Coastline cities - Sea not getting proper water color

[rjambor11]

Hi!

I really like the project and been testing it a bit and I'm finding that it's not properly coloring the sea when I use coordinate near a coastline. The coastline itself is missing.

I'm not sure if it's a bug, or this simply isn't intended to use on a coastline.

The exemple:
uv run ./create_map_poster.py -c "Katadisis" -C "Greece" -lat 40.109706 -long 23.990685 -W 7.2 -H 12.8 -d 6000 -t terracotta

[rjambor11]

With some tinkering I was able to fix this:

Here's what I did:

coastal rendering fix

@@ -XX,12 +XX,23 @@ def create_poster(...):

     # 2. Fetch Water Features
     pbar.set_description("Downloading water features")
-    water = fetch_features(
-        point,
-        compensated_dist,
-        tags={"natural": ["water", "bay", "strait"], "waterway": "riverbank"},
-        name="water",
-    )
+
+    # fetch water from larger area to avoid clipping
+    water_fetch_dist = compensated_dist * 3
+
+    water = fetch_features(
+        point,
+        water_fetch_dist,
+        tags={
+            "natural": ["water", "bay", "strait"],
+            "waterway": "riverbank",
+            "place": ["sea", "ocean"],
+        },
+        name="water",
+    )
     pbar.update(1)

+    # fetch coastline separately (OSM often stores sea as coastline only)
+    coastline = fetch_features(
+        point,
+        water_fetch_dist,
+        tags={"natural": "coastline"},
+        name="coastline",
+    )
@@ -XX,6 +XX,22 @@ def create_poster(...):

     # 5. Plot everything
     pbar.set_description("Rendering")

+    # fallback: reconstruct sea if no water polygons available
+    if water.empty and not coastline.empty:
+        from shapely.geometry import box
+        import geopandas as gpd
+
+        bbox = box(*ax.get_xlim(), *ax.get_ylim())
+        bbox_gdf = gpd.GeoDataFrame(geometry=[bbox], crs=coastline.crs)
+
+        try:
+            sea = gpd.overlay(bbox_gdf, coastline, how="difference")
+            water = sea
+        except Exception:
+            pass
+
     plot_gdf(ax, water, water_color, zorder=1)

@@ -XX,6 +XX,11 @@ def create_poster(...):
     plot_gdf(ax, parks, park_color, zorder=2)
     plot_gdf(ax, buildings, building_color, zorder=3)
     plot_gdf(ax, roads, road_color, linewidth=0.5, zorder=4)
+
+    # coastline rendering (theme fallback to black)
+    coast_color = theme.get("coastline_primary", "#000000")
+    plot_gdf(ax, coastline, coast_color, linewidth=1, zorder=5)
+
     pbar.update(1)
     pbar.close()

fetch_features fix

@@ def fetch_features(...):
-    except Exception as e:
-        print(f"Error fetching {name}: {e}")
-        return None
+    except Exception as e:
+        print(f"Error fetching {name}: {e}")
+        return gpd.GeoDataFrame()