gistfile1.py

from __future__ import division, print_function

import pygame, random

import gameobject
import vector
import constants

class Creature(gameobject.GameObject):
    OBJECT_TYPE = "Swarm particles"
    MAX_SPEED = 10
    ACCELERATION = 15/constants.FPS
    SIZE = 2
    TARGET_ATTRACTION = 10000
    
    def __init__(self, pos, game):
        super(Creature, self).__init__(pos, game)
        self.velocity = vector.Vector((random.randint(0, 5), random.randint(0, 5)))

    def step(self, game):
        goal = vector.Vector((0, 0))# A number larger than the distance to the nearest red point
        for target in game.targets:
            vec = target.pos - self.pos
            vec.length = self.TARGET_ATTRACTION/vec.length**2
            goal += vec
        goal.length *= self.ACCELERATION
        self.velocity += vec

    def render(self, surface):
        pygame.draw.circle(surface, constants.COLOR_GREEN, (int(self.pos.x), int(self.pos.y)), self.SIZE)


class Target(gameobject.GameObject):
    OBJECT_TYPE = "Swarm target"
    SIZE = 2
    RANGE_MIN = 1/5
    RANGE_MAX = 4/5

    def __init__(self, game):
        pos = vector.Vector()
        pos.x = random.randint(int(constants.WINDOW_WIDTH*self.RANGE_MIN), int(constants.WINDOW_WIDTH*self.RANGE_MAX))
        pos.y = random.randint(int(constants.WINDOW_HEIGHT*self.RANGE_MIN), int(constants.WINDOW_HEIGHT*self.RANGE_MAX))
        gameobject.GameObject.__init__(self, pos, game)

    def step(self, game):
        for creature in game.entities["Swarm particles"]:
            if abs(creature.pos - self.pos) < self.SIZE + creature.SIZE and False:
                self.pos.x = random.randint(int(constants.WINDOW_WIDTH*self.RANGE_MIN), int(constants.WINDOW_WIDTH*self.RANGE_MAX))
                self.pos.y = random.randint(int(constants.WINDOW_HEIGHT*self.RANGE_MIN), int(constants.WINDOW_HEIGHT*self.RANGE_MAX))

    def render(self, surface):
        pygame.draw.circle(surface, constants.COLOR_RED, (int(self.pos.x), int(self.pos.y)), self.SIZE)