[comp.sys.mac.programmer] 24bit QuickDraw

castan@munnari.oz (Jason Castan) (06/14/88)

	1988	    ---------- 		  A/UX [E]
					  System 6.0 [E]
					      -Notification Manager
					  System 7.0 [E]
					      -24 bit Color Quickdraw
					      -Interapplication Communication

	What does the 24 bit QuickDraw mean?

	Does that mean it uses 24 bits per R/G/B? 

	How does that differ from a 32bit graphics coprocessors which are soon
	to be here.

		Thanks,
					Jason.

kaufman@polya.Stanford.EDU (Marc T. Kaufman) (06/17/88)

In article <2183@munnari.oz> castan@munnari.oz (Jason Castan) writes:

>	What does the 24 bit QuickDraw mean?
>	Does that mean it uses 24 bits per R/G/B? 

Yes, actually 32 bits per pixel, with 8 bits each of R/G/B and 8 bits spare
for your use (Alpha, etc.).  There are two variations of 24-bit R/G/B defined
by Apple:  8-bits per pixel in separate R,G,B planes (chunky-planar), and
32-bits per pixel with R/G/B packed in (chunky).  Apple has announced that they
will ONLY support chunky format.  This has the side effect of restricting such
PixMaps to a maximum of 2047 pixel elements per row.

>	How does that differ from a 32bit graphics coprocessors which are soon
>	to be here.

a coprocessor just manipulates graphics data.  24-bit QuickDraw IS the data
format.  I don't know which coprocessors, if any, will be conformant to 24-bit
QD.

-----
Marc Kaufman (kaufman@polya.stanford.edu)