import math
import os
import re
from glob import glob
from pathlib import Path
from PIL import Image
from . import DUMP, MAP_FILE, MAPS
# Obtains area maps in the US to overlay radar images on.
class AreaMap:
# Max latitude of US map in a linear form.
LAT_MAX = 1.0799224683069641
# Reference latitude in linear form.
REF_LAT = 0.7380009964270406
def __init__(self):
# Coordinates of area.
self.lat1 = None
self.lon1 = None
self.lat2 = None
self.lon2 = None
# Area ID.
self.area_id = None
# The area map.
self.map = None
# Get map configuration information.
def get_config(self):
"""
:return: True if successful, False if not
"""
# Look for any radar map config files.
files = glob(os.path.join(DUMP, '*DWRI*'))
if not files:
return False
# Extract info from first file.
file = open(files[0], 'r')
for line in file:
if 'DWR_Area_ID' in line:
self.area_id = re.findall(r'\"(.+?)\"', line)[0]
elif 'Coordinates' in line:
coords = re.findall(r"[-+]?\d*\.\d+|\d+", line)
self.lat1, self.lon1, self.lat2, self.lon2 = (float(x) for x in coords)
return True
# Checks if a config file has been received.
def has_config(self):
return self.area_id is not None
# Render an area map from the US map.
def render(self):
# Open US map.
us_map = Image.open(MAP_FILE)
# Convert latitudes to a linear form.
self.lat1 = AreaMap.LAT_MAX - math.asinh(math.tan(math.radians(self.lat1)))
self.lat2 = AreaMap.LAT_MAX - math.asinh(math.tan(math.radians(self.lat2)))
# Calculate x-coords using a ratio of a known location on the map.
x1 = (self.lon1 + 130.781250) * 7162 / 39.34135
x2 = (self.lon2 + 130.781250) * 7162 / 39.34135
# Use another ratio of a known location to find the latitudes.
den = AreaMap.LAT_MAX - AreaMap.REF_LAT
y1 = self.lat1 * 3565 / den
y2 = self.lat2 * 3565 / den
# Crop the map.
cropped = us_map.crop((
int(x1),
int(y1),
int(x2),
int(y2)
))
# Resize to 900x900, convert to right format, and save.
self.map = cropped.resize((900, 900))
self.map = self.map.convert('RGBA')
name = '{0}.png'.format(self.area_id)
self.map.save(os.path.join(MAPS, name))
# Get an area map for the predefined area.
def get_map(self):
# If already in memory, just return it.
if self.map is not None:
return self.map
# Check if an area map has already been rendered.
name = '{0}.png'.format(self.area_id)
file = Path(os.path.join(MAPS, name))
if file.is_file():
# Open and return image.
self.map = Image.open(file.absolute()).convert('RGBA')
return self.map
else:
# Else, render it and return.
self.render()
return self.map
