svg-mapper/bin/TileJsonGenerator.js

Tool to slice big, annotated SVG into WebMercator tiles

// Generated by LiveScript 1.2.0
/*
    This module provides method for generating the UTFGrid JSON. First, all
    exportable fields (paths) should be loaded by getExportableIndex and colored
    with getColorByIndex. Then, canvas with a such colored tile should be passed
    to generateJson, which outputs the resulting UTFGrid JSON.
*/
(function(){
  var TileJsonGenerator;
  module.exports = TileJsonGenerator = (function(){
    TileJsonGenerator.displayName = 'TileJsonGenerator';
    var prototype = TileJsonGenerator.prototype, constructor = TileJsonGenerator;
    prototype.exportables = null;
    prototype.colorInterval = 5;
    prototype.jsonGranularity = 4;
    function TileJsonGenerator(exportables){
      this.exportables = exportables != null
        ? exportables
        : [null];
    }
    prototype.generateJson = function(canvas){
      var ctx, keys, data, grid, res$, i$, ref$, len$, y, cols, res1$, j$, ref1$, len1$, x, id, index, len, chr;
      ctx = canvas.getContext('2d');
      keys = ["0"];
      data = {
        "0": null
      };
      res$ = [];
      for (i$ = 0, len$ = (ref$ = (fn$.call(this))).length; i$ < len$; ++i$) {
        y = ref$[i$];
        res1$ = [];
        for (j$ = 0, len1$ = (ref1$ = (fn1$.call(this))).length; j$ < len1$; ++j$) {
          x = ref1$[j$];
          id = this.getJsonCellId(ctx, x, y);
          index = keys.indexOf(id);
          if (index === -1) {
            len = keys.push(id);
            data[id] = JSON.parse(this.exportables[id]);
            index = len - 1;
          }
          chr = this.idToChar(index);
          res1$.push(chr);
        }
        cols = res1$;
        res$.push(cols.join(''));
      }
      grid = res$;
      return {
        grid: grid,
        keys: keys,
        data: data
      };
      function fn$(){
        var i$, step$, to$, results$ = [];
        for (i$ = 0, to$ = canvas.height, step$ = this.jsonGranularity; step$ < 0 ? i$ > to$ : i$ < to$; i$ += step$) {
          results$.push(i$);
        }
        return results$;
      }
      function fn1$(){
        var i$, step$, to$, results$ = [];
        for (i$ = 0, to$ = canvas.width, step$ = this.jsonGranularity; step$ < 0 ? i$ > to$ : i$ < to$; i$ += step$) {
          results$.push(i$);
        }
        return results$;
      }
    };
    prototype.getExportableIndex = function(str){
      var index, length;
      index = this.exportables.indexOf(str);
      if (index !== -1) {
        return index;
      }
      length = this.exportables.push(str);
      return length - 1;
    };
    prototype.getColorByIndex = function(index){
      var color;
      index *= this.colorInterval;
      color = index.toString(16);
      while (color.length < 6) {
        color = "0" + color;
      }
      return "#" + color;
    };
    prototype.getJsonCellId = function(ctx, x, y){
      var scores, attemptCount, i$, ref$, len$, dx, j$, ref1$, len1$, dy, that, maxScore, maxScoreId, id, score;
      scores = {};
      attemptCount = Math.pow(this.jsonGranularity, 2);
      for (i$ = 0, len$ = (ref$ = (fn$.call(this))).length; i$ < len$; ++i$) {
        dx = ref$[i$];
        for (j$ = 0, len1$ = (ref1$ = (fn1$.call(this))).length; j$ < len1$; ++j$) {
          dy = ref1$[j$];
          if (that = this.getCellIdAtPixel(ctx, x + dx, y + dy)) {
            scores[that] == null && (scores[that] = 0);
            scores[that]++;
          }
        }
      }
      maxScore = -Infinity;
      maxScoreId = null;
      for (id in scores) {
        score = scores[id];
        if (score >= attemptCount / 2) {
          return id;
        } else if (score > maxScore) {
          maxScore = score;
          maxScoreId = id;
        }
      }
      if (maxScore >= attemptCount / 4) {
        return maxScoreId;
      }
      return 0;
      function fn$(){
        var i$, to$, results$ = [];
        for (i$ = 0, to$ = this.jsonGranularity; i$ < to$; ++i$) {
          results$.push(i$);
        }
        return results$;
      }
      function fn1$(){
        var i$, to$, results$ = [];
        for (i$ = 0, to$ = this.jsonGranularity; i$ < to$; ++i$) {
          results$.push(i$);
        }
        return results$;
      }
    };
    prototype.getCellIdAtPixel = function(ctx, x, y){
      var data, r, g, b, id;
      data = ctx.getImageData(x, y, 1, 1).data;
      r = data[0], g = data[1], b = data[2];
      id = r << 16 | g << 8 | b;
      id /= this.colorInterval;
      if (this.exportables[id]) {
        return id;
      } else {
        return null;
      }
    };
    prototype.idToChar = function(id){
      id += 32;
      if (id >= 34) {
        id += 1;
      }
      if (id >= 92) {
        id += 1;
      }
      return String.fromCharCode(id);
    };
    return TileJsonGenerator;
  }());
}).call(this);