gaia.py

"""Defending the earth mother."""
from __future__ import print_function

import numpy as np

import grimoire
from utils import inventories

P = np.exp(-np.log(2.0)/52.0)
"""Cone survival probability per week"""

def drop(trans):
    """Drops magic cones, maybe."""
    spells = list(grimoire.SPELLBOOK.keys())
    nspells = len(spells)
    hist = trans['history']
    invs = inventories(trans)
    for player, inv in invs.items():
        p = np.random.rand()
        cones = inv['cones']
        if (cones <= 512 and p <= cones / 1024.0) or \
           (cones > 512 and p <= cones / 2.0**(int(np.log2(cones)) + 2)):
            hist.append({'player': player, 'kind': 'drop', 
                         'magic': {spells[np.random.randint(0, nspells)]: 1}})

def decay(trans):
    """Decays cones weekly - you must stay active!"""
    hist = trans['history']
    invs = inventories(trans)
    for player, inv in invs.items():
        p = np.random.rand()
        cones = inv['cones']
        # trick to obtain average decay behaviour, even in small samples, 
        # without having to roll for each cone individually.
        q, r = divmod(cones*P, 1)
        n = int(q) + int(p <= r)
        if n != cones:
            hist.append({'player': player, 'kind': 'decay', 'cones': n - cones})