text: #pragma once
  
  const int SECONDS = 1000;
  
  struct Timer {
    Timer(int defaultDuration = 0);
  
    void go();
    void go(int d);
    void stop();
    bool done();
    int now();
  
    // Time left scaled 0-1.
    float pc();
  
    int defaultDuration;
  
    bool running = false;
    int start = 0;
    int duration = 0;
  };
  