On Wed, Aug 6, 2008 at 4:37 PM, Vitaly Ovchinnikov <[EMAIL PROTECTED]> wrote: > Yes, he right. I've just tested it and it works fine. > I though that -translateXBy:yBy: will move my object, but it moved > pivot point... This is hard, especially with revesed OY axis ;)
Well, it all happens in one transformation matrix. If I recall matrix math correctly (probably not), rotation is a linear transformation, but translation isn't, so in order to get rotation to work right the pivot point must be the origin. Since you want to rotate the object around its center, you need to translate it twice. This is all chained together in one transformation matrix, so when the multiplication's done the net result is one matrix that does all three operations. Anyone, please feel free to correct me, I would very much appreciate any clarification. :D --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]
