{"id":793,"date":"2012-11-02T20:53:11","date_gmt":"2012-11-02T19:53:11","guid":{"rendered":"http:\/\/www.aymericlamboley.fr\/blog\/?p=793"},"modified":"2014-11-01T14:47:42","modified_gmt":"2014-11-01T13:47:42","slug":"create-combination-of-physics-objects-in-citrus-engine","status":"publish","type":"post","link":"http:\/\/www.aymericlamboley.fr\/blog\/create-combination-of-physics-objects-in-citrus-engine\/","title":{"rendered":"Create combination of physics objects in Citrus Engine"},"content":{"rendered":"

Some days ago, I said that November will be an awesome month for the Citrus Engine<\/a>. So what is coming?<\/p>\n

We’re the 2nd, November is already here and something huge is already happened to the CE : a tutorial on gotoandlearn<\/a> made by Lee Brimelow<\/a>, an Adobe Game Developer Evangelist! Definitely, an excellent tutorial to get start with the Citrus Engine. There’ll be other tutorials later, a new website and the forum’ll move on Starling <\/a>website. Most of the future game will use Starling so that’s a good move! We’re not forgetting the 3D part, don’t worry \ud83d\ude09<\/p>\n

Everything should be ready for the next Adobe Game Jam<\/a> in Chicago. So that’s the plan. Now let’s go for a small tutorial.<\/p>\n

<\/p>\n

Someone asked me what is the best way to create a combination of physics objects in CE, like this one<\/a>. You have to create the Box2D physics bodies and associate arts. Firstly, don’t forget that view can lies, but never physics. For example, on the CE’s demo on the actual website the mill’s arms are one Box2D object (with two bodies) and a single picture.
\nExample :
\n\"\"<\/a>
\nThe Box2D Alchemy code :<\/p>\n

package\r\n{\r\n\timport Box2DAS.Collision.Shapes.b2PolygonShape;\r\n\timport Box2DAS.Common.V2;\r\n\timport Box2DAS.Dynamics.Joints.b2RevoluteJoint;\r\n\timport Box2DAS.Dynamics.Joints.b2RevoluteJointDef;\r\n\timport Box2DAS.Dynamics.b2Body;\r\n\timport Box2DAS.Dynamics.b2BodyDef;\r\n\timport Box2DAS.Dynamics.b2Fixture;\r\n\timport Box2DAS.Dynamics.b2FixtureDef;\r\n\t\r\n\timport com.citrusengine.objects.PhysicsObject;\r\n\t\r\n\tpublic class WindmillArms extends PhysicsObject\r\n\t{\r\n\t\tprivate var _hingeBodyDef:b2BodyDef;\r\n\t\tprivate var _hingeBody:b2Body;\r\n\t\tprivate var _shape2:b2PolygonShape;\r\n\t\tprivate var _fixtureDef2:b2FixtureDef;\r\n\t\tprivate var _fixture2:b2Fixture;\r\n\t\tprivate var _jointDef:b2RevoluteJointDef;\r\n\t\tprivate var _joint:b2RevoluteJoint;\r\n\t\t\r\n\t\tpublic function WindmillArms(name:String, params:Object=null)\r\n\t\t{\r\n\t\t\tsuper(name, params);\r\n\t\t}\r\n\t\t\r\n\t\toverride public function destroy():void\r\n\t\t{\r\n\t\t\t_hingeBody.destroy();\r\n\t\t\t_hingeBodyDef.destroy();\r\n\t\t\t_fixtureDef2.destroy();\r\n\t\t\tsuper.destroy();\r\n\t\t}\r\n\t\t\r\n\t\toverride public function set x(value:Number):void\r\n\t\t{\r\n\t\t\tsuper.x = value;\r\n\t\t\t\r\n\t\t\tif (_hingeBody)\r\n\t\t\t{\r\n\t\t\t\tvar pos:V2 = _hingeBody.GetPosition();\r\n\t\t\t\tpos.x = _x;\r\n\t\t\t\t_hingeBody.SetTransform(pos, _hingeBody.GetAngle());\r\n\t\t\t}\r\n\t\t}\r\n\t\t\r\n\t\toverride public function set y(value:Number):void\r\n\t\t{\r\n\t\t\tsuper.y = value;\r\n\t\t\t\r\n\t\t\tif (_hingeBody)\r\n\t\t\t{\r\n\t\t\t\tvar pos:V2 = _hingeBody.GetPosition();\r\n\t\t\t\tpos.y = _y;\r\n\t\t\t\t_hingeBody.SetTransform(pos, _hingeBody.GetAngle());\r\n\t\t\t}\r\n\t\t}\r\n\t\t\r\n\t\toverride protected function defineBody():void\r\n\t\t{\r\n\t\t\tsuper.defineBody();\r\n\t\t\t\r\n\t\t\t_hingeBodyDef = new b2BodyDef();\r\n\t\t\t_hingeBodyDef.type = b2Body.b2_staticBody;\r\n\t\t\t_hingeBodyDef.position.v2 = new V2(_x, _y);\r\n\t\t}\r\n\t\t\r\n\t\toverride protected function createBody():void\r\n\t\t{\r\n\t\t\tsuper.createBody();\r\n\t\t\t\r\n\t\t\t_hingeBody = _box2D.world.CreateBody(_hingeBodyDef);\r\n\t\t\t_hingeBody.SetUserData(this);\r\n\t\t}\r\n\t\t\r\n\t\toverride protected function createShape():void\r\n\t\t{\r\n\t\t\tsuper.createShape();\r\n\t\t\t\r\n\t\t\t_shape2 = new b2PolygonShape();\r\n\t\t\t_shape2.SetAsBox(_width \/ 2, _height \/ 2, null, _rotation + (Math.PI \/ 2));\r\n\t\t}\r\n\t\t\r\n\t\toverride protected function defineFixture():void\r\n\t\t{\r\n\t\t\tsuper.defineFixture();\r\n\t\t\t\r\n\t\t\t_fixtureDef2 = new b2FixtureDef();\r\n\t\t\t_fixtureDef2.shape = _shape2;\r\n\t\t\t_fixtureDef2.density = _fixtureDef.density;\r\n\t\t\t_fixtureDef2.friction = _fixtureDef.friction;\r\n\t\t\t_fixtureDef2.restitution = _fixtureDef.restitution;\r\n\t\t}\r\n\t\t\r\n\t\toverride protected function createFixture():void\r\n\t\t{\r\n\t\t\tsuper.createFixture();\r\n\t\t\t_fixture2 = _body.CreateFixture(_fixtureDef2);\r\n\t\t}\r\n\t\t\r\n\t\toverride protected function defineJoint():void\r\n\t\t{\r\n\t\t\tsuper.defineJoint();\r\n\t\t\t\r\n\t\t\t_jointDef = new b2RevoluteJointDef();\r\n\t\t\t_jointDef.bodyA = _hingeBody;\r\n\t\t\t_jointDef.bodyB = _body;\r\n\t\t\t_jointDef.enableMotor = true;\r\n\t\t\t_jointDef.maxMotorTorque = 6\r\n\t\t\t_jointDef.motorSpeed = 0;\r\n\t\t\t_jointDef.localAnchorA.v2 = new V2();\r\n\t\t\t_jointDef.localAnchorB.v2 = new V2();\r\n\t\t}\r\n\t\t\r\n\t\toverride protected function createJoint():void\r\n\t\t{\r\n\t\t\tsuper.createJoint();\r\n\t\t\t\r\n\t\t\t_joint = _box2D.world.CreateJoint(_jointDef) as b2RevoluteJoint;\r\n\t\t\t_joint.SetUserData(this);\r\n\t\t}\r\n\t}\r\n}<\/pre>\n
Easier than it sounds, right? The key is to override defined methods and add your new boddie.<\/p>\n
Let’s go back to the first example on Emanuele’s website<\/a>.
\nClick here for the web demo<\/a>.
\nAs usal, all the source code is available on the CE’s GitHub dedicated to examples<\/a>.
\nActually, you see the Box2D debug view, to see arts use the console :
\nPress tab<\/em> key, write :<\/p>\n
set box2D visible false<\/pre>\n
And press enter<\/em>.<\/p>\n
There are two ways to achieve it, one is not better than the other, it’s just different. You will certainly prefer one depending what you’re trying to achieve.<\/p>\n
Create lots of CE’s object<\/strong>
\nThis is the game state :<\/p>\n
package complexbox2dobject{\r\n\r\n\timport com.citrusengine.core.State;\r\n\timport com.citrusengine.objects.platformer.box2d.Platform;\r\n\timport com.citrusengine.physics.box2d.Box2D;\r\n\r\n\t\/**\r\n\t * @author Aymeric\r\n\t *\/\r\n\tpublic class ComplexBox2DObjectGameState extends State {\r\n\r\n\t\tpublic function ComplexBox2DObjectGameState() {\r\n\t\t\tsuper();\r\n\t\t}\r\n\r\n\t\toverride public function initialize():void {\r\n\r\n\t\t\tsuper.initialize();\r\n\r\n\t\t\tvar box2D:Box2D = new Box2D(\"box2D\");\r\n\t\t\tbox2D.visible = true;\r\n\t\t\tadd(box2D);\r\n\r\n\t\t\tvar platTop:Platform = new Platform(\"platTop\", {x:stage.stageWidth \/ 2, width:stage.stageWidth, y:20});\r\n\t\t\tadd(platTop);\r\n\r\n\t\t\tvar chain:Chain;\r\n\t\t\tvar vecChain:Vector. = new Vector.();\r\n\t\t\tfor (var i:uint = 0; i < 4; ++i) {\r\n\r\n\t\t\t\tif (i == 0)\r\n\t\t\t\t\tchain = new Chain(\"chain\" + i, {x:stage.stageWidth \/ 2, y:70 + i * 40, width:15, hangTo:platTop, distance:i, view:new ChainGraphic()});\r\n\t\t\t\telse\r\n\t\t\t\t\tchain = new Chain(\"chain\" + i, {x:stage.stageWidth \/ 2, y:70 + i * 40, width:15, hangTo:vecChain[i - 1], distance:i, view:new ChainGraphic()});\r\n\r\n\t\t\t\tvecChain.push(chain);\r\n\t\t\t\tadd(chain);\r\n\t\t\t}\r\n\r\n\t\t\tchain = new Chain(\"chain\" + i, {x:2, y:70 + (i + 1) * 40, radius:15, hangTo:vecChain[i - 1], distance:i + 1, last:true, registration:\"topLeft\", view:new ChainGraphic(15)});\r\n\t\t\tadd(chain);\r\n\t\t\tvecChain.push(chain);\r\n\t\t}\r\n\r\n\t}\r\n}<\/pre>\n
Here we create many CE objects, with lots of similar informations. The good thing is all the arts are managed by SpriteView and SpriteArt classes.
\nThe Box2D Chain class :<\/p>\n
package complexbox2dobject{\r\n\r\n\timport Box2D.Common.Math.b2Vec2;\r\n\timport Box2D.Dynamics.Joints.b2RevoluteJointDef;\r\n\r\n\timport com.citrusengine.objects.Box2DPhysicsObject;\r\n\r\n\t\/**\r\n\t * @author Aymeric\r\n\t *\/\r\n\tpublic class Chain extends Box2DPhysicsObject {\r\n\r\n\t\tpublic var hangTo:Box2DPhysicsObject;\r\n\t\tpublic var distance:uint;\r\n\t\tpublic var last:Boolean = false;\r\n\r\n\t\tprivate var _revoluteJointDef:b2RevoluteJointDef;\r\n\r\n\t\tpublic function Chain(name:String, params:Object) {\r\n\t\t\tsuper(name, params);\r\n\t\t}\r\n\r\n\t\toverride protected function defineJoint():void {\r\n\r\n\t\t\t_revoluteJointDef = new b2RevoluteJointDef();\r\n\r\n\t\t\tif (last) {\r\n\t\t\t\t_revoluteJointDef.localAnchorA.Set(0, (distance + 75) \/ _box2D.scale);\r\n\t\t\t\t_revoluteJointDef.localAnchorB.Set(0, 0);\r\n\t\t\t\t_revoluteJointDef.bodyA = hangTo.body;\r\n\t\t\t\t_revoluteJointDef.bodyB = _body;\r\n\t\t\t} else\r\n\t\t\t\t_revoluteJointDef.Initialize(hangTo.body, _body, new b2Vec2(275 \/ _box2D.scale, (70 + distance * 40) \/ _box2D.scale));\r\n\t\t}\r\n\r\n\t\toverride protected function createJoint():void {\r\n\r\n\t\t\t_box2D.world.CreateJoint(_revoluteJointDef);\r\n\t\t}\r\n\t}\r\n}<\/pre>\n
Nothing too complex, we just create a joint in the right method.<\/p>\n
And finally the ChainGraphic class :<\/p>\n
package complexbox2dobject{\r\n\r\n\timport flash.display.Sprite;\r\n\r\n\t\/**\r\n\t * @author Aymeric\r\n\t *\/\r\n\tpublic class ChainGraphic extends Sprite {\r\n\r\n\t\tpublic function ChainGraphic(radius:uint = 0) {\r\n\t\t\t\r\n\t\t\tthis.graphics.beginFill(Math.random() * 0xFFFFFF);\r\n\t\t\t\r\n\t\t\tif (radius != 0)\r\n\t\t\t\tthis.graphics.drawCircle(0, 0, radius);\r\n\t\t\telse\r\n\t\t\t\tthis.graphics.drawRect(0, 0, 15, 30);\r\n\t\t\t\t\r\n\t\t\tthis.graphics.endFill();\r\n\t\t}\r\n\t}\r\n}<\/pre>\n
That's it for the first method, the most obvious.<\/p>\n
Only one complex Box2D and art classes<\/strong><\/p>\n
For the second method, like the mill's arms we create several Box2D bodies in one Box2DPhysicsObject class.
\nThe GameState :<\/p>\n
package complexbox2dobject{\r\n\r\n\timport com.citrusengine.core.State;\r\n\timport com.citrusengine.objects.platformer.box2d.Platform;\r\n\timport com.citrusengine.physics.box2d.Box2D;\r\n\r\n\t\/**\r\n\t * @author Aymeric\r\n\t *\/\r\n\tpublic class ComplexBox2DObjectGameState extends State {\r\n\r\n\t\tpublic function ComplexBox2DObjectGameState() {\r\n\t\t\tsuper();\r\n\t\t}\r\n\r\n\t\toverride public function initialize():void {\r\n\r\n\t\t\tsuper.initialize();\r\n\r\n\t\t\tvar box2D:Box2D = new Box2D(\"box2D\");\r\n\t\t\tbox2D.visible = true;\r\n\t\t\tadd(box2D);\r\n\r\n\t\t\tvar platTop:Platform = new Platform(\"platTop\", {x:stage.stageWidth \/ 2, width:stage.stageWidth, y:20});\r\n\t\t\tadd(platTop);\r\n\r\n\t\t\tvar ropeChain:RopeChain = new RopeChain(\"ropeChain\", {hangTo:platTop, radius:15, y:150, x:30, view:new RopeChainGraphics(), registration:\"topLeft\"});\r\n\t\t\tadd(ropeChain);\r\n\t\t}\r\n\r\n\t}\r\n}<\/pre>\n
The object created there is basically a circle hang to the platform top with several chains.
\nThe RopeChain class :<\/p>\n
package complexbox2dobject{\r\n\r\n\timport Box2D.Collision.Shapes.b2PolygonShape;\r\n\timport Box2D.Collision.Shapes.b2Shape;\r\n\timport Box2D.Common.Math.b2Vec2;\r\n\timport Box2D.Dynamics.Joints.b2RevoluteJointDef;\r\n\timport Box2D.Dynamics.b2Body;\r\n\timport Box2D.Dynamics.b2BodyDef;\r\n\timport Box2D.Dynamics.b2FixtureDef;\r\n\r\n\timport com.citrusengine.objects.Box2DPhysicsObject;\r\n\timport com.citrusengine.physics.PhysicsCollisionCategories;\r\n\r\n\timport flash.geom.Point;\r\n\r\n\t\/**\r\n\t * @author Aymeric\r\n\t *\/\r\n\tpublic class RopeChain extends Box2DPhysicsObject {\r\n\r\n\t\tpublic var hangTo:Box2DPhysicsObject;\r\n\r\n\t\tpublic var numChain:uint = 5;\r\n\t\tpublic var widthChain:uint = 15;\r\n\t\tpublic var heightChain:uint = 30;\r\n\t\tpublic var attach:Point = new Point(275, 60);\r\n\t\tpublic var distance:uint = 32;\r\n\r\n\t\tprivate var _vecBodyDefChain:Vector.;\r\n\t\tprivate var _vecBodyChain:Vector.;\r\n\t\tprivate var _vecFixtureDefChain:Vector.;\r\n\t\tprivate var _vecRevoluteJointDef:Vector.;\r\n\t\tprivate var _shapeChain:b2Shape;\r\n\r\n\t\tpublic function RopeChain(name:String, params:Object = null) {\r\n\t\t\tsuper(name, params);\r\n\t\t}\r\n\t\t\t\r\n\t\toverride public function initialize(poolObjectParams:Object = null):void {\r\n\t\t\tsuper.initialize(poolObjectParams);\r\n\t\t\t\r\n\t\t\tif (view)\r\n\t\t\t\t(view as RopeChainGraphics).init(numChain, widthChain, heightChain);\r\n\t\t}\r\n\t\t\t\r\n\t\toverride public function update(timeDelta:Number):void {\r\n\t\t\tsuper.update(timeDelta);\r\n\t\t\t\r\n\t\t\tif (view)\r\n\t\t\t\t(view as RopeChainGraphics).update(_vecBodyChain, _box2D.scale);\r\n\t\t}\r\n\r\n\t\toverride protected function defineBody():void {\r\n\t\t\tsuper.defineBody();\r\n\t\t\r\n\t\t\t_vecBodyDefChain = new Vector.();\r\n\t\t\tvar bodyDefChain:b2BodyDef;\r\n\t\t\t\r\n\t\t\tfor (var i:uint = 0; i < numChain; ++i) {\r\n\t\t\t\r\n\t\t\t\tbodyDefChain = new b2BodyDef();\r\n\t\t\t\tbodyDefChain = new b2BodyDef();\r\n\t\t\t\tbodyDefChain.type = b2Body.b2_dynamicBody;\r\n\t\t\t\tbodyDefChain.position = new b2Vec2(attach.x \/ _box2D.scale, (attach.y + i * distance) \/ _box2D.scale);\r\n\t\t\t\tbodyDefChain.angle = _rotation;\r\n\t\t\t\r\n\t\t\t\t_vecBodyDefChain.push(bodyDefChain);\r\n\t\t\t}\r\n\t\t}\r\n\r\n\t\toverride protected function createBody():void {\r\n\t\t\tsuper.createBody();\r\n\r\n\t\t\t_vecBodyChain = new Vector.();\r\n\t\t\tvar bodyChain:b2Body;\r\n\r\n\t\t\tfor each (var bodyDefChain:b2BodyDef in _vecBodyDefChain) {\r\n\r\n\t\t\t\tbodyChain = _box2D.world.CreateBody(bodyDefChain);\r\n\t\t\t\tbodyChain.SetUserData(this);\r\n\t\t\t\t\r\n\t\t\t\t_vecBodyChain.push(bodyChain);\r\n\t\t\t}\r\n\r\n\t\t}\r\n\r\n\t\toverride protected function createShape():void {\r\n\t\t\tsuper.createShape();\r\n\r\n\t\t\t_shapeChain = new b2PolygonShape();\r\n\t\t\tb2PolygonShape(_shapeChain).SetAsBox(widthChain \/ 2 \/ _box2D.scale, heightChain \/ 2 \/ _box2D.scale);\r\n\t\t}\r\n\r\n\t\toverride protected function defineFixture():void {\r\n\t\t\tsuper.defineFixture();\r\n\r\n\t\t\t_vecFixtureDefChain = new Vector.();\r\n\t\t\tvar fixtureDefChain:b2FixtureDef;\r\n\r\n\t\t\tfor (var i:uint = 0; i < numChain; ++i) {\r\n\r\n\t\t\t\tfixtureDefChain = new b2FixtureDef();\r\n\t\t\t\tfixtureDefChain.shape = _shapeChain;\r\n\t\t\t\tfixtureDefChain.density = 1;\r\n\t\t\t\tfixtureDefChain.friction = 0.6;\r\n\t\t\t\tfixtureDefChain.restitution = 0.3;\r\n\t\t\t\tfixtureDefChain.filter.categoryBits = PhysicsCollisionCategories.Get(\"Level\");\r\n\t\t\t\tfixtureDefChain.filter.maskBits = PhysicsCollisionCategories.GetAll();\r\n\r\n\t\t\t\t_vecFixtureDefChain.push(fixtureDefChain);\r\n\t\t\t}\r\n\t\t}\r\n\r\n\t\toverride protected function createFixture():void {\r\n\t\t\tsuper.createFixture();\r\n\r\n\t\t\tvar i:uint = 0;\r\n\r\n\t\t\tfor each (var fixtureDefChain:b2FixtureDef in _vecFixtureDefChain) {\r\n\t\t\t\t_vecBodyChain[i].CreateFixture(fixtureDefChain);\r\n\t\t\t\t++i;\r\n\t\t\t}\r\n\r\n\t\t}\r\n\r\n\t\toverride protected function defineJoint():void {\r\n\r\n\t\t\t_vecRevoluteJointDef = new Vector.();\r\n\t\t\tvar revoluteJointDef:b2RevoluteJointDef;\r\n\r\n\t\t\tfor (var i:uint = 0; i < numChain; ++i) {\r\n\r\n\t\t\t\trevoluteJointDef = new b2RevoluteJointDef();\r\n\r\n\t\t\t\tif (i == 0)\r\n\t\t\t\t\trevoluteJointDef.Initialize(hangTo.body, _vecBodyChain[i], new b2Vec2(attach.x \/ _box2D.scale, (attach.y + i * distance) \/ _box2D.scale));\r\n\t\t\t\telse\r\n\t\t\t\t\trevoluteJointDef.Initialize(_vecBodyChain[i - 1], _vecBodyChain[i], new b2Vec2(attach.x \/ _box2D.scale, (attach.y + i * distance) \/ _box2D.scale));\r\n\t\t\t\t\r\n\t\t\t\t_vecRevoluteJointDef.push(revoluteJointDef);\r\n\t\t\t}\r\n\r\n\t\t\t\r\n\t\t\trevoluteJointDef = new b2RevoluteJointDef();\r\n\t\t\trevoluteJointDef.localAnchorA.Set(0, distance \/ _box2D.scale);\r\n\t\t\trevoluteJointDef.localAnchorB.Set(0, 0);\r\n\t\t\trevoluteJointDef.bodyA = _vecBodyChain[numChain - 1];\r\n\t\t\trevoluteJointDef.bodyB = _body;\r\n\r\n\t\t\t_vecRevoluteJointDef.push(revoluteJointDef);\r\n\t\t}\r\n\r\n\t\toverride protected function createJoint():void {\r\n\r\n\t\t\tfor each (var revoluteJointDef:b2RevoluteJointDef in _vecRevoluteJointDef) {\r\n\t\t\t\t_box2D.world.CreateJoint(revoluteJointDef);\r\n\t\t\t}\r\n\t\t}\r\n\t\t\r\n\t}\r\n}<\/pre>\n
We create Vectors with all our new chains' bodies.<\/p>\n
And finally the most complex part on this second way, the graphic class :<\/p>\n
package complexbox2dobject{\r\n\r\n\timport Box2D.Dynamics.b2Body;\r\n\r\n\timport com.citrusengine.math.MathUtils;\r\n\r\n\timport flash.display.Sprite;\r\n\timport flash.geom.Point;\r\n\r\n\t\/**\r\n\t * @author Aymeric\r\n\t *\/\r\n\tpublic class RopeChainGraphics extends Sprite {\r\n\r\n\t\tprivate var _numChain:uint;\r\n\t\tprivate var _vecSprites:Vector.;\r\n\t\tprivate var _width:uint;\r\n\t\tprivate var _height:uint;\r\n\r\n\t\tpublic function RopeChainGraphics() {\r\n\r\n\t\t\tthis.graphics.beginFill(0xFF0000);\r\n\t\t\tthis.graphics.drawCircle(0, 0, 15);\r\n\t\t\tthis.graphics.endFill();\r\n\t\t}\r\n\r\n\t\tpublic function init(numChain:uint, width:uint, height:uint):void {\r\n\r\n\t\t\t_numChain = numChain;\r\n\t\t\t_width = width;\r\n\t\t\t_height = height;\r\n\r\n\t\t\t_vecSprites = new Vector.();\r\n\t\t\tvar sprite:Sprite;\r\n\r\n\t\t\tfor (var i:uint = 0; i < _numChain; ++i) {\r\n\r\n\t\t\t\tsprite = new Sprite();\r\n\t\t\t\tsprite.graphics.beginFill(Math.random() * 0xFFFFFF);\r\n\t\t\t\tsprite.graphics.drawRect(0, 0, _width, _height);\r\n\t\t\t\tsprite.graphics.endFill();\r\n\r\n\t\t\t\taddChild(sprite);\r\n\t\t\t\t_vecSprites.push(sprite);\r\n\t\t\t}\r\n\t\t}\r\n\r\n\t\tpublic function update(vecBodyChain:Vector., box2DScale:Number):void {\r\n\r\n\t\t\tvar i:uint = 0;\r\n\t\t\t\r\n\t\t\tfor each (var body:b2Body in vecBodyChain) {\r\n\r\n\t\t\t\t_vecSprites[i].x = body.GetPosition().x * box2DScale - this.parent.x - _width * 0.5;\r\n\t\t\t\t_vecSprites[i].y = body.GetPosition().y * box2DScale - this.parent.y - _height * 0.5;\r\n\t\t\t\t\r\n\t\t\t\tMathUtils.RotateAroundExternalPoint(_vecSprites[i], new Point(_width * 0.5 + _vecSprites[i].x, _height * 0.5 + _vecSprites[i].y), body.GetAngle() * 180 \/ Math.PI - _vecSprites[i].rotation - this.parent.rotation);\r\n\t\t\t\t\r\n\t\t\t\t++i;\r\n\t\t\t}\r\n\t\t}\r\n\t}\r\n}<\/pre>\n
Since chains' graphics aren't managed by SpriteView and the SpriteArt (only the circle), we have to update them manually! Note that there is a little bug on the rotation, I'm missing something here but can't find the issue... Damn math knowledge \ud83d\ude00 Anyway it shouldn't prevent you to use this method!<\/p>\n","protected":false},"excerpt":{"rendered":"
Some days ago, I said that November will be an awesome month for the Citrus Engine. So what is coming? We’re the 2nd, November is already here and something huge is already happened to the CE : a tutorial on gotoandlearn made by Lee Brimelow, an Adobe Game Developer Evangelist! Definitely, an excellent tutorial to … Continue reading Create combination of physics objects in Citrus Engine<\/span> →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0},"categories":[4,115,51,33,11,114],"tags":[15,27,50,34,26],"_links":{"self":[{"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/posts\/793"}],"collection":[{"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/comments?post=793"}],"version-history":[{"count":5,"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/posts\/793\/revisions"}],"predecessor-version":[{"id":1261,"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/posts\/793\/revisions\/1261"}],"wp:attachment":[{"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/media?parent=793"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/categories?post=793"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.aymericlamboley.fr\/blog\/wp-json\/wp\/v2\/tags?post=793"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}