a href="glBegin.3G.xml"><tt>glBegin</tt></a> and the corresponding execution of <a href="glBegin.3G.xml"><tt>glEnd</tt></a>.
</p><p>
<tt>GL_INVALID_OPERATION</tt> is generated if <i><tt>type</tt></i> is one of
<tt>GL_UNSIGNED_BYTE_3_3_2</tt>, <tt>GL_UNSIGNED_BYTE_2_3_3_REV</tt>,
<tt>GL_UNSIGNED_SHORT_5_6_5</tt>, or <tt>GL_UNSIGNED_SHORT_5_6_5_REV</tt> and
<i><tt>format</tt></i> is not <tt>GL_RGB</tt>.
</p><p>
<tt>GL_INVALID_OPERATION</tt> is generated if <i><tt>type</tt></i> is one of
<tt>GL_UNSIGNED_SHORT_4_4_4_4</tt>, <tt>GL_UNSIGNED_SHORT_4_4_4_4_REV</tt>,
<tt>GL_UNSIGNED_SHORT_5_5_5_1</tt>, <tt>GL_UNSIGNED_SHORT_1_5_5_5_REV</tt>,
<tt>GL_UNSIGNED_INT_8_8_8_8</tt>, <tt>GL_UNSIGNED_INT_8_8_8_8_REV</tt>,
<tt>GL_UNSIGNED_INT_10_10_10_2</tt>, or <tt>GL_UNSIGNED_INT_2_10_10_10_REV</tt> and
<i><tt>format</tt></i> is neither <tt>GL_RGBA</tt> nor <tt>GL_BGRA</tt>.
</p></div><div class="refsect1" lang="en"><a name="glGetHistogram.3G-see_also"/><h2>See Also</h2><p>
<span class="simplelist"><a href="glHistogram.3G.xml">glHistogram</a>, <a href="glResetHistogram.3G.xml">glResetHistogram</a>, <a href="glGetHistogramParameter.3G.xml">glGetHistogramParameter</a></span>
</p></div></div><div class="navfooter"><hr/><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="glGetError.3G.xml">Prev</a></td><td width="20%" align="center"><a accesskey="u" href="reference-GL.xml">Up</a></td><td width="40%" align="right"><a accesskey="n" href="glGetHistogramParameter.3G.xml">Next</a></td></tr><tr><td width="40%" align="left" valign="top">glGetError</td><td width="20%" align="center"><a accesskey="h" href="index.xml">Home</a></td><td width="40%" align="right" valign="top">glGetHistogramParameter</td></tr></table></div></body></html>
|
