Comments on: ‘Discrete’ NSLevelIndicatorCell too slow

By: schwa

schwa — Tue, 27 Jun 2006 14:43:47 +0000

Hey Ken,

I took out my code and replaced it with your simple clipping fix.

It certainly improved performance over the non-posed version but I think the caching version is still the fastest. Which is a shame, as your code is certainly cleaner and simpler.

You can compare all three versions here: http://toxic-public.googlecode.com//trunk/Misc/...

By: schwa

schwa — Tue, 27 Jun 2006 13:43:47 +0000

Hey Ken,

I took out my code and replaced it with your simple clipping fix.

It certainly improved performance over the non-posed version but I think the caching version is still the fastest. Which is a shame, as your code is certainly cleaner and simpler.

You can compare all three versions here: http://toxic-public.googlecode.com//trunk/Misc/CachingLevelIndicator/Output/

By: ken

ken — Tue, 27 Jun 2006 07:52:30 +0000

I think I recognize this one..

Try writing a subclass with this as its only implementation:

- (void)drawWithFrame:(NSRect)cellFrame inView:(NSView *)controlView {
[NSGraphicsContext saveGraphicsState];
NSRectClip(cellFrame);
[super drawWithFrame:cellFrame inView:controlView];
[NSGraphicsContext restoreGraphicsState];
}

The issue is with CG transparency layers (see CGContextBeginTransparencyLayer). They're a nice, clean way to a bunch of drawing, then put a shadow or a focus ring on the whole thing. Problem is, when you composite a transparency layer, it'll do calculations over the whole clip. It happens that when a cell is drawn in a tableview, the only clip is to the whole table.

That's, uh, bad.

By: ken

ken — Tue, 27 Jun 2006 06:52:30 +0000

I think I recognize this one..

Try writing a subclass with this as its only implementation:

(void)drawWithFrame:(NSRect)cellFrame inView:(NSView *)controlView { [NSGraphicsContext saveGraphicsState]; NSRectClip(cellFrame); [super drawWithFrame:cellFrame inView:controlView]; [NSGraphicsContext restoreGraphicsState]; }

The issue is with CG transparency layers (see CGContextBeginTransparencyLayer). They're a nice, clean way to a bunch of drawing, then put a shadow or a focus ring on the whole thing. Problem is, when you composite a transparency layer, it'll do calculations over the whole clip. It happens that when a cell is drawn in a tableview, the only clip is to the whole table.

That's, uh, bad.

By: schwa

schwa — Tue, 27 Jun 2006 02:59:12 +0000

Anything I post in my public subversion repository is public domain unless stated overwise. Do with it what you will.

I should make an exception for you though Chrisâ€¦ How about commercial - $1,000,000 per seat?

By: Chris

Chris — Tue, 27 Jun 2006 02:56:09 +0000

License on your CCachingLevelIndicatorCell?

By: schwa

schwa — Tue, 27 Jun 2006 02:30:03 +0000

Thanks for the support. It shouldn't be too difficult to fix I'd imagine.

Awesome treehouse(s) by the way.

By: corbin

corbin — Tue, 27 Jun 2006 02:12:29 +0000

You rock for logging this bug AND putting the link into your page. More people need to do this; it will help issues like this get fixed. thanks!