Added a sampler for iterated function systems.

1 files changed, 24 insertions, 2 deletions

diff --git a/ka_utils.py b/ka_utils.py
index 22f0a4a..df51e8d 100644
--- a/ka_utils.py
+++ b/ka_utils.py
@@ -14,6 +14,9 @@
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+import cairo
+
+ICON_WIDTH = ICON_HEIGHT = 48
 
 def explain_points(head, points):
     """
@@ -24,5 +27,24 @@ def explain_points(head, points):
     for point in points:
         description += '%4.3f, %4.3f; ' % (point[0], point[1])
     description += ']'
-    return head + ' ' + description if head is not None and len(head) \
-                                   else description
+    text = head + ' ' + description if head is not None and len(head) \
+                                    else description
+
+    surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, ICON_WIDTH, ICON_HEIGHT)
+    ctx = cairo.Context(surface)
+    ctx.scale(ICON_WIDTH, ICON_HEIGHT)
+    # paint background
+    ctx.set_operator(cairo.OPERATOR_OVER)
+    ctx.set_source_rgb(1.0, 1.0, 1.0)
+    ctx.paint()
+    radius = 0.1
+    ctx.set_line_width(0.02)
+    for point in points:
+        # paint a cross for each position
+        ctx.set_source_rgb(0.0, 0.0, 0.0)
+        ctx.move_to(0.5+point[0]-radius, 0.5+point[1]-radius)
+        ctx.line_to(0.5+point[0]+radius, 0.5+point[1]+radius)
+        ctx.move_to(0.5+point[0]+radius, 0.5+point[1]-radius)
+        ctx.line_to(0.5+point[0]-radius, 0.5+point[1]+radius)
+        ctx.stroke()
+    return text, surface, head