Source
void scale(num scaleX, num scaleY, num scaleZ) {
_data[00] *= scaleX;
_data[01] *= scaleX;
_data[02] *= scaleX;
_data[03] *= scaleX;
_data[04] *= scaleY;
_data[05] *= scaleY;
_data[06] *= scaleY;
_data[07] *= scaleY;
_data[08] *= scaleZ;
_data[09] *= scaleZ;
_data[10] *= scaleZ;
_data[11] *= scaleZ;
}