gestures.js

class Gestures {
    constructor(canvas) {
        this.canvas = canvas;
        this.fingerPointers = [];
    }
    
    // finger pointers appearing and disappearing
    addFinger(event) { ... }
    updateFinger(event) { ... }
    removeFinger(event) { ... }
    cancelFingers(event) { ... }

    // determining which gesture message to broadcast    
    sendInitialGesture() { ... }
    sendIntermediateGesture() { ... }
    sendFinalGesture() { ... }

    // helpers to identify stationary versus travelers
    fingerCount() { ... }
    stationaryCount() { ... }
    travelerCount() { ... }
    getStationary() { ... }
    getSecondStationary() { ... }
    getTraveler() { ... }
    getSecondTraveler() { ... }
}