/*
  * Copyright (c) 2006-2007 Erin Catto 
* This software is provided 'as-is', without any express or implied
* warranty.  In no event will the authors be held liable for any damages
* arising from the use of this software.
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked, and must not be
* misrepresented the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/

//typedef b2Contact* b2ContactCreateFcn(b2Shape* shape1, b2Shape* shape2, b2BlockAllocator* allocator);
//typedef void b2ContactDestroyFcn(b2Contact* contact, b2BlockAllocator* allocator);

var b2Contact = Class.create();
b2Contact.prototype = 
{
        GetManifolds: function(){return null},
        GetManifoldCount: function()
        {
                return this.m_manifoldCount;
        },

        GetNext: function(){
                return this.m_next;
        },

        GetShape1: function(){
                return this.m_shape1;
        },

        GetShape2: function(){
                return this.m_shape2;
        },

        //--------------- Internals Below -------------------

        // this.m_flags
        // enum

        initialize: function(s1, s2)
        {
                // initialize instance variables for references
                this.m_node1 = new b2ContactNode();
                this.m_node2 = new b2ContactNode();
                //

                this.m_flags = 0;

                if (!s1 || !s2){
                        this.m_shape1 = null;
                        this.m_shape2 = null;
                        return;
                }

                this.m_shape1 = s1;
                this.m_shape2 = s2;

                this.m_manifoldCount = 0;

                this.m_friction = Math.sqrt(this.m_shape1.m_friction * this.m_shape2.m_friction);
                this.m_restitution = b2Math.b2Max(this.m_shape1.m_restitution, this.m_shape2.m_restitution);

                this.m_prev = null;
                this.m_next = null;

                this.m_node1.contact = null;
                this.m_node1.prev = null;
                this.m_node1.next = null;
                this.m_node1.other = null;

                this.m_node2.contact = null;
                this.m_node2.prev = null;
                this.m_node2.next = null;
                this.m_node2.other = null;
        },

        //virtual ~b2Contact() {}

        Evaluate: function(){},

        m_flags: 0,

        // World pool and list pointers.
        m_prev: null,
        m_next: null,

        // Nodes for connecting bodies.
        m_node1: new b2ContactNode(),
        m_node2: new b2ContactNode(),

        m_shape1: null,
        m_shape2: null,

        m_manifoldCount: 0,

        // Combined friction
        m_friction: null,
        m_restitution: null};
b2Contact.e_islandFlag = 0x0001;
b2Contact.e_destroyFlag = 0x0002;
b2Contact.AddType = function(createFcn, destroyFcn, type1, type2)
        {
                //b2Settings.b2Assert(b2Shape.e_unknownShape < type1 && type1 < b2Shape.e_shapeTypeCount);
                //b2Settings.b2Assert(b2Shape.e_unknownShape < type2 && type2 < b2Shape.e_shapeTypeCount);

                b2Contact.s_registers[type1][type2].createFcn = createFcn;
                b2Contact.s_registers[type1][type2].destroyFcn = destroyFcn;
                b2Contact.s_registers[type1][type2].primary = true;

                if (type1 != type2)
                {
                        b2Contact.s_registers[type2][type1].createFcn = createFcn;
                        b2Contact.s_registers[type2][type1].destroyFcn = destroyFcn;
                        b2Contact.s_registers[type2][type1].primary = false;
                }
        };
b2Contact.InitializeRegisters = function(){
                b2Contact.s_registers = new Array(b2Shape.e_shapeTypeCount);
                for (var i = 0; i < b2Shape.e_shapeTypeCount; i++){
                        b2Contact.s_registers[i] = new Array(b2Shape.e_shapeTypeCount);
                        for (var j = 0; j < b2Shape.e_shapeTypeCount; j++){
                                b2Contact.s_registers[i][j] = new b2ContactRegister();
                        }
                }

                b2Contact.AddType(b2CircleContact.Create, b2CircleContact.Destroy, b2Shape.e_circleShape, b2Shape.e_circleShape);
                b2Contact.AddType(b2PolyAndCircleContact.Create, b2PolyAndCircleContact.Destroy, b2Shape.e_polyShape, b2Shape.e_circleShape);
                b2Contact.AddType(b2PolyContact.Create, b2PolyContact.Destroy, b2Shape.e_polyShape, b2Shape.e_polyShape);

        };
b2Contact.Create = function(shape1, shape2, allocator){
                if (b2Contact.s_initialized == false)
                {
                        b2Contact.InitializeRegisters();
                        b2Contact.s_initialized = true;
                }

                var type1 = shape1.m_type;
                var type2 = shape2.m_type;

                //b2Settings.b2Assert(b2Shape.e_unknownShape < type1 && type1 < b2Shape.e_shapeTypeCount);
                //b2Settings.b2Assert(b2Shape.e_unknownShape < type2 && type2 < b2Shape.e_shapeTypeCount);

                var createFcn = b2Contact.s_registers[type1][type2].createFcn;
                if (createFcn)
                {
                        if (b2Contact.s_registers[type1][type2].primary)
                        {
                                return createFcn(shape1, shape2, allocator);
                        }
                        else
                        {
                                var c = createFcn(shape2, shape1, allocator);
                                for (var i = 0; i < c.GetManifoldCount(); ++i)
                                {
                                        var m = c.GetManifolds()[ i ];
                                        m.normal = m.normal.Negative();
                                }
                                return c;
                        }
                }
                else
                {
                        return null;
                }
        };
b2Contact.Destroy = function(contact, allocator){
                //b2Settings.b2Assert(b2Contact.s_initialized == true);

                if (contact.GetManifoldCount() > 0)
                {
                        contact.m_shape1.m_body.WakeUp();
                        contact.m_shape2.m_body.WakeUp();
                }

                var type1 = contact.m_shape1.m_type;
                var type2 = contact.m_shape2.m_type;

                //b2Settings.b2Assert(b2Shape.e_unknownShape < type1 && type1 < b2Shape.e_shapeTypeCount);
                //b2Settings.b2Assert(b2Shape.e_unknownShape < type2 && type2 < b2Shape.e_shapeTypeCount);

                var destroyFcn = b2Contact.s_registers[type1][type2].destroyFcn;
                destroyFcn(contact, allocator);
        };
b2Contact.s_registers = null;
b2Contact.s_initialized = false;



  *
  * This software is provided 'as-is', without any express or implied
  * warranty.  In no event will the authors be held liable for any damages
  * arising from the use of this software.
  * Permission is granted to anyone to use this software for any purpose,
  * including commercial applications, and to alter it and redistribute it
  * freely, subject to the following restrictions:
  * 1. The origin of this software must not be misrepresented; you must not
  * claim that you wrote the original software. If you use this software
  * in a product, an acknowledgment in the product documentation would be
  * appreciated but is not required.
  * 2. Altered source versions must be plainly marked, and must not be
  * misrepresented the original software.
  * 3. This notice may not be removed or altered from any source distribution.
  */
  
  //typedef b2Contact* b2ContactCreateFcn(b2Shape* shape1, b2Shape* shape2, b2BlockAllocator* allocator);
  //typedef void b2ContactDestroyFcn(b2Contact* contact, b2BlockAllocator* allocator);
  
  var b2Contact = Class.create();
  b2Contact.prototype = 
  {
          GetManifolds: function(){return null},
          GetManifoldCount: function()
          {
                  return this.m_manifoldCount;
          },
  
          GetNext: function(){
                  return this.m_next;
          },
  
          GetShape1: function(){
                  return this.m_shape1;
          },
  
          GetShape2: function(){
                  return this.m_shape2;
          },
  
          //--------------- Internals Below -------------------
  
          // this.m_flags
          // enum
  
          initialize: function(s1, s2)
          {
                  // initialize instance variables for references
                  this.m_node1 = new b2ContactNode();
                  this.m_node2 = new b2ContactNode();
                  //
  
                  this.m_flags = 0;
  
                  if (!s1 || !s2){
                          this.m_shape1 = null;
                          this.m_shape2 = null;
                          return;
                  }
  
                  this.m_shape1 = s1;
                  this.m_shape2 = s2;
  
                  this.m_manifoldCount = 0;
  
                  this.m_friction = Math.sqrt(this.m_shape1.m_friction * this.m_shape2.m_friction);
                  this.m_restitution = b2Math.b2Max(this.m_shape1.m_restitution, this.m_shape2.m_restitution);
  
                  this.m_prev = null;
                  this.m_next = null;
  
                  this.m_node1.contact = null;
                  this.m_node1.prev = null;
                  this.m_node1.next = null;
                  this.m_node1.other = null;
  
                  this.m_node2.contact = null;
                  this.m_node2.prev = null;
                  this.m_node2.next = null;
                  this.m_node2.other = null;
          },
  
          //virtual ~b2Contact() {}
  
          Evaluate: function(){},
  
          m_flags: 0,
  
          // World pool and list pointers.
          m_prev: null,
          m_next: null,
  
          // Nodes for connecting bodies.
          m_node1: new b2ContactNode(),
          m_node2: new b2ContactNode(),
  
          m_shape1: null,
          m_shape2: null,
  
          m_manifoldCount: 0,
  
          // Combined friction
          m_friction: null,
          m_restitution: null};
  b2Contact.e_islandFlag = 0x0001;
  b2Contact.e_destroyFlag = 0x0002;
  b2Contact.AddType = function(createFcn, destroyFcn, type1, type2)
          {
                  //b2Settings.b2Assert(b2Shape.e_unknownShape < type1 && type1 < b2Shape.e_shapeTypeCount);
                  //b2Settings.b2Assert(b2Shape.e_unknownShape < type2 && type2 < b2Shape.e_shapeTypeCount);
  
                  b2Contact.s_registers[type1][type2].createFcn = createFcn;
                  b2Contact.s_registers[type1][type2].destroyFcn = destroyFcn;
                  b2Contact.s_registers[type1][type2].primary = true;
  
                  if (type1 != type2)
                  {
                          b2Contact.s_registers[type2][type1].createFcn = createFcn;
                          b2Contact.s_registers[type2][type1].destroyFcn = destroyFcn;
                          b2Contact.s_registers[type2][type1].primary = false;
                  }
          };
  b2Contact.InitializeRegisters = function(){
                  b2Contact.s_registers = new Array(b2Shape.e_shapeTypeCount);
                  for (var i = 0; i < b2Shape.e_shapeTypeCount; i++){
                          b2Contact.s_registers[i] = new Array(b2Shape.e_shapeTypeCount);
                          for (var j = 0; j < b2Shape.e_shapeTypeCount; j++){
                                  b2Contact.s_registers[i][j] = new b2ContactRegister();
                          }
                  }
  
                  b2Contact.AddType(b2CircleContact.Create, b2CircleContact.Destroy, b2Shape.e_circleShape, b2Shape.e_circleShape);
                  b2Contact.AddType(b2PolyAndCircleContact.Create, b2PolyAndCircleContact.Destroy, b2Shape.e_polyShape, b2Shape.e_circleShape);
                  b2Contact.AddType(b2PolyContact.Create, b2PolyContact.Destroy, b2Shape.e_polyShape, b2Shape.e_polyShape);
  
          };
  b2Contact.Create = function(shape1, shape2, allocator){
                  if (b2Contact.s_initialized == false)
                  {
                          b2Contact.InitializeRegisters();
                          b2Contact.s_initialized = true;
                  }
  
                  var type1 = shape1.m_type;
                  var type2 = shape2.m_type;
  
                  //b2Settings.b2Assert(b2Shape.e_unknownShape < type1 && type1 < b2Shape.e_shapeTypeCount);
                  //b2Settings.b2Assert(b2Shape.e_unknownShape < type2 && type2 < b2Shape.e_shapeTypeCount);
  
                  var createFcn = b2Contact.s_registers[type1][type2].createFcn;
                  if (createFcn)
                  {
                          if (b2Contact.s_registers[type1][type2].primary)
                          {
                                  return createFcn(shape1, shape2, allocator);
                          }
                          else
                          {
                                  var c = createFcn(shape2, shape1, allocator);
                                  for (var i = 0; i < c.GetManifoldCount(); ++i)
                                  {
                                          var m = c.GetManifolds()[ i ];
                                          m.normal = m.normal.Negative();
                                  }
                                  return c;
                          }
                  }
                  else
                  {
                          return null;
                  }
          };
  b2Contact.Destroy = function(contact, allocator){
                  //b2Settings.b2Assert(b2Contact.s_initialized == true);
  
                  if (contact.GetManifoldCount() > 0)
                  {
                          contact.m_shape1.m_body.WakeUp();
                          contact.m_shape2.m_body.WakeUp();
                  }
  
                  var type1 = contact.m_shape1.m_type;
                  var type2 = contact.m_shape2.m_type;
  
                  //b2Settings.b2Assert(b2Shape.e_unknownShape < type1 && type1 < b2Shape.e_shapeTypeCount);
                  //b2Settings.b2Assert(b2Shape.e_unknownShape < type2 && type2 < b2Shape.e_shapeTypeCount);
  
                  var destroyFcn = b2Contact.s_registers[type1][type2].destroyFcn;
                  destroyFcn(contact, allocator);
          };
  b2Contact.s_registers = null;
  b2Contact.s_initialized = false;