fix: handle coordinate swapping and fix 'Shell empty' geometry error

app.py

@@ -194,10 +194,14 @@ def generate_poster(
     cmp.THEME = cmp.load_theme(theme_name)
 
     if location_mode == "自定义坐标" or location_mode == "Custom Coordinates":
-        if custom_lat is None or custom_lon is None:
-            return None, "❌ 请输入有效的经纬度"
-
-        coords = (float(custom_lat), float(custom_lon))
+        lat_val = float(custom_lat)
+        lon_val = float(custom_lon)
+        
+        # Basic validation: Latitude must be between -90 and 90
+        if lat_val < -90 or lat_val > 90:
+            return None, f"❌ 纬度超出范围 (-90 到 90)。你是否填反了经纬度？(当前填入: {lat_val})"
+
+        coords = (lat_val, lon_val)
         display_city = custom_city_name if custom_city_name else ""
         display_country = custom_country_name if custom_country_name else ""
 

create_map_poster.py

@@ -343,8 +343,8 @@ def create_poster(
     delta_lat = dist_ns / 111320.0
     delta_lon = dist_ew / (111320.0 * math.cos(math.radians(lat)))
 
-    north, south = lat + delta_lat, lat - delta_lat
-    west, east = lon - delta_lon, lon + delta_lon
+    north, south = max(lat + delta_lat, lat - delta_lat), min(lat + delta_lat, lat - delta_lat)
+    west, east = min(lon - delta_lon, lon + delta_lon), max(lon - delta_lon, lon + delta_lon)
 
     bbox = (west, south, east, north)
 
@@ -396,9 +396,13 @@ def create_poster(
                     water.geometry.type.isin(["Polygon", "MultiPolygon"])
                 ]
                 if not water_polys.empty:
+                    # Fix invalid geometries if any, then simplify
+                    water_polys.geometry = water_polys.geometry.apply(lambda g: g.buffer(0) if not g.is_valid else g)
                     water_polys.geometry = water_polys.geometry.simplify(
                         tolerance=0.00001, preserve_topology=True
                     )
+                    # Filter out any that became empty after simplification
+                    water_polys = water_polys[~water_polys.geometry.is_empty]
 
                 # Water Lines (Rivers, Streams represented as lines)
                 water_lines = water[
@@ -427,10 +431,16 @@ def create_poster(
             parks = features[park_mask]
             if not parks.empty:
                 parks = parks[parks.geometry.type.isin(["Polygon", "MultiPolygon"])]
-                # Simplify geometries
-                parks.geometry = parks.geometry.simplify(
-                    tolerance=0.00001, preserve_topology=True
-                )
+                # Fix invalid geometries, then simplify
+                if not parks.empty:
+                    parks.geometry = parks.geometry.apply(lambda g: g.buffer(0) if not g.is_valid else g)
+                    parks.geometry = parks.geometry.simplify(
+                        tolerance=0.00001, preserve_topology=True
+                    )
+                    # Filter empty
+                    parks = parks[~parks.geometry.is_empty]
+                else:
+                    parks = None
             else:
                 parks = None  # No park features found
         else: