# tk_Gravitational.py

# tk_Gravitational.py

import tkinter as tk
import random
import math

root = tk.Tk()
root.title("Gravity")
canvas = tk.Canvas(root, width=600, height=600, bg='black')
canvas.pack()

attractor_x = 300
attractor_y = 300
attractor_mass = 20
attractor_r = math.sqrt(attractor_mass) * 2

movers = []

def init_movers():
    global movers
    movers = []
    for _ in range(12):
        x = random.uniform(50, 100)
        y = random.uniform(50, 100)
        vx = random.uniform(-1, 1)
        vy = random.uniform(-1, 1)
        mass = random.uniform(0.5, 5)
        r = math.sqrt(mass) * 2
        movers.append({'x': x, 'y': y, 'vx': vx, 'vy': vy, 'ax': 0, 'ay': 0, 'mass': mass, 'r': r})

def constrain(val, min_val, max_val):
    return max(min_val, min(max_val, val))

def attract(mover):
    fx = attractor_x - mover['x']
    fy = attractor_y - mover['y']
    dist_sq = fx*fx + fy*fy
    dist_sq = constrain(dist_sq, 100, 1000)
    G = 5
    strength = G * (attractor_mass * mover['mass']) / dist_sq
    mag = math.sqrt(fx*fx + fy*fy)
    if mag > 0:
        fx = (fx / mag) * strength
        fy = (fy / mag) * strength
    mover['ax'] += fx / mover['mass']
    mover['ay'] += fy / mover['mass']

def attract_movers(m1, m2):
    fx = m2['x'] - m1['x']
    fy = m2['y'] - m1['y']
    dist_sq = fx*fx + fy*fy
    if dist_sq < 1:
        return
    dist_sq = constrain(dist_sq, 100, 1000)
    G = 0.5
    strength = G * (m1['mass'] * m2['mass']) / dist_sq
    mag = math.sqrt(fx*fx + fy*fy)
    if mag > 0:
        fx = (fx / mag) * strength
        fy = (fy / mag) * strength
    m1['ax'] += fx / m1['mass']
    m1['ay'] += fy / m1['mass']

def update():
    canvas.delete('all')

    for mover in movers:
        mover['ax'] = 0
        mover['ay'] = 0

    for mover in movers:
        attract(mover)

    for i in range(len(movers)):
        for j in range(i+1, len(movers)):
            attract_movers(movers[i], movers[j])
            attract_movers(movers[j], movers[i])

    for mover in movers:
        mover['vx'] += mover['ax']
        mover['vy'] += mover['ay']
        mover['x'] += mover['vx']
        mover['y'] += mover['vy']

        canvas.create_oval(
            mover['x'] - mover['r'],
            mover['y'] - mover['r'],
            mover['x'] + mover['r'],
            mover['y'] + mover['r'],
            fill='cyan',
            outline=''
        )

    canvas.create_oval(
        attractor_x - attractor_r,
        attractor_y - attractor_r,
        attractor_x + attractor_r,
        attractor_y + attractor_r,
        fill='#ff0064',
        outline=''
    )

    root.after(10, update)

def reset(event):
    init_movers()

root.bind('<space>', reset)

init_movers()
update()
root.mainloop()