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Copy pathmain.js
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214 lines (156 loc) · 4.42 KB
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// define variable for ball count paragraph
var para = document.querySelector('p');
var count = 0;
// setup canvas
var canvas = document.querySelector('canvas');
var ctx = canvas.getContext('2d');
var width = canvas.width = window.innerWidth;
var height = canvas.height = window.innerHeight;
// function to generate random number
function random(min,max) {
var num = Math.floor(Math.random()*(max-min)) + min;
return num;
}
// define shape constructor
function Shape() {
this.x = random(0,width);
this.y = random(0,height);
this.velX = random(-7,7);
this.velY = random(-7,7);
this.exists = true;
}
// define Ball constructor, inheriting from Shape
function Ball(x, y, velX, velY, exists) {
Shape.call(this, x, y, velX, velY, exists);
this.color = 'rgb(' + random(0,255) + ',' + random(0,255) + ',' + random(0,255) +')';
this.size = random(10,20);
}
Ball.prototype = Object.create(Shape.prototype);
Ball.prototype.constructor = Ball;
// define ball draw method
Ball.prototype.draw = function() {
ctx.beginPath();
ctx.fillStyle = this.color;
ctx.arc(this.x, this.y, this.size, 0, 2 * Math.PI);
ctx.fill();
}
// define ball update method
Ball.prototype.update = function() {
if((this.x + this.size) >= width) {
this.velX = -(this.velX);
}
if((this.x - this.size) <= 0) {
this.velX = -(this.velX);
}
if((this.y + this.size) >= height) {
this.velY = -(this.velY);
}
if((this.y - this.size) <= 0) {
this.velY = -(this.velY);
}
this.x += this.velX;
this.y += this.velY;
}
// define ball collision detection
Ball.prototype.collisionDetect = function() {
for(j = 0; j < balls.length; j++) {
if( (!(this.x === balls[j].x && this.y === balls[j].y && this.velX === balls[j].velX && this.velY === balls[j].velY)) ) {
var dx = this.x - balls[j].x;
var dy = this.y - balls[j].y;
var distance = Math.sqrt(dx * dx + dy * dy);
if (distance < this.size + balls[j].size) {
balls[j].color = this.color = 'rgb(' + random(0,255) + ',' + random(0,255) + ',' + random(0,255) +')';
}
}
}
}
// define EvilCircle constructor, inheriting from Shape
function EvilCircle(x, y, exists) {
Shape.call(this, x, y, exists);
this.color = 'white';
this.size = 10;
this.velX = 20;
this.velY = 20;
}
EvilCircle.prototype = Object.create(Shape.prototype);
EvilCircle.prototype.constructor = EvilCircle;
// define EvilCircle draw method
EvilCircle.prototype.draw = function() {
ctx.beginPath();
ctx.strokeStyle = this.color;
ctx.lineWidth = 3;
ctx.arc(this.x, this.y, this.size, 0, 2 * Math.PI);
ctx.stroke();
}
// define EvilCircle checkBounds method
EvilCircle.prototype.checkBounds = function() {
if((this.x + this.size) >= width) {
this.x -= this.size;
}
if((this.x - this.size) <= 0) {
this.x += this.size;
}
if((this.y + this.size) >= height) {
this.y -= this.size;
}
if((this.y - this.size) <= 0) {
this.y += this.size;
}
}
// define EvilCircle setControls method
EvilCircle.prototype.setControls = function() {
var _this = this;
window.onkeydown = function(e) {
if(e.keyCode === 65) { // a
_this.x -= _this.velX;
} else if(e.keyCode === 68) { // d
_this.x += _this.velX;
} else if(e.keyCode === 87) { // w
_this.y -= _this.velY;
} else if(e.keyCode === 83) { // s
_this.y += _this.velY;
}
}
}
// define EvilCircle collision detection
EvilCircle.prototype.collisionDetect = function() {
for(j = 0; j < balls.length; j++) {
if( balls[j].exists ) {
var dx = this.x - balls[j].x;
var dy = this.y - balls[j].y;
var distance = Math.sqrt(dx * dx + dy * dy);
if (distance < this.size + balls[j].size) {
balls[j].exists = false;
count--;
para.textContent = 'Ball count: ' + count;
}
}
}
}
// define array to store balls
var balls = [];
// define loop that keeps drawing the scene constantly
var evil = new EvilCircle();
evil.setControls();
function loop() {
ctx.fillStyle = 'rgba(0,0,0,0.25)';
ctx.fillRect(0,0,width,height);
while(balls.length < 25) {
var ball = new Ball();
balls.push(ball);
count++;
para.textContent = 'Ball count: ' + count;
}
for(i = 0; i < balls.length; i++) {
if(balls[i].exists) {
balls[i].draw();
balls[i].update();
balls[i].collisionDetect();
}
}
evil.draw();
evil.checkBounds();
evil.collisionDetect();
requestAnimationFrame(loop);
}
loop();