#!/usr/bin/python

import pygame
import random
import math

SCRN_SCALE = 2
DISP_SIZE = (320, 240)
SCRN_SIZE = (DISP_SIZE[0] * SCRN_SCALE, DISP_SIZE[1] * SCRN_SCALE)

def get_rand_col():
	#return (random.randint(0, 255), random.randint(0, 255), random.randint(0, 255))
	return (random.randint(100, 150), random.randint(150, 200), random.randint(200, 255))
	
def norm(x, y):
	h = math.hypot(x, y)
	if h!=0:
		return (x/h, y/h, h)
	return (0.0, 0.0, 1.0)

class Particle:
	def __init__(self):
		self.x = float(random.randint(0, DISP_SIZE[0]))
		self.y = float(random.randint(0, DISP_SIZE[1]))
		self.vx = (random.random() - 0.5) * 10.0
		self.vy = (random.random() - 0.5) * 10.0
		self.c = get_rand_col()
		
	def update(self, td):
		#mx = mouse_pos[0] / SCRN_SCALE
		#my = mouse_pos[1] / SCRN_SCALE
		
		for mx,my in attractor:
			v = norm(mx - self.x, my - self.y)
			
			if v[2] > 4:
				self.vx += v[0] * (5000/v[2]**2) * td
				self.vy += v[1] * (5000/v[2]**2) * td
			else:
				h = math.hypot(self.vx, self.vy)
				
				self.vx -= v[0] * h
				self.vy -= v[1] * h
				
				self.x = mx - v[0] * 4
				self.y = my - v[1] * 4
		
		for mx,my in repulsor:
			v = norm(mx - self.x, my - self.y)
			
			self.vx -= v[0] * (5000/v[2]**2) * td
			self.vy -= v[1] * (5000/v[2]**2) * td
		
		#self.vx -= self.vx * (td * 0.01)
		#self.vy -= self.vy * (td * 0.01)
		
		self.x += self.vx * td
		self.y += self.vy * td
		
		if (self.x < 0) or (self.x >= DISP_SIZE[0]):
			self.x -= self.vx * td
			self.vx = -self.vx
			self.vx -= self.vx * td * 50
			
		if (self.y < 0) or (self.y >= DISP_SIZE[1]):
			self.y -= self.vy * td
			self.vy = -self.vy
			self.vy -= self.vy * td * 50
		
	def draw(self):
		#pygame.draw.rect(disp, self.c, (int(self.x), int(self.y), 1, 1))
		disp.fill(self.c, (int(self.x), int(self.y), 1, 1))

screen = pygame.display.set_mode(SCRN_SIZE, pygame.DOUBLEBUF)
disp = pygame.surface.Surface(DISP_SIZE)
disp.fill((0,0,0))

fade = pygame.surface.Surface(DISP_SIZE)
fade.fill((1,1,1))

particles = [Particle() for i in xrange(10)]

attractor = []
repulsor = []

done = False
while not done:
	m = pygame.mouse.get_pos()
	mouse_pos = (random.gauss(m[0], 10.0), random.gauss(m[1], 10.0))
	
	#disp.fill((10,10,10), None, pygame.BLEND_ADD)
	#disp.fill((255,255,255))
	disp.blit(fade, (0,0), None, pygame.BLEND_SUB)
	
	for p in particles:
		p.update(0.015)
		p.draw()
		
	for a in attractor:
		pygame.draw.circle(disp, (0, 100, 200), a, 3)
		
	for a in repulsor:
		pygame.draw.circle(disp, (0, 0, 100), a, 3)
		
	#pygame.draw.line(disp, (0,0,0), (m[0]/SCRN_SCALE, m[1]/SCRN_SCALE), (mouse_pos[0]/SCRN_SCALE, mouse_pos[1]/SCRN_SCALE))
	
	pygame.transform.scale(disp, SCRN_SIZE, screen)
	
	pygame.display.flip()
			
	for event in pygame.event.get():
		if event.type == pygame.MOUSEBUTTONDOWN:
			if event.button==1:
				attractor.append((int(m[0] / SCRN_SCALE), int(m[1] / SCRN_SCALE)))
				
			if event.button==3:
				repulsor.append((int(m[0] / SCRN_SCALE), int(m[1] / SCRN_SCALE)))
				
			if event.button==4:
				particles.append(Particle())
				
			if event.button==5:
				if len(particles) > 0:
					del particles[0]
				
		if event.type == pygame.KEYDOWN:
			if event.key == pygame.K_ESCAPE:
				done = True
				
			if event.key == pygame.K_SPACE:
				attractor = []
				repulsor = []
				
		if event.type == pygame.QUIT: 
			done = True