[gimp-help] Flip tool: add using guide

[Julien Hardlin <jhardlin src gnome org>]

commit 6524d5d808dd035d5e446d422cb7a668b69dfc65
Author: Julien Hardelin <jhardlin orange fr>
Date:   Thu Apr 11 18:02:59 2019 +0200

    Flip tool: add using guide

 images/C/toolbox/flip-guide.png | Bin 0 -> 55785 bytes
 src/toolbox/transform/flip.xml  |  25 +++++++++++++++++++++++++
 2 files changed, 25 insertions(+)
---
diff --git a/images/C/toolbox/flip-guide.png b/images/C/toolbox/flip-guide.png
new file mode 100644
index 000000000..22d8f340f
Binary files /dev/null and b/images/C/toolbox/flip-guide.png differ
diff --git a/src/toolbox/transform/flip.xml b/src/toolbox/transform/flip.xml
index 8baf3661d..c2ac3e499 100644
--- a/src/toolbox/transform/flip.xml
+++ b/src/toolbox/transform/flip.xml
@@ -1,6 +1,7 @@
 <?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:
+  2019-04-11 j.h: add using guide
   2018-10-25 j.h Update to v2.10
 -->
 <sect2 xmlns:xi="http://www.w3.org/2001/XInclude"; id="gimp-tool-flip">
@@ -114,6 +115,30 @@ format="PNG"/>
           <xi:include href="about-common-transform-options.xml"/>
         </listitem>
       </varlistentry>
+      <varlistentry>
+        <term>Using Guides</term>
+        <listitem>
+          <para>
+            With <acronym>GIMP</acronym>-2.10, you can use guides as flipping 
+            axis, instead of the default layer center: place a guide, open Flip 
+            tool and click on the guide.
+          </para>
+          <mediaobject>
+            <imageobject>
+              <imagedata fileref="images/toolbox/flip-guide.png" 
+                format="PNG"/>
+            </imageobject>
+            <caption>
+              <para>
+                On the left: original image with a guide activated.
+              </para>
+              <para>
+                On the right: result with Clipping option = Clip.
+              </para>
+            </caption>
+          </mediaobject>
+        </listitem>
+      </varlistentry>
     </variablelist>
   </sect3>
 </sect2>