I noticed a fun post in early December that implements a mapping between current time and a "unique" RGBA color. I thought it might be fun to use Factor to implement a colored clock.
The basic concept is to map the 4,294,967,296 unique RGBA colors to seconds, which gives just over 136 years of unique colors.
timestamp>rgba
We calculate timestamps as an offset from Dennis Ritchie's birthday:
: start-date ( -- timestamp ) 1941 9 9 <date> ; inline
The offset is an elapsed number of seconds from the start date:
: elapsed ( timestamp -- seconds ) start-date time- duration>seconds >integer ;
The conversion from a timestamp into a unique RGBA color does successive divmod operations to map into Red, Green, Blue, and Alpha values:
: timestamp>rgba ( timestamp -- color/f ) elapsed dup 0 32 2^ between? [ 24 2^ /mod 16 2^ /mod 8 2^ /mod [ 255 /f ] 4 napply <rgba> ] [ drop f ] if ;
You can try it for yourself, showing how the values change over time:
IN: scratchpad start-date timestamp>rgba . T{ rgba { red 0.0 } { green 0.0 } { blue 0.0 } { alpha 0.0 } } IN: scratchpad now timestamp>rgba . T{ rgba { red 0.5176470588235295 } { green 0.3803921568627451 } { blue 0.4313725490196079 } { alpha 0.3333333333333333 } }
<rgba-clock>
Let's use the timestamp>rgba
word to make an updating "colored clock". Specifically, we can use an arrow model to update a label every second to create an RGBA clock:
: update-colors ( color label -- ) [ font>> background<< ] [ [ <solid> ] dip [ interior<< ] [ boundary<< ] 2bi ] 2bi ; : <rgba-clock> ( -- gadget ) f <label-control> time get over '[ [ timestamp>rgba _ update-colors ] [ timestamp>hms ] bi ] <arrow> >>model "HH:MM:SS" >>string monospace-font >>font ;
Use the gadget. word to try it in your listener, and watch it update:
IN: scratchpad <rgba-clock> gadget.
The code for this is on my Github.
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