Finder vs. Quartz performance.

FROM : Toby Smith
DATE : Wed Dec 22 23:03:59 2004

I feel like there's a standard mantra of disclaimers to be made before a
posting of this sort.  Yes, I have done some searching through the
archives.  And yes, I have considered OpenGL.

The Quartz API is beautiful.  It's exactly what I want.  I want perfectly
rendered text, at any size, at any angle.  Transparency?  Yes, please.
For text rendering, Quartz is far superior to OpenGL.

But lord, it's dog slow, isn't it.

Here's what I don't get.  I have an ancient G3 Mac running 10.3.  If I
cobble up a bit of code with a single CGContextDrawImage() and a single
CGContextShowTextAtPoint(), with an image that's 1024x768, I get a frame
rate that's maybe 10fps.  If I add shadows to that text, I'm at about
1fps.  Not exactly ready to ship.

Now, on that same machine, whose monitor is 1280x1024, with a pretty
little desktop image, I drag a window around, that window drags itself
around just great, with a shadow, keeping up with the mouse with no
problems.

So what the dilly.  Does Finder use some API I'm not privy to?  Is there
some magic CGContextDrawFaster() method or something?  Apple has such a
great API with the Quartz stuff, but I feel like I'm missing some huge
piece of the puzzle.  Or does the Finder use OpenGL, bypassing Quartz
entirely?

Regards,
Tob