// forgets sub-pixels
// nearest neighbor, basically
// TODO: fix?
sclass TruncatedIBWIntegralImage > Meta is IBWIntegralImage {
  IBWIntegralImage img;
  int w, h;

  *(IBWIntegralImage *img) {
    w = img.getWidth();
    h = img.getHeight();
  }
    
  public int getWidth() { ret w; }
  public int getHeight() { ret h; }
    
  // normal range [0; pixelCount*256)
  public double getIIValue(dbl x, dbl y) {
    int xFloor = ifloor(x), yFloor = ifloor(y);
    
    // get value at top left corner of pixel
    double val = img.getIIValue(xFloor, yFloor);
    
    // at integer coordinate? done
    if (xFloor == x && yFloor == y)
      ret val;
      
    double xFrac = x-xFloor, yFrac = y-yFloor;
    
    // at non-integer coordinate, perform subpixel calculation
    double area = xFrac*yFrac;
    double pixelColor = img.getPixelBrightness(xFloor+1, yFloor+1);
    
    ret val+area*pixelColor;
  }
}

Began life as a copy of #1033566