Fix in visualization that showed circles on wrong locations.

voronoi/algorithm.py

@@ -86,7 +86,6 @@ def create_diagram(self, points: list):
 
             # Pop the event queue with the highest priority
             event = self.event_queue.get()
-            self.event = event
 
             # Set genesis point
             genesis_point = genesis_point or event.point
@@ -123,7 +122,11 @@ def create_diagram(self, points: list):
 
                 # Handle the event
                 self.handle_site_event(event)
+            else:
+                # Skip the step if circle event is no longer valid
+                continue
 
+            self.event = event
             self.notify_observers(Message.STEP_FINISHED)
 
         self.notify_observers(Message.DEBUG, payload="# Sweep finished")

voronoi/observers/voronoi_observer.py

@@ -30,6 +30,7 @@ def update(self, subject: Algorithm, message: Message, **kwargs):
             vis = Visualizer(subject, canvas_offset=self.canvas_offset)
             settings = dict(outgoing_edges=False)
             settings.update(self.settings)
+            assert subject.sweep_line == subject.event.y
             result = vis.plot_all(**settings)
             plt.title(str(subject.event) + "\n")
         elif message == Message.SWEEP_FINISHED and self.visualize_before_clipping:

voronoi/visualization/visualizer.py

@@ -1,3 +1,4 @@
+from copy import copy
 from decimal import Decimal
 
 import numpy as np
@@ -195,7 +196,7 @@ def plot_sweep_line(self, sweep_line=None):
         return self
 
     def plot_events(self, triangles=False):
-        for event in [self.voronoi.event]: # event_queue.queue:
+        for event in [self.voronoi.event]:  # event_queue.queue:
             if isinstance(event, CircleEvent):
                 self._plot_circle(event, show_triangle=triangles)
 
@@ -218,7 +219,6 @@ def _plot_circle(self, evt, show_triangle=False):
 
         return self
 
-
     def _plot_edge(self, edge, sweep_line=None, print_name=True, color=Colors.EDGE, **kwargs):
 
         start, end = self._origins(edge, sweep_line)
@@ -264,6 +264,7 @@ def _origins(self, edge, sweep_line=None):
         # Get start and end of edges
         start = edge.get_origin(sweep_line, max_y)
         end = edge.twin.get_origin(sweep_line, max_y)
+        start, end = copy(start), copy(end)
         start, end = self._cut_line(start, end)
 
         return start, end