習作:Box2D

by moriyoshi 01 Sep 2009

Embed

/**
 * Copyright moriyoshi ( http://wonderfl.net/user/moriyoshi )
 * MIT License ( http://www.opensource.org/licenses/mit-license.php )
 * Downloaded from: http://wonderfl.net/c/vUjL
 */

package {
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.text.*;
    import Box2D.Dynamics.*;
    import Box2D.Collision.*;
    import Box2D.Collision.Shapes.*;
    import Box2D.Common.Math.*;
    public class FlashTest extends Sprite {
        protected var world:b2World;
        protected var zoomFactor:Number = 4.5;
        protected var debugSprite:Sprite = null;

        public function addBox(x:Number, y:Number, width:Number, height:Number, angle:Number):Array {
            var itemdef:b2BodyDef = new b2BodyDef();
            itemdef.position.Set(x, y);
            itemdef.angle = angle;
            var itemshape:b2PolygonDef = new b2PolygonDef();
            itemshape.SetAsBox(width / 2, height / 2);
            var itemsprite:Sprite = new Sprite();
            with (itemsprite.graphics) {
                beginFill(0xff000000);
                var w:Number = zoomFactor * width / 2, h:Number = zoomFactor * height / 2;
                drawRect(-w / 2, -h / 2, w, h);
                endFill();
            }
            itemsprite.x = zoomFactor * x;
            itemsprite.y = zoomFactor * y;
            itemsprite.width = zoomFactor * width;
            itemsprite.height = zoomFactor * height;
            var item:b2Body = world.CreateBody(itemdef);
            item.CreateShape(itemshape);
            item.SetUserData(itemsprite);
            addChild(itemsprite);
            return [item, itemdef];
        }

        public function FlashTest() {
            var aabb: b2AABB = new b2AABB();
            aabb.lowerBound.Set(0., 0.);
            aabb.upperBound.Set(100., 100.);
            var g:b2Vec2 = new b2Vec2(0., 10.);
            world = new b2World(aabb, g, true);

            {
                var text:TextField = new TextField();
                var newFormat:TextFormat = new TextFormat();
                newFormat.font = "明朝";
                newFormat.size = 24;
                text.defaultTextFormat = newFormat;
                text.appendText("義務教育");
                text.x = 40.;
                text.y = 20.;
                text.height = 50;
                addChild(text);
            }
            if (false) {
                debugSprite = new Sprite();
                var debugDraw:b2DebugDraw = new b2DebugDraw();
                debugDraw.m_sprite = debugSprite;
                debugDraw.m_drawScale = zoomFactor;
                debugDraw.m_fillAlpha = .0;
                debugDraw.m_lineThickness = 1.;
                debugDraw.m_drawFlags = 0xffffffff;
                world.SetDebugDraw(debugDraw);
                addChild(debugSprite);
            }
 
            var item:b2Body;
            item = addBox(50., 90., 100., 5., 0.)[0];
            with (item.GetShapeList()) {
                m_friction = .3;
                m_density = .0;
            }
            item.SetMassFromShapes();

            item = addBox(2.5, 45., 5., 90., 0.)[0];
            with (item.GetShapeList()) {
                m_friction = .3;
                m_density = .0;
            }
            item.SetMassFromShapes();

            item = addBox(97.5, 45., 5., 90., 0.)[0];
            with (item.GetShapeList()) {
                m_friction = .3;
                m_density = .0;
            }
            item.SetMassFromShapes();
 
 
            for (var j:int = 0; j < 16; j++) {
                item = addBox(Math.random() * 90 + 5., Math.random() * 50., 5., 5., Math.random() * Math.PI)[0];
                with (item.GetShapeList()) {
                    m_friction = .3;
                    m_density = .5;
                    m_restitution = 1;
                }
                item.SetMassFromShapes();
            }
            
            addEventListener(Event.ENTER_FRAME, updateFrame, false, 0, true);
        }

        protected function updateFrame(ev:Event):void {
            world.Step(1/10., 10);
            for (var b:b2Body = world.GetBodyList(); b; b = b.GetNext()) {
                if (b.GetUserData() is Sprite) {
                    var itemsprite:Sprite = b.GetUserData();
                    var pos:b2Vec2 = b.GetPosition();
                    itemsprite.x = pos.x * zoomFactor;
                    itemsprite.y = pos.y * zoomFactor;
                    itemsprite.rotation = b.GetAngle() * 180. / Math.PI;
               }
            }
        }
    }
}