# Artifical Life 0.0.1
# Copyright 2003 Lja MultiMedia
# May be used under the GNU GPL

import pygame, math, random

black          = (000, 000, 000)
white          = (255, 255, 255)
prey_color     = (000, 000, 255)
predator_color = (255, 000, 000)

class lifeform(object):
   def __init__(self, world, x=None, y=None, color=black, speed=2.5, heading=0, size=5):
      if x == None:
         x = random.randrange(100, 501)
      if y == None:
         y = random.randrange(100, 501)
      self.world = world
      self.color = color
      self.speed = float(speed)
      self.heading = float(heading)
      self.rect = pygame.rect.Rect((x, y, size, size))
   def __getattr__(self, name):
      if name == "x":
         return self.rect[0]
      elif name == "y":
         return self.rect[1]
      elif name == "size":
         return self.rect[2]
      else:
         raise AttributeError
   def __setattr__(self, name, value):
      if name == "x":
         self.rect[0] = value
      elif name == "y":
         self.rect[1] = value
      elif name == "size":
         self.rect[2] = value
         self.rect[3] = value
      else:
         self.__dict__[name] = value
   def move(self):
      xd = self.speed * math.cos(self.heading)
      yd = self.speed * math.sin(self.heading)
      self.world.move(self, xd, yd)
   def random_heading(self):
      self.heading = random.random() * 2 * math.pi

class plant(lifeform):
   def __init__(self, world, x=None, y=None):
      lifeform.__init__(self, world, x, y, (000, 255, 000), 0)
      self.energy = 0
   def move(self):
      self.energy += 1
      if self.energy <= 0:
         plant_list.remove(self)
      elif self.energy >= 200:
         self.energy -= 100
         x = self.x + random.randrange(5, 16) * random.choice((1, -1))
         y = self.y + random.randrange(5, 16) * random.choice((1, -1))
         offspring = plant(self.world, x, y)
         plant_list.append(offspring)
      lifeform.move(self)

class mobile(lifeform):
   def __init__(self, world, x=None, y=None, color=(0, 0, 0)):
      lifeform.__init__(self, world, x, y, color)
      self.mode = "search"
      self.energy = 100
   def move(self):
      self.energy -= 1
      if self.energy <= 0:
         eval(self.__class__.__name__ + '_list.remove(self)')
      elif self.energy >= 200:
         self.energy -= 100
         offspring = self.__class__(self.world, self.x, self.y)
         eval(self.__class__.__name__ + '_list.append(offspring)')
      self.__class__.__dict__[self.mode + "_act"](self)

class prey(mobile):
   def __init__(self, world, x=None, y=None):
      mobile.__init__(self, world, x, y, prey_color)
   def search_act(self):
      try:
         self.plant = random.choice(plant_list)
         self.mode = "hunt"
      except IndexError:
         pass
   def hunt_act(self):
      for plant in plant_list:
         if self.rect.colliderect(plant.rect):
            plant_list.remove(plant)
            self.energy += plant.energy
      if self.plant in plant_list:
         x = self.plant.x - self.x
         y = self.plant.y - self.y
         self.heading = math.atan2(y, x)
         lifeform.move(self)
      else:
         self.mode = "search"

class predator(mobile):
   def __init__(self, world, x=None, y=None):
      mobile.__init__(self, world, x, y, predator_color)
   def search_act(self):
      try:
         self.prey = random.choice(prey_list)
         self.mode = "hunt"
      except IndexError:
         pass
   def hunt_act(self):
      for prey in prey_list:
         if self.rect.colliderect(prey.rect):
            prey_list.remove(prey)
            self.energy += prey.energy
      if self.prey in prey_list:
         x = self.prey.x - self.x
         y = self.prey.y - self.y
         self.heading = math.atan2(y, x)
         lifeform.move(self)
      else:
         self.mode = "search"

class world:
   def __init__(self, x, y, color):
      self.x = x
      self.y = y
      self.color = color
      self.surface = pygame.display.set_mode((x, y))
      self.surface.fill(color)
      pygame.display.update()
      self.rect = self.surface.get_rect()
   def move(self, thing, x, y):
      old_rect = thing.rect
      self.surface.fill(self.color, old_rect)
      thing.rect = thing.rect.move(x, y).clamp(self.rect)
      self.surface.fill(thing.color, thing.rect)   
      #pygame.display.update(thing.rect.union(old_rect))

def main():
   global predator_list, prey_list, plant_list
   pygame.init()
   screen = world(600, 600, white)
   plant_list = []
   prey_list = []
   predator_list = []
   for i in range(100): plant_list.append(plant(screen))
   for i in range(50): prey_list.append(prey(screen))
   for i in range(10): predator_list.append(predator(screen))
   done = 0
   while not done:
      for event in pygame.event.get():
         if event.type == pygame.QUIT:
            done = 1
      all = plant_list + prey_list + predator_list
      if len(all) == 0:
         done = 1
      screen.surface.fill((255, 255, 255))
      for creature in all:
         creature.move()
      pygame.display.update()

if __name__ == "__main__":
   main()