racing game - hintergrund bewegen

[option]

hi

ich hab ein schönes "racing-game" tutorial gefunden:
> Flash Games Tutorials / Open Source Flash Games on GameSheep.com
> download der .fla datei: http://www.gamesheep.com/free/flash-...art1_step4.zip

allerdings versteh ich nicht wie das auto mit der instanz "car1" überhaupt angesprochen wird!
ich würde gerne das spiel so ändern das der wagen in der mitte fixiert ist und sich stattdessen der hintergrund bewegen. (der effekt nennt sich glaube ich "top down scroller" o.ä.?)

kann mir jemand helfen das problem zu lösen?

hier mal ein ausschnitt aus dem AS:

if (_root["car"+who].code == "player") {
        //we will constantly decrease speed by multiplying it with a number below 1
        //trace(this);
 
        if (this["speed"+who]>0.3) {
            this["speed"+who] *= _root.speedDecay;
        } else {
            this["speed"+who] = 0;
        }
        //---------------------------------------------------------------
        //the car will react to certain keys
        //accelerate
        if (Key.isDown(Key.UP) && this["speed"+who]<_root.maxSpeed) {
            //if the acceleration key is down, the engine sound volume is set to 100
            this["speed"+who] += _root.acceleration;
        }
        //brake (reverse)      
        if (Key.isDown(Key.DOWN)) {
            this["speed"+who] -= _root.backSpeed;
        }
        //steer left       
        if (Key.isDown(Key.LEFT) && Math.abs(this["speed"+who])>0.3) {
            _root["car"+who]._rotation -= _root.rotationStep*(this["speed"+who]/_root.maxSpeed)/1.25
            //_root["car"+who].drehen(-_root.rotationStep*(this["speed"+who]/_root.maxSpeed), 8);
            //drehle = _root["car"+who]._rotation -= _root.rotationStep*(this["speed"+who]/_root.maxSpeed);
            //_root["car"+who].drehen(drehle, 10);
        }
        //steer right       
        if (Key.isDown(Key.RIGHT) && Math.abs(this["speed"+who])>0.3) {
            _root["car"+who]._rotation += _root.rotationStep*(this["speed"+who]/_root.maxSpeed)/1.25
        }
        //---------------------------------------------------------------  
        this["rotation"+who] = _root["car"+who]._rotation;
        //we calculate the two components of speed (X axis and Y axis)
        this["speedx"+who] = Math.sin(this["rotation"+who]*(Math.PI/180))*this["speed"+who];
        this["speedy"+who] = Math.cos(this["rotation"+who]*(Math.PI/180))*this["speed"+who]*-1;
        //apply the components on the actual position of the car
        _root["car"+who]._x += this["speedx"+who];
        _root["car"+who]._y += this["speedy"+who];
        //the collisions
        //define the four collision points
        _root["car"+who].pointLeft = {x:-20, y:0};
        _root["car"+who].localToGlobal(_root["car"+who].pointLeft);
        _root["car"+who].pointRight = {x:20, y:0};
        _root["car"+who].localToGlobal(_root["car"+who].pointRight);
        _root["car"+who].pointFront = {x:0, y:-25};
        _root["car"+who].localToGlobal(_root["car"+who].pointFront);
        _root["car"+who].pointBack = {x:0, y:25};
        _root["car"+who].localToGlobal(_root["car"+who].pointBack);
        //let's use some shorter variable names :)
        this["lpx"+who] = _root["car"+who].pointLeft.x;
        this["lpy"+who] = _root["car"+who].pointLeft.y;
        this["rpx"+who] = _root["car"+who].pointRight.x;
        this["rpy"+who] = _root["car"+who].pointRight.y;
        this["fpx"+who] = _root["car"+who].pointFront.x;
        this["fpy"+who] = _root["car"+who].pointFront.y;
        this["bpx"+who] = _root["car"+who].pointBack.x;
        this["bpy"+who] = _root["car"+who].pointBack.y;
        //check for collisions
        if (_root.terrain.hitTest(this["lpx"+who], this["lpy"+who], true)) {
            _root["car"+who]._rotation += 5;
            this["speed"+who] *= 0.85;
        }
        if (_root.terrain.hitTest(this["rpx"+who], this["rpy"+who], true)) {
            _root["car"+who]._rotation -= 5;
            this["speed"+who] *= 0.85;
        }
        if (_root.terrain.hitTest(this["fpx"+who], this["fpy"+who], true)) {
            this["speed"+who] = -1;
        }
        if (_root.terrain.hitTest(this["bpx"+who], this["bpy"+who], true)) {
            this["speed"+who] = 1;
        }