3
何らかの理由で私のコードが機能しません。それは衝突シミュレーションでなければならないが、ボールは一緒にくっついているだけなので、なぜその理由が分からないようだ。私はhttps://en.wikipedia.org/wiki/Elastic_collision#Two-dimensional_collision_with_two_moving_objectsから式を使用していると、私の知る限り、私は完全にそれをコピーしている見ることができるように、私も、操作の順序が正しいことを確認するためにブラケットを追加したが、それでもここで運Javascriptの衝突が機能しない
は私のコードではありません。
手始めにvar canvas = document.getElementById("canvas"),
ctx = canvas.getContext("2d");
function Ball(){
this.pos = {
"x": Math.random() * canvas.width,
"y": Math.random() * canvas.height
};
this.vel = {
"x": Math.random() - 0.5,
"y": Math.random() - 0.5
};
this.r = 16;
this.colliding = false;
this.m = 1;
}
function mag(v){
return Math.sqrt((v.x * v.x) + (v.y * v.y));
}
function dir(v){
return Math.atan2(v.y, v.x);
}
function dist(a, b){
var dx = b.x - a.x,
dy = b.y - a.y;
return Math.sqrt(dx * dx + dy * dy);
}
var balls = [];
for(var i = 0; i < 10; i++){
balls.push(new Ball());
}
setInterval(function(){
for(var i = 0; i < balls.length; i++){
balls[i].pos.x += balls[i].vel.x;
balls[i].pos.y += balls[i].vel.y;
if(balls[i].pos.x + balls[i].r > canvas.width){
balls[i].pos.x = canvas.width - balls[i].r;
balls[i].vel.x *= -1;
}
if(balls[i].pos.x < balls[i].r){
balls[i].pos.x = balls[i].r;
balls[i].vel.x *= -1;
}
if(balls[i].pos.y + balls[i].r > canvas.height){
balls[i].pos.y = canvas.height - balls[i].r;
balls[i].vel.y *= -1;
}
if(balls[i].pos.y < balls[i].r){
balls[i].pos.y = balls[i].r;
balls[i].vel.y *= -1;
}
balls[i].colliding = false;
}
for(var i = 0; i < balls.length; i++){
for(var j = i + 1; j < balls.length; j++){
if(mag(balls[i].vel) < 0){
break;
}
if(dist(balls[i].pos, balls[j].pos) < balls[i].r + balls[j].r){
balls[i].colliding = true;
var contact = Math.atan2(balls[j].pos.y - balls[i].pos.y, balls[j].pos.x - balls[i].pos.x);
balls[i].vel.x = ((((mag(balls[i].vel) * Math.cos(dir(balls[i].vel) - contact) * (balls[i].m - balls[j].m)) + (2 * balls[j].m * mag(balls[j].vel) * Math.cos(dir(balls[j].vel) - contact)))/(balls[i].m + balls[j].m)) * Math.cos(contact)) + (mag(balls[i].vel) * Math.sin(dir(balls[i].vel) - contact) * Math.cos(contact + (Math.PI/2)));
balls[i].vel.y = ((((mag(balls[i].vel) * Math.cos(dir(balls[i].vel) - contact) * (balls[i].m - balls[j].m)) + (2 * balls[j].m * mag(balls[j].vel) * Math.cos(dir(balls[j].vel) - contact)))/(balls[i].m + balls[j].m)) * Math.sin(contact)) + (mag(balls[i].vel) * Math.sin(dir(balls[i].vel) - contact) * Math.sin(contact + (Math.PI/2)));
balls[j].vel.x = ((((mag(balls[j].vel) * Math.cos(dir(balls[j].vel) - contact) * (balls[j].m - balls[i].m)) + (2 * balls[i].m * mag(balls[i].vel) * Math.cos(dir(balls[i].vel) - contact)))/(balls[j].m + balls[i].m)) * Math.cos(contact)) + (mag(balls[j].vel) * Math.sin(dir(balls[j].vel) - contact) * Math.cos(contact + (Math.PI/2)));
balls[j].vel.y = ((((mag(balls[j].vel) * Math.cos(dir(balls[j].vel) - contact) * (balls[j].m - balls[i].m)) + (2 * balls[i].m * mag(balls[i].vel) * Math.cos(dir(balls[i].vel) - contact)))/(balls[j].m + balls[i].m)) * Math.sin(contact)) + (mag(balls[j].vel) * Math.sin(dir(balls[j].vel) - contact) * Math.sin(contact + (Math.PI/2)));
}
}
}
ctx.clearRect(0, 0, canvas.width, canvas.height);
for(var i = 0; i < balls.length; i++){
ctx.beginPath();
if(balls[i].colliding){
ctx.fillStyle = "#f00";
}else{
ctx.fillStyle = "#0f0";
}
ctx.arc(balls[i].pos.x, balls[i].pos.y, balls[i].r, 0, 2 * Math.PI);
ctx.fill();
}
}, 16);<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<canvas id="canvas" width="640" height="480"></canvas>
<script src="main.js"></script>
</body>
</html>
@TJCrowderは何の違い –
@TJCrowder追加スニペットを行いませんパフォーマンスのためにも –