Add ability to convert landmap to/from miz.

This PR adds utility functions that import/export landmap files to .miz
polygons. In addition to the unit test, this PR has been tested by
writing the Caucuses & Syria landmaps to a .miz file, loading the
generated .miz file back in and checking that the loaded landmap object
is identical to the original files.

game/theater/landmap.py

@@ -3,8 +3,13 @@ import pickle
 from dataclasses import dataclass
 from functools import cached_property
 from pathlib import Path
-from typing import Optional, Union
+from typing import Optional, Union, List
 
+from dcs.drawing.drawing import LineStyle, Rgba
+from dcs.drawing.polygon import FreeFormPolygon
+from dcs.mapping import Point
+from dcs.mission import Mission
+from dcs.terrain.terrain import Terrain
 from shapely import geometry
 from shapely.geometry import MultiPolygon, Polygon
 
@@ -39,3 +44,94 @@ def load_landmap(filename: Path) -> Optional[Landmap]:
 
 def poly_contains(x: float, y: float, poly: Union[MultiPolygon, Polygon]) -> bool:
     return poly.contains(geometry.Point(x, y))
+
+
+def to_miz(landmap: Landmap, terrain: Terrain, mission_filename: str) -> None:
+    """
+    Writes landmap to .miz file so that zones can be visualized and edited in the
+    mission editor.
+    """
+
+    def multi_polygon_to_miz(
+        mission: Mission,
+        terrain: Terrain,
+        multi_polygon: MultiPolygon,
+        color: Rgba,
+        prefix: str,
+        layer_index: int = 4,
+        layer_name: str = "Author",
+    ) -> None:
+        reference_position = Point(0, 0, terrain)
+        for i in range(len(multi_polygon.geoms)):
+            polygon = multi_polygon.geoms[i]
+            if len(polygon.interiors) > 0:
+                raise ValueError(
+                    f"Polygon hole found when trying to export {prefix} {i}. to_miz() does not support landmap zones with holes."
+                )
+            coordinates = polygon.exterior.xy
+            points = []
+            for j in range(len(coordinates[0])):
+                points.append(Point(coordinates[0][j], coordinates[1][j], terrain))
+            polygon_drawing = FreeFormPolygon(
+                visible=True,
+                position=reference_position,
+                name=f"{prefix}-{i}",
+                color=color,
+                layer_name=layer_name,
+                fill=color,
+                line_thickness=10,
+                line_style=LineStyle.Solid,
+                points=points,
+            )
+            mission.drawings.layers[layer_index].objects.append(polygon_drawing)
+
+    mission = Mission(terrain=terrain)
+    multi_polygon_to_miz(
+        mission, terrain, landmap.exclusion_zones, Rgba(255, 0, 0, 128), "Exclusion"
+    )
+    multi_polygon_to_miz(
+        mission, terrain, landmap.sea_zones, Rgba(0, 0, 255, 128), "Sea"
+    )
+    multi_polygon_to_miz(
+        mission, terrain, landmap.inclusion_zones, Rgba(0, 255, 0, 128), "Inclusion"
+    )
+    mission.save(mission_filename)
+
+
+def from_miz(mission_filename: str, layer_index: int = 4) -> Landmap:
+    """
+    Generate Landmap object from Free Form Polygons drawn in a .miz file.
+    Landmap.inclusion_zones are expected to be named Inclusion-<suffix>
+    Landmap.exclusion_zones are expected to be named Exclusion-<suffix>
+    Landmap.sea_zones are expected to be named Sea-<suffix>
+    """
+    mission = Mission()
+    mission.load_file(mission_filename)
+    polygons: dict[str, List[Polygon]] = {"Inclusion": [], "Exclusion": [], "Sea": []}
+    for draw_object in mission.drawings.layers[layer_index].objects:
+        if type(draw_object) != FreeFormPolygon:
+            logging.debug(
+                f"Object {draw_object.name} is not a FreeFormPolygon, ignoring"
+            )
+            continue
+        name_split = draw_object.name.split(
+            "-"
+        )  # names are in the format <Inclusion|Exclusion|Sea>-<suffix>
+        zone_type = name_split[0]
+        if len(name_split) != 2 or zone_type not in ("Exclusion", "Sea", "Inclusion"):
+            logging.debug(
+                f"Object name {draw_object.name} does not conform to expected format <Exclusion|Sea|Inclusion>-<suffix>, ignoring"
+            )
+            continue
+        polygon_points = []
+        for point in draw_object.points:
+            polygon_points.append(
+                (point.x + draw_object.position.x, point.y + draw_object.position.y)
+            )
+        polygons[zone_type].append(Polygon(polygon_points))
+    landmap = Landmap(
+        inclusion_zones=MultiPolygon(polygons["Inclusion"]),
+        exclusion_zones=MultiPolygon(polygons["Exclusion"]),
+        sea_zones=MultiPolygon(polygons["Sea"]),
+    )
+    return landmap

tests/theater/test_landmap.py

@@ -0,0 +1,32 @@
+import os
+import pytest
+
+from shapely.geometry import MultiPolygon, Polygon
+
+from dcs.terrain.caucasus.caucasus import Caucasus
+from game.theater import landmap
+
+
+def test_miz() -> None:
+    """
+    Test miz generation and loading
+    """
+    test_map = landmap.Landmap(
+        inclusion_zones=MultiPolygon([Polygon([(0, 0), (0, 1), (1, 0)])]),
+        exclusion_zones=MultiPolygon([Polygon([(1, 1), (0, 1), (1, 0)])]),
+        sea_zones=MultiPolygon([Polygon([(0, 0), (0, 2), (1, 0)])]),
+    )
+    test_filename = "test.miz"
+    landmap.to_miz(test_map, Caucasus(), test_filename)
+    assert os.path.isfile("test.miz")
+    loaded_map = landmap.from_miz("test.miz")
+    assert test_map.inclusion_zones.equals_exact(
+        loaded_map.inclusion_zones, tolerance=1e-6
+    )
+    assert test_map.sea_zones.equals_exact(loaded_map.sea_zones, tolerance=1e-6)
+    assert test_map.exclusion_zones.equals_exact(
+        loaded_map.exclusion_zones, tolerance=1e-6
+    )
+
+    if os.path.isfile(test_filename):
+        os.remove(test_filename)