/*
* TODO Give the Box2dWeb related properties their real types
*/
/**
* Box2D Physics System
*
* Box2dWeb implementation.
*
* @class box2d
* @namespace zerk.game.engine.system.physics
* @extends zerk.game.engine.system.physics
* @module zerk
**/
zerk.define({
name: 'zerk.game.engine.system.physics.box2d',
extend: 'zerk.game.engine.system.physics'
},{
/**
* Physics configuration
*
* @property _config
* @type Object
* @protected
*/
_config: null,
/**
* Box2D world
*
* @property _world
* @type Box2D.Dynamics.b2World
* @protected
*/
_world: null,
/**
* Handle for the mouse joint
*
* @property _mouseJoint
* @type Object
* @protected
*/
_mouseJoint: null,
/**
* Stores a vector for the mouse joint function
*
* @property _mouseJointVec
* @type Object
* @protected
*/
_mouseJointVec: null,
/**
* Stores the last selected body
*
* @property _selectedBody
* @type Object
* @protected
*/
_selectedBody: null,
/**
* List of bodies to be destroyed after current simulation tick
*
* @property _destroyBodyList
* @type Array
* @protected
*/
_destroyBodyList: null,
/**
* List of joints to be destroyed after current simulation tick
*
* @property __destroyJointList
* @type Array
* @protected
*/
_destroyJointList: null,
/**
* Shortcut for Box2D.Common.Math.b2Vec2
*
* @property _b2Vec2
* @type Object
* @protected
*/
_b2Vec2: Box2D.Common.Math.b2Vec2,
/**
* Shortcut for Box2D.Collision.b2AABB
*
* @property _b2AABB
* @type Object
* @protected
*/
_b2AABB: Box2D.Collision.b2AABB,
/**
* Shortcut for Box2D.Dynamics.b2BodyDef
*
* @property _b2BodyDef
* @type Object
* @protected
*/
_b2BodyDef: Box2D.Dynamics.b2BodyDef,
/**
* Shortcut for Box2D.Dynamics.b2Body
*
* @property _b2Body
* @type Object
* @protected
*/
_b2Body: Box2D.Dynamics.b2Body,
/**
* Shortcut for Box2D.Dynamics.b2FixtureDef
*
* @property _b2FixtureDef
* @type Object
* @protected
*/
_b2FixtureDef: Box2D.Dynamics.b2FixtureDef,
/**
* Shortcut for Box2D.Dynamics.b2World
*
* @property _b2World
* @type Object
* @protected
*/
_b2World: Box2D.Dynamics.b2World,
/**
* Shortcut for Box2D.Collision.Shapes.b2PolygonShape
*
* @property _b2PolygonShape
* @type Object
* @protected
*/
_b2PolygonShape: Box2D.Collision.Shapes.b2PolygonShape,
/**
* Shortcut for Box2D.Collision.Shapes.b2CircleShape
*
* @property _b2CircleShape
* @type Object
* @protected
*/
_b2CircleShape: Box2D.Collision.Shapes.b2CircleShape,
/**
* Shortcut for Box2D.Dynamics.b2DebugDraw
*
* @property _b2DebugDraw
* @type Object
* @protected
*/
_b2DebugDraw: Box2D.Dynamics.b2DebugDraw,
/**
* Shortcut for Box2D.Dynamics.Joints.b2MouseJointDef
*
* @property _b2MouseJointDef
* @type Object
* @protected
*/
_b2MouseJointDef: Box2D.Dynamics.Joints.b2MouseJointDef,
/**
* Shortcut for Box2D.Dynamics.Joints.b2RevoluteJointDef
*
* @property _b2RevoluteJointDef
* @type Object
* @protected
*/
_b2RevoluteJointDef: Box2D.Dynamics.Joints.b2RevoluteJointDef,
/**
* Shortcut for Box2D.Dynamics.Joints.b2DistanceJointDef
*
* @property _b2DistanceJointDef
* @type Object
* @protected
*/
_b2DistanceJointDef: Box2D.Dynamics.Joints.b2DistanceJointDef,
/**
* Shortcut for Box2D.Dynamics.b2ContactListener
*
* @property _b2ContactListener
* @type Object
* @protected
*/
_b2ContactListener: Box2D.Dynamics.b2ContactListener,
/**
* Class constructor
*
* @method init
* @param {zerk.game.engine} engine Game engine
*/
init: function(engine,config) {
zerk.parent('zerk.game.engine.system.physics.box2d').init.apply(
this,
arguments
);
this._destroyBodyList=[];
this._destroyJointList=[];
this._world=new this._b2World(
new this._b2Vec2(
this._config.gravityX,
this._config.gravityY
), // Setup gravity
true // allow sleep
);
// Box2D debug draw
if (this._config.debugDraw) {
this.canvas=this._getSystem('viewport').getCanvasPhysicsDebug();
/*
* TODO Sync the view position with the game viewport
*
* this.canvas.getContext("2d").translate(200,200);
*/
var debugDraw = new this._b2DebugDraw();
debugDraw.SetSprite(this.canvas.getContext("2d"));
debugDraw.SetDrawScale(30.0);
debugDraw.SetFillAlpha(0.5);
debugDraw.SetLineThickness(1.0);
debugDraw.SetFlags(
this._b2DebugDraw.e_shapeBit | this._b2DebugDraw.e_jointBit
);
this._world.SetDebugDraw(debugDraw);
}
this._addContactListener();
this._log('Ready');
},
/**
* Physics engine tick
*
* @method tick
*/
_tick: function() {
this._processMouseJoint();
/*
* TODO Make world step settings configurable
*/
// World step
this._world.Step(
1/60, // Frame rate
10, // Velocity iterations
10 // Position iterations
);
if (this._config.debugDraw) {
this._world.DrawDebugData();
}
this._world.ClearForces();
this._cleanup();
},
getBody: function(entity,key) {
return entity.components.physics.bodies[key];
},
/**
* Applies an impulse to given body
*
* @method _bodyApplyImpulse
* @param {String} bodyKey
* @param {Integer} degrees
* @param {Integer} power
* @protected
*/
bodyApplyImpulse: function(entity,bodyKey,degrees,power) {
var physicsBody=entity.components.physics.bodies[bodyKey]._physicsHandle;
physicsBody.ApplyImpulse(
new this._b2Vec2(
Math.cos(degrees*(Math.PI/180))*power,
Math.sin(degrees*(Math.PI/180))*power
),
physicsBody.GetWorldCenter()
);
},
/**
* Sets the linear velocity of given body
*
* @method __setLinearVelocity
* @param {String} bodyKey
* @param {Integer} degrees
* @param {Integer} power
* @protected
*/
setLinearVelocity: function(entity,bodyKey,degrees,power) {
var physicsBody=entity.components.physics.bodies[bodyKey]._physicsHandle;
physicsBody.SetLinearVelocity(
new this._b2Vec2(
Math.cos(degrees*(Math.PI/180))*power,
Math.sin(degrees*(Math.PI/180))*power
)
);
},
/**
* Sets the position of given body
*
* @method _setBodyPosition
* @param {String} bodyKey
* @param {Object} position
* @protected
*/
setBodyPosition: function(entity,bodyKey,position) {
var physicsBody=entity.components.physics.bodies[bodyKey]._physicsHandle;
return physicsBody.SetPosition(position);
},
/**
* Sets whether given body is allowed to sleep
*
* @method _setBodySleepingAllowed
* @param {String} bodyKey
* @param {Boolean} allowed
* @protected
*/
setBodySleepingAllowed: function(entity,bodyKey,allowed) {
entity.components.physics.bodies[bodyKey]._physicsHandle
.SetSleepingAllowed(allowed);
},
/**
* Sets whether given body is moveable
*
* @method _setBodyMoveable
* @param {String} bodyKey
* @param {Boolean} moveable
* @protected
*/
setBodyMoveable: function(entity,bodyKey,moveable) {
var type=((moveable)
? this._b2Body.b2_dynamicBody
: this._b2Body.b2_staticBody);
entity.components.physics.bodies[bodyKey]._physicsHandle.SetType(
type
);
},
/**
* Sets given body to be kinematic
*
* @method __setBodyKinematic
* @param {String} bodyKey
* @protected
*/
setBodyKinematic: function(entity,bodyKey) {
entity.components.physics.bodies[bodyKey]._physicsHandle.SetType(
this._b2Body.b2_kinematicBody
);
},
isBodyActive: function(body) {
return (
body._physicsHandle.IsActive()==true
);
},
isBodyAwake: function(body) {
return (
body._physicsHandle.IsAwake()==true
);
},
isBodyStatic: function(body) {
return (
body._physicsHandle.GetType()==this._b2Body.b2_staticBody
);
},
isBodyKinematic: function(body) {
return (
body._physicsHandle.GetType()==this._b2Body.b2_kinematicBody
);
},
/**
* Returns position of given body
*
* @method _getBodyPosition
* @param {String} bodyKey
* @return {Object} Position
* @protected
*/
getBodyPosition: function(entity,bodyKey) {
entity.components.physics.bodies[bodyKey]._physicsHandle.GetPosition();
},
/**
* Returns the linear velocity of given body
*
* @method _getBodyLinearVelocity
* @param {String} bodyKey
* @return {Object}
* @protected
*/
getBodyLinearVelocity: function(entity,bodyKey) {
var physicsBody=entity.components.physics.bodies[bodyKey]._physicsHandle;
return physicsBody.GetLinearVelocity();
},
/**
* Destroys given body
*
* @method _destroyBody
* @param {String} bodyKey
* @protected
*/
destroyBody: function(entity,bodyKey) {
// Detroy the physics body
this._scheduleDestroyBody(
entity.components.physics.bodies[bodyKey]._physicsHandle
);
// Delete the body
delete entity.components.physics.bodies[bodyKey];
// Delete the bodyList entry
var found=false;
for (var i=0;i<entity.components.physics._bodyList.length;i++) {
if (entity.components.physics._bodyList[i].key==bodyKey) {
found=true;
break;
}
}
if (!found) return;
entity.components.physics._bodyList.splice(i,1);
return true;
},
/**
* Destroy bodies and joints schedules to be removed from the world
*
* @method _cleanup
* @protected
*/
_cleanup: function() {
for (var i=0;i<this._destroyJointList.length;i++) {
this._destroyJoint(this._destroyJointList[i]);
this._destroyJointList[i]=null;
}
this._destroyJointList=[];
for (var i=0;i<this._destroyBodyList.length;i++) {
this._destroyBody(this._destroyBodyList[i]);
this._destroyBody[i]=null;
}
this._destroyBodyList=[];
},
/**
* Schedules a body to be destroyed after current simulation tick
*
* @method _scheduleDestroyBody
* @param {zerk.game.engine.entity} entity
* @param {zerk.game.engine.system.physics.box2d.body} body
*/
_scheduleDestroyBody: function(physicsHandle) {
this._destroyBodyList.push(physicsHandle);
},
/**
* Schedules a join to be destroyed after current simulation tick
*
* @method _scheduleDestroyJoint
* @param {zerk.game.engine.entity} entity
* @param {zerk.game.engine.system.physics.box2d.join} body
*/
_scheduleDestroyJoint: function(physicsHandle) {
this._destroyJointList.push(physicsHandle);
},
/**
* Destroys a body
*
* @method _destroyBody
* @param {zerk.game.engine.entity} entity Entity
* @param {zerk.game.engine.system.physics.box2d.body} body Body
* @protected
*/
_destroyBody: function(physicsHandle) {
if (this._world.IsLocked()) {
console.error('Cannot destroy body, world is locked');
}
this._world.DestroyBody(physicsHandle);
},
/**
* Destroys a joint
*
* @method _destroyJoint
* @param {zerk.game.engine.entity} entity Entity
* @param {zerk.game.engine.system.physics.box2d.joint} joint Joint
* @protected
*/
_destroyJoint: function(physicsHandle) {
if (this._world.IsLocked()) {
console.error('Cannot destroy joint, world is locked');
}
this._world.DestroyJoint(physicsHandle);
},
/**
* Returns body at current cursor position if present
*
* @method getBodyAtMouse
* @return {Object} Box2D body
*/
getBodyAtMouse: function() {
/*
* TODO Try to remove dependency to control here
*/
var systemControl=this._getSystem('control');
this._mouseJointVec=new this._b2Vec2(
systemControl.mouse.mouseX,
systemControl.mouse.mouseY
);
var aabb=new this._b2AABB();
aabb.lowerBound.Set(
systemControl.mouse.mouseX-0.001,
systemControl.mouse.mouseY-0.001
);
aabb.upperBound.Set(
systemControl.mouse.mouseX+0.001,
systemControl.mouse.mouseY+0.001
);
this._selectedBody=null;
this._world.QueryAABB(this._getBodyAtMouseCallback,aabb);
return this._selectedBody;
},
/**
* Returns an array of entities inside given area
*
* @method getEntitiesInArea
* @param {Float} x1
* @param {Float} y1
* @param {Float} x2
* @param {Float} y2
* @return {Array} Entities inside given area
*/
getEntitiesInArea: function(x1,y1,x2,y2) {
var aabb=new this._b2AABB();
aabb.lowerBound.Set(x1,y1);
aabb.upperBound.Set(x2,y2);
var entitiesById={};
this._world.QueryAABB(
function (fixture) {
var entity=fixture.GetBody().GetUserData().entity;
if (typeof entitiesById[entity.id]
=='undefined') {
entitiesById[entity.id]=entity;
}
return true;
},
aabb
);
var result=[];
for (var id in entitiesById) {
if (this._engine.getEntityById(id)!=null) {
result.push(entitiesById[id]);
}
}
return result;
},
/**
* Dumps elements currently contained in physics simulation to console
*
* @method dumpPhysicsData
*/
dumpPhysicsData: function() {
var body=this._world.GetBodyList();
console.log('--- Elements in physics simulation ---');
while (body!=null) {
var zerkBody=body.GetUserData();
if (zerkBody) {
console.log('BODY: '+zerkBody._entity.config.id);
} else {
console.log('UNKNOWN BODY',body);
}
body=body.GetNext();
}
},
/**
* Synchronize the physic simulation properties of an entity
*
* @method syncEntityPhysics
* @param {zerk.game.engine.entity} entity Entity
*/
_syncEntityPhysics: function(entity) {
var bodies=entity.components.physics.bodies;
for (var key in bodies) {
if (bodies[key]._physicsHandle && bodies[key].origin) {
entity.components.position.x=
bodies[key]._physicsHandle.GetPosition().x;
entity.components.position.y=
bodies[key]._physicsHandle.GetPosition().y;
entity.components.position.angle=
bodies[key]._physicsHandle.GetAngle();
}
}
for (var key in bodies) {
if (bodies[key]._physicsHandle) {
bodies[key].x=
bodies[key]._physicsHandle.GetPosition().x
-entity.components.position.x;
bodies[key].y=
bodies[key]._physicsHandle.GetPosition().y
-entity.components.position.y;
bodies[key].angle=
bodies[key]._physicsHandle.GetAngle();
}
}
},
/**
* Contact begin event handler
*
* @method _onContactBegin
* @param {Object} contact Contact information
* @protected
*/
_onContactBegin: function(contact) {
var sourceInfo=contact.GetFixtureA().GetUserData();
var targetInfo=contact.GetFixtureB().GetUserData();
/**
* Fires when two fixtures start colliding
*
* @event contactbegin
* @param {zerk.game.engine.system.physics.box2d.fixture} sourceFixture Source fixture
* @param {zerk.game.engine.system.physics.box2d.fixture} targetFixture Target fixture
* @return {Boolean} Return false to Cancel bubble
*/
this.fireEvent(
'contactbegin',
sourceInfo,
targetInfo
);
},
/**
* Contact end event handler
*
* @method _onContactEnd
* @param {Object} contact Contact information
* @protected
*/
_onContactEnd: function(contact) {
var sourceInfo=contact.GetFixtureA().GetUserData();
var targetInfo=contact.GetFixtureB().GetUserData();
/**
* Fires when two fixtures stop colliding
*
* @event contactend
* @param {zerk.game.engine.system.physics.box2d.fixture} sourceFixture Source
* fixture
* @param {zerk.game.engine.system.physics.box2d.fixture} targetFixture Target
* fixture
* @return {Boolean} Return false to Cancel bubble
*/
this.fireEvent(
'contactend',
sourceInfo,
targetInfo
);
},
/**
* Contact post solve event handler
*
* @method _onContactPostSolve
* @param {Object} contact Contact information
* @param {Object} impulse Impulse information
* @protected
*/
_onContactPostSolve: function(contact,impulse) {
var sourceFixture=contact.GetFixtureA().GetUserData();
var targetFixture=contact.GetFixtureB().GetUserData();
var sourceEntity=sourceFixture.body._entity;
var targetEntity=targetFixture.body._entity;
/**
* Fires before two fixtures start colliding
*
* @event contactpostsolve
* @param {zerk.game.engine.system.physics.box2d.fixture} sourceFixture Source fixture
* @param {zerk.game.engine.system.physics.box2d.fixture} targetFixture Target fixture
* @param {Object} impulse
* @return {Boolean} Return false to Cancel bubble
*/
this.fireEvent(
'contactpostsolve',
sourceFixture,
targetFixture,
impulse
);
},
/**
* Contact pre solve event handler
*
* @method _onContactPreSolve
* @param {Object} contact Contact information
* @param {Object} oldManifold
* @protected
*/
_onContactPreSolve: function(contact,oldManifold) {
/*
* TODO Implement ContactPreSolve event
*/
},
/**
* Registers the contact listener event handlers
*
* @method _addContactListener
* @protected
*/
_addContactListener: function() {
var listener=new this._b2ContactListener();
var self=this;
listener.BeginContact=function(contact) {
self._onContactBegin(contact);
};
listener.EndContact=function(contact) {
self._onContactEnd(contact);
};
listener.PostSolve=function(contact,impulse) {
self._onContactPostSolve(contact,impulse);
};
listener.PreSolve=function(contact,oldManifold) {
self._onContactPreSolve(contact,oldManifold);
};
this._world.SetContactListener(listener);
},
/**
* Create the physics engine representation for an entity
*
* @method createPhysics
* @param {zerk.game.engine.entity} entity Entity
*/
_createPhysics: function(entity) {
for (var key in entity.components.physics.bodies) {
this._createBody(entity,entity.components.physics.bodies[key]);
}
for (var key in entity.components.physics.joints) {
this._createJoint(entity,entity.components.physics.joints[key]);
}
},
/**
* Removes the physics engine representation for an entity
*
* @method removePhysics
* @param {zerk.game.engine.entity} entity Entity
*/
_removePhysics: function(entity) {
for (var key in entity.components.physics.bodies) {
this._scheduleDestroyBody(
entity.components.physics.bodies[key]._physicsHandle
);
}
for (var key in entity.components.physics.joints) {
this._scheduleDestroyJoint(
entity.components.physics.joints[key]._physicsHandle
);
}
},
/**
* Creates a body
*
* @method _createBody
* @param {zerk.game.engine.entity} entity Entity
* @param {zerk.game.engine.system.physics.box2d.body} body Body
* @return {Object} Body handle
* @protected
*/
_createBody: function(entity,body) {
var bodyDef=new this._b2BodyDef;
if (typeof body.moveable!='undefined' && body.moveable) {
bodyDef.type=this._b2Body.b2_dynamicBody;
} else if (typeof body.kinematic!='undefined' && body.kinematic) {
bodyDef.type=this._b2Body.b2_kinematicBody;
} else {
bodyDef.type=this._b2Body.b2_staticBody;
}
var bodyState=entity.components.physics.bodies[body.key];
var position=entity.components.position;
// Setup position
bodyDef.position.x=position.x+bodyState.x;
bodyDef.position.y=position.y+bodyState.y;
bodyDef.angle=bodyState.angle*Math.PI*2;
bodyDef.fixedRotation=body.fixedRotation;
bodyDef.userData={
entity: entity,
body: body.key
};
body._physicsHandle=this._world.CreateBody(bodyDef);
// Create all fixtures of the body
for (var key in body.fixtures) {
body.fixtures[key]._physicsHandle=body._physicsHandle.CreateFixture(
this._createFixture(
entity,
body,
body.fixtures[key]
)
);
}
return body._physicsHandle;
},
/**
* Delegate method for fixture creation
*
* @method _createFixture
* @param {zerk.game.engine.entity} entity Entity
* @param {zerk.game.engine.system.physics.box2d.body} body Body
* @param {zerk.game.engine.system.physics.box2d.fixture} fixture Fixture
* @return {Object} Fixture handle
* @protected
*/
_createFixture: function(entity,body,fixture) {
switch (fixture.shape) {
case 'box':
return this._createFixtureRectangle(
entity,
body,
fixture
);
break;
case 'circle':
return this._createFixtureCircle(
entity,
body,
fixture
);
break;
case 'polygon':
return this._createFixturePolygon(
entity,
body,
fixture
);
}
},
/**
* Creates a rectangle shaped fixture
*
* @method _createFixtureRectangle
* @param {zerk.game.engine.entity} entity Entity
* @param {zerk.game.engine.system.physics.box2d.body} body Body
* @param {zerk.game.engine.system.physics.box2d.fixture} fixture Fixture
* @return {Object} Fixture handle
* @protected
*/
_createFixtureRectangle: function(
entity,
body,
fixture
) {
var fixDef=new this._b2FixtureDef;
if (fixture.categoryBits!=null) {
fixDef.filter.categoryBits=fixture.categoryBits;
}
if (fixture.maskBits!=null) {
fixDef.filter.maskBits=fixture.maskBits;
}
fixDef.density=fixture.density;
fixDef.friction=fixture.friction;
fixDef.restitution=fixture.restitution;
fixDef.isSensor=fixture.isSensor;
fixDef.userData={
entity: entity,
body: body.key,
fixture: fixture.key
};
fixDef.shape=new this._b2PolygonShape;
var center=new this._b2Vec2(fixture.x, fixture.y);
var width=((typeof fixture.width=='string')
? (body.width/100)*parseInt(fixture.width)
: fixture.width);
var height=((typeof fixture.height=='string')
? (body.height/100)*parseInt(fixture.height)
: fixture.height);
fixDef.shape.SetAsOrientedBox(
width/2,
height/2,
center,
fixture.angle
);
return fixDef;
},
/**
* Creates a circle shaped fixture
*
* @method _createFixtureCircle
* @param {zerk.game.engine.entity} entity Entity
* @param {zerk.game.engine.system.physics.box2d.body} body Body
* @param {zerk.game.engine.system.physics.box2d.fixture} fixture Fixture
* @return {Object} Fixture handle
* @protected
*/
_createFixtureCircle: function(
entity,
body,
fixture
) {
var fixDef=new this._b2FixtureDef;
if (fixture.categoryBits!=null) {
fixDef.filter.categoryBits=fixture.categoryBits;
}
if (fixture.maskBits!=null) {
fixDef.filter.maskBits=fixture.maskBits;
}
fixDef.density=fixture.density;
fixDef.friction=fixture.friction;
fixDef.restitution=fixture.restitution;
fixDef.isSensor=fixture.isSensor;
fixDef.userData={
entity: entity,
body: body.key,
fixture: fixture.key
};
fixDef.shape=new this._b2CircleShape(
fixture.radius
);
fixDef.shape.SetLocalPosition(
new this._b2Vec2(fixture.x, fixture.y)
);
return fixDef;
},
/**
* Creates a polygon shaped fixture
*
* @method _createFixturePolygon
* @param {zerk.game.engine.entity} entity Entity
* @param {zerk.game.engine.system.physics.box2d.body} body Body
* @param {zerk.game.engine.system.physics.box2d.fixture} fixture Fixture
* @return {Object} Fixture handle
* @protected
*/
_createFixturePolygon: function(
entity,
body,
fixture
) {
var fixDef=new this._b2FixtureDef;
if (fixture.categoryBits!=null) {
fixDef.filter.categoryBits=fixture.categoryBits;
}
if (fixture.maskBits!=null) {
fixDef.filter.maskBits=fixture.maskBits;
}
fixDef.density=fixture.density;
fixDef.friction=fixture.friction;
fixDef.restitution=fixture.restitution;
fixDef.isSensor=fixture.isSensor;
fixDef.userData={
entity: entity,
body: body.key,
fixture: fixture.key
};
fixDef.shape=new this._b2PolygonShape;
// Check if the polygon is specified in clockwise order since Box2D requires that
if (!zerk.helper.isPolygonClockwise(fixture.vertices)) {
zerk.error({
message: 'Polygon is not specified in clockwise order. Change'
+' the order of the vertices in the fixture definition.',
entityName: entity.name,
bodyKey: body.key,
fixtureKey: fixture.key,
polygon: fixture.vertices,
source: this
});
}
// Create array of vertice instances
var arr=[];
for (var i=0;i<fixture.vertices.length;i++) {
arr.push(
new this._b2Vec2(
fixture.vertices[i][0],
fixture.vertices[i][1]
)
);
}
fixDef.shape.SetAsArray(arr, arr.length);
return fixDef;
},
/**
* Delgate method for joint creation
*
* @method _createJoint
* @param {zerk.game.engine.entity} entity Entity
* @param {zerk.game.engine.system.physics.box2d.joint} joint Joint
* @return {Object} Joint handle
* @protected
*/
_createJoint: function(entity,joint) {
switch (joint.type) {
case 'distance':
return this._createJointDistance(entity,joint);
case 'revolute':
return this._createJointRevolute(entity,joint);
}
},
/**
* Creates a distance joint
*
* @method _createJointDistance
* @param {zerk.game.engine.entity} entity Entity
* @param {zerk.game.engine.system.physics.box2d.joint} joint Joint
* @return {Object} Joint handle
* @protected
*/
_createJointDistance: function(entity,joint) {
var bodySource=entity.getBody(joint.source)._physicsHandle;
var bodyTarget=entity.getBody(joint.target)._physicsHandle;
var jointDef=new this._b2DistanceJointDef();
jointDef.collideConnected=joint.collideConnected;
jointDef.frequencyHz=joint.frequencyHz;
jointDef.dampingRatio=joint.dampingRatio;
// Create anchor vectors
var anchorSource=bodySource.GetWorldCenter();
var anchorTarget=bodyTarget.GetWorldCenter();
jointDef.Initialize(
bodySource,
bodyTarget,
anchorSource,
anchorTarget
);
// Set local anchors
jointDef.localAnchorA.Set(
joint.anchorSourceX,
joint.anchorSourceY
);
jointDef.localAnchorB.Set(
joint.anchorTargetX,
joint.anchorTargetY
);
return this._world.CreateJoint(jointDef);
},
/**
* Creates a revolute join
*
* @method _createJointRevolute
* @param {zerk.game.engine.entity} entity Entity
* @param {zerk.game.engine.system.physics.box2d.joint} joint Joint
* @return {Object} Joint handle
* @protected
*/
_createJointRevolute: function(entity,joint) {
var bodySource=this.getBody(entity,joint.source)._physicsHandle;
var bodyTarget=this.getBody(entity,joint.target)._physicsHandle;
var jointDef=new this._b2RevoluteJointDef();
jointDef.enableLimit=joint.enableLimit;
jointDef.lowerAngle=joint.lowerAngle;
jointDef.upperAngle=joint.upperAngle;
jointDef.enableMotor=joint.enableMotor;
jointDef.motorSpeed=joint.motorSpeed;
jointDef.maxMotorTorque=joint.maxMotorTorque;
var anchorSource=bodySource.GetWorldCenter();
anchorSource.x+=joint.anchorSourceX;
anchorSource.y+=joint.anchorSourceY;
jointDef.Initialize(
bodySource,
bodyTarget,
anchorSource
);
return this._world.CreateJoint(jointDef);
},
/**
* Creates a mouse joint
*
* @method _createJointMouse
* @param {Object} body Box2dWeb body
* @param {Float} targetX Horizontal position
* @param {Float} targetY Vertical position
* @return {Object} Joint handle
* @protected
*/
_createJointMouse: function(body,targetX,targetY) {
var jointDef=new this._b2MouseJointDef();
jointDef.bodyA=this._world.GetGroundBody();
jointDef.bodyB=body;
jointDef.target.Set(targetX,targetY);
jointDef.collideConnected=true;
jointDef.maxForce=300.0*body.GetMass();
var joint=this._world.CreateJoint(jointDef);
body.SetAwake(true);
return joint;
},
/**
* Process mouse joint
*
* @method _processMouseJoint
* @protected
*/
_processMouseJoint: function() {
if (!this._config.enableMouseJoint) {
return;
}
/*
* TODO Remove the mouse joint from the physics system
*/
var systemControl=this._getSystem('control');
if (systemControl
&& systemControl.mouse.mouseLeftDown
&& !this._mouseJoint) {
var body=this.getBodyAtMouse();
if (body) {
this._mouseJoint=this._createJointMouse(
body,
systemControl.mouse.mouseX,
systemControl.mouse.mouseY
);
}
}
if (this._mouseJoint) {
if (systemControl.mouse.mouseLeftDown) {
this._mouseJoint.SetTarget(
new this._b2Vec2(
systemControl.mouse.mouseX,
systemControl.mouse.mouseY
)
);
} else {
this._destroyJoint(this._mouseJoint);
this._mouseJoint=null;
}
}
},
/**
* Callbak method for internal processing of getBodyAtMouse
*
* @method _getBodyAtMouseCallback
* @param {Object} fixture Box2D fixture
* @return {Boolean}
* @protected
*/
_getBodyAtMouseCallback: function(fixture) {
/*
* TODO Remove global call zerk.game._engine._system.physics
*/
var me=zerk.game._engine._system.physics;
if (fixture.GetBody().GetType()
!=me._b2Body.b2_staticBody) {
if (fixture.GetShape().TestPoint(
fixture.GetBody().GetTransform(),
self._mouseJointVec
)) {
self._selectedBody=fixture.GetBody();
return false;
}
}
return true;
}
});
