On 20.10.2009, at 14:03, Ben Haller wrote:
implying that doing things this way is faster than NSStringDrawing. Is that actually true? Why would that be? NSStringDrawing does more or less exactly this, doesn't it, using cached a cached textstorage/layout/container set? If NSStringDrawing is less efficient than doing it yourself, where does that inefficiency lie, and why doesn't Apple fix that inefficiency? Presumably because Apple's way has some other benefit? So what is that benefit? I.e. I'm trying to understand what the tradeoffs are here.
Apple's code has to be generic. It can only cache the last call, or maybe a few. It has to be conservative in its decision whether to cache so it doesn't cache stuff that's actually changed. You know your array storage, so you could cache more aggressively. Only you know your code, it might not make sense there, but in a lucky case, you could probably keep around the text system objects for each of your cells, and thus draw way faster than the OS's functions could do.
AFAIK even -[NSAttributedString drawWithRect:options:] doesn't let you draw a string centered or right-aligned in the rect, which seems like a big oversight. I've just logged 7318495 on that.
Haven't tried that, but have you tried setting the paragraph style in the attributed string to use the right alignment?
But if you're drawing text left-aligned, and thus don't need to measure it, is there any speedup doing things yourself?
If you draw the same bunch of strings repeatedly, and you know their lifetime, you can definitely make them draw faster.
Cheers, -- Uli Kusterer "The witnesses of TeachText are everywhere..." _______________________________________________ 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 arch...@mail-archive.com
