Building the Realtime User Experience

The Basic Models

This game contains a fair bit more application logic than the previous examples and requires a decent number of model classes to define how everything behaves. To get these set up, we need to create a file to contain these models and set up the basics. In your appengine directory, create a file called models.py and fill it with the following code:

from geo.geomodel import GeoModel
import geo.geotypes as geotypes

from google.appengine.api import xmpp, users, urlfetch, memcache
from google.appengine.ext import db
from django.utils import simplejson as json
import logging, os, string, random, urllib
from datetime import datetime, timedelta
import math

class Game(object): 
    # setup some gameplay variables
    default_score = 5
    default_germ_spread = 0.03
    default_germ_speed = 0.0055
    default_germ_slowdown = 0.00015
    default_germ_strength = 0.03
    default_disease_strength = 0.5
    default_disease_strength_increment = 0.001
    
    # the color of the germs as they get displayed on the map
    default_color_friendly = "#577ff5"
    default_color_enemy = "#007b00"
    default_color_threat = "#ff0000"

This codes does all the imports that we’re going to need for this file in the future. Then, we define a number of variables that we’ll use to govern the gameplay of iPandemic. There is no real science behind these numbers, so feel free to modify them as much as you wish.

default_score

Every user has a score, which is the number of points she has accumulated. When user join the game, we’ll give them some points just ...