static Rect scaleRect_floor(Rect r, double factorX, double factorY default factorX) {
  ret rectFromPoints(
    ifloor(r.x*factorX),
    ifloor(r.y*factorY),
    ifloor(r.x2()*factorX),
    ifloor(r.y2()*factorY));
}

static Rect scaleRect_floor(double factor, Rect r) {
  ret scaleRect_floor(r, factor);
}

static Rect scaleRect_floor(DoubleRect r, double factorX, double factorY default factorX) {
  ret rect(
    ifloor(r.x*factorX),
    ifloor(r.y*factorY),
    ifloor(r.w*factorX),
    ifloor(r.h*factorY));
}

Began life as a copy of #1005837