Changes to radius offset path generation to accept open polygons.

1) There was a piece of code that erroneously closed polygons.
2) Inside polygon culling was falsly catching open polygons. At best this code needs to be rewritten to correctly detect inside polygons.

Whitham D. Reeve II

pycam/Geometry/Polygon.py

@@ -895,7 +895,7 @@ class Polygon(TransformableContainer):
                                 if not index1 + 1 in group_starts:
                                     group_starts.append(index1 + 1)
                                 # don't update index2 -> maybe there are other hits
-                            elif intersection and (intersection == line1.p1):
+                            elif intersection and (pnorm(psub(intersection, line1.p1)) < epsilon):
                                 if not index1 in group_starts:
                                     group_starts.append(index1)
                                 index2 += 1
@@ -964,9 +964,9 @@ class Polygon(TransformableContainer):
         for index in range(len(self._points)):
             points.append(get_shifted_vertex(index, offset))
         new_lines = []
-        for index in range(len(points)):
+        for index in range(len(points) - 1):
             p1 = points[index]
-            p2 = points[(index + 1) % len(points)]
+            p2 = points[(index + 1)]
             new_lines.append(Line(p1, p2))
         if callback and callback():
             return None
@@ -983,26 +983,13 @@ class Polygon(TransformableContainer):
             self_is_outer = self.is_outer()
             groups = []
             for lines in cleaned_line_groups:
+                log.info("run 3 len: " + str(len(lines)) + " " + str(lines))
                 if callback and callback():
                     return None
                 group = Polygon(self.plane)
                 for line in lines:
                     group.append(line)
-                if group.is_outer() != self_is_outer:
-                    # We ignore groups that changed the direction. These
-                    # parts of the original group are flipped due to the
-                    # offset.
-                    log.debug("Ignoring reversed polygon: %s / %s" % \
-                            (self.get_area(), group.get_area()))
-                    continue
-                # Remove polygons that should be inside the original,
-                # but due to float inaccuracies they are not.
-                if ((self.is_outer() and (offset < 0)) \
-                        or (not self.is_outer() and (offset > 0))) \
-                        and (not self.is_polygon_inside(group)):
-                    log.debug("Ignoring inaccurate polygon: %s / %s" \
-                            % (self.get_area(), group.get_area()))
-                    continue
+
                 groups.append(group)
             if not groups:
                 log.debug("Skipping offset polygon: toggled polygon removed")