sclass Hi15ScanlineIndex {
  Hi15Image image;
  int[] indexed;
  new IntBuffer scanlines;
  
  *() {}
  *(Hi15Image *image) {}
  
  run {
    int w = image.getWidth(), h = image.getHeight();
    short[] pixels = image.pixels;
    
    int lineStart = 0;
    indexed = new int[w*h];
    
    for y to h: {
      int i = lineStart;
      int lineEnd = lineStart+w;
      
      while (i < lineEnd) {
        short color = pixels[i];
        int j = i+1;
        if (j < lineEnd && pixels[j] == color) {
          do
            ++j;
          while (j < lineEnd && pixels[j] == color);
          scanlines.add(i);
          scanlines.add(j);
          int iScanline = scanlines.size();
          for (int k = i; k < j; k++)
            indexed[k] = iScanline;
        }
        i = j;
      }
      
      lineStart += w;
    }
  }
}