Re: [9fans] graphical clock demo at IWP9

[John DeGood <john@degood.org>]

I hate it when that happens. :-)  Sorry, I dropped the tarball in the
wrong place, please try again.

Francisco J Ballesteros wrote:
> 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
>>
>>
>>     
>
>