gistfile1.txt

#!/bin/python2
import pygame
import itertools
import random
import math

# Initialize the game engine
pygame.init()

# Define some colors
RED = (255, 0, 0)
ORANGE = (255, 128, 0)
YELLOW = (255, 255, 0)
GREEN = (0, 255, 0)
BLUE = (0, 0, 255)
VIOLETT = (255, 0, 255)
COLORS = [RED, ORANGE, YELLOW, GREEN, BLUE, VIOLETT]

PIXEL = 5
#WIDTH = 1440
#HEIGHT = 900
WIDTH = 720
HEIGHT = 450
MAX_PARTICLES = 2000
MAX_SPAWNED_PARTICLES_PER_TICK = 10
VELOCITY = 0.5
FPS = 60
ARMS = 4
ARM_ANGLE = 1.0/ARMS
MAX_ROTATION_VELOCITY = 0.02

PIXEL_WIDTH = WIDTH // PIXEL
PIXEL_HEIGHT = HEIGHT // PIXEL

source = {'x': PIXEL_WIDTH / 2.0,
          'y': PIXEL_HEIGHT / 2.0,
          'vx': 0.0, #math.cos(math.pi/4)*VELOCITY/2,
          'vy': 0.0, #math.sin(math.pi/4)*VELOCITY/2,
          'ax': 0.01,
          'ay': 0.01,
          'r': 0.0,
          'rv': 0.0,
          'ra': 0.00003}
tick = 0

# Set the height and width of the screen
size = (WIDTH, HEIGHT)
screen = pygame.display.set_mode(size)
buf = pygame.Surface((WIDTH, HEIGHT), pygame.SRCALPHA)
buf.fill((0,0,0,255))

pygame.display.set_caption("Particles")

# Loop until the user clicks the close button.
done = False
clock = pygame.time.Clock()

particles = []

# Loop as long as done == False
while not done:

    # events
    for event in pygame.event.get():  # User did something
        if event.type == pygame.QUIT:  # If user clicked close
            done = True  # Flag that we are done so we exit this loop

    # update state
    def gen_particle():
        angle = random.random()
        color_offset = 0
        if (angle+source['r']) % (2*ARM_ANGLE) < ARM_ANGLE:
            color_offset = 2
        color = COLORS[(tick//FPS//2 + color_offset) % len(COLORS)]
        angle *= 2*math.pi
        return {'x': source['x'],
                'y': source['y'],
                'vx': math.cos(angle)*VELOCITY + source['vx'],
                'vy': math.sin(angle)*VELOCITY + source['vy'],
                'color': color}
    def move_particle(p):
        p['x'] += p['vx']
        p['y'] += p['vy']
    def wrap_particle(p):
        p['x'] %= PIXEL_WIDTH
        p['y'] %= PIXEL_HEIGHT
    particles_to_add = min(MAX_PARTICLES - len(particles), MAX_SPAWNED_PARTICLES_PER_TICK)
    for _ in xrange(0, particles_to_add):
        particles.append(gen_particle())
    for i in xrange(0, len(particles)):
        p = particles[i]
        move_particle(p)
        if p['x'] < 0 or p['x'] >= PIXEL_WIDTH or p['y'] < 0 or p['y'] >= PIXEL_HEIGHT:
            particles[i] = gen_particle()
    source['vx'] += random.uniform(-0.5, 0.5) * source['ax']
    source['vy'] += random.uniform(-0.5, 0.5) * source['ay']
    move_particle(source)
    wrap_particle(source)
    source['r'] += source['rv']
    source['rv'] += source['ra']
    if source['rv'] < -MAX_ROTATION_VELOCITY or source['rv'] > MAX_ROTATION_VELOCITY:
        source['ra'] *= -1

    # render
    buf.fill((0,0,0,40))

    def draw_pixel(coords):
        buf.fill(
                coords['color'],
                rect=[int(coords['x'])*PIXEL, int(coords['y'])*PIXEL, PIXEL-1, PIXEL-1],
                special_flags=pygame.BLEND_ADD)
                #)

    for p in particles:
        draw_pixel(p)

    screen.blit(buf, (0,0))
    pygame.display.flip()

    # sleep
    clock.tick(FPS)
    tick += 1

# Be IDLE friendly
pygame.quit()