added TestModel as the default fallback in case of a model loading failure

prevent Exception in case of a empty arc


git-svn-id: https://pycam.svn.sourceforge.net/svnroot/pycam/trunk@1021 bbaffbd6-741e-11dd-a85d-61de82d9cad9

src/pycam/Geometry/__init__.py

@@ -105,6 +105,8 @@ def get_points_of_arc(center, radius, a1, a2, plane=None, cords=32):
     angle_diff = a2 - a1
     if angle_diff < 0:
         angle_diff += 2 * math.pi
+    if angle_diff == 0:
+        return []
     num_of_segments = ceil(angle_diff / (2 * math.pi) * cords)
     angle_segment = angle_diff / num_of_segments
     points = []

src/pycam/Gui/Project.py

@@ -29,6 +29,7 @@ import pycam.Cutters
 import pycam.Toolpath.Generator
 import pycam.Toolpath
 import pycam.Importers.CXFImporter
+import pycam.Importers.TestModel
 import pycam.Importers
 from pycam.Geometry.Point import Point, Vector
 from pycam.Geometry.Plane import Plane
@@ -439,7 +440,8 @@ class ProjectGui:
         self._font_dialog_window_visible = False
         self._font_dialog_window_position = None
         # set defaults
-        self.model = None
+        # fallback - in case of a failure when opening a model file
+        self.model = pycam.Importers.TestModel.get_test_model()
         self.toolpath = pycam.Toolpath.ToolpathList()
         self.cutter = None
         self.tool_list = []