Simon Willison’s Weblog

Polymaps. Absurdly classy: “a JavaScript library for image- and vector-tiled maps using SVG”. It can pull in image tiles from sources such as OpenStreetMap, then overlay SVG paths specified using GeoJSON. The demos make use of GeoJSON tiles for US states and counties hosted on AppEngine. The library is developed by Stamen and SimpleGeo, and released under a BSD license. SVG support in the browser is required. # 20th August 2010, 6:46 pm

canto.js: An Improved HTML5 Canvas API (via) Improved is an understatement: canto adds jQuery-style method chaining, the ability to multiple coordinates to e.g. lineTo at once, relative coordinate methods (regular Canvas does everything in terms of absolute coordinates), the ability to use degrees instead of radians, a rounded corner shortcut, a more convenient .revert() method and a simple parser that can understand SVG path expressions! The only catch: it uses getters and setters so won’t work in IE. # 29th July 2010, 9:39 am

Smokescreen demo: a Flash player in JavaScript. Chris Smoak’s Smokescreen, “a Flash player written in JavaScript”, is an incredible piece of work. It runs entirely in the browser, reads in SWF binaries, unzips them (in native JS), extracts images and embedded audio and turns them in to base64 encoded data:uris, then stitches the vector graphics back together as animated SVG. Open up the Chrome Web Inspector while the demo is running and you can see the SVG changing in real time. Smokescreen even implements its own ActionScript bytecode interpreter. It’s stated intention is to allow Flash banner ads to execute on the iPad and iPhone, but there are plenty of other interesting applications (such as news site infographics). The company behind it have announced plans to open source it in the near future. My one concern is performance—the library is 175 KB and over 8,000 lines of JavaScript which might cause problems on low powered mobile devices. # 29th May 2010, 11:32 am