I've read where the swastika design may have been derived from the visual in the sky of a particular comet passing overhead - fifteen hundred years ago (roughly) a comet with four points ejecting gas and debris as it spun over the sky and looked very much like a swastika. Ancient Chinese astronomic records show a drawing of this swastika-like comet. I'm not saying that all swastika designs are from this, but it's very likely as it was witnessed all over the world by ancient peoples at the time - and subsequently remembered as an iconic symbol.