1<?xml version="1.0" encoding="UTF-8"?>
2<!DOCTYPE sect2 PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
3                       "http://www.docbook.org/xml/4.3/docbookx.dtd">
4<!-- section history:
5  2019-05-14 j.h: update to v2.10.10
6-->
7<sect2 id="gimp-filter-motion-blur-circular">
8  <title>Circular Motion Blur</title>
9
10  <indexterm>
11    <primary>Filters</primary>
12    <secondary>Blur</secondary>
13    <tertiary>Circular Motion</tertiary>
14  </indexterm>
15  <indexterm>
16    <primary>Circular Motion Blur</primary>
17  </indexterm>
18
19  <sect3>
20    <title>Overview</title>
21    <figure>
22      <title>The Circular Motion Blur filter</title>
23      <mediaobject>
24        <imageobject>
25          <imagedata fileref="images/filters/examples/taj_orig.jpg"
26            format="JPG"/>
27        </imageobject>
28        <caption>
29          <para>Original</para>
30        </caption>
31      </mediaobject>
32      <mediaobject>
33        <imageobject>
34          <imagedata fileref="images/filters/examples/blur-taj-circular.jpg"
35            format="JPG"/>
36        </imageobject>
37        <caption>
38          <para>Blur applied</para>
39        </caption>
40      </mediaobject>
41    </figure>
42    <para>
43      This filters creates a circular blur around a center. The default center
44      is the center of the layer or selection. You can set center somewhere in
45      the layer and this center is applied to the layer or to a selection if it
46      exists.
47    </para>
48  </sect3>
49
50  <sect3>
51    <title>Options</title>
52    <figure>
53      <title><quote>Circular Motion Blur</quote> filter options</title>
54      <mediaobject>
55        <imageobject>
56          <imagedata format="PNG"
57            fileref="images/filters/blur/circular-options.png"/>
58        </imageobject>
59      </mediaobject>
60    </figure>
61
62    <variablelist>
63      <varlistentry>
64        <term><guilabel>Presets</guilabel>, <guilabel>Preview</guilabel>,
65          <guilabel>Split view</guilabel></term>
66        <listitem>
67          <para>
68            These options are common to GEGL-based filters. Please refer to
69            <xref linkend="gimp-filters-common"/>.
70          </para>
71        </listitem>
72      </varlistentry>
73
74      <varlistentry>
75        <term><guilabel>Center X</guilabel></term>
76        <term><guilabel>Center Y</guilabel></term>
77        <listitem>
78          <para>
79            Here, you can set the rotation center. Sliders and spin buttons
80            control the position of rotation center on horizontal and vertical
81            axis. You can also click on the rectangle button with an arrow on
82            the right and then click on the image to pick coordinates.
83          </para>
84        </listitem>
85      </varlistentry>
86
87      <varlistentry>
88        <term><guilabel>Angle</guilabel></term>
89        <listitem>
90          <para>
91            More Angle will result in more blurring in a circular direction.
92          </para>
93        </listitem>
94      </varlistentry>
95
96      <varlistentry>
97        <term><guilabel>Use selection as input</guilabel></term>
98        <listitem>
99          <para>
100            Explained in <xref linkend="gimp-filter-pixelize"/>.
101          </para>
102        </listitem>
103      </varlistentry>
104
105      <varlistentry>
106        <term><guilabel>On-canvas controls</guilabel></term>
107        <listitem>
108          <para>
109            This option (default) allows you to modify blur settings directly
110            on canvas, for easier visual tweaking of blur settings. It displays
111            a line with handle on both ends to move rotation center and
112            transform.
113          </para>
114          <para>
115            Press <keycap>Alt</keycap> key to only move rotation center without
116            transforming.
117          </para>
118          <para>
119            Press <keycap>Ctrl</keycap> key to rotate by 15° steps.
120          </para>
121        </listitem>
122      </varlistentry>
123    </variablelist>
124  </sect3>
125</sect2>