maputils.py

import pickle
import math
import polyline
import yaml

geoCache        = pickle.load(open('geoCache.p', 'rb'))
directionsCache = pickle.load(open('directions.p','rb'))
config          = yaml.load(open("config.yml", 'r'))

def getCoords(place):
	return geoCache[place]

def getCoordString(place):
	return str(geoCache[place][0]) + ',' + str(geoCache[place][1])

def getDirections(origin, destination):
	return directionsCache[(origin, destination)]

def roughDist(point1, point2):
	return math.sqrt((point1[0] - point2[0])**2 + (point1[1] - point2[1])**2)

def perpendicularDistance(point, lineStart, lineEnd):
	numerator = math.fabs( (lineEnd[0]-lineStart[0])*point[1] - (lineEnd[1]-lineStart[1])*point[0] + lineEnd[1]*lineStart[0] - lineEnd[0]*lineStart[1] )
	denominator = math.sqrt( (lineEnd[0]-lineStart[0])**2 + (lineEnd[1]-lineStart[1])**2 )
	return numerator / denominator

def DouglasPeucker(pointList, epsilon):
    # Find the point with the maximum distance
    dmax = 0
    index = 0
    end = len(pointList)
    for i in xrange(1, end-1):
        d = perpendicularDistance(pointList[i], pointList[0], pointList[-1]) 
        if d > dmax:
            index = i
            dmax = d
    # If max distance is greater than epsilon, recursively simplify
    if dmax > epsilon:
        # Recursive call
        recResults1 = DouglasPeucker(pointList[:index+1], epsilon)
        recResults2 = DouglasPeucker(pointList[index:], epsilon)

        # Build the result list
        resultList = recResults1[:-1] + recResults2
    else:
        resultList = [pointList[0], pointList[-1]]
    # Return the result
    return resultList

def getPoly(route, epsilon):
	route = [ CAPITALS[i] for i in route ]
	legs = zip(route, route[1:] + route[:1])
	coordinates = []
	for leg in legs:
		legCoords = DouglasPeucker(getDirections(*leg), epsilon)
		if leg == legs[-1]:
			coordinates += legCoords
		else:
			coordinates += legCoords[:-1]
	return polyline.encode(coordinates)

def mapUrl(poly):
	BASE_URL = 'https://maps.googleapis.com/maps/api/staticmap?size=640x640&scale=2'
	API_KEY = config['api_keys']['google_static_maps']
	url = BASE_URL
	iconUrl = 'http://i.imgur.com/n84gQUv.png'
	# iconUrl = 'http://i.imgur.com/cyy5Me4.png'
	url += '&markers=shadow:false|icon:' + iconUrl
	for city in CAPITALS:
		url += '|' + getCoordString(city)
	url += '&path=color:0x0000ffaa|weight:2|enc:' + poly + '&key=' + API_KEY
	return url

def drawLeg(place1, place2, m):
	location1 = getCoords(place1)
	location2 = getCoords(place2)

	m.drawgreatcircle(location1[1], location1[0], location2[1], location2[0], color='#0000ff80')

def drawRoute(route, m):
	list1 = route
	list2 = route[1:] + route[:1]
	legs = zip(list1, list2)
	for leg in legs:
		place1 = CAPITALS[leg[0]]
		place2 = CAPITALS[leg[1]]
		drawLeg(place1, place2, m)

CAPITALS = [
	'Montgomery,AL',
	'Juneau,AK',
	'Phoenix,AZ',
	'Little Rock,AR',
	'Sacramento,CA',
	'Denver,CO',
	'Hartford,CT',
	'Dover,DE',
	'Tallahassee,FL',
	'Atlanta,GA',
	'Boise,ID',
	'Springfield,IL',
	'Indianapolis,IN',
	'Des Moines,IA',
	'Topeka,KS',
	'Frankfort,KY',
	'Baton Rouge,LA',
	'Augusta,ME',
	'Annapolis,MD',
	'Boston,MA',
	'Lansing,MI',
	'St. Paul,MN',
	'Jackson,MS',
	'Jefferson City,MO',
	'Helena,MT',
	'Lincoln,NE',
	'Carson City,NV',
	'Concord,NH',
	'Trenton,NJ',
	'Santa Fe,NM',
	'Albany,NY',
	'Raleigh,NC',
	'Bismarck,ND',
	'Columbus,OH',
	'Oklahoma City,OK',
	'Salem,OR',
	'Harrisburg,PA',
	'Providence,RI',
	'Columbia,SC',
	'Pierre,SD',
	'Nashville,TN',
	'Austin,TX',
	'Salt Lake City,UT',
	'Montpelier,VT',
	'Richmond,VA',
	'Olympia,WA',
	'Charleston,WV',
	'Madison,WI',
	'Cheyenne,WY',
]