asclass DynWebCamAnalyzer > DynImageSurfaceAndEnabled {

  switchable bool overlay;

  transient ReliableSingleThread rstUpdateImage = dm_rst(this, r updateImage);

  transient S info;

  transient JLabel lblInfo;

  transient L<Renderable> overlays;

  transient BufferedImage inputImage;

  transient int w, h; // will be set to width & height of inputImage

  transient bool analyzing;

  transient S tempInfo;

  transient RegularlyClearedAverage analysisTime = new(nto_10seconds()); // nanoseconds for analysis

  start {

    set zoomToWindowOnSetImage;

    dm_doEvery(100, rstUpdateImage);

  }

  afterVisualize {

    imageSurface_pixelated(imageSurface);

    containerAddFirst(buttons,

      lblInfo = dm_label info(),

      dm_checkBox('overlay));

  }

  void updateImage enter {

    if (imageSurface == null || !enabled) ret;

    BufferedImage img = dm_webCamImage();

    if (img == null || img == inputImage) ret;

    inputImage = img;

    w = img.getWidth();

    h = img.getHeight();

    long time = nanoTime();

    pcall {

      set analyzing;

      tempInfo = null;

      prepareImage();

      time = nanoTime();

      analyzeImage();

    }

    analyzing = false;

    analysisTime.add(nanoTime()-time);

    setInfo(joinNemptiesWithSpacedDot(tempInfo, "Recognition time: " + n2(iceil(analysisTime!)) + " ns"));

    BufferedImage img2 = img;

    if (overlay)

      pcall { drawOverlays(img2 = cloneBufferedImage(img)); }

    setImage(img2);

  }

  // overload me for preparation (e.g. making integral image)

  void prepareImage {}

  // overlord me, uh, i mean, overload me

  // can use inputImage, w, h and setInfo

  void analyzeImage() {

  }

  // overlooooad me if you want

  void drawOverlays(BufferedImage img) {

    renderRenderables(img, overlays);

  }

  void setInfo(S info) {

    if (analyzing) tempInfo = info;

    else setField(+info);

  }

}