commit

main.py

@@ -0,0 +1,133 @@
+from tkinter import *
+from math import sqrt
+from time import sleep
+
+WIDTH = 900
+HEIGHT = 600
+
+class Planet:
+    def __init__(self, canvas, size, mass, color, x, y):
+        self.canvas = canvas
+
+        self.size = size
+        self.mass = mass
+        self.color = color
+
+        self.x = x
+        self.y = y
+
+        self.dx = 0
+        self.dy = 0
+
+        self.ax = 0
+        self.ay = 0
+
+    def draw(self, scale, dt):
+        self.x += self.dx * dt
+        self.y += self.dy * dt
+
+        x1 = (self.x + self.size) / scale + WIDTH / 2
+        y1 = (self.y + self.size) / scale + HEIGHT / 2
+        x2 = (self.x + self.size * 3) / scale + WIDTH / 2
+        y2 = (self.y + self.size * 3) / scale + HEIGHT / 2
+
+        self.canvas.create_oval(x1, y1, x2, y2, fill=self.color)
+
+    def calculate_acceleration(self, planet):
+        G = 6.67 * pow(10, -11)
+        dx = planet.x - self.x
+        dy = planet.y - self.y
+        d = sqrt(dx ** 2 + dy ** 2)
+
+        if d == 0:
+            return (0, 0)
+
+        F = G * self.mass * planet.mass / d ** 2
+
+        self.ax += F * dx / (d * self.mass)
+        self.ay += F * dy / (d * self.mass)
+    
+    def update_velocity(self, dt):
+        self.dx += self.ax * dt
+        self.dy += self.ay * dt
+
+        self.ax = 0
+        self.ay = 0
+
+    def set_initial_velocity(self, dx, dy):
+        self.dx = dx
+        self.dy = dy
+
+    def orbit(self, planet):
+        G = 6.67e-11
+        M = planet.mass
+        r = sqrt((self.x - planet.x)**2 + (self.y - planet.y)**2)
+
+        print(r)
+
+        v = sqrt(G * M / r)
+
+        self.set_initial_velocity(0, v)
+
+class System():
+    def __init__(self, canvas):
+        self.planets = []
+        self.canvas = canvas
+
+    def add(self, planet):
+        self.planets.append(planet)
+
+    def update_all(self, dt, scale):
+        for planet1 in self.planets:
+            for planet2 in self.planets:
+                if planet1 != planet2:
+                    planet1.calculate_acceleration(planet2)
+
+            planet1.update_velocity(dt)
+
+        self.canvas.delete("all")
+
+        for planet in self.planets:
+            planet.draw(scale, dt)
+
+def main():
+    window = Tk()
+
+    fps_limit = 75
+
+    canvas = Canvas(window, bg="black", width=WIDTH, height=HEIGHT)
+    canvas.pack()
+
+    time = Scale(window, from_=1, to=1_000_000, orient=HORIZONTAL, length=400)
+    time.pack()
+
+    scale = Scale(window, to=1, from_=5_000_000, orient=HORIZONTAL, length=400)
+    scale.pack()
+    scale.set(460_000)
+
+    fps = Scale(window, from_=1, to=1000, orient=HORIZONTAL)
+    fps.pack()
+    fps.set(75)
+
+    system = System(canvas)
+
+    earth = Planet(canvas, 6371000, 5.972e24, "green", 4_000_000, 30_000_000)
+    moon = Planet(canvas, 1737400, 7.348e22, "grey", 4_000_000 + 384_400_000, 30_000_000)
+    iss = Planet(canvas, 1737400, 400_000, "grey", 4_000_000 + 408_000, 30_000_000)
+
+    system.add(earth)
+    system.add(moon)
+    system.add(iss)
+
+    iss.orbit(earth)
+    moon.orbit(earth)
+
+    while True:
+        system.update_all(time.get() / fps_limit, scale.get())
+        window.update_idletasks()
+        window.update()
+        sleep(1 / fps_limit)
+
+
+if __name__ == "__main__":
+    main()