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JavaScript Game Engine

Fix Twoway jump

Fix Twoway jump to set the vertical velocity to `-jumpSpeed` instead of subtracting it from the current vertical velocity.   
This makes for better behaviour especially when double jumping.
latest commit d14124a238
mucaho mucaho authored

Crafty JS Build Status

Crafty is a JavaScript game library that can help you create games in a structured way…

Key Features:

  • Entities & Components - A clean and decoupled way to organize game elements. No inheritance needed!
  • Eventbinding - Event system for custom events that can be triggered whenever, whatever and bound just as easily.
  • No dom manipulation or custom drawing routines required.

Other Goodies:

  • Thriving community - Help is readily available in the forum.
  • Community modules - A growing collection of user-generated code you can use.
  • Pure JavaScript - No magic. Works in all major browsers and can be combined with your favorite js library.

Using Crafty

A simple game of pong:

Crafty.init(600, 300);
Crafty.e("Paddle, 2D, DOM, Color, Multiway")
    .attr({ x: 20, y: 100, w: 10, h: 100 })
    .multiway(4, { W: -90, S: 90 });
Crafty.e("Paddle, 2D, DOM, Color, Multiway")
    .attr({ x: 580, y: 100, w: 10, h: 100 })
    .multiway(4, { UP_ARROW: -90, DOWN_ARROW: 90 });
Crafty.e("2D, DOM, Color, Collision")
    .attr({ x: 300, y: 150, w: 10, h: 10,
            dX: Crafty.math.randomInt(2, 5),
            dY: Crafty.math.randomInt(2, 5) })
    .bind('EnterFrame', function () {
        //hit floor or roof
        if (this.y <= 0 || this.y >= 290)
            this.dY *= -1;

        if (this.x > 600) {
            this.x = 300;
            Crafty("LeftPoints").each(function () {
                this.text(++this.points + " Points") });
        if (this.x < 10) {
            this.x = 300;
            Crafty("RightPoints").each(function () {
                this.text(++this.points + " Points") });

        this.x += this.dX;
        this.y += this.dY;
    .onHit('Paddle', function () {
    this.dX *= -1;

//Score boards
Crafty.e("LeftPoints, DOM, 2D, Text")
    .attr({ x: 20, y: 20, w: 100, h: 20, points: 0 })
    .text("0 Points");
Crafty.e("RightPoints, DOM, 2D, Text")
    .attr({ x: 515, y: 20, w: 100, h: 20, points: 0 })
    .text("0 Points");


If you want to fix a bug, please submit a pull request against the development branch. Some guides to help you can be found on the wiki

If you would like to make larger contributions please catch us in the forum and we will help you get started. Much appreciated :-)

Quick build instructions

The easiest way to build crafty uses gruntjs, which requires node and npm. If you have grunt, node, and npm already installed, then run npm install from Crafty's root directory. (This will pull down about 30MB of node packages.) From then on, just run grunt to build.

(Full instructions here.)

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