text: var Engine, Render, World, Bodies, Composites, engine;
  var width, height;
  
  var Physics = {
  
      init: function(canvasId) {
          // module aliases
          Engine = Matter.Engine,
          Render = Matter.Render,
          World = Matter.World,
          Bodies = Matter.Bodies,
          Composites = Matter.Composites;
  
          // create an engine
          engine = Engine.create();
  
          width = $(window).innerWidth();
          height = $(window).innerHeight();
  
          // create a renderer
          var render = Render.create({
              element: document.body,
              canvas: document.getElementById('canvas'),
              engine: engine,
              options: {
                  wireframes: false,
                  width: width,
                  height: height
              }
          });
  
  
          this.addBodies();
  
          // run the engine
          Engine.run(engine);
  
          // run the renderer
          Render.run(render);
      },
  
      addBodies:function(){
  
          World.clear(engine.world)
  
          var boxWidth = width * 0.04
  
          var stack = Composites.stack(40, 40, 10, 10, 0, 0, function(x, y) {
              return Bodies.rectangle(x, y, boxWidth, boxWidth)
          })
  
          var supports = Composites.stack(40, 40, 5, 4, 0, 0, function(x, y) {
              return Bodies.rectangle(x, y, boxWidth, boxWidth)
          })
  
          var suport1 = Bodies.rectangle(width / 2, height / 10, width * 5 / 10, 10, {
              angle: Math.PI * 0.05,
              isStatic: true
          })
  
          var suport2 = Bodies.rectangle(width / 2, height * 3 / 10, width * 4 / 10, 10, {
              angle: -Math.PI * 0.05,
              isStatic: true
          })
  
          var suport3 = Bodies.rectangle(width * 7 / 10, height * 5 / 10, width * 5 / 10, 10, {
              angle: Math.PI * 0.05,
              isStatic: true
          })
  
          var suport4 = Bodies.rectangle(width * 1 / 4, height * 7 / 10, width * 5 / 10, 10, {
              angle: Math.PI * 0.05,
              isStatic: true
          })
  
          var ground = Bodies.rectangle(width/2, height, width, 10, {
              isStatic: true
          });
  
          // add all of the bodies to the world
          World.add(engine.world, [stack, ground, suport1, suport2, suport3, suport4]);
  
  
      }
  
  }