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Re: Save/Restore a Context
From: |
Adam Fedor |
Subject: |
Re: Save/Restore a Context |
Date: |
Tue, 12 Mar 2002 20:56:45 -0700 |
User-agent: |
Mozilla/5.0 (X11; U; Linux ppc; en-US; rv:0.9.7) Gecko/20020120 |
Fred Kiefer wrote:
As far as I can see the changes that Georg Fleischmann did do to support
the saving and restoring of a graphic context are no longer used by the
gui library, is there still a reason to keep this methods and all the
overhead they cause for a xgps context? Or to ask the other way round:
Is this a concept we should support in princible for DPS?
Well the short answer is no. After an initial reading of the NSView
-lockFocus documentation, I thought it was necessary, but after A LOT of
thinking I realized this didn't make sense.
There isn't really a need to use save/restore except in programs that
are heavily PostScript dependant. You might use save/restore when
displaying an EPS file, for instance.
And there is another concept I did not fully understand.That of the
viewclip, we have this on the XGContext, where as all other state is on
XGGState. Waht is the reasoning behind this and when should the clipview
be applied to the XGGState. This is currently only done when restoring a
Context, shouldn't we do it when doing a DPSGrestore?
This is another concept I thought I needed in NSView (it's use was also
recommended in Programming DPS with X) and realized later it wasn't
really needed (It's sort of a safty clip rect that's not altered by the
normal clipping operations, but any program that wanted to be malicious
about the clip rect, could just as easily alter the viewclip).
--
Adam Fedor, Digital Optics Corp. | I'm glad I hate spinach, because
http://www.doc.com | if I didn't, I'd eat it, and you
| know how I hate the stuff.