This week is really challenging : my second year school project has started this week. It’s a team project with a graphic designer, a designer, a project manager and me as a developer. Our concept sounds very promising!<\/p>\n
No matter, this short introduction explained that I’m really busy, so this experimentation is not perfect<\/strong> due to a lack of time… <\/p>\n To create this effect, I used Box2D ApplyImpulse<\/em> method on my Bars. I also used one Rope Joint by bar to link them all to an horizontal platform and try to not make them bounces everywhere. Uncomment the line box2D.visible = true;<\/em> to see box2d objects with joints (don’t forget to comment stage bitmap addChilded). Here is a part of the code :<\/p>\n The Box2D Bar class :<\/p>\n And Bar graphics art : <\/p>\n Objects drop (after music start) don't use the bitmap data to render graphics but a simple Sprite. This is not optimized! The zip file<\/a>.<\/p>\n If I have some time to focus on it, I will make some improvements... but it's not my priority. You should have enough information to make a cool Sound Spectrum with box2d \ud83d\ude09 This week is really challenging : my second year school project has started this week. It’s a team project with a graphic designer, a designer, a project manager and me as a developer. Our concept sounds very promising! No matter, this short introduction explained that I’m really busy, so this experimentation is not perfect due … Continue reading Box2D Sound Spectrum<\/span>
\nAnyway, click here<\/a><\/strong> to see a sound spectrum made with Box2D and the Citrus Engine using BitmapData.<\/p>\n
\nThere is a bug, sometimes objects pass between two bars and move them. I tried to change some object params like density, friction, restitution… but can’t find a good result.<\/p>\npackage {\r\n\r\n\timport Box2DAS.Common.V2;\r\n\r\n\timport graphics.BarEqualizerArt;\r\n\timport graphics.ElementCircleArt;\r\n\timport graphics.ElementSquareArt;\r\n\r\n\timport objects.BarEqualizer;\r\n\timport objects.Element;\r\n\r\n\timport utils.Const;\r\n\r\n\timport com.citrusengine.core.CitrusEngine;\r\n\timport com.citrusengine.core.State;\r\n\timport com.citrusengine.objects.platformer.Platform;\r\n\timport com.citrusengine.physics.Box2D;\r\n\r\n\timport flash.display.Bitmap;\r\n\timport flash.display.BitmapData;\r\n\timport flash.media.SoundMixer;\r\n\timport flash.utils.ByteArray;\r\n\timport flash.utils.setTimeout;\r\n\t\r\n\t\/**\r\n\t * @author Aymeric\r\n\t *\/\r\n\tpublic class SoundSpectrumState extends State {\r\n\t\t\r\n\t\tprivate var _ce:CitrusEngine;\r\n\t\t\r\n\t\tprivate var _vectBars:Vector.package objects{\r\n\r\n\timport Box2DAS.Common.V2;\r\n\timport Box2DAS.Dynamics.Joints.b2RopeJoint;\r\n\timport Box2DAS.Dynamics.Joints.b2RopeJointDef;\r\n\r\n\timport com.citrusengine.objects.PhysicsObject;\r\n\timport com.citrusengine.objects.platformer.Platform;\r\n\r\n\t\/**\r\n\t * @author Aymeric\r\n\t *\/\r\n\tpublic class BarEqualizer extends PhysicsObject {\r\n\r\n\t\tpublic function BarEqualizer(name:String, params:Object = null) {\r\n\t\t\t\r\n\t\t\tsuper(name, params);\r\n\t\t}\r\n\t\t\t\r\n\t\toverride public function destroy():void {\r\n\t\t\t\r\n\t\t\tsuper.destroy();\r\n\t\t}\r\n\r\n\t\toverride public function update(timeDelta:Number):void {\r\n\t\t\t\r\n\t\t\tsuper.update(timeDelta);\r\n\t\t}\r\n\r\n\t\toverride protected function createBody():void {\r\n\t\t\t\r\n\t\t\tsuper.createBody();\r\n\t\t\t\r\n\t\t\t_body.SetFixedRotation(true);\r\n\t\t}\r\n\t\t\r\n\t\tpublic function initJoint(platform:Platform, posX:uint):void {\r\n\t\t\t\r\n\t\t\tvar jointDefPlatform:b2RopeJointDef = new b2RopeJointDef();\r\n\t\t\tjointDefPlatform.Initialize(body, platform.body, body.GetPosition(), new V2(posX \/ _box2D.scale, platform.body.GetPosition().y));\r\n\t\t\t\r\n\t\t\tvar joint:b2RopeJoint = b2RopeJoint(_box2D.world.CreateJoint(jointDefPlatform));\r\n\t\t\tjoint.m_maxLength = 3;\r\n\t\t}\r\n\r\n\t}\r\n}<\/pre>\npackage graphics {\r\n\r\n\timport utils.Const;\r\n\r\n\timport flash.display.BitmapData;\r\n\timport flash.display.DisplayObject;\r\n\timport flash.events.Event;\r\n\timport flash.geom.Point;\r\n\timport flash.geom.Rectangle;\r\n\r\n\t\/**\r\n\t * @author Aymeric\r\n\t *\/\r\n\tpublic class BarEqualizerArt extends AArt {\r\n\r\n\t\tpublic function BarEqualizerArt() {\r\n\r\n\t\t\tsuper();\r\n\t\t\t\r\n\t\t\t_art.graphics.clear();\r\n\t\t\t_art.graphics.beginFill(Math.random() * 0xFFFFFF);\r\n\t\t\t_art.graphics.drawRect(0, 0, Const.BarEqualizerWidth, Const.BarEqualizerHeight);\r\n\t\t\t_art.graphics.endFill();\r\n\r\n\t\t\t_bmpD = new BitmapData(Const.BarEqualizerWidth, Const.BarEqualizerHeight);\r\n\t\t\t_bmpD.draw(_art);\r\n\t\t}\r\n\r\n\t\toverride protected function _ef(evt:Event):void {\r\n\t\t\t\r\n\t\t\tvar point:Point = new Point((this as DisplayObject).localToGlobal(new Point()).x - Const.BarEqualizerWidth * 0.5, (this as DisplayObject).localToGlobal(new Point()).y - Const.BarEqualizerHeight * 0.5);\r\n\t\t\tConst.bmpDStage.applyFilter(_bmpD, _bmpD.rect, point, _setBitmapFilter());\r\n\t\t\tConst.bmpDStage.fillRect(new Rectangle(point.x, 0, Const.bmpDStage.width, Const.bmpDStage.height), 0);\r\n\t\t\tConst.bmpDStage.copyPixels(_bmpD, _bmpD.rect, point, null, null, true);\r\n\t\t}\r\n\t}\r\n}<\/pre>\n
\nTo make it properly use only one bitmap data (no sprite) and one enter frame in the stat class. Then call a render method on each object (bars and other objects). Finally think to use : bitmapData.lock() and bitmapData.unlock() (and make your bitmap data update between them) for a better control.<\/p>\n
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\nOh and the music is an Abba cover song, made by Therion!<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"