flash on 2011-10-16

Box2D

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favorite:8
lines:242
license : MIT License
modified : 2011-10-17 09:33:10

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// forked from o_healer's Box2D試作：間接Drag
package {
    import flash.display.*;
    import flash.events.*;
    import flash.filters.*;
    import flash.geom.*;
    import flash.net.*;
    import flash.system.*;
    import flash.text.*;

//Box2D
    import Box2D.Dynamics.*;
    import Box2D.Collision.*;
    import Box2D.Collision.Shapes.*;
    import Box2D.Common.*;
    import Box2D.Common.Math.*;
    import Box2D.Dynamics.Joints.*;

[SWF(width="465", height="465", frameRate="30", backgroundColor="0x000000")]
    public class GameMain extends Sprite {
        //==Const==

//画面サイズ
        static public const VIEW_W:int = 465;
        static public const VIEW_H:int = 465;

//重力
        static public const GRAVITY:Number = 0.0;//9.8*30;

//Box2Dと実際の表示の比率(Box2Dに大きすぎる値を入れると上手く動かなかったりする)
        static public const PHYS_SCALE:Number = 10;
        static public function PHYS_to_IMAGE(in_Val:Number):Number{return in_Val * PHYS_SCALE;}
        static public function IMAGE_to_PHYS(in_Val:Number):Number{return in_Val / PHYS_SCALE;}
        //Box2Dの画面外の余白
        static public const BOX2D_RANGE_OFFSET:int = 100;

//効果範囲
        static public const EFFECT_RANGE:Number = VIEW_W/8;

//==Var==

//Box2D
        public var m_Box2D_World:b2World;

//マウスで動かせる球
        public var m_MouseBallBody:b2Body;
        public var m_MouseJoint:b2MouseJoint;

//エフェクト用Graphics
        public var m_EffectGraphics:Graphics;

//マウス用フラグ
        public var m_MouseDown_Now:Boolean = false;
        public var m_MouseDown_Old:Boolean = false;

//==Function==

//Init
        public function GameMain(){
            //Box2D
            {
                //考慮する領域
                var worldAABB:b2AABB = new b2AABB();
                worldAABB.lowerBound.Set(IMAGE_to_PHYS(-BOX2D_RANGE_OFFSET), IMAGE_to_PHYS(-BOX2D_RANGE_OFFSET));
                worldAABB.upperBound.Set(IMAGE_to_PHYS(VIEW_W+BOX2D_RANGE_OFFSET), IMAGE_to_PHYS(VIEW_H+BOX2D_RANGE_OFFSET));
                //重力ベクトル
                var gravity:b2Vec2 = new b2Vec2(0.0, GRAVITY);
                //Sleep
                var useSleep:Boolean = true;
                //物理world
                m_Box2D_World = new b2World(worldAABB, gravity, useSleep);
            }

//Effect
            {
                var eff_sprite:Sprite = new Sprite();
                m_EffectGraphics = eff_sprite.graphics;
                addChild(eff_sprite);
            }

//Mouse
            {
                CreateCollision_MouseSphere(10);
            }

//周囲
            {
                //D
                CreateCollision_Box(
                    VIEW_W/2,//X
                    VIEW_H - 5,//Y

VIEW_W,//W
                    10,//H

0,//Rot

true//IsFix
                );

//U
                CreateCollision_Box(
                    VIEW_W/2,//X
                    5,//Y

VIEW_W,//W
                    10,//H

0,//Rot

true//IsFix
                );

//L
                CreateCollision_Box(
                    5,//X
                    VIEW_H/2,//Y

10,//W
                    VIEW_H,//H

0,//Rot

true//IsFix
                );

//R
                CreateCollision_Box(
                    VIEW_W - 5,//X
                    VIEW_H/2,//Y

10,//W
                    VIEW_H,//H

0,//Rot

true//IsFix
                );
            }

//ブロック
            {
                for(var x:int = 1; x < 8; x++){
                    for(var y:int = 1; y < 8; y++){
                        CreateCollision_Box(
                            VIEW_W*x/8,//X
                            VIEW_H*y/8,//Y

VIEW_W/16,//W
                            VIEW_W/16//H
                        );
                    }
                }
            }

//Update
            {
                addEventListener(Event.ENTER_FRAME, Update);
            }

//Mouse
            {
                stage.addEventListener(MouseEvent.MOUSE_DOWN, function(e:Event):void{m_MouseDown_Now = true;});
                stage.addEventListener(MouseEvent.MOUSE_UP,   function(e:Event):void{m_MouseDown_Now = false;});
            }
        }

//Create : Collision : Box
        public function CreateCollision_Box(in_X:int, in_Y:int, in_W:int, in_H:int, in_Rot:Number = 0, in_FixFlag:Boolean = false):void{
            //Image
            var sprite:Sprite;
            {
                sprite = new Sprite();
                sprite.graphics.beginFill(0xDDDDDD);
                sprite.graphics.drawRect(-in_W/2, -in_H/2, in_W, in_H);
                sprite.graphics.endFill();
                addChild(sprite);
            }

//Shape Def
            var shapeDef:b2PolygonDef;
            {
                shapeDef = new b2PolygonDef();
                shapeDef.SetAsBox(IMAGE_to_PHYS(in_W/2), IMAGE_to_PHYS(in_H/2));
                if(in_FixFlag){
                    shapeDef.density = 0;//Fix
                }else{
                    shapeDef.density = 0.01;//tekitou
                }
            }

//Body Def
            var bodyDef:b2BodyDef;
            {
                bodyDef = new b2BodyDef();
                bodyDef.position.Set(IMAGE_to_PHYS(in_X), IMAGE_to_PHYS(in_Y));
                bodyDef.angle = in_Rot;
            }

//Body
            var body:b2Body;
            {
                body = m_Box2D_World.CreateBody(bodyDef);
                body.CreateShape(shapeDef);
                body.SetMassFromShapes();
                body.m_userData = sprite;
            }
        }

//Create : Collision : Sphere for Mouse
        public function CreateCollision_MouseSphere(in_R:int):void{
            //Image
            var sprite:Sprite;
            {
                sprite = new Sprite();
                sprite.graphics.beginFill(0xDDDDDD);
                sprite.graphics.drawCircle(0,0, in_R);
                sprite.graphics.endFill();
                addChild(sprite);
            }

//Shape Def
            var shapeDef:b2CircleDef;
            {
                shapeDef = new b2CircleDef();
                shapeDef.radius = IMAGE_to_PHYS(in_R);
                shapeDef.density = 1;//tekitou
            }

//Body Def
            var bodyDef:b2BodyDef;
            {
                bodyDef = new b2BodyDef();
                bodyDef.position.Set(IMAGE_to_PHYS(VIEW_W/2), IMAGE_to_PHYS(VIEW_H/2));
            }

//Body
            var body:b2Body;
            {
                body = m_Box2D_World.CreateBody(bodyDef);
                body.CreateShape(shapeDef);
                body.SetMassFromShapes();
                body.m_userData = sprite;
            }

//Joint
            {
                var mjd:b2MouseJointDef = new b2MouseJointDef();
                mjd.body1 = m_Box2D_World.GetGroundBody();
                mjd.body2 = body;
                //mjd.target.Set(IMAGE_to_PHYS(mouseX), IMAGE_to_PHYS(mouseY));
                mjd.target.Set(bodyDef.position.x, bodyDef.position.y);
                mjd.maxForce = 300.0 * body.GetMass();
                mjd.timeStep = 1.0/30.0;
                m_MouseJoint = m_Box2D_World.CreateJoint(mjd) as b2MouseJoint;
            }

m_MouseBallBody = body;
        }

//Update
        public function Update(e:Event=null):void{
            //今回進める時間
            var DeltaTime:Number = 1.0/30.0;

//物理まわりの更新
            Update_Phys(DeltaTime);

//リンクまわりの更新
            Update_Link();
        }

//物理まわりの更新
        public function Update_Phys(in_DeltaTime:Number):void{
            //マウスのところに移動
            m_MouseJoint.SetTarget(new b2Vec2(IMAGE_to_PHYS(mouseX), IMAGE_to_PHYS(mouseY)));

//物理エンジンをDeltaTimeだけ進める
            m_Box2D_World.Step(in_DeltaTime, 10);

//
            for(var b:b2Body = m_Box2D_World.m_bodyList; b; b = b.m_next){
                //画像との同期
                if(b.m_userData != null){
                    var sprite:Sprite = b.m_userData as Sprite;
                    sprite.x = PHYS_to_IMAGE(b.GetPosition().x);
                    sprite.y = PHYS_to_IMAGE(b.GetPosition().y);
                    //b.m_userData.m_VX = PHYS_to_IMAGE(b.m_linearVelocity.x);
                    //b.m_userData.m_VY = PHYS_to_IMAGE(b.m_linearVelocity.y);

sprite.rotation = b.GetAngle() * 180/Math.PI;
                }

//擬似摩擦
                {
                    const Ratio:Number = 0.8;//本当はDeltaTime依存の値にした方が良い
                    b.GetLinearVelocity().x *= Ratio;
                    b.GetLinearVelocity().y *= Ratio;
                    b.SetAngularVelocity(b.GetAngularVelocity() * Ratio);
                }
            }
        }

//リンクわりの更新
        public function Update_Link():void{
            var j:b2Joint;

var BallX:Number = PHYS_to_IMAGE(m_MouseBallBody.GetPosition().x);
            var BallY:Number = PHYS_to_IMAGE(m_MouseBallBody.GetPosition().y);

if(m_MouseDown_Now){
                //まだリンクしていなければリンク処理
                if(m_MouseDown_Old != m_MouseDown_Now){
                    for(var b:b2Body = m_Box2D_World.m_bodyList; b; b = b.m_next){
                        if(b == m_MouseBallBody){continue;}//自分自身はリンクしない
                        if(b.IsStatic()){continue;}//固定されているものはリンクしない

var GapX:Number = PHYS_to_IMAGE(b.GetPosition().x - m_MouseBallBody.GetPosition().x);
                        var GapY:Number = PHYS_to_IMAGE(b.GetPosition().y - m_MouseBallBody.GetPosition().y);
                        var Len:Number = Math.sqrt(GapX*GapX + GapY*GapY);

if(Len <= EFFECT_RANGE){
                            var jointDef:b2DistanceJointDef = new b2DistanceJointDef();
                            jointDef.Initialize(b, m_MouseBallBody, b.GetWorldCenter() , m_MouseBallBody.GetWorldCenter());
                            m_Box2D_World.CreateJoint(jointDef);
                        }
                    }
                }

//リンクの可視化
                {
                    m_EffectGraphics.clear();
                    m_EffectGraphics.lineStyle(3, 0x00FFFF, 1.0);

for(j = m_Box2D_World.GetJointList(); j; j = j.m_next){
                        if(j == m_MouseJoint){continue;}//マウスとの接続は可視化しない
                        m_EffectGraphics.moveTo(PHYS_to_IMAGE(j.GetAnchor1().x), PHYS_to_IMAGE(j.GetAnchor1().y));
                        m_EffectGraphics.lineTo(PHYS_to_IMAGE(j.GetAnchor2().x), PHYS_to_IMAGE(j.GetAnchor2().y));
                    }
                }
            }else{
                //以前にリンクしていたなら切断
                if(m_MouseDown_Old != m_MouseDown_Now){
                    for(j = m_Box2D_World.GetJointList(); j; ){
                        if(j == m_MouseJoint){j = j.m_next; continue;}
                        var jj:b2Joint = j.m_next;
                        m_Box2D_World.DestroyJoint(j);
                        j = jj;
                    }
                }

//効果範囲の可視化
                {
                    m_EffectGraphics.clear();
                    m_EffectGraphics.lineStyle(3, 0x00FFFF, 1.0);
                    m_EffectGraphics.drawCircle(BallX,BallY, EFFECT_RANGE);
                }
            }

m_MouseDown_Old = m_MouseDown_Now;
        }
    }
}

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