hmm .. actually it looks like I can TOTALLY use CALayer for this. I need a better book, the one I have doesn't cover this. Hitting google.
On 23 Oct, 2012, at 7:37 PM, Roland King <[email protected]> wrote: > I want to animate the drawing of CGPath in a UIView, so it looks as if it's > being drawn. I have the UIView, I have the CGPath, I am able to split the > CGPath at any point from 0 to 100% into that which should be drawn and that > which shouldn't yet, that's all done, so I can, fairly efficiently, call > -(CGPath)[ myObject fractionalPath:(CGFloat)fraction ] and get a path. > > The idea is to call setNeedsDisplay on the UIView from time to time, then > figure out, when I get my -drawRect call how far through the animation I am, > call fractionalPath: for that fraction of the total animation time, and draw > it. The path isn't that complex, it doesn't take very long to draw and I'm > compositing already-fully-drawn paths into a backing UIImage so there's only > one 'live one' at any time. > > The bit I'm not sure about is how to sync this up with the natural framerate > of the device. I could call setNeedsDisplay on a timer, or with a delay after > each drawRect, but there is surely a better way to do this, is there not? If > I do call setNeedsDisplay a lot, will I only get drawRect at most at the > natural framerate of the device. > > Is there an obvious technology I'm missing? This is a pretty simple way to do > a quick animation of a single path, so OpenGL or anything like that is > massive overkill and I didn't see anything CALayer would give me which would > help, but wondered if I'd missed something there as that does have the > concept of animating a property, even a custom one, between two values and I > wondered if I could hook into that. > _______________________________________________ > > Cocoa-dev mailing list ([email protected]) > > 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: > https://lists.apple.com/mailman/options/cocoa-dev/rols%40rols.org > > This email sent to [email protected] _______________________________________________ Cocoa-dev mailing list ([email protected]) 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: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [email protected]
