only look through holes to levels below

src/c3nav/mapdata/render/base.py

@@ -13,6 +13,13 @@ class LevelGeometries:
         self.altitudeareas = []
         self.walls = None
         self.doors = None
+        self.holes = None
+
+    @staticmethod
+    def crop(self, geometry, crop_to):
+        if crop_to is None:
+            return geometry
+        return geometry.intersection(crop_to)
 
     @staticmethod
     def rebuild():
@@ -32,6 +39,9 @@ class LevelGeometries:
             spaces_geom = unary_union([s.geometry for s in level.spaces.all()])
             geoms.doors = unary_union([d.geometry for d in level.doors.all()])
             walkable_geom = unary_union([s.walkable_geom for s in level.spaces.all()]).union(geoms.doors)
+            if level.on_top_of_id is None:
+                geoms.holes = spaces_geom.difference(walkable_geom)
+                print(level.pk, geoms.holes.area)
 
             for altitudearea in level.altitudeareas.all():
                 geoms.altitudeareas.append((altitudearea.geometry.intersection(walkable_geom), altitudearea.altitude))

src/c3nav/mapdata/render/svg.py

@@ -10,13 +10,34 @@ def render_svg(level, miny, minx, maxy, maxx, scale=1):
     within_coords = (minx-2, miny-2, maxx+2, maxy+2)
     bbox = box(*within_coords)
 
-    for geoms, default_height in get_render_level_data(level):
-        for altitudearea_geom, altitude in geoms.altitudeareas:
-            svg.add_geometry(bbox.intersection(altitudearea_geom), fill_color='#eeeeee', altitude=altitude)
+    render_level_data = get_render_level_data(level)
 
-        svg.add_geometry(bbox.intersection(geoms.walls),
+    crop_to = None
+    primary_level_count = 0
+    for geoms, default_height in reversed(render_level_data):
+        if geoms.holes is not None:
+            print(geoms.holes.area)
+            primary_level_count += 1
+
+        geoms.crop_to = crop_to if primary_level_count > 1 else None
+
+        if geoms.holes is not None:
+            if crop_to is None:
+                crop_to = geoms.holes
+            else:
+                crop_to = crop_to.intersection(geoms.holes)
+
+    for geoms, default_height in render_level_data:
+        crop_to = bbox
+        if geoms.crop_to is not None:
+            crop_to = crop_to.intersection(geoms.crop_to)
+
+        for altitudearea_geom, altitude in geoms.altitudeareas:
+            svg.add_geometry(crop_to.intersection(altitudearea_geom), fill_color='#eeeeee', altitude=altitude)
+
+        svg.add_geometry(crop_to.intersection(geoms.walls),
                          fill_color='#aaaaaa', stroke_px=0.5, stroke_color='#aaaaaa', elevation=default_height)
 
-        svg.add_geometry(bbox.intersection(geoms.doors), fill_color='#ffffff', elevation=0)
+        svg.add_geometry(crop_to.intersection(geoms.doors), fill_color='#ffffff', elevation=0)
 
     return svg