Use width and depth to do projections

map_to_kml.py

@@ -34,33 +34,31 @@ def lat_lon_distance(lat1, lon1, lat2, lon2):
   c = 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
   return 6371e3 * c
 
-def longitude_to_X(lon, map_size):
+def longitude_to_X(lon, width):
   """Mercator projection of longitude."""
-  return (map_size / 360) * (180 + lon)
+  return (width / 360) * (180 + lon)
 
-def latitude_to_Y(lat, map_size):
+def latitude_to_Y(lat, depth):
   """Mercator projection latitude."""
-  return (map_size / 180) * (90 - lat)
+  return (depth / 180) * (90 - lat)
 
-def convert_to_local_coordinates(latitude, longitude, map_info, map_size):
+def convert_to_local_coordinates(latitude, longitude, map_info):
   """Convert coordinates into local values."""
-  x = longitude_to_X(longitude, map_size)
-  y = latitude_to_Y(latitude, map_size)
-  local_x = ((x - map_info['min_x']) / (map_info['max_x'] - map_info['min_x'])) \
-            * 1000 - map_size / 2
-  local_y = ((y - map_info['min_y']) / (map_info['max_y'] - map_info['min_y'])) \
-            * 1000 - map_size / 2
+  x = longitude_to_X(longitude, map_info['width'])
+  y = latitude_to_Y(latitude, map_info['depth'])
+  local_x = (((x - map_info['min_x']) / (map_info['max_x'] - map_info['min_x'])) - 0.5) * map_info['width']
+  local_y = (((y - map_info['min_y']) / (map_info['max_y'] - map_info['min_y'])) - 0.5) * map_info['depth']
   return local_x, local_y
 
-def convert_to_geo_coordinates(x, y, map_info, map_size):
+def convert_to_geo_coordinates(x, y, map_info):
   """Convert local values to coordinates."""
-  lon = (x + map_size / 2) / 1000
+  lon = (x / map_info['width']) + 0.5
   lon = lon * (map_info['max_x'] - map_info['min_x']) + map_info['min_x']
-  lon = lon / (map_size / 360) - 180
+  lon = lon / (map_info['width'] / 360) - 180
 
-  lat = (y + map_size / 2) / 1000
+  lat = (y / map_info['depth']) + 0.5
   lat = lat * (map_info['max_y'] - map_info['min_y']) + map_info['min_y']
-  lat = 90 - lat / (map_size / 180)
+  lat = 90 - lat / (map_info['depth'] / 180)
 
   return lon, lat
 
@@ -111,9 +109,9 @@ def rotate(x, y, x_o, y_o, rotation):
   )
 
 def build_rectangle(root, lat, lon, length, width, height, rotation,
-                    style_map_id, map_info, map_size):
+                    style_map_id, map_info):
   """Build a rectangle."""
-  local_x, local_y = convert_to_local_coordinates(lat, lon, map_info, map_size)
+  local_x, local_y = convert_to_local_coordinates(lat, lon, map_info)
   min_x = local_x - length / 2
   max_x = local_x + length / 2
   min_y = local_y - width / 2
@@ -122,7 +120,7 @@ def build_rectangle(root, lat, lon, length, width, height, rotation,
   polygone_coordinates = []
   for x, y in ((min_x, min_y), (max_x, min_y), (max_x, max_y), (min_x, max_y), (min_x, min_y)):
     rotated_x, rotated_y = rotate(x, y, local_x, local_y, rotation)
-    corner_lon, corner_lat = convert_to_geo_coordinates(rotated_x, rotated_y, map_info, map_size)
+    corner_lon, corner_lat = convert_to_geo_coordinates(rotated_x, rotated_y, map_info)
     polygone_coordinates.append((corner_lat, corner_lon, height))
 
   add_polygone(root, polygone_coordinates, style_map_id)
@@ -146,17 +144,17 @@ def write_kml(filename, map_dict):
     (map_dict['min_lat'], map_dict['min_lon'], 0),
   ), 'terrain')
 
-  map_size = math.ceil(max(
-    lat_lon_distance(
-      map_dict['min_lat'], map_dict['min_lon'], map_dict['min_lat'], map_dict['max_lon']),
-    lat_lon_distance(
-      map_dict['min_lat'], map_dict['min_lon'], map_dict['max_lat'], map_dict['min_lon']),
-  ))
+  depth = lat_lon_distance(map_dict['min_lat'], map_dict['min_lon'],
+                           map_dict['max_lat'], map_dict['min_lon'])
+  width = lat_lon_distance(map_dict['min_lat'], map_dict['min_lon'],
+                           map_dict['min_lat'], map_dict['max_lon'])
   map_info = {
-    'min_x': longitude_to_X(map_dict['min_lon'], map_size),
-    'min_y': latitude_to_Y(map_dict['min_lat'], map_size),
-    'max_x': longitude_to_X(map_dict['max_lon'], map_size),
-    'max_y': latitude_to_Y(map_dict['max_lat'], map_size),
+    'depth': depth,
+    'min_x': longitude_to_X(map_dict['min_lon'], width),
+    'min_y': latitude_to_Y(map_dict['min_lat'], depth),
+    'max_x': longitude_to_X(map_dict['max_lon'], width),
+    'max_y': latitude_to_Y(map_dict['max_lat'], depth),
+    'width': width,
   }
 
   for obstacle in map_dict['obstacle_list']:
@@ -172,13 +170,12 @@ def write_kml(filename, map_dict):
       - obstacle['rotation']['z'] * math.pi / 180,
       'obstacle',
       map_info,
-      map_size,
     )
 
   for flag in map_dict['flag_list']:
     position = flag['position']
     build_rectangle(document, position['latitude'], position['longitude'],
-                    1, 1, position['altitude'], 0, 'flag', map_info, map_size)
+                    1, 1, position['altitude'], 0, 'flag', map_info)
 
   tree = ET.ElementTree(root)
   ET.indent(tree, '   ')