Constrain front lines better.

Holes in the inclusion zone are defined by exclusion zones, not by holes
in the inclusion zone. Add a cached property for the inclusion zone that
is not also sea or exclusion zone and use that boundary instead.

resources/tools/generate_landmap.py

@@ -1,11 +1,37 @@
 import pickle
+from functools import singledispatch
 
 from dcs.mission import Mission
-from shapely import geometry
-from shapely.geometry import MultiPolygon
+from shapely.geometry import GeometryCollection, MultiPolygon, Polygon
+from shapely.ops import unary_union
 
 from game.theater.landmap import Landmap
 
+
+@singledispatch
+def to_multipoly(obj) -> MultiPolygon:
+    raise NotImplementedError(
+        f"to_multipoly not implemented for {obj.__class__.__name__}")
+
+
+@to_multipoly.register
+def _poly_to_multipoly(obj: Polygon) -> MultiPolygon:
+    return MultiPolygon([obj])
+
+
+@to_multipoly.register
+def _multipoly_to_multipoly(obj: MultiPolygon) -> MultiPolygon:
+    return obj
+
+
+@to_multipoly.register
+def _geometry_collection_to_multipoly(obj: GeometryCollection) -> MultiPolygon:
+    if obj.is_empty:
+        return MultiPolygon()
+    raise RuntimeError(
+        f"Not sure how to convert collection to multipoly: {obj.wkt}")
+
+
 for terrain in ["cau", "nev", "syria", "channel", "normandy", "gulf"]:
     print("Terrain " + terrain)
     m = Mission()
@@ -19,19 +45,22 @@ for terrain in ["cau", "nev", "syria", "channel", "normandy", "gulf"]:
 
         if terrain == "cau" and inclusion_zones:
             # legacy
-            exclusion_zones.append(geometry.Polygon(zone))
+            exclusion_zones.append(Polygon(zone))
         else:
+            poly = Polygon(zone)
+            if not poly.is_valid:
+                raise RuntimeError(f"{plane_group} is invalid")
             if plane_group.units[0].type == "F-15C":
-                exclusion_zones.append(geometry.Polygon(zone))
+                exclusion_zones.append(poly)
             else:
-                inclusion_zones.append(geometry.Polygon(zone))
+                inclusion_zones.append(poly)
 
     for ship_group in m.country("USA").ship_group:
         zone = [(x.position.x, x.position.y) for x in ship_group.points]
-        seas_zones.append(geometry.Polygon(zone))
+        seas_zones.append(Polygon(zone))
 
     with open("../{}landmap.p".format(terrain), "wb") as f:
         print(len(inclusion_zones), len(exclusion_zones), len(seas_zones))
-        pickle.dump(Landmap(MultiPolygon(inclusion_zones),
-                            MultiPolygon(exclusion_zones),
-                            MultiPolygon(seas_zones)), f)
+        pickle.dump(Landmap(to_multipoly(unary_union(inclusion_zones)),
+                            to_multipoly(unary_union(exclusion_zones)),
+                            to_multipoly(unary_union(seas_zones))), f)