Example #1
0
        /// <summary>
        /// Adds a body to the controller list.
        /// </summary>
        public void AddBody(Body body)
        {
            ControllerEdge edge = new ControllerEdge();

            edge.body       = body;
            edge.controller = this;

            //Add edge to controller list
            edge.nextBody = _bodyList;
            edge.prevBody = null;
            if (_bodyList != null)
            {
                _bodyList.prevBody = edge;
            }
            _bodyList = edge;
            ++_bodyCount;

            //Add edge to body list
            edge.nextController = body._controllerList;
            edge.prevController = null;
            if (body._controllerList != null)
            {
                body._controllerList.prevController = edge;
            }
            body._controllerList = edge;
        }
Example #2
0
        public Controller(PhysicsSimulator world)
        {
            _bodyList  = null;
            _bodyCount = 0;

            _world = world;
        }
Example #3
0
        /// <summary>
        /// Removes a body from the controller list.
        /// </summary>
        public void RemoveBody(Body body)
        {
            //Assert that the controller is not empty
            //Box2DXDebug.Assert(_bodyCount > 0);

            //Find the corresponding edge
            ControllerEdge edge = _bodyList;

            while (edge != null && edge.body != body)
            {
                edge = edge.nextBody;
            }

            //Assert that we are removing a body that is currently attached to the controller
            //Box2DXDebug.Assert(edge != null);

            //Remove edge from controller list
            if (edge.prevBody != null)
            {
                edge.prevBody.nextBody = edge.nextBody;
            }
            if (edge.nextBody != null)
            {
                edge.nextBody.prevBody = edge.prevBody;
            }
            if (edge == _bodyList)
            {
                _bodyList = edge.nextBody;
            }
            --_bodyCount;

            //Remove edge from body list
            if (edge.prevController != null)
            {
                edge.prevController.nextController = edge.nextController;
            }
            if (edge.nextController != null)
            {
                edge.nextController.prevController = edge.prevController;
            }
            if (edge == body._controllerList)
            {
                body._controllerList = edge.nextController;
            }

            //Free the edge
            edge = null;
        }
Example #4
0
 public Controller()
 {
     _bodyList  = null;
     _bodyCount = 0;
 }
 public override void Step(TimeStep step)
 {
     if (_bodyList == null)
     {
         return;
     }
     if (useWorldGravity)
     {
         gravity = _world.Gravity;
     }
     for (ControllerEdge i = _bodyList; i != null; i = i.nextBody)
     {
         Body body = i.body;
         if (body.IsSleeping())
         {
             //Buoyancy force is just a function of position,
             //so unlike most forces, it is safe to ignore sleeping bodes
             continue;
         }
         Vector2 areac = new Vector2(0, 0);
         Vector2 massc = new Vector2(0, 0);
         float   area  = 0;
         float   mass  = 0;
         for (Shape shape = body.GetShapeList(); shape != null; shape = shape.GetNext())
         {
             Vector2 sc;
             float   sarea = shape.ComputeSubmergedArea(normal, offset, body.GetXForm(), out sc);
             area    += sarea;
             areac.X += sarea * sc.X;
             areac.Y += sarea * sc.Y;
             float shapeDensity = 0;
             if (useDensity)
             {
                 //TODO: Expose density publicly
                 shapeDensity = shape.Density;
             }
             else
             {
                 shapeDensity = 1;
             }
             mass    += sarea * shapeDensity;
             massc.X += sarea * sc.X * shapeDensity;
             massc.Y += sarea * sc.Y * shapeDensity;
         }
         areac.X /= area;
         areac.Y /= area;
         massc.X /= mass;
         massc.Y /= mass;
         if (area < Settings.FLT_EPSILON)
         {
             continue;
         }
         //Buoyancy
         Vector2 buoyancyForce = -density * area * gravity;
         body.ApplyForce(buoyancyForce, massc);
         //Linear drag
         Vector2 dragForce = body.GetLinearVelocityFromWorldPoint(areac) - velocity;
         dragForce *= -linearDrag * area;
         body.ApplyForce(dragForce, areac);
         //Angular drag
         //TODO: Something that makes more physical sense?
         body.ApplyTorque(-body.GetInertia() / body.GetMass() * area * body.GetAngularVelocity() * angularDrag);
     }
 }