- fix the Transform plugin, buffer functionality for Geometry objects such that the buffer with negative values will work by crating a buffer toward the interior of that geometry

CHANGELOG.md

@@ -13,6 +13,7 @@ CHANGELOG for FlatCAM beta
 - fixed the Cutout plugin for the rectangular cutout: the name of the resulting object is now correct if there is no extension in the source file
 - modified the bounding box utility feature in the Gerber Object UI to work with buffer value of 0.0 and rounded corners
 - in Cutout plugin added the ability to create Manual Geometries with negative tool diameters
+- fix the Transform plugin, buffer functionality for Geometry objects such that the buffer with negative values will work by crating a buffer toward the interior of that geometry
 
 25.01.2022
 

camlib.py

@@ -2630,7 +2630,13 @@ class Geometry(object):
             except TypeError:
                 try:
                     if factor is None or factor is False or factor == 0:
-                        new_obj = obj.buffer(distance, resolution=self.geo_steps_per_circle, join_style=join)
+                        if distance >= 0:
+                            new_obj = obj.buffer(distance, resolution=self.geo_steps_per_circle, join_style=join)
+                        else:
+                            new_obj = obj.buffer(abs(distance*2), resolution=self.geo_steps_per_circle, join_style=join)
+                            new_obj = unary_union(new_obj.interiors)
+                            new_obj = new_obj.buffer(-distance, resolution=self.geo_steps_per_circle, join_style=join)
+                            new_obj = new_obj.exterior
                         if isinstance(obj, (LinearRing, LineString)) and only_exterior is True:
                             new_obj = new_obj.exterior
                     else: