From http://www.jwz.org/xscreensaver/xscreensaver-5.40.tar.gz

[xscreensaver] / hacks / config / tessellimage.xml

diff --git a/hacks/config/tessellimage.xml b/hacks/config/tessellimage.xml
index b7a4face226e75871d3d4fa0e50f86c8fd00f36b..f6e1a3caf4cddf5e860deff65993d33c51def44e 100644 (file)
--- a/hacks/config/tessellimage.xml
+++ b/hacks/config/tessellimage.xml
@@ -4,6 +4,8 @@
 
   <command arg="-root"/>
 
+  <video href="https://www.youtube.com/watch?v=JNgybysnYU8"/>
+
   <hgroup>
    <vgroup>
     <number id="delay" type="slider" arg="-delay %"
@@ -22,10 +24,16 @@
     <number id="depth" type="slider" arg="-max-depth %"
             _label="Complexity" _low-label="Shallow" _high-label="Deep"
             low="1000" high="100000" default="30000"/>
-
    </vgroup>
 
    <vgroup>
+
+    <select id="mode">
+     <option id="random" _label="Delaunay or voronoi"/>
+     <option _label="Delaunay" arg-set="-mode delaunay"/>
+     <option _label="Voronoi"  arg-set="-mode voronoi"/>
+    </select>
+
     <xscreensaver-image />
 
     <boolean id="fill"    _label="Fill screen" arg-unset="-no-fill-screen"/>
@@ -37,18 +45,21 @@
   </hgroup>
 
   <_description>
-Converts an image to triangles using Delaunay tessellation, and
-animates the result at various depths.
+Converts an image to triangles using Delaunay tessellation, or to
+polygons using Voronoi tesselation, and animates the result at
+various depths.
 
-More triangles are allocated to visually complex parts of the image.
+More polygons are allocated to visually complex parts of the image.
 This is accomplished by first computing the first derivative of the
 image: the distance between each pixel and its neighbors (which is
-essentially edge detection or embossing).  Then the Delaunay control
-points are chosen by selecting those pixels whose distance value is
-above a certain threshold: those are the pixels that have the largest
-change in color/brightness.
+essentially edge detection or embossing).  Then the Delaunay or
+Voronoi control points are chosen by selecting those pixels whose
+distance value is above a certain threshold: those are the pixels that
+have the largest change in color/brightness.
 
-http://en.wikipedia.org/wiki/Delaunay_triangulation
+https://en.wikipedia.org/wiki/Delaunay_triangulation
+https://en.wikipedia.org/wiki/Voronoi_diagram
+https://en.wikipedia.org/wiki/Tessellation
 
 Written by Jamie Zawinski; 2014.
   </_description>