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  • Committer: Bazaar Package Importer
  • Author(s): Ed Boraas
  • Date: 2002-02-20 06:39:24 UTC
  • Revision ID: james.westby@ubuntu.com-20020220063924-amlzj7tqkeods4eq
Tags: upstream-1.4
Import upstream version 1.4

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examples/stars.py
 
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#!/usr/bin/env python
 
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"""A simple starfield example. Note you can move the 'center' of
 
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the starfield by leftclicking in the window. This example show
 
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the basics of creating a window, simple pixel plotting, and input
 
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event management"""
 
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import random, math, pygame
 
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from pygame.locals import *
 
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#constants
 
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WINSIZE = [640, 480]
 
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WINCENTER = [320, 240]
 
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NUMSTARS = 150
 
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def init_star():
 
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        "creates new star values"
 
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        dir = random.randrange(100000)
 
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        velmult = random.random()*.6+.4
 
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        vel = [math.sin(dir) * velmult, math.cos(dir) * velmult]
 
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        return vel, WINCENTER[:]
 
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def initialize_stars():
 
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        "creates a new starfield"
 
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        stars = []
 
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        for x in range(NUMSTARS):
 
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                star = init_star()
 
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                vel, pos = star
 
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                steps = random.randint(0, WINCENTER[0])
 
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                pos[0] = pos[0] + (vel[0] * steps)
 
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                pos[1] = pos[1] + (vel[1] * steps)
 
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                vel[0] = vel[0] * (steps * .09)
 
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                vel[1] = vel[1] * (steps * .09)
 
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                stars.append(star)
 
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        move_stars(stars)
 
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        return stars
 
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def draw_stars(surface, stars, color):
 
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        "used to draw (and clear) the stars"
 
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        for vel, pos in stars:
 
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                surface.set_at(pos, color)
 
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def move_stars(stars):
 
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        "animate the star values"
 
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        for vel, pos in stars:
 
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                pos[0] = pos[0] + vel[0]
 
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                pos[1] = pos[1] + vel[1]
 
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                if not 0 <= pos[0] <= WINSIZE[0] or not 0 <= pos[1] <= WINSIZE[1]:
 
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                        vel[:], pos[:] = init_star()
 
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                else:
 
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                        vel[0] = vel[0] * 1.05
 
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                        vel[1] = vel[1] * 1.05
 
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def main():
 
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        "This is the starfield code"
 
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        #create our starfield
 
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        random.seed()
 
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        stars = initialize_stars()
 
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        #initialize and prepare screen
 
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        pygame.init()
 
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        screen = pygame.display.set_mode(WINSIZE)
 
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        pygame.display.set_caption('pygame Stars Example')
 
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        white = 255, 240, 200
 
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        black = 20, 20, 40
 
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        screen.fill(black)
 
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        #main game loop
 
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        done = 0
 
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        while not done:
 
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                draw_stars(screen, stars, black)
 
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                move_stars(stars)
 
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                draw_stars(screen, stars, white)
 
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                pygame.display.update()
 
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                for e in pygame.event.get():
 
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                        if e.type == QUIT or (e.type == KEYUP and e.key == K_ESCAPE):
 
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                                done = 1
 
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                                break
 
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                        elif e.type == MOUSEBUTTONDOWN and e.button == 1:
 
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                                WINCENTER[:] = list(e.pos)
 
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# if python says run, then we should run
 
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if __name__ == '__main__':
 
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        main()
 
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