Add new modes for the improved calculations, to avoid breaking existing projects.

Author: karliss

Resources/panels/FlangeParameters.ui

@@ -1408,6 +1408,26 @@ min-width: 28px;</string>
                    </iconset>
                   </property>
                  </item>
+                 <item>
+                  <property name="text">
+                   <string>Material Inside (90° legacy)</string>
+                  </property>
+                  <property name="icon">
+                   <iconset>
+                    <normalon>Icons:SheetMetal_WallPosMatIns.svg</normalon>
+                   </iconset>
+                  </property>
+                 </item>
+                 <item>
+                  <property name="text">
+                   <string>Thickness Outside (legacy)</string>
+                  </property>
+                  <property name="icon">
+                   <iconset>
+                    <normalon>Icons:SheetMetal_WallPosThkOut.svg</normalon>
+                   </iconset>
+                  </property>
+                 </item>
                 </widget>
                </item>
               </layout>

SheetMetalCmd.py

@@ -1263,10 +1263,16 @@ def smBend(
     if BendType == "Material Outside":
         offset = 0.0
         inside = False
-    elif BendType == "Material Inside":
+    elif BendType == "Material Inside": # legacy mode for backwards compatibility
+        offset = -(thk + bendR)
+        inside = True
+    elif BendType == "Thickness Outside": # legacy mode for backwards compatibility
+        offset = -bendR
+        inside = True
+    elif BendType == "Material Inside V2":
         offset = -(thk + bendR) * abs(math.tan(math.radians(bendA * 0.5)))
         inside = True
-    elif BendType == "Thickness Outside":
+    elif BendType == "Thickness Outside V2":
         offset = -bendR * abs(math.tan(math.radians(bendA * 0.5)))
         inside = True
     elif BendType == "Offset":
@@ -1781,7 +1787,9 @@ def addVerifyProperties(self, obj, refAngOffset=None, checkRefFace=False):
             obj,
             "BendType",
             translate("App::Property", "Bend Type"),
-            ["Material Outside", "Material Inside", "Thickness Outside", "Offset"],
+            ["Material Outside", "Material Inside V2", "Thickness Outside V2", "Offset",
+             # legacy modes
+             "Material Inside", "Thickness Outside"],
         )
         SheetMetalTools.smAddEnumProperty(
             obj,