title: ios view coordinate system
body: <p>I've just started iOS drawing programming and I found out that the coordinate system is different from Mac OS X, basically the point of origin on iOS is on the top left instead of the bottom left as on the mac. Just wondering if anyone knows why Apple made this change, and will it change on the future for Mac as well? I also saw on the docs that the coordinate system on iOS cannot be flipped, so I need to rewrite the code?</p>