Редактирование: Участник:StarfloFr

{{#widget:Iframe | url=http://tm.spbstu.ru/htmlets/js2020/Natalin/Kursach1.html | width=1920 | height=1080 | border=0}}

==Код программы==
<div class="mw-collapsible mw-collapsed">
'''Код программы на языке JavaScript:''' <div class="mw-collapsible-content">
<syntaxhighlight lang="javascript" line start="1" enclose="div">

	class Ball {
		constructor(x, y, r, vx, vy,color){
		    this.x = x;
			this.y = y;
			this.r = r;
			this.vx = vy;
			this.vy = vx;

			this.calculateMass();

			this.color = color;
		}

		calculateMass() {
			this.m = (this.r * this.r * this.r)/50 ;
		}

		getVx() {
			return this.vx * Math.pow(2, timeSpeed);
		}

		getVy() {
			return this.vy * Math.pow(2, timeSpeed);
		}

		move() {
			this.x += this.getVx();
			this.y += this.getVy();
		}
		
	}

	var count = 50;

	var MAX_SPEED = 20;
	var MIN_RADIUS = 100;
	var MAX_RADIUS = 100;
	var WIDTH = 10000;

	var timeSpeed = 0;

	var balls = [];

	var canvas;
	var ctx;
	var T = 300;
	var pathx = [];
	var pathy = [];
		
	function random(min, max) {
		return Math.random() * (max - min) + min;	
	}

	function move() {

		for (var i = 0; i < count; i++) {
			var ball = balls[i];

			if (ball.x < ball.r && ball.vx < 0)
				ball.vx *=-1;
			if (ball.x > WIDTH-ball.r && ball.vx > 0)
				ball.vx *=-1;
			if (ball.y < ball.r && ball.vy < 0)
				ball.vy *=-1;
			if (ball.y > WIDTH-ball.r && ball.vy > 0)
				ball.vy *=-1;
			
			for (var j = i + 1; j < count; j++) {
				var ball2= balls[j];
				var z = (ball.x - ball2.x) * (ball.getVx() - ball2.getVx()) + (ball.y - ball2.y) * (ball.getVy() - ball2.getVy());
				var l = Math.pow(ball.getVx() - ball2.getVx(), 2) + Math.pow(ball.getVy() - ball2.getVy(), 2);
				var m = Math.pow(ball.x - ball2.x, 2) + Math.pow(ball.y - ball2.y, 2) - Math.pow(ball.r + ball2.r, 2);
				
				var d = z*z - l*m;
				
				var t0 = -(z + Math.sqrt(d)) / l;

				var p = Math.pow(ball.x - ball2.x, 2) + Math.pow(ball.y - ball2.y, 2);

				if (t0 >= 0 && t0 <= 1 || p < Math.pow(ball.r + ball2.r, 2)) {
					ball.x += t0 * ball.getVx();
					ball.y += t0 * ball.getVy();	
					ball2.x += t0 * ball2.getVx();	
					ball2.y += t0 * ball2.getVy();	
					
					var px = ball.x - ball2.x;
					var py = ball.y - ball2.y;

					var q = 2 * (px * (ball2.vx - ball.vx) + py * (ball2.vy - ball.vy))
					
					var dvx = q * px / (Math.pow(px, 2) + Math.pow(py,2)) * ball.m * ball2.m / (ball.m + ball2.m);
					var dvy = q * py / (Math.pow(px, 2) + Math.pow(py,2)) * ball.m * ball2.m / (ball.m + ball2.m);
					var k = 1.38 * Math.pow(10,-23);

					ball.vx += dvx / ball.m;
					ball.vy += dvy / ball.m;
					ball2.vx -= dvx / ball2.m;
					ball2.vy -= dvy / ball2.m;
										
				}
				
			}
			
			ball.move();
		}


		draw();	
	}

		
	
	function draw() {
		ctx.clearRect(0, 0, canvas.width, canvas.height);

		var c = canvas.width / WIDTH;

		for (var i = 0; i < count; i++) {
			var ball= balls[i];
			ctx.beginPath();
			ctx.arc(ball.x * c, ball.y * c, ball.r * c, 0, 2 * Math.PI, false);
			
			if (document.getElementById('color').checked)
				ctx.fillStyle = ball.color;
			else
				ctx.fillStyle = 'blue';

			ctx.fill();
			
			
		
		}
		drawPath();
	}
			
	function start() {
		balls[0]= new Ball( WIDTH/2  , WIDTH/2, 500, 0, 0,'red');
		for (var i = 1; i < count; i++) {
			var r = random(MIN_RADIUS, MAX_RADIUS);
			balls[i] = new Ball(random(r, WIDTH - r), random(r, WIDTH - r), r, random(-MAX_SPEED, MAX_SPEED), random(-MAX_SPEED, MAX_SPEED),'blue');
			
		}
		
		canvas = document.getElementById('GG');
		ctx = canvas.getContext('2d');
		
		setInterval(move, 1);
	}

	function weight() {
		
		var r = parseInt(document.getElementById('weight').value);
		if (r > WIDTH / 2 || r < 50) 
			return;

		var oldMass = balls[0].m;
		balls[0].r = r;
		balls[0].calculateMass();

		balls[0].vx *= Math.sqrt(oldMass / balls[0].m);
		balls[0].vy *= Math.sqrt(oldMass / balls[0].m);

		if (balls[0].x > WIDTH - r)
			balls[0].x = WIDTH - r;
		if (balls[0].x < r)
			balls[0].x = r;
		if (balls[0].y > WIDTH - r)
			balls[0].y = WIDTH - r;
		if (balls[0].y < r)
			balls[0].y = r;
		
	}

	function changeSize() {
		canvas.width = document.getElementById('size').value;
		canvas.height = document.getElementById('size').value;
	}
		var tander = 0;
		
		 function drawPath() {
			 tander++;
			 if(tander === 5){
				 tander=0;
			 if ( pathx.length>=1000){
				 pathx.shift();
				 pathy.shift();
			 }
			 
		 var c = canvas.width / WIDTH;
		pathx.push( balls[0].x*c);
		pathy.push( balls[0].y*c);
			 }
		ctx.beginPath();
            ctx.lineWidth = 2;
	        ctx.strokeStyle = 'Black';
            ctx.moveTo(pathx[0], pathy[0]);
			 for (i=1;i<pathx.length; i++)
				 {
	        ctx.lineTo(pathx[i], pathy[i]);
				 }
			 
			 ctx.stroke();
		}
		
		
		
	function add() {
		var k = parseInt(document.getElementById('addCount').value);
		k = Math.min(k , 250 - balls.length);
		for (var i = 0; i < k; i++) {
			var r = random(MIN_RADIUS, MAX_RADIUS);
			balls[count + i] = new Ball(random(r, WIDTH - r), random(r, WIDTH - r), r, random(-MAX_SPEED, MAX_SPEED), random(-MAX_SPEED, MAX_SPEED));
		
		}
		count += k;
	}
		
	function del() {
		var k = Math.min(count - 1, parseInt(document.getElementById('addCount').value));
		balls = balls.slice(0, count - k);
		count -= k;
	}

	function slowly() {
		if (timeSpeed > -3)
			timeSpeed--;
	}

	function faster() {
		if (timeSpeed < 3)
			timeSpeed++;
	}
</syntaxhighlight>
</div>