svg-mapper/bin/TileMaker.js

Tool to slice big, annotated SVG into WebMercator tiles

// Generated by LiveScript 1.2.0
/*
    Slices provides sourceCanvas to tiles dimensioned tileWidth x tileHeight
    Emits Tile event with tile number (web mercator - zoomlevel/x/y) and Canvas
    containing the tile imagery
*/
(function(){
  var Canvas, EventEmitter, TileMaker, log2;
  Canvas = require('canvas');
  EventEmitter = require('events').EventEmitter;
  module.exports = TileMaker = (function(superclass){
    var prototype = extend$((import$(TileMaker, superclass).displayName = 'TileMaker', TileMaker), superclass).prototype, constructor = TileMaker;
    function TileMaker(sourceCanvas, arg$, zoomLevel){
      this.sourceCanvas = sourceCanvas;
      this.tileWidth = arg$[0], this.tileHeight = arg$[1];
      this.zoomLevel = zoomLevel;
    }
    prototype.makeTiles = function(){
      var sourceContext, cols, rows, tileCount, z, this$ = this;
      sourceContext = this.sourceCanvas.getContext('2d');
      cols = Math.ceil(this.sourceCanvas.width / this.tileWidth);
      rows = Math.ceil(this.sourceCanvas.height / this.tileHeight);
      tileCount = cols * rows;
      z = this.zoomLevel;
      process.nextTick(function(){
        var tile, tileCtx, i$, ref$, len$, x, lresult$, j$, ref1$, len1$, y, offX, offY, imageData, results$ = [];
        tile = new Canvas(this$.tileWidth, this$.tileHeight);
        tileCtx = tile.getContext('2d');
        for (i$ = 0, len$ = (ref$ = (fn$())).length; i$ < len$; ++i$) {
          x = ref$[i$];
          lresult$ = [];
          for (j$ = 0, len1$ = (ref1$ = (fn1$())).length; j$ < len1$; ++j$) {
            y = ref1$[j$];
            offX = x * this$.tileWidth;
            offY = y * this$.tileHeight;
            imageData = sourceContext.getImageData(offX, offY, this$.tileWidth, this$.tileHeight);
            tileCtx.clearRect(0, 0, this$.tileWidth, this$.tileHeight);
            tileCtx.putImageData(imageData, 0, 0);
            lresult$.push(this$.emit('tile', z, x, y, tile));
          }
          results$.push(lresult$);
        }
        return results$;
        function fn$(){
          var i$, to$, results$ = [];
          for (i$ = 0, to$ = cols; i$ < to$; ++i$) {
            results$.push(i$);
          }
          return results$;
        }
        function fn1$(){
          var i$, to$, results$ = [];
          for (i$ = 0, to$ = rows; i$ < to$; ++i$) {
            results$.push(i$);
          }
          return results$;
        }
      });
      return tileCount;
    };
    return TileMaker;
  }(EventEmitter));
  log2 = function(val){
    return Math.log(val / Math.LN2);
  };
  function extend$(sub, sup){
    function fun(){} fun.prototype = (sub.superclass = sup).prototype;
    (sub.prototype = new fun).constructor = sub;
    if (typeof sup.extended == 'function') sup.extended(sub);
    return sub;
  }
  function import$(obj, src){
    var own = {}.hasOwnProperty;
    for (var key in src) if (own.call(src, key)) obj[key] = src[key];
    return obj;
  }
}).call(this);