function drawWorld(world, context) {
          for (var j = world.m_jointList; j; j = j.m_next) {
                  drawJoint(j, context);
          }
          for (var b = world.m_bodyList; b; b = b.m_next) {
                  for (var s = b.GetShapeList(); s != null; s = s.GetNext()) {
                          drawShape(s, context);
                  }
          }
  }
  function drawJoint(joint, context) {
          var b1 = joint.m_body1;
          var b2 = joint.m_body2;
          var x1 = b1.m_position;
          var x2 = b2.m_position;
          var p1 = joint.GetAnchor1();
          var p2 = joint.GetAnchor2();
          context.strokeStyle = '#00eeee';
          context.beginPath();
          switch (joint.m_type) {
          case b2Joint.e_distanceJoint:
                  context.moveTo(p1.x, p1.y);
                  context.lineTo(p2.x, p2.y);
                  break;
  
          case b2Joint.e_pulleyJoint:
                  // TODO
                  break;
  
          default:
                  if (b1 == world.m_groundBody) {
                          context.moveTo(p1.x, p1.y);
                          context.lineTo(x2.x, x2.y);
                  }
                  else if (b2 == world.m_groundBody) {
                          context.moveTo(p1.x, p1.y);
                          context.lineTo(x1.x, x1.y);
                  }
                  else {
                          context.moveTo(x1.x, x1.y);
                          context.lineTo(p1.x, p1.y);
                          context.lineTo(x2.x, x2.y);
                          context.lineTo(p2.x, p2.y);
                  }
                  break;
          }
          context.stroke();
  }
  function drawShape(shape, context) {
          context.strokeStyle = '#ffffff';
          context.beginPath();
          switch (shape.m_type) {
          case b2Shape.e_circleShape:
                  {
                          var circle = shape;
                          var pos = circle.m_position;
                          var r = circle.m_radius;
                          var segments = 16.0;
                          var theta = 0.0;
                          var dtheta = 2.0 * Math.PI / segments;
                          // draw circle
                          context.moveTo(pos.x + r, pos.y);
                          for (var i = 0; i < segments; i++) {
                                  var d = new b2Vec2(r * Math.cos(theta), r * Math.sin(theta));
                                  var v = b2Math.AddVV(pos, d);
                                  context.lineTo(v.x, v.y);
                                  theta += dtheta;
                          }
                          context.lineTo(pos.x + r, pos.y);
          
                          // draw radius
                          context.moveTo(pos.x, pos.y);
                          var ax = circle.m_R.col1;
                          var pos2 = new b2Vec2(pos.x + r * ax.x, pos.y + r * ax.y);
                          context.lineTo(pos2.x, pos2.y);
                  }
                  break;
          case b2Shape.e_polyShape:
                  {
                          var poly = shape;
                          var tV = b2Math.AddVV(poly.m_position, b2Math.b2MulMV(poly.m_R, poly.m_vertices[0]));
                          context.moveTo(tV.x, tV.y);
                          for (var i = 0; i < poly.m_vertexCount; i++) {
                                  var v = b2Math.AddVV(poly.m_position, b2Math.b2MulMV(poly.m_R, poly.m_vertices[i]));
                                  context.lineTo(v.x, v.y);
                          }
                          context.lineTo(tV.x, tV.y);
                  }
                  break;
          }
          context.stroke();
  }