Re: [9fans] graphical clock demo at IWP9

["Francisco J Ballesteros" <nemo@lsub.org>]

Sorry,

not in server.

On Dec 18, 2007 4:06 PM, John DeGood <john@degood.org> wrote:
> Ron Minnich encouraged me to bring my incomplete little graphical clock
> program to IWP9, and then he encouraged me to complete it.  So please
> blame Ron for this:
>
>   http://degood.org/plan9/mclock.tar
>
> History of this clock program:  in the 1970s Dave Robinson, an EE
> professor at UDel, wrote a cute graphical clock program in PDP-11 BASIC
> that displayed on a Tektronix vector graphics terminal
> <http://www.selectric.org/tek4010/index.html> in his lab.  The clock
> image was drawn as vectors, with the filled areas composed of hundreds
> of side-by-side vectors.
>
> In 1982 I got a printout of the program from Dave, typed in all the
> vector coordinates, and then rewrote the program in FORTRAN for an HP
> 3000 timeshared minicomputer, outputting escape sequences to an HP 2648
> raster graphics terminal
> <http://www.atariarchives.org/cgp/Ch02_Sec16_14.php> in my lab.
>
> Flash forward ~25 years:  I stumbled across a line printer listing (on
> green bar paper, of course) of my 1982 program in my basement, and on a
> whim decided to rewrite it in C for Plan 9 using draw(2).  It looked
> very retro.  I tried adding color, but it still wasn't satisfying
> because the hundreds of vectors used for area fill weren't compatible
> with variable size windows.  So I tediously determined bounding polygons
> for each of the filled areas and called fillpoly() instead.
>
> Magic feature:  when the clock diameter is > 600 pixels (e.g.
> fullscreen) the linewidth increases from thick=0 (1 pixel) to thick=1 (3
> pixels) to make the clock more readable from a distance.
>
> Have fun.
>
> John
>
>