# Matter.js

*Matter.js* is a 2D rigid body physics engine for the web written in JavaScript (yes, another)

[brm.io/matter-js](http://brm.io/matter-js)

### Demos

- [Mixed Shapes](http://brm.io/matter-js-demo#mixed)
- [Solid Shapes](http://brm.io/matter-js-demo#mixedSolid)
- [Stack](http://brm.io/matter-js-demo#stack)
- [Circle Stack](http://brm.io/matter-js-demo#circleStack)
- [Pyramid](http://brm.io/matter-js-demo#pyramid)
- [Car](http://brm.io/matter-js-demo#car)
- [Newton's Cradle](http://brm.io/matter-js-demo#newtonsCradle)
- [Restitution](http://brm.io/matter-js-demo#restitution)
- [Friction](http://brm.io/matter-js-demo#friction)
- [Air Friction](http://brm.io/matter-js-demo#airFriction)
- [Reverse Gravity](http://brm.io/matter-js-demo#gravity)
- [Sleeping](http://brm.io/matter-js-demo#sleeping)
- [Grid Broadphase](http://brm.io/matter-js-demo#broadphase)
- [Chains](http://brm.io/matter-js-demo#chains)
- [Ball Pool](http://brm.io/matter-js-demo#ballPool)
- [Wrecking Ball](http://brm.io/matter-js-demo#wreckingBall)
- [Avalanche](http://brm.io/matter-js-demo#avalanche)
- [Beach Balls](http://brm.io/matter-js-demo#beachBalls)
- [Stress 1](http://brm.io/matter-js-demo#stress)
- [Stress 2](http://brm.io/matter-js-demo#stress2)

### Features

-   Physical properties (mass, area, density etc.)
-   Rigid bodies of any convex polygon
-   Stable stacking and resting
-   Restitution (elastic and inelastic collisions)
-   Conservation of momentum
-   Friction and resistance
-   Constraints
-   Gravity
-   Composite bodies
-   Sleeping and static bodies
-   Original JavaScript physics implementation (not a port)
-   HTML5 canvas renderer
-   Mobile-compatible (touch, scaleable)
-   Cross-browser (chrome, firefox, IE8+)
-   World state serialisation (requires
    [resurrect.js](https://github.com/skeeto/resurrect-js))
-   Built in GUI for testing (requires
    [dat.gui.js](http://workshop.chromeexperiments.com/examples/gui/))
-   Time scaling (slow-mo, speed-up)
-   Broad-phase, mid-phase and narrow-phase collisions

### Status

Matter.js is currently only *alpha* status, so production use should be avoided.

This engine is the result of [learning game physics](http://brm.io/game-physics-for-beginners/) and getting a bit carried away. 
<br>There's no intention to compete with other engines, so I'm not sure yet if it will be developed further. 
<br>That said, the engine is reasonably stable and performs well, it's just not feature complete.

Though if I get time and people are interested, I may continue working on it.
<br>Contributions are also welcome, if you'd like to help.

### Install

Download [matter.js](https://raw2.github.com/liabru/matter-js/master/build/matter.js) or [matter.min.js](https://raw2.github.com/liabru/matter-js/master/build/matter.min.js) and include the script in your HTML file:

	<script src="matter.js" type="text/javascript"></script>

### Usage

See [Demo.js](https://raw2.github.com/liabru/matter-js/master/demo/js/Demo.js) and [DemoMobile.js](https://raw2.github.com/liabru/matter-js/master/demo/js/DemoMobile.js) for many usage examples. No docs at the moment, sorry.
<br>When loaded, all functions are under the global <code>Matter.*</code> namespace.

### Implementation

The technical details for physics nerds and game devs.
<br>This engine is using the following techniques:

-   Time-corrected position Verlet integrator
-   Adaptive grid broad-phase detection
-   AABB mid-phase detection
-   SAT narrow-phase detection
-   Iterative sequential impulse solver and position solver
-   Resting collisions with resting constraints ala Erin Catto's method
    (GDC08)
-   Temporal coherence impulse caching and warming
-   Collision pairs, contacts and impulses maintained with a pair
    manager
-   Approximate Coulomb friction model using friction constraints
-   Constraints solved with the Gauss-Siedel method
-   Semi-variable time step, synced with rendering
- 	A basic sleeping strategy
-   HTML5 canvas renderer

### References

See my post on [Game physics for beginners](http://brm.io/game-physics-for-beginners/).

### License

Matter.js is licensed under [The MIT License (MIT)](http://opensource.org/licenses/MIT)
<br/>Copyright (c) 2014 Liam Brummitt

This license is also supplied with the release and source code.
<br/>As stated in the license, absolutely no warranty is provided.

### Similar Projects

If you need a more complete engine, check out jswiki's list of [Physics libraries](https://github.com/bebraw/jswiki/wiki/Physics-libraries)