Display PostScript: Difference between revisions

Revision as of 02:11, 30 August 2005

Revision as of 02:12, 30 August 2005

Line 21:

The developers of [[NeXT]] wrote a completely new windowing engine to take full advantage of NeXT's [[object oriented]] [[operating system]]. A number of commands were added to DPS to actually create the windows and to react to events, similar to but simpler than [[NeWS]]. The single API made programming at higher levels much easier and made NeXT one of the few systems to extensively use DPS. The user-space windowing system library [[NeXTStep]] used PostScript to draw items like titlebars and scrollers. This, in turn, made extensive use of <code>pswrap</code>s, which were in turn wrapped in objects and presented to the programmer in object form.

[[Apple Computer|Apple]]'s [[Mac OS X]] operating system now makes use of a similar imaging model to Display PostScript, but does not have the same level of programmability. The new system, known as [[Quartz (graphics layer)|Quartz]], is based on the [[Portable Document Format|PDF]] model in which the source of the image is not the PostScript code itself, but the result of interpreting that code. It keeps the basic graphics primitives, font handling and measurements, and in many cases looks and feels like DPS. The PDF format also features several enhancements over PostScript, including superior color management, [[Data compression|compression]], and font management,. It is not entirely clear why this switch happened, but speculation suggests that Adobe was asking for a high licensing fee. Adobe's copyright stipulations regarding their PDF standard are much less restrictive, granting conditional copyright permission to anyone to use the format in software applications, free of charge.

==See also==