Re: [MACTCL] Cap styles, stipples, arcs, etc

[Jim I. <ji...@ap...>]

James,

None of this stuff was supported on classic MacOS because it was not
supported in the toolbox, and I never had time to get it to work well by
hand.  The misaligned graphics is because the Tk line drawing model - taken
from X - is different from the QuickDraw grid-aligned rectangular pen model.

The Quartz drawing model is both much more flexible than QuickDraw, and more
importantly it is a line drawing model rather than a moving pen model, which
is what Tk expects.  Using it we should be able to fix a lot of the glitches
in MacTk drawing. 

I started the task of converting line drawing from QuickDraw to Quartz a
while ago (it is checked in but not enabled).  But I will need to find
another couple of free weeks to get it into a useable shape.  This would
actually be a pretty fun little project for folks that like Euclidean
geometry...  Don't know when I will get time to do it, though...

Jim

> Looking at the tk demos, specifically at "The canvas item types" plot, I see
> there are numerous things not implemented correctly on the Mac (tested on
> MacOS X). I remember hearing that stipples have never been implemented on the
> Mac, so it's not so much as a bug of the MacOS X version as simply a mac
> specific issue.
> 
> Are there any plans on solving these problems? I can see the following:
> 
> * Capstyle round appears to be ignore - it always come out square looking.
> 
> * Stipples are ignore.
> 
> * The arrow positions are often incorrect (see zig-zag arrow in top-left
> "Lines" plot of the mentioned demo).
> 
> * Missing pixels when drawing circle chords.
> 
> * Misaligned graphics giving rise to gaps between an object and its border.
> 
> * No smoothed lines.
> 
> 
> Are these missing because the Mac graphics does not support an equivalent? If
> so then it seems likely that they aren't trivial to fix. I'm currently making
> use of stipples in some cases, but I'd like to know whether it's worth time
> working on an alternative for our application.
> 
> James
> 
> PS. If anyone is interested in an example of a Unix app which, thanks greatly
> to Tcl/Tk, has been successfully ported to both Windows and now MacOS X, then
> feel free to look at my .sig and try the Staden Package. (It's very specialist
> software so it's not going to be useful to most people, but it does
> demonstrate the power of Tcl/Tk quite well and so, I hope, promotes it.)

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Jim Ingham                              ji...@ap...
Developer Tools - gdb