Add feature registry dispatch

blender/generate_scene.py

@@ -34,6 +34,7 @@ if _HERE not in sys.path:
     sys.path.insert(0, _HERE)
 
 from osmassets import catalog  # noqa: E402
+from osmassets import features as _features  # noqa: E402
 from osmassets.geom import (  # noqa: E402  (needs the sys.path line above)
     distance_to_ring,
     point_in_polygon,
@@ -669,46 +670,71 @@ def build(args):
         return obj
 
     focus_points = []
-    for way in ways:
-        coords = way["coords"]
-        if not any(projector.inside(c) for c in coords):
-            continue
-        ring = projector.ring(coords)
-        tag = way["tags"]
-        if tag.get("natural") == "water" or tag.get("water") == "lake":
-            counts["lake_count"] += _water.assemble(ring, scene_xmin, scene_xmax,
-                                          scene_ymin, scene_ymax,
-                                          water_c, water_mat)
-        elif tag.get("landuse") == "grass":
-            added, tufts, ring_pts = _grass.assemble(
-                ring, way["id"], scene_xmin, scene_xmax, scene_ymin, scene_ymax,
-                green_c, grass_mat, tuft_variants, add_grass_tufts)
-            counts["grass_count"] += added
-            counts["grass_tuft_count"] += tufts
-            if ring_pts:
-                grass_rings.append(ring_pts)
-                focus_points.extend(ring_pts)
-        elif tag.get("natural") == "scrub" and len(ring) >= 3:
-            added, ring_pts = _scrub.assemble(ring, way["id"], scene_xmin, scene_xmax,
-                                              scene_ymin, scene_ymax, green_c, scrub_mat,
-                                              add_scrub_patch_with_bushes)
-            counts["scrub_count"] += added
-            if ring_pts:
-                focus_points.extend(ring_pts)
-                new_scrub_trees = sample_scrub_interior_trees(ring_pts, way["id"])
-                scrub_trees.extend(new_scrub_trees)
-                counts["scrub_tree_count"] += len(new_scrub_trees)
-        elif tag.get("natural") == "tree_row":
-            tree_rows.append((ring, tag))
-            focus_points.extend(ring)
-        elif "building" in tag and len(ring) >= 3:
-            added, ind_added, ring_pts = _building.assemble(
-                ring, str(way["id"]), tag, args["office_overrides"],
-                buildings_c, building_mats)
-            counts["building_count"] += added
-            counts["industrial_count"] += ind_added
-            if ring_pts:
-                focus_points.extend(ring_pts)
+
+    def handle_water(way, tag, ring):
+        counts["lake_count"] += _water.assemble(ring, scene_xmin, scene_xmax,
+                                      scene_ymin, scene_ymax,
+                                      water_c, water_mat)
+
+    def handle_grass(way, tag, ring):
+        added, tufts, ring_pts = _grass.assemble(
+            ring, way["id"], scene_xmin, scene_xmax, scene_ymin, scene_ymax,
+            green_c, grass_mat, tuft_variants, add_grass_tufts)
+        counts["grass_count"] += added
+        counts["grass_tuft_count"] += tufts
+        if ring_pts:
+            grass_rings.append(ring_pts)
+            focus_points.extend(ring_pts)
+
+    def handle_scrub(way, tag, ring):
+        added, ring_pts = _scrub.assemble(ring, way["id"], scene_xmin, scene_xmax,
+                                          scene_ymin, scene_ymax, green_c, scrub_mat,
+                                          add_scrub_patch_with_bushes)
+        counts["scrub_count"] += added
+        if ring_pts:
+            focus_points.extend(ring_pts)
+            new_scrub_trees = sample_scrub_interior_trees(ring_pts, way["id"])
+            scrub_trees.extend(new_scrub_trees)
+            counts["scrub_tree_count"] += len(new_scrub_trees)
+
+    def handle_tree_row(way, tag, ring):
+        tree_rows.append((ring, tag))
+        focus_points.extend(ring)
+
+    def handle_building(way, tag, ring):
+        added, ind_added, ring_pts = _building.assemble(
+            ring, str(way["id"]), tag, args["office_overrides"],
+            buildings_c, building_mats)
+        counts["building_count"] += added
+        counts["industrial_count"] += ind_added
+        if ring_pts:
+            focus_points.extend(ring_pts)
+
+    way_handlers = (
+        _features.FeatureHandler(
+            "water",
+            lambda way, tag, ring: tag.get("natural") == "water"
+            or tag.get("water") == "lake",
+            handle_water),
+        _features.FeatureHandler(
+            "grass",
+            lambda way, tag, ring: tag.get("landuse") == "grass",
+            handle_grass),
+        _features.FeatureHandler(
+            "scrub",
+            lambda way, tag, ring: tag.get("natural") == "scrub"
+            and len(ring) >= 3,
+            handle_scrub),
+        _features.FeatureHandler(
+            "tree_row",
+            lambda way, tag, ring: tag.get("natural") == "tree_row",
+            handle_tree_row),
+        _features.FeatureHandler(
+            "building",
+            lambda way, tag, ring: "building" in tag and len(ring) >= 3,
+            handle_building),
+    )
+    _features.dispatch_ways(ways, projector, way_handlers)
 
     geojson_dir = args.get("geojson")
     road_counts = {}

blender/osmassets/features.py

@@ -0,0 +1,20 @@
+"""Feature registry and dispatch helpers for scene assembly phases."""
+
+from collections import namedtuple
+
+
+FeatureHandler = namedtuple("FeatureHandler", ("name", "matches", "handle"))
+
+
+def dispatch_ways(ways, projector, handlers):
+    """Dispatch OSM ways to the first matching handler, preserving order."""
+    for way in ways:
+        coords = way["coords"]
+        if not any(projector.inside(c) for c in coords):
+            continue
+        ring = projector.ring(coords)
+        tag = way["tags"]
+        for handler in handlers:
+            if handler.matches(way, tag, ring):
+                handler.handle(way, tag, ring)
+                break