!7

static int levels = 8;

static Color bgColor = Color.red;

sbool showBorders = true;

sclass Element {}

Element > SingleColor { int color; }

Element > Quad { Element[] subs; }

Element > Abort {}

p {

  RGBImage img = rgbShootScreen();

  Element e = split(img, 0, 0, img.w(), img.h(), 1, levels);

  //printStructure(e);

  showImage(reconstruct(img.w(), img.h(), e));

}

static Element split(RGBImage img, int x1, int y1, int w, int h, int level, int maxLevel) {

  if (rgbAllOneColor(img, x1, y1, w, h)) {

    int color = img.getInt(x1, y1);

    //print("one color: " + color);

    ret nu SingleColor(+color;

  }

  if (level >= maxLevel) {

    //print("abort");

    ret nu Abort;

  } else {

    //print("split");

    int x = x1+(w+1)/2, y = y1+(h+1)/2;

    Element[] subs = {

      split(img, x1, y1, x-x1, y-y1, level+1, maxLevel),

      split(img, x, y1, x1+w-x, y-y1, level+1, maxLevel),

      split(img, x1, y, x-x1, y1+h-y, level+1, maxLevel),

      split(img, x, y, x1+w-x, y1+h-y, level+1, maxLevel) };

    ret nu Quad(+subs;

  }

}

static RGBImage reconstruct(int w, int h, Element e) {

  RGBImage img = new RGBImage(w, h, bgColor);

  reconstruct(img, 0, 0, w, h, e);

  ret img;

}

svoid reconstruct(RGBImage img, int x1, int y1, int w, int h, Element e) {

  if (w <= 0 || h <= 0) ret;

  if (e << SingleColor) {

    if (showBorders)

      rgbFill(img, x1, y1, w-1, h-1, e/SingleColor.color);

    else

      rgbFill(img, x1, y1, w, h, e/SingleColor.color);

    ret;

  }

  if (e << Quad) {

    Element[] subs = e/Quad.subs;

    int x = x1+(w+1)/2, y = y1+(h+1)/2;

    reconstruct(img, x1, y1, x-x1, y-y1, subs[0]);

    reconstruct(img, x, y1, x1+w-x, y-y1, subs[1]);

    reconstruct(img, x1, y, x-x1, y1+h-y, subs[2]);

    reconstruct(img, x, y, x1+w-x, y1+h-y, subs[3]);

  }

}