On Sun, Nov 9, 2008 at 10:58 PM, Michael Ash <[EMAIL PROTECTED]> wrote: > Whoops, you're right. Still, NSAffineTransform can obviously do > translations, so surely this objection does not make sense?
It's a gut reaction. Not being a linear algebra guru, I'm wondering if it's done to avoid confusion; perhaps it's rather easy to create a case in which a set of rotations and translations looks like it should map one way but does another. If I remember correctly, matrix multiplication does not distribute over matrix addition, and since a transformation matrix stack is essentially a product of sums, the API designers might, as you suggest, have simply left the functionality out for the sake of clarity. Interestingly enough, I can't recall seeing any graphics API that provided rotation around a point. I know DirectX doesn't. --Kyle Sluder _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [EMAIL PROTECTED]
