class Gauge {
  
  float curVal;
  float step;
  
  Gauge() {
    curVal = 0;
    step = 0.05;
  }  
  
  float get() {
    return curVal;
  }
  
  void set(float newVal) {
    curVal = newVal;
  }
  
  void increment() {
    curVal += step;
    curVal = constrain(curVal, 0, 1);
  }
  
  void decrement() {
    curVal -= step;
    curVal = constrain(curVal, 0, 1);
  }
  
  void display() {
    stroke(0);
    fill(255);
    rect(0, 0, 100, 15);
    noStroke();
    fill(0);
    rect(1, 1, 99*curVal, 14);
  }
  
}