sclass ShootLoop implements Runnable {
  BWImage screen;
  BufferedImage originalScreen;
  int screenWidth, screenHeight;
  ImageSurface isThumb;
  new L<Rect> selections;
  S state = "Shooting & recognizing";
  float precision = 1f; // how sharply to look at the screen
  bool showThumbnail;

  public void run() {
    while licensed {
      sleepSeconds(1);
      once();
    }
  }
  
  // one step of the loop (shoot, recognize & print)
  void step { once(); }
  void once {
    long time = now(); // todo: switch to sysNow() (will need to change implementations of this class too)
    shoot();
    recognizeEtc(time);
  }
  
  void recognizeEtc(long time) {
    recognize();
    printState(time);
    if (showThumbnail) showThumbnail();
  }

  // override me
  void recognize {
  }

  // override me
  void printState(long time) {
    done_always(time, state);
  }

  void shoot {
    setScreen(shootScreen2());
  }
  
  void setScreen(BufferedImage img) {
    originalScreen = img;
    screenWidth = originalScreen.getWidth();
    screenHeight = originalScreen.getHeight();
    screen = new BWImage(originalScreen);
  }
  
  BWImage screen() { ret screen; }

  bool hasImageOnScreen(S imageID) {
    ret findImage(imageID) != null;
  }
  
  // Simple version - searches full screenshot
  Rect findImage(S imageID) {
    ret findImageSingle(screen(), imageID, precision);
  }
  
  Rect findImage(S imageID, float precision) {
    ret findImageSingle(screen(), imageID, precision);
  }
  
  L<Rect> findImageAll(S... imageIDs) {
    ret main.findImagesAll(screen(), asList(imageIDs), precision);
  }
  
  L<Rect> findImageAll(S imageID, float similarity) {
    ret main.findImageAll(screen(), imageID, similarity);
  }
  
  L<Rect> findImageAllOnRow(S imageID, int row) {
    Rect r = new Rect(0, row, screenWidth, 1);
    ret main.findImageAllInPart(screen(), imageID, r, precision);
  }
  
  L<Rect> findImageAllOnColumn(S imageID, int x) {
    Rect r = new Rect(x, 0, 1, screenHeight);
    ret main.findImageAllInPart(screen(), imageID, r, precision);
  }
  
  void showThumbnail() {
    BufferedImage thumb = shrinkScreenshot(originalScreen);
    double factor = thumb.getWidth()/(double) screenWidth;
    new L<Rect> l;
    for (Rect r : selections)
      l.add(scaleRect(r, factor));
    isThumb = showImageWithSelections(thumb, isThumb, l);
  }
  
  bool topRightCornerIs(S imageID) {
    BWImage pat = loadBWImage_cached(imageID);
    ret bwImageSectionsSimilar(screen(), pat, screenWidth-pat.getWidth(), 0, precision);
  }
  
  float topRightCornerSimilarity(S imageID) {
    BWImage pat = loadBWImage_cached(imageID);
    ret bwImageSectionsSimilarity2(screen(), pat, screenWidth-pat.getWidth(), 0, 0f);
  }
  
  void doSingle(BufferedImage screen) {
    setScreen(screen);
    long time = now();
    recognizeEtc(time);
  }
  
  void setSelection(FoundImg fi) {
    selections = fi == null ? (L) ll() : ll(fi.r);
  }
  
  void runWithThumbnails() {
    set showThumbnail;
    this.run(); // "this." to soothe standard function adder
  }
  
  RGBImage rgb(Rect r) {
    ret new RGBImage(clipBufferedImage(originalScreen, r));
  }
}