Orbital simalation

commit c4a2c22b8838fecd7c7f5163b1179ed2506d8586 Author: Sergey Fokin Date: Tue Oct 4 22:13:17 2022 +0300 init diff --git a/index.html b/index.html new file mode 100644 index 0000000..29c6ac8 --- /dev/null +++ b/index.html @@ -0,0 +1,20 @@ + + + + + + + + + Orbital simalation + + + + +

+ + + \ No newline at end of file diff --git a/kepplerObject.js b/kepplerObject.js new file mode 100644 index 0000000..b947981 --- /dev/null +++ b/kepplerObject.js @@ -0,0 +1,59 @@ +import { Vector } from "./vector.js"; + +export class KepplerObject { + constructor(name, mass, radius, position, velocity, color) { + this.mass = mass; + this.name = name; + this.radius = radius; + this.position = position; + this.velocity = velocity; + this.color = color; + this.trails = []; + } + + draw(ctx) { + for (let t of this.trails) { + ctx.strokeStyle = this.color; + ctx.moveTo(t.x, t.y); + ctx.lineTo(t.x + 1, t.y + 1); + ctx.stroke(); + } + + ctx.strokeStyle = this.color; + ctx.fillStyle = this.color; + ctx.beginPath(); + ctx.arc(this.position.x, this.position.y, this.radius, 0, 2 * Math.PI); + ctx.fill(); + } + + track() { + let maxTrack = 100; + this.trails.push(this.position.copy()); + + if (this.trails.length > maxTrack) { + this.trails = this.trails.slice(1, maxTrack); + } + } + + attrackt(kepObj) { + let f = this.getForce(kepObj); + + let direction = new Vector(this.position.x - kepObj.position.x, this.position.y - kepObj.position.y).normalize(); + + let velocity = f / this.mass; + this.velocity.x -= velocity * direction.x; + this.velocity.y -= velocity * direction.y; + } + + move() { + this.position.x += this.velocity.x; + this.position.y += this.velocity.y; + } + + getForce(o2) { + let G = 5; + let dist = this.position.getDistance(o2.position); + let f = G * (this.mass * o2.mass) / (dist * dist); + return f; + } +} \ No newline at end of file diff --git a/orbital.js b/orbital.js new file mode 100644 index 0000000..18624df --- /dev/null +++ b/orbital.js @@ -0,0 +1,58 @@ +import { Vector } from './vector.js' +import { KepplerObject } from './kepplerObject.js' +import * as utils from './utils.js' + + +let ctx; +let planets = []; +let G = 5; +let sun = {}; + +function update(dt) { + for (let p of planets) { + p.track(); + p.attrackt(sun); + p.move(); + } +} + +window.onload = function () { + let canvas = document.getElementById("canvas"); + ctx = canvas.getContext("2d"); + + document.querySelector('#canvas').addEventListener('click', setPlanet) + sun = new KepplerObject("sun", 100, 20, new Vector(canvas.clientWidth / 2, canvas.clientHeight / 2), new Vector(0, 0), "yellow"); + + window.requestAnimationFrame(draw); +} + +function addPlanet(position) { + let startVel = Math.sqrt(2 * G * 10 / position.getDistance(sun.position)); + let colors = ['red', 'blue', 'pink', 'green', 'grey']; + + startVel *= utils.random(1, 100) <= 10 ? -1 : 1; + startVel *= 1.4; + + let planet = new KepplerObject("planet", utils.random(5, 25), utils.random(5, 15), position, new Vector(startVel, startVel), colors[utils.random(0, colors.length)]); + planets.push(planet); +} + +function setPlanet(event) { + let position = new Vector(event.x, event.y); + addPlanet(position); +} + +function draw(time) { + let dt = utils.getDeltaTime(time); + utils.clearScreen(ctx, '#000000'); + + sun.draw(ctx); + + update(dt); + + for (let p of planets) { + p.draw(ctx); + } + + window.requestAnimationFrame(draw); +} \ No newline at end of file diff --git a/utils.js b/utils.js new file mode 100644 index 0000000..4659dc0 --- /dev/null +++ b/utils.js @@ -0,0 +1,22 @@ +let dt = 0; +let oldTime = 0; + +export function clearScreen(ctx, color) { + ctx.fillStyle = color; + ctx.fillRect(0, 0, ctx.canvas.clientWidth, ctx.canvas.clientHeight); +} + +export function random(min, max) { + return Math.floor(Math.random() * (max - min)) + min; +} + +export function getDeltaTime(time) { + dt = time - oldTime; + oldTime = time; + + if (dt != 0) { + dt = dt * 0.001; + } + + return dt; +} \ No newline at end of file diff --git a/vector.js b/vector.js new file mode 100644 index 0000000..85b2fa8 --- /dev/null +++ b/vector.js @@ -0,0 +1,32 @@ +export class Vector { + constructor(x, y) { + this.x = x; + this.y = y; + } + + normalize() { + let length = this.getLength(); + return new Vector(this.x / length, this.y / length); + } + + getLength() { + return Math.sqrt(this.x * this.x + this.y * this.y); + } + + getDistance(target) { + let v = new Vector(target.x - this.x, target.y - this.y); + return v.getLength(); + } + + dotProduct(vector) { + return this.x * vector.x + this.y * vector.y; + } + + getAngle(vector) { + return this.dotProduct(vector) / (this.getLength() * vector.getLength()) + } + + copy() { + return new Vector(this.x, this.y); + } +} \ No newline at end of file