Re: MacOSX

[M. Grabert]

On Sat, 18 Jan 2003, John Davidorff Pell wrote:

> http://developer.apple.com/pdf/mactech_quartz.pdf
>
> I think this says (under "Drawing Functionality") that Quartz 2D
> provides postscript-like features. As I understand it, OSX is NeXTSTEP
> version 5 (jag is version 6). U can tell by looking at the version
> reported by the darwin layer (10.0,10.1 reported 5, 10.2 reports 6). So
> this should mean (unless I'm very wrong) that its grafix engine is an
> evolved implementation of NeXT's engine. DPS, right?

Nope.
Rhapsody was, MacOS X Server also still had DPS (at least the first
versions i know), but MacOS X uses DisplayPDF, not DPS.
Nowadays there are just some simple (D)PS-alike functions in MacOS X
implemented (probably these so-called "postscript-like features" you
mentioned); they got rid of DPS because *rumour* they didn't want to pay
license fees to Adobe anymore.

> OSX now also
> includes PDF, QuickTime, and OpenGL in its quartz layer, but I think
> that an app (or group of apps) that use postscript to draw should be
> able to use Quarts w/ little modification. Please correct me if I'm
> wrong.

Well no. Yes, Quarz is AFAIK the summary of DPDF, OpenGL, (Quicktime?) and
all other low/-highlevel screen drawing stuff of MacOS X, but it doesn't
include DPS. If you use an Cocoa/Carbon app, you automatically use Quartz,
but you can access Quartz directly (correct me if I'm wrong, I don't
program under MacOS X, and I just use it occationally).

The OpenStep API itself includes DPS. But actually not many applications
use the DPS functions directly, but they rather use the AppKit to draw
something on the screen (but which itself then may use DPS to draw things
on the screen, on NeXTSTEP for example. But on MacOS X the backend would
be DPDF/Quartz).

So most OpenStep apps can be easily ported to MacOS X (sometimes just a
recompile) if they just use AppKit. But if an OpenStep app uses full DPS
functionality it can't be easily ported to MacOS X.

> I'm not interested in porting quartz to other systems (that'd be
> a bit more than I can chew) but I am interested in getting GNUStep
> closer to OSX/NeXT/Cocoa, and making it able to use Quartz would pave
> the way for better integration, i think.  I'm going to go look at
> GNUStep Renaissance, that sounds like it may be very useful.

GNUstep is primarily focussed on implementing the OpenStep standart, so
it also features DPS (but the DPS backend is - uhmm - not really usable,
so you should stick to the other backends GNUstep provides).

AFAIK nobody is implementing DPDF for GNUstep, but DPDF would be just one
part of Quartz. Implementing Quartz altogether is very unlikely, because
Apple wouldn't allow us ;)

Moreover I don't know how many Cocoa programs use Quartz directly (and
not only the basic AppKit), and whether it is therefore really worth the
effort ...


greetings max