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Title	this (with constructor) demo
ID	2366788078
Created	12 years ago, 1383015231335
Updated	5 years ago, 1604336996002
Code	/* * "Ball" is a CONSTRUCTOR function. It magically RETURNS an * object referred to as "this". Note that we do not declare * "var this"; we simply start using "this". We also do not use * the "return" key word. An object is constructed when the * function invocation is done in conjunction with the "new" * keyword. * * This ball will have unique values for all its properties * such as color, size, shape, location and velocity. / var Ball = function() { this.radius = random(10, 31); this.x = random(this.radius, width - this.radius); this.y = random(this.radius, height - this.radius); this.dx = random(-12, 12); this.dy = random(-12, 12); this.shape = (random(0, 1) < 0.5) ? rect : ellipse; this.color = color(random(50, 200), random(50, 200), random(50, 200)); }; / Render this Ball / Ball.prototype.render = function() { fill(this.color); this.shape(this.x, this.y, 2 this.radius, random(1.5, 2.5) * this.radius, 5); }; /* Update this Ball's properties / Ball.prototype.update = function() { / * move this x location forward and change this * x velocity if this ball has gone off canvas. / this.x += this.dx; if (this.x <= this.radius \|\| this.x >= width - this.radius) { this.dx = -1; } /* same for this y location and this y velocity / this.y += this.dy; if (this.y <= this.radius \|\| this.y >= height - this.radius) { this.dy = -1; } }; var balls; /* array of managed balls / / Initialize all global scope data upon (re)start. / var initialize = function() { var cnt = floor(random(2, 9)); / number of balls / balls = []; / where we keep track of the balls / while (--cnt >= 0) { var newBall = new Ball(); / get another new ball / balls.push(newBall); / put that ball in the array / } rectMode(CENTER); }; / * Called numerous times per second by Processingjs. * My advice: Always update everything first. Then draw everthing. / draw = function() { for (var b = 0; b < balls.length; b++) { balls[b].update(); } for (b = 0; b < balls.length; b++) { balls[b].render(); } }; initialize(); / Let's light this candle! */ // I am honored any time anybody uses my code for any purpose. // Copy freely! All my programs are at // https://www.khanacademy.org/profile/BobLyon/programs
Folds
Fork	false
Key	ag5zfmtoYW4tYWNhZGVteXIUCxIKU2NyYXRjaHBhZBjuo8noCAw
Votes	386
Spin-Offs	25
Type	PJS
Width	400
Height	400
User Flagged	false
Origin Scratchpad	null
Hidden From Hotlist	false
Restricted Posting	false
By Child	false
Author Nick	Bob Lyon
Author Name	BobLyon
Author ID	kaid_1116520053705160540512971
Author Profile Access	COACH

Archive Data

Added	10 months ago, 1739284772771
Updated	8 months ago, 1744828506181
Source Deleted	unknown