Python-turtle设计太阳系模拟程序
#!/usr/bin/env python3
"""
使用turtle模块的太阳系模拟程序
快捷键:
按Ctrl+“+”或Ctrl+“-”进行缩放。
按↑，↓，←，→键移动。
按“+”或“-”键增加或者降低速度。
单击屏幕开启或关闭轨道显示。
"""
from time import perf_counter
from random import randrange
from turtle import Shape, Turtle, update, Screen, Terminator, Vec2D as Vec, mainloop
__author__="七分诚意 qq:3076711200"
__email__="[email protected]"
__version__="1.0.3"
G = 8
# 各个行星的质量
SUN_MASS=1000000
MERCURY_MASS=125
VENUS_MASS=3000
EARTH_MASS=4000
MOON_MASS=30
MARS_MASS=600
PHOBOS_MASS=2
JUPITER_MASS=7000
SATURN_MASS=6000
URANUS_MASS=9000
NEPTUNE_MASS=8000
scr=None
class GravSys:
# 引力系统
__slots__=['planets', 'removed_planets', 't', 'dt', 'frameskip',
'scale', 'scr_x', 'scr_y',
'show_fps','__last_time','writer','fps','following']
def __init__(self):
self.planets = []
self.removed_planets=[]
self.t = 0
self.dt = 0.01 # 速度
#frameskip: 程序在绘制一帧之前跳过的帧数
self.frameskip=4
self.scale=1
self.scr_x=0
self.scr_y=0
self.show_fps=True
self.writer=Turtle()
self.writer.hideturtle()
self.writer.penup()
self.writer.color("white")
#following: 跟随某个行星
self.following=None
def init(self):
for p in self.planets:
p.init()
def start(self):
while True:
self.__last_time=perf_counter()
# 计算行星的位置
for _ in range(self.frameskip):
self.t += self.dt
for p in self.planets:
p.step()
if self.following!=None:
self.scr_x=-self.following._pos[0]
self.scr_y=-self.following._pos[1]
#
for p in self.planets:
p.update()
update()
self.fps=1/(perf_counter()-self.__last_time)
# 显示帧率
if self.show_fps:
self.writer.clear()
self.writer.goto(
scr.window_width()//2-90,scr.window_height()//2-35
)
self.writer.write(
"fps:%d" % self.fps,
font = (None,12)
)
def increase_speed(self,event):
self.dt+=0.001
def decrease_speed(self,event):
self.dt-=0.001
def zoom(self,event):
if event.keysym=="equal":
# 放大
self.scale*=1.33
else:
# 缩小
self.scale/=1.33
for planet in self.planets:
planet.shapesize(planet.size*self.scale)
scr.ontimer(self.clear_scr, int(1000/self.fps))
def clear_scr(self):
for planet in self.planets:
planet.clear()
def up(self,event=None):
self.scr_y-=50
scr.ontimer(self.clear_scr, int(1000/self.fps))
def down(self,event=None):
self.scr_y+=50
scr.ontimer(self.clear_scr, int(1000/self.fps))
def left(self,event=None):
self.scr_x+=50
scr.ontimer(self.clear_scr, int(1000/self.fps))
def right(self,event=None):
self.scr_x-=50
scr.ontimer(self.clear_scr, int(1000/self.fps))
class Star(Turtle):
__slots__=['screen', '_angleOffset', '_angleOrient', '_mode', 'undobuffer', '_fullcircle', '_degreesPerAU', '_position', '_orient', '_resizemode', '_pensize', '_shown', '_pencolor', '_fillcolor', '_drawing', '_speed', '_stretchfactor', '_shearfactor', '_tilt', '_shapetrafo', '_outlinewidth', 'drawingLineItem', 'turtle', '_poly', '_creatingPoly', '_fillitem', '_fillpath', '_hidden_from_screen', 'currentLineItem', 'currentLine', 'items', 'stampItems', '_undobuffersize', 'size', 'm', '_pos', 'v', 'can_switchpen', 'gravSys', 'a']
def __init__(self, gravSys, m, x, v,
shape,shapesize=1,orbit_color=None,can_switchpen=True):
Turtle.__init__(self)
self.shape(shape)
self.size=shapesize
self.shapesize(shapesize)
if orbit_color is not None:
self.pencolor(orbit_color)
self.penup()
self.m = m
self._pos=x
self.setpos(x)
self.v = v
self.can_switchpen=can_switchpen
gravSys.planets.append(self)
self.gravSys = gravSys
self.resizemode("user")
def init(self):
if self.can_switchpen:
self.pendown()
dt = self.gravSys.dt
self.a = self.acc()
self.v = self.v + 0.5*dt*self.a
def acc(self):
a = Vec(0,0)
for planet in self.gravSys.planets:
if planet is not self:
v = planet._pos-self._pos
try:
a += (G*planet.m/abs(v)**3)*v
except ZeroDivisionError:pass
return a
def step(self):
dt = self.gravSys.dt
self._pos += dt*self.v
self.a = self.acc()
self.v = self.v + dt*self.a
def update(self):
self.setpos((self._pos+(self.gravSys.scr_x,
self.gravSys.scr_y))*self.gravSys.scale)
if self.size>0.05:
self.setheading(self.towards(self.gravSys.planets[0]))
if abs(self._pos[0])>10000 or abs(self._pos[1])>10000:
self.gravSys.removed_planets.append(self)
self.gravSys.planets.remove(self)
self.hideturtle()
class Sun(Star):
# 太阳不移动, 固定在引力系统的中心
def step(self):
pass
def update(self):
if self.size*self.gravSys.scale<0.08:
self.shapesize(0.08)
self.setpos((self._pos+(self.gravSys.scr_x,
self.gravSys.scr_y))*self.gravSys.scale)
#Star.update(self)
def main():
global scr
scr=Screen()
scr.screensize(10000,10000)
try:
scr._canvas.master.state("zoomed")
except:pass
scr.bgcolor("black")
scr.tracer(0,0)
# create compound turtleshape for planets
s = Turtle()
s.reset()
s.ht()
s.pu()
s.fd(6)
s.lt(90)
s.begin_poly()
s.circle(8, 180)
s.end_poly()
_light = s.get_poly()
s.begin_poly()
s.circle(8, 180)
s.end_poly()
_dark = s.get_poly()
s.begin_poly()
s.circle(8)
s.end_poly()
_circle = s.get_poly()
## _gh=[] # 光环
## for i in range(4,7,2):
## s.begin_poly()
## s.setheading(0)
## s.setx(i+6)
## s.setheading(90)
## s.circle(i+8)
## s.setheading(0)
## s.setx(i+7)
## s.setheading(90)
## s.circle(i+9)
## s.end_poly()
## _gh.append(s.get_poly())
update()
s.hideturtle()
def create_shape(screen,name,light,dark=None): #,gh=False):
shape = Shape("compound")
if dark is not None:
shape.addcomponent(_light,light)
shape.addcomponent(_dark,dark)
else:
shape.addcomponent(_circle,light)
## if gh:
## for circ in _gh:
## shape.addcomponent(circ,dark)
screen.register_shape(name, shape)
## def gas_giant_shape(screen,name,light,dark):
## # create shapes for gas-giant planets
create_shape(scr,"mercury","gray70","grey50")
create_shape(scr,"venus","gold","brown")
create_shape(scr,"earth","blue","blue4")
create_shape(scr,"moon","gray70","grey30")
create_shape(scr,"mars","red","red4")
create_shape(scr,"jupiter","burlywood1","burlywood4")
create_shape(scr,"saturn","khaki1","khaki4")
create_shape(scr,"uranus","light blue","blue")
create_shape(scr,"neptune","blue","dark slate blue")
# setup gravitational system
gs = GravSys()
sun = Sun(gs,SUN_MASS, Vec(0,0), Vec(0,0),
"circle",1.8,can_switchpen=False)
sun.color("yellow")
sun.penup()
# 水星
mercury = Star(gs,MERCURY_MASS, Vec(60,0), Vec(0,330),
"mercury",0.5, "gray30")
# 金星
venus = Star(gs,VENUS_MASS, Vec(-130,0), Vec(0,-250),
"venus",0.7, "gold4")
# 地球
earth = Star(gs,EARTH_MASS, Vec(260,0), Vec(0,173),
"earth",0.8, "blue")
# 月球
moon = Star(gs,MOON_MASS, Vec(269,0), Vec(0,230),
"moon",0.5, can_switchpen=False)
# 火星及卫星
mars = Star(gs,MARS_MASS, Vec(0,430), Vec(-140, 0),
"mars",0.6, "red")
phobos = Star(gs,PHOBOS_MASS, Vec(0,438), Vec(-165, 0),
"circle",0.1, "orange", can_switchpen=False)
phobos.fillcolor("orange")
# 创建小行星
for i in range(15):
ast=Star(gs,100,Vec(0,0),Vec(0,0),
"circle",0.05,can_switchpen=False)
ast.setheading(randrange(360))
ast.forward(randrange(700,800))
pos=ast._pos=ast.pos()
ast.v=Vec(-pos[1]/7, pos[0]/7)
ast.pu()
ast.color("gray")
# 木星及卫星
jupiter = Star(gs, JUPITER_MASS, Vec(1100,0), Vec(0, 86),
"jupiter", 1.2, "darkgoldenrod4")
mw1 = Star(gs,MOON_MASS, Vec(1125,0), Vec(0,130),
"circle",0.05, "yellow", can_switchpen=False)
mw2 = Star(gs,MOON_MASS, Vec(1145,0), Vec(0,122),
"circle",0.07, "darkgoldenrod3", can_switchpen=False)
# 土星
saturn = Star(gs, SATURN_MASS, Vec(2200,0), Vec(0, 60),
"saturn", 1.0, "khaki4")
# 天王星
uranus = Star(gs, URANUS_MASS, Vec(0, 4300), Vec(-43, 0),
"uranus", 0.8, "blue")
# 海王星
neptune = Star(gs, NEPTUNE_MASS, Vec(7500,0), Vec(0, 34),
"neptune", 0.8, "midnight blue")
# 绑定键盘事件
cv=scr.getcanvas()
cv.bind_all("" ,gs.up)
cv.bind_all("" ,gs.down)
cv.bind_all("" ,gs.left)
cv.bind_all("" ,gs.right)
cv.bind_all("" ,gs.increase_speed)
cv.bind_all("" ,gs.decrease_speed)
cv.bind_all("" ,gs.zoom) #Ctrl+"+"
cv.bind_all("" ,gs.zoom) #Ctrl+"-"
#scr.tracer(1,0)
def switchpen(x=None,y=None):
for planet in gs.planets+gs.removed_planets:
if not planet.can_switchpen:
continue
if planet.isdown():
planet.penup()
else:planet.pendown()
planet.clear()
scr.onclick(switchpen)
#gs.following=earth
gs.init()
gs.start()
if __name__ == '__main__':
main()
mainloop()
注: 程序改编自Python标准库中的turtledemo\planet_and_moon.py