[gimp-help] Add Bayer Matrix filter (draft)

[Julien Hardlin <jhardlin src gnome org>]

commit 311fd556c4564ef79bd1ad8a93e3aef2bb89cb08
Author: Julien Hardelin <jhardlin orange fr>
Date:   Thu Dec 5 20:25:25 2019 +0100

    Add Bayer Matrix filter (draft)

 .../C/filters/examples/render/bayer_matrix-ex.jpg  | Bin 0 -> 11023 bytes
 images/C/filters/render/bayer_matrix-dialog.png    | Bin 0 -> 44205 bytes
 src/filters/render.xml                             |   2 +
 src/filters/render/bayer-matrix.xml                | 143 +++++++++++++++++++++
 4 files changed, 145 insertions(+)
---
diff --git a/images/C/filters/examples/render/bayer_matrix-ex.jpg 
b/images/C/filters/examples/render/bayer_matrix-ex.jpg
new file mode 100644
index 000000000..41a59b783
Binary files /dev/null and b/images/C/filters/examples/render/bayer_matrix-ex.jpg differ
diff --git a/images/C/filters/render/bayer_matrix-dialog.png b/images/C/filters/render/bayer_matrix-dialog.png
new file mode 100644
index 000000000..f25f2cbff
Binary files /dev/null and b/images/C/filters/render/bayer_matrix-dialog.png differ
diff --git a/src/filters/render.xml b/src/filters/render.xml
index 78d9672ae..ba77c881f 100644
--- a/src/filters/render.xml
+++ b/src/filters/render.xml
@@ -21,11 +21,13 @@
   <xi:include href="render/difference-clouds.xml"/>
 
   <!--Patterns-->
+  <xi:include href="render/bayer-matrix.xml"/>
   <xi:include href="render/checkerboard.xml"/>
   <xi:include href="render/diffraction.xml"/>
   <xi:include href="render/grid.xml"/>
   <xi:include href="render/maze.xml"/>
   <xi:include href="render/sinus.xml"/>
+  
   <!--<xi:include href="render/spiral.xml"/>-->
   <xi:include href="render/checkerboard-legacy.xml"/>
   <xi:include href="render/cmlexplorer.xml"/>
diff --git a/src/filters/render/bayer-matrix.xml b/src/filters/render/bayer-matrix.xml
new file mode 100644
index 000000000..d71a305f4
--- /dev/null
+++ b/src/filters/render/bayer-matrix.xml
@@ -0,0 +1,143 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE sect2 PUBLIC "-//OASIS//DTD DocBook XML V4.3//EN"
+                       "http://www.docbook.org/xml/4.3/docbookx.dtd";>
+<!-- section history:
+  2019-12-05 j.h: initial version (draft)
+-->
+
+<sect2 xmlns:xi="http://www.w3.org/2001/XInclude"; id="gimp-filter-bayer-matrix">
+  <title>Bayer Matrix</title>
+
+  <indexterm>
+    <primary>Filters</primary>
+    <secondary>Render</secondary>
+    <tertiary>Bayer Matrix</tertiary>
+  </indexterm>
+  <indexterm>
+    <primary>Bayer Matrix</primary>
+  </indexterm>
+
+  <sect3>
+    <title>Overview</title>
+    <figure>
+      <title>Example for the Bayer Matrix filter</title>
+      <mediaobject>
+        <imageobject>
+          <imagedata format="JPG"
+            fileref="images/filters/examples/render/bayer_matrix-ex.jpg"/>
+        </imageobject>
+        <caption>
+          <para>
+            <quote>Bayer Matrix</quote> filter applied with Scale X, Y = 20
+          </para>
+        </caption>
+      </mediaobject>
+    </figure>
+    <para>
+      A grand-sounding name for a simple filter. Bayer matrix is related to 
+      <emphasis>ordered dithering</emphasis>, which is an image dithering 
+      algorithm used to display a continuous image on a display of smaller 
+      color depth. The algorithm reduces the number of colors by applying a 
+      threshold map known as Bayer matrix (Wikipedia). The present filter 
+      uses the Bayer matrix only to create a pattern.
+    </para>
+  </sect3>
+  
+  <sect3>
+    <title>Starting filter</title>
+    <para>
+      You can find this filter in the image menu through
+      <menuchoice>
+        <guimenu>Filters</guimenu>
+        <guisubmenu>Render</guisubmenu>
+        <guisubmenu>Pattern</guisubmenu>
+        <guimenuitem>Bayer Matrix…</guimenuitem>
+      </menuchoice>
+    </para>
+  </sect3>
+  
+  <sect3>
+    <title>Options</title>
+    <figure>
+      <title><quote>Bayer Matrix</quote> filter options</title>
+      <mediaobject>
+        <imageobject>
+          <imagedata format="PNG"
+            fileref="images/filters/render/bayer_matrix-dialog.png"/>
+        </imageobject>
+      </mediaobject>
+    </figure>
+    <variablelist>
+      <varlistentry>
+        <term>Presets, Preview, Split view</term>
+        <listitem>
+          <xi:include href="../about-common-features.xml"/>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Subdivision</term>
+        <listitem>
+          <para>
+            TODO
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>X Scale, Y Scale</term>
+        <listitem>
+          <para>
+            Horizontal, Vertical pattern size.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Rotation</term>
+        <listitem>
+          <para>
+            TODO
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Reflect</term>
+        <listitem>
+          <para>
+            Reflect the pattern horizontally.
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Amplitude</term>
+        <listitem>
+          <para>
+            TODO
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Offset</term>
+        <listitem>
+          <para>
+            TODO
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>Exponent</term>
+        <listitem>
+          <para>
+            TODO
+          </para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
+        <term>X, Y Offset</term>
+        <listitem>
+          <para>
+            TODO
+          </para>
+        </listitem>
+      </varlistentry>
+    </variablelist>
+  </sect3>
+</sect2>