Re: CATiledLayer documentation
Re: CATiledLayer documentation
- Subject: Re: CATiledLayer documentation
- From: David Duncan <email@hidden>
- Date: Mon, 18 Aug 2008 12:08:55 -0700
On Aug 18, 2008, at 10:54 AM, Houdah - ML Pierre Bernard wrote:
Unfortunately, the sample code left me confused. Seems to me that
your drawing method always does the same thing. I find no notion of
tiling. Obviously there is: when I set a breakpoint on the drawing
method I can clearly see the view being drawn bit by bit. I just
don't understand how it works.
Actually, thats the intended model. When a tiled layer calls on its
delegate's -drawLayer:inContext: (or its own -drawInContext:) method,
the context has already been transformed and clipped to capture what
is necessary for the tile that its drawing. This allows for a model
where you don't have to be concerned with the tiling if you don't want
to be.
If you do want to be concerned with the tiles, then you can use
CGContextGetClipBoundingBox() to determine the tile that you are being
asked to draw. If your using the level of detail as well, you can
either use that same clip box (carefully) to deduce the scale, or use
CGContextGetCTM() to get the current transform matrix and use that to
deduce the scale (although this relies on certain assumptions about
the CTM that will be applied).
Of course, I would have hoped for an example with multiple image
source containing tiles.
Noted. :).
--
David Duncan
Apple DTS Animation and Printing
_______________________________________________
Cocoa-dev mailing list (email@hidden)
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:
This email sent to email@hidden