geo 2 rect test

.block

license: mit

README.md

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geo2rect.js

(function (global, factory) {
  typeof exports === 'object' && typeof module !== 'undefined' ? factory(exports) :
  typeof define === 'function' && define.amd ? define(['exports'], factory) :
  (factory((global.geo2rect = global.geo2rect || {})));
}(this, function (exports) { 'use strict';

  function compute (data) {

    //TODO: check if data is in a valid format

    data.features.forEach(function (d, di) {
      //Preserve original coordinates
      d.geometry["ocoordinates"] = d.geometry.coordinates;

      //As we can only transform one polygon into a rectangle, we need to get rid of holes and small additional polygons (islands and stuff)
      if (d.geometry.type === "MultiPolygon") {
        //choose the largest polygon
        d.geometry.coordinates = largestPoly(d.geometry);
        d.geometry.type = "Polygon";
      }

      //Getting rid of holes
      if (d.geometry.coordinates.length > 1) {
        //We are too lazy to calculate if poly is clockwise or counter-clockwise, so we again just keep the largest poly
        d.geometry.coordinates = largestPoly(d.geometry);
      }

      var b = turf.bbox(d);
      d.geometry["centroid"] = [(b[2] - b[0]) / 2 + b[0], (b[1] - b[3]) / 2 + b[3]];

      //Not supported geometries (length<4) we simply duplicate the first point
      //TODO: the new points could be evenly distributed between the existing points
      //TODO: but this only for triangles anyway, anything with (length<3) is actually an error
      if (d.geometry.coordinates[0].length < 4) {
        while (d.geometry.coordinates[0].length < 4) {
          d.geometry.coordinates[0].push(d.geometry.coordinates[0][0]);
        }
      }

      var geom = d.geometry.coordinates[0],
          corners = [];

      //Moving through the four corners of the rectangle we find the closest point on the polygon line, making sure the next point is always after the last

      var _loop = function _loop(i) {

        var corner = void 0,
            dist = Number.MAX_VALUE,
            pc = void 0;

        switch (i) {
          case 0:
            pc = [b[0], b[3]];
            break;
          case 1:
            pc = [b[2], b[3]];
            break;
          case 2:
            pc = [b[2], b[1]];
            break;
          case 3:
            pc = [b[0], b[1]];
            break;
        }

        geom.forEach(function (dd, ddi) {
          var t_dist = Math.abs(Math.sqrt(Math.pow(pc[0] - dd[0], 2) + Math.pow(pc[1] - dd[1], 2)));
          if (t_dist < dist && (ddi < corners[0] || ddi > corners[corners.length - 1] || corners.length === 0)) {
            dist = t_dist;
            corner = ddi;
          }
        });

        if (corners.length >= 1) {
          //Counting the points already used up
          var pointCount = 0;
          if (corners.length >= 2) {
            for (var _j = 1; _j < corners.length; _j++) {
              var _c3 = corners[_j],
                  _c4 = corners[_j - 1],
                  _numPoints2 = void 0;

              if (_c4 < _c3) {
                _numPoints2 = _c3 - _c4;
              } else {
                _numPoints2 = _c3 + (geom.length - _c4);
              }

              pointCount += _numPoints2;
            }
          }

          //get numpoints for new potential point
          var _c = corners[corners.length - 1],
              _c2 = corner,
              _numPoints = void 0;

          if (_c < _c2) {
            _numPoints = _c2 - _c;
          } else {
            _numPoints = _c2 + (geom.length - _c);
          }

          //If there are not enough points left to finish the rectangle go step back
          if (geom.length - _numPoints - pointCount < 4 - i) {
            corner -= 4 - i;
            if (corner < 0) {
              corner += geom.length;
            }
          }
        }

        corners.push(corner);
      };

      for (var i = 0; i < 4; i++) {
        _loop(i);
      }

      //NOTE: to myself Outer rings are counter clockwise

      //Finding the closest point to each corner

      var ngeom = {};

      for (var i = 0; i < 4; i++) {
        var p1 = void 0,
            p2 = void 0,
            ox = void 0,
            oy = void 0;
        switch (i) {
          case 0:
            ox = 0;oy = 0;
            p1 = [b[0], b[3]];
            p2 = [b[2], b[3]];
            break;
          case 1:
            ox = 1;oy = 0;
            p1 = [b[2], b[3]];
            p2 = [b[2], b[1]];
            break;
          case 2:
            ox = 1;oy = 1;
            p1 = [b[2], b[1]];
            p2 = [b[0], b[1]];
            break;
          case 3:
            ox = 0;oy = 1;
            p1 = [b[0], b[1]];
            p2 = [b[0], b[3]];
            break;
        }

        var x = p2[0] - p1[0],
            y = p2[1] - p1[1];

        if (x != 0) {
          x = x / Math.abs(x);
        }
        if (y != 0) {
          y = y / Math.abs(y);
        }

        y *= -1;

        var c1 = corners[i],
            c2 = i === corners.length - 1 ? corners[0] : corners[i + 1],
            numPoints = void 0;

        if (c1 < c2) {
          numPoints = c2 - c1;
        } else {
          numPoints = c2 + (geom.length - c1);
        }

        for (var j = 0; j < numPoints; j++) {
          var tp = c1 + j;
          if (tp > geom.length - 1) {
            tp -= geom.length;
          }
          ngeom[tp] = {
            c: d.geometry.centroid,
            x: ox + x / numPoints * j,
            y: oy + y / numPoints * j
          };
        }
      }

      d.geometry['qcoordinates'] = [];

      //Okey, i have no clue why the first point is broken (i=0 > i=1)
      for (var _i = 1; _i < geom.length; _i++) {
        if (_i === geom.length - 1) {
          d.geometry.qcoordinates.push(ngeom[0]);
        } else {
          d.geometry.qcoordinates.push(ngeom[_i]);
        }
      }
    });

    //polys: d.geometry object (GeoJSON)
    function largestPoly(geom) {
      var size = -Number.MAX_VALUE,
          poly = null;

      //We will select the largest polygon from the multipolygon (this has worked out so far, for your project you might need to reconsider or just provide (single) polygons in the first place)
      for (var c = 0; c < geom.coordinates.length; c++) {
        //we are using turf.js area function
        //if you don't want to include the full turf library, turf is build in modular fashion, npm install turf-area
        var tsize = turf.area({
          type: 'Feature',
          properties: {},
          geometry: {
            type: 'Polygon',
            coordinates: geom.type === 'MultiPolygon' ? [geom.coordinates[c][0]] : [geom.coordinates[c]]
          }
        });

        if (tsize > size) {
          size = tsize;
          poly = c;
        }
      }

      return [geom.type === 'MultiPolygon' ? geom.coordinates[poly][0] : geom.coordinates[poly]];
    }

    return data;
  };

  var asyncGenerator = function () {
    function AwaitValue(value) {
      this.value = value;
    }

    function AsyncGenerator(gen) {
      var front, back;

      function send(key, arg) {
        return new Promise(function (resolve, reject) {
          var request = {
            key: key,
            arg: arg,
            resolve: resolve,
            reject: reject,
            next: null
          };

          if (back) {
            back = back.next = request;
          } else {
            front = back = request;
            resume(key, arg);
          }
        });
      }

      function resume(key, arg) {
        try {
          var result = gen[key](arg);
          var value = result.value;

          if (value instanceof AwaitValue) {
            Promise.resolve(value.value).then(function (arg) {
              resume("next", arg);
            }, function (arg) {
              resume("throw", arg);
            });
          } else {
            settle(result.done ? "return" : "normal", result.value);
          }
        } catch (err) {
          settle("throw", err);
        }
      }

      function settle(type, value) {
        switch (type) {
          case "return":
            front.resolve({
              value: value,
              done: true
            });
            break;

          case "throw":
            front.reject(value);
            break;

          default:
            front.resolve({
              value: value,
              done: false
            });
            break;
        }

        front = front.next;

        if (front) {
          resume(front.key, front.arg);
        } else {
          back = null;
        }
      }

      this._invoke = send;

      if (typeof gen.return !== "function") {
        this.return = undefined;
      }
    }

    if (typeof Symbol === "function" && Symbol.asyncIterator) {
      AsyncGenerator.prototype[Symbol.asyncIterator] = function () {
        return this;
      };
    }

    AsyncGenerator.prototype.next = function (arg) {
      return this._invoke("next", arg);
    };

    AsyncGenerator.prototype.throw = function (arg) {
      return this._invoke("throw", arg);
    };

    AsyncGenerator.prototype.return = function (arg) {
      return this._invoke("return", arg);
    };

    return {
      wrap: function (fn) {
        return function () {
          return new AsyncGenerator(fn.apply(this, arguments));
        };
      },
      await: function (value) {
        return new AwaitValue(value);
      }
    };
  }();

  var classCallCheck = function (instance, Constructor) {
    if (!(instance instanceof Constructor)) {
      throw new TypeError("Cannot call a class as a function");
    }
  };

  var createClass = function () {
    function defineProperties(target, props) {
      for (var i = 0; i < props.length; i++) {
        var descriptor = props[i];
        descriptor.enumerable = descriptor.enumerable || false;
        descriptor.configurable = true;
        if ("value" in descriptor) descriptor.writable = true;
        Object.defineProperty(target, descriptor.key, descriptor);
      }
    }

    return function (Constructor, protoProps, staticProps) {
      if (protoProps) defineProperties(Constructor.prototype, protoProps);
      if (staticProps) defineProperties(Constructor, staticProps);
      return Constructor;
    };
  }();

  var draw = function () {
    function draw() {
      classCallCheck(this, draw);

      this._data = null;
      this._svg = null;
      this._col_size = 1;
      this._row_size = 1;
      this._cols = 1;
      this._rows = 1;
      this._init = false;
      this._mode = 'geo';
      this._rPath = d3.line();
      this._path = d3.geoPath();
      this._config = {
        width: null,
        height: null,
        padding: 20,
        key: null,
        projection: d3.geoMercator(),
        grid: null,
        duration: 500
      };
    }

    createClass(draw, [{
      key: "update",
      value: function update() {
        var _this2 = this;

        if (this._data !== null && this._config.width !== null && this._config.height !== null) {
          (function () {
            var init_zoom = 200;

            _this2._config.projection.center(d3.geoCentroid(_this2._data)).scale(init_zoom).translate([_this2._config.width / 2, _this2._config.height / 2]);

            _this2._path.projection(_this2._config.projection);

            //Calculate optimal zoom

            var bounds = _this2._path.bounds(_this2._data),
                dx = bounds[1][0] - bounds[0][0],
                dy = bounds[1][1] - bounds[0][1],
                scale = Math.max(1, 0.9 / Math.max(dx / (_this2._config.width - 2 * _this2._config.padding), dy / (_this2._config.height - 2 * _this2._config.padding)));

            _this2._config.projection.scale(scale * init_zoom);

            _this2._data.features.forEach(function (f) {
              f.geometry.qcoordinates.forEach(function (d) {
                var pc = _this2._config.projection(d.c);
                d["pc"] = pc;
              });
            });

            var _this = _this2;

            _this2._rPath.x(function (d) {
              return (d.x - 0.5) * _this._col_size + d.pc[0];
            }).y(function (d) {
              return (d.y - 0.5) * _this._row_size + d.pc[1];
            });
          })();
        }

        this._init = true;
      }
    }, {
      key: "draw",
      value: function draw() {
        var _this3 = this;

        if (this._init) {
          (function () {
            var _this = _this3;
            var tPath = _this3._svg.selectAll("path").data(_this3._data.features);
            tPath.exit();
            tPath.enter().append("path").attr('class', function (d) {
              return 'id-' + _this.config.key(d);
            });

            _this3._svg.selectAll("path").transition().duration(_this3._config.duration).attr('transform', function (d) {
              var tx = 0,
                  ty = 0;
              if (_this.mode != 'geo') {
                var g = _this.config.grid[_this.config.key(d)];
                var pc = _this.config.projection(d.geometry.centroid);
                tx = g.ox - pc[0];
                ty = g.oy - pc[1];
              }
              return 'translate(' + tx + ',' + ty + ')';
            }).attr('d', function (d, i) {
              if (_this._mode === 'geo') {
                return _this._path(d);
              } else {
                return _this._rPath(d.geometry.qcoordinates) + "Z";
              }
            });
          })();
        } else {
          console.error('You must run update() first.');
        }
      }
    }, {
      key: "toggle",
      value: function toggle() {
        if (this._mode == 'geo') {
          this._mode = 'rect';
        } else {
          this._mode = 'geo';
        }
      }
    }, {
      key: "data",
      get: function get() {
        return this._data;
      },
      set: function set(d) {
        if (d) {
          this._data = d;
          this.update();
        }
      }
    }, {
      key: "mode",
      get: function get() {
        return this._mode;
      },
      set: function set(m) {
        if (m) {
          this._mode = m;
        }
      }
    }, {
      key: "svg",
      get: function get() {
        return this._svg;
      },
      set: function set(s) {
        if (s) {
          this._svg = s;
          this.update();
        }
      }
    }, {
      key: "config",
      get: function get() {
        return this._config;
      },
      set: function set(c) {
        if (c) {
          for (var key in this._config) {
            if (this._config[key] === null && !(key in c)) {
              console.error('The config object must provide ' + key);
            } else if (key in c) {
              this._config[key] = c[key];
            }
          }

          var _g = this._config.grid;
          for (var _key in _g) {
            if (_g[_key].x + 1 > this._cols) {
              this._cols = _g[_key].x + 1;
            }
            if (_g[_key].y + 1 > this._rows) {
              this._rows = _g[_key].y + 1;
            }
          }

          this._col_size = (this._config.width - this._config.padding * 2) / this._rows;
          this._row_size = (this._config.height - this._config.padding * 2) / this._cols;

          if (this._col_size < this._row_size) {
            this._row_size = this._col_size;
          } else {
            this._col_size = this._row_size;
          }

          for (var _g in this._config.grid) {
            this._config.grid[_g]['ox'] = this._config.width / 2 - this._cols / 2 * this._col_size + this._config.grid[_g].x * this._col_size + this._col_size / 2;
            this._config.grid[_g]['oy'] = this._config.height / 2 - this._rows / 2 * this._row_size + this._config.grid[_g].y * this._row_size + this._row_size / 2;
          }

          this.update();
        }
      }
    }]);
    return draw;
  }();

  exports.compute = compute;
  exports.draw = draw;

  Object.defineProperty(exports, '__esModule', { value: true });

}));

index.html

<!DOCTYPE html>
<meta charset="utf-8">
<style>

body {
  font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
}

path{
  fill:transparent;
  stroke:rgba(0,0,0,1);
}

/*4,*/

.class-4 circle{
  fill:red;
}

</style>
<body>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://npmcdn.com/@turf/turf/turf.min.js"></script>
<script src="geo2rect.js"></script>

<script>

var config = {
  width : 700,
  height : 700,
  padding : 70,
  projection : d3.geoMercator(),
  duration : 1000,
  key:function(d){return d.properties.short; },
  grid : {
    alaska:{x:0,y:0},
    maine:{x:11,y:0},
    vt:{x:10,y:1},
    nh:{x:11,y:1},
    wash:{  x:1, y:2},
    idaho:{ x:2, y:2},
    mont:{  x:3, y:2},
    nd:{    x:4, y:2},
    minn:{  x:5, y:2},
    ill:{   x:6, y:2},
    wis:{   x:7, y:2},
    mich:{  x:8, y:2},
    ny:{    x:9, y:2},
    ri:{    x:10,y:2},
    mass:{  x:11,y:2},
    ore:{   x:1,y:3},
    nev:{   x:2,y:3},
    wyo:{   x:3,y:3},
    sd:{    x:4,y:3},
    iowa:{  x:5,y:3},
    ind:{   x:6,y:3},
    ohio:{  x:7,y:3},
    pa:{    x:8,y:3},
    nj:{    x:9,y:3},
    conn:{  x:10,y:3},
    calif:{ x:1,y:4},
    utah:{  x:2,y:4},
    colo:{  x:3,y:4},
    neb:{   x:4,y:4},
    mo:{    x:5,y:4},
    ky:{    x:6,y:4},
    wva:{   x:7,y:4},
    va:{    x:8,y:4},
    md:{    x:9,y:4},
    del:{   x:10,y:4},
    ariz:{  x:2,y:5},
    nm:{    x:3,y:5},
    kan:{   x:4,y:5},
    ark:{   x:5,y:5},
    tenn:{  x:6,y:5},
    nc:{    x:7,y:5},
    sc:{    x:8,y:5},
    dc:{    x:9,y:5},
    okla:{  x:4,y:6},
    la:{    x:5,y:6},
    miss:{  x:6,y:6},
    ala:{   x:7,y:6},
    ga:{    x:8,y:6},
    hawaii:{x:0,y:7},
    texas:{ x:4,y:7},
    fla:{   x:9,y:7},
    pc:{    x:11,y:7}
  }
};

var svg = d3.select('body').append('svg').attr('width',config.width).attr('height',config.height);

var g2r = new geo2rect.draw();

d3.json('https://github.com/sebastian-meier/d3.geo2rect/blob/master/example/data/us.geojson', function(err, data){
  var geojson = geo2rect.compute(data);

  g2r.config = config;
  g2r.data = geojson;
  g2r.svg = svg.append('g');

  g2r.draw();
});

d3.select('body').append('a').text('Toggle').on('click', function(){
  g2r.toggle();
  g2r.draw();
  console.log(g2r.mode);
});

</script>
</body>
</html>