LoopController.ts

@component
export class LoopController extends BaseScriptComponent {

    @input 
    audio:AudioComponent

    private loopMat:Material;
    private updateEvent:UpdateEvent;
    private targetOpacity:number;
    private isInLoopZone:boolean;
    private isLocking:boolean;
    private startLockAnimationTime:number;
    private openRange:vec2;
    private tr:Transform;

    start(startTr:Transform){
        this.tr = this.sceneObject.getTransform();
        this.tr.setWorldPosition(startTr.getWorldPosition());
        this.tr.setWorldRotation(startTr.getWorldRotation());

        this.openRange = new vec2(.05, .2);
        this.loopMat = this.sceneObject.getComponent("RenderMeshVisual").mainMaterial;
        this.targetOpacity = 0;
        this.loopMat.mainPass.GlobalOpacity = 0;
        this.isLocking = false;
        this.isInLoopZone = false;

        this.updateEvent = this.createEvent("UpdateEvent");
        this.updateEvent.bind(()=>this.onUpdate());
    }

    stop(){
        this.removeEvent(this.updateEvent);
        this.updateEvent = undefined;

        this.targetOpacity = 0;
        this.loopMat.mainPass.GlobalOpacity = 0;
        this.isInLoopZone = false;
    }

    onUpdate(){
        let dt = getDeltaTime();

        // Set opacity
        this.loopMat.mainPass.GlobalOpacity = MathUtils.lerp(this.loopMat.mainPass.GlobalOpacity, this.targetOpacity, 7 * dt);

        if(this.isLocking){
            let t = getTime()-this.startLockAnimationTime;
            this.loopMat.mainPass.Tweak_N12 = this.pingPong(this.openRange.x, this.openRange.y, t);
            if(t>.8){
                this.loopMat.mainPass.Tweak_N12 = this.openRange.x;
                this.isLocking = false;
                this.stop();
            }
        }
    }

    pingPong(min:number, max:number, t:number) {
        var range = max - min;
        var freq = t * (Math.PI * 2);
        return min + (0.5 * (1 + Math.sin(freq)) * range);
    }

    show(){
        this.isInLoopZone = true;
        this.targetOpacity = 1;
    }

    hide(){
        this.isInLoopZone = false;
        if(!this.isLocking){
            this.targetOpacity = 0;
        }
    }

    getIsInLoopZone(){
        return this.isInLoopZone;
    }

    onLock(){
        this.startLockAnimationTime = getTime();
        if(!this.isLocking){
            this.isLocking = true;
            this.audio.play(1);
        }
    }
}