Tag: javascript

svgo: silently destroying creators’ rights since whenever

svgo is, on the face of it, pretty neat: it takes those huge vector graphic files and squozes them down to something more acceptable. Unfortunately, though, the authors have seen too many files with junk machine-generated <metadata> sections, and decided that it’s all worthless.

Metadata isn’t junk; it’s provenance. Your RDF? Gone. Your diligently researched and carefully crafted Dublin Core entries? Blown away. The licence you agonized over? teh g0ne, man. svgo does this by default. It would be very easy to use this tool to take someone else’s graphic, strip out the ownership information, and claim it as your own. It would be wrong to do that, but the original creator would have to find your rip-off and go to the effort of challenging your use of it. All so much work, all so easily avoided.

You can make svgo do the right thing by calling it this way:

svgo  --disable=removeMetadata -i infile.svg -o outfile.svg

There’s apparently a config option to make this permanent, but the combination of javascript, no docs and YAML brings me out in hives. Given that the metadata section of a complex file is typically a couple of percent of the total, it’s worth keeping. Software passes; but data lives forever, so be kind to it.

HTML Canvas string-rewriting fractal

I’d hoped to have a working demo in here, but WordPress doesn’t like the <canvas> element, so here are a couple of static screendumps:

looks like a buffalo being attacked by crinkle-cut chipsI wrote a routine in JavaScript that recursively rewrites strings of instructions, then interprets them as a simple turtle-like language to draw on the canvas. In my copious free time, I’ll release it as a simple web app that you can play with these L-systems. But you can do some fun stuff here until I get it written.

(for more details, see Appendix C of H. Peitgen and D. Saupe, Eds. The Science of Fractal Images, New York: Springer, 1988.)

sometimes you just have to …

… calculate the number of seconds in the current year using JavaScript:

function seconds_in_this_year() {
      // get length of this year by subtracting "Jan 1st, /This Year/"
      // from  "Jan 1st, /Next Year/"
      var now = new Date();
      var current_year = now.getFullYear();
      var jan_first = new Date(current_year, 0, 1, 0, 0, 0, 0);
      var jan_next = new Date(current_year + 1, 0, 1, 0, 0, 0, 0);
      return (jan_next.getTime() - jan_first.getTime()) / 1000;
}