Re: Thousands of colors
Re: Thousands of colors
- Subject: Re: Thousands of colors
- From: "John C. Randolph" <email@hidden>
- Date: Mon, 4 Feb 2002 18:21:33 -0800
On Monday, February 4, 2002, at 06:07 PM, Bill Chin wrote:
Hi,
When trying to draw bitmaps using Quartz in thousands of colors
mode, I'm finding my application is spending a lot of time in
decode_data, an internal Quartz function. This doesn't happen
in 24 bit color mode, only in 16 bit color mode. I've
experimented with both 444 and 555 depths when I create my
CGImage, but both seem to use decode_data. Matter of fact, even
with the display mode set to thousands of colors, it seems that
drawing 888 is faster than drawing 444 or 555. I don't have the
real numbers yet (I have to clean up my testbench app,
including adding in better timers), but does someone know what
the real deal is here? Should I just go ahead and up-convert my
bitmap data to 888?
24- and 32-bit pixel formats don't have to do any shifting or
multiplying to line up with the hardware.
-jcr
John C. Randolph <email@hidden> (408) 974-8819
Sr. Software Engineer, Cocoa Evangelism
Apple Worldwide Developer Relations