// This file comes from Box2D-JS, Copyright (c) 2008 ANDO Yasushi.
// The original version is available at http://box2d-js.sourceforge.net/ under the
// zlib/libpng license (see License.txt).
// This version has been modified to make it work with O3D.

demos.crank = {};
demos.crank.initWorld = function(world) {
  var ground = world.m_groundBody;

  // Define crank.
  var sd = new b2BoxDef();
  sd.extents.Set(5, 25);
  sd.density = 1.0;

  var bd = new b2BodyDef();
  bd.userData = g.mgr.createBox(5, 25);
  bd.AddShape(sd);

  var rjd = new b2RevoluteJointDef();

  var prevBody = ground;

  bd.position.Set(500/2, 210);
  bd.userData = g.mgr.createBox(5, 25);
  var body = world.CreateBody(bd);

  rjd.anchorPoint.Set(500/2, 235);
  rjd.body1 = prevBody;
  rjd.body2 = body;
  rjd.motorSpeed = -1.0 * Math.PI;
  rjd.motorTorque = 500000000.0;
  rjd.enableMotor = true;
  world.CreateJoint(rjd);

  prevBody = body;

  // Define follower.
  sd.extents.Set(5, 45);
  bd.position.Set(500/2, 140);
  bd.userData = g.mgr.createBox(5, 45);
  body = world.CreateBody(bd);

  rjd.anchorPoint.Set(500/2, 185);
  rjd.body1 = prevBody;
  rjd.body2 = body;
  rjd.enableMotor = false;
  world.CreateJoint(rjd);

  prevBody = body;

  // Define piston
  sd.extents.Set(20, 20);
  bd.position.Set(500/2, 95);
  bd.userData = g.mgr.createBox(20, 20);
  body = world.CreateBody(bd);

  rjd.anchorPoint.Set(500/2, 95);
  rjd.body1 = prevBody;
  rjd.body2 = body;
  world.CreateJoint(rjd);

  var pjd = new b2PrismaticJointDef();
  pjd.anchorPoint.Set(500/2, 95);
  pjd.body1 = ground;
  pjd.body2 = body;
  pjd.axis.Set(0.0, 1.0);
  pjd.motorSpeed = 0.0; // joint friction
  pjd.motorForce = 100000.0;
  pjd.enableMotor = true;

  world.CreateJoint(pjd);

  // Create a payload
  sd.density = 2.0;
  bd.position.Set(500/2, 10);
  bd.userData = g.mgr.createBox(20, 20);
  world.CreateBody(bd);
}
demos.InitWorlds.push(demos.crank.initWorld);