extlib/leaflet/src/geometry/Transformation.js

   1 /*
   2  * L.Transformation is an utility class to perform simple point transformations through a 2d-matrix.
   3  */
   4
   5 L.Transformation = L.Class.extend({
   6         initialize: function(/*Number*/ a, /*Number*/ b, /*Number*/ c, /*Number*/ d) {
   7                 this._a = a;
   8                 this._b = b;
   9                 this._c = c;
  10                 this._d = d;
  11         },
  12
  13         transform: function(point, scale) {
  14                 return this._transform(point.clone(), scale);
  15         },
  16
  17         // destructive transform (faster)
  18         _transform: function(/*Point*/ point, /*Number*/ scale) /*-> Point*/ {
  19                 scale = scale || 1;
  20                 point.x = scale * (this._a * point.x + this._b);
  21                 point.y = scale * (this._c * point.y + this._d);
  22                 return point;
  23         },
  24
  25         untransform: function(/*Point*/ point, /*Number*/ scale) /*-> Point*/ {
  26                 scale = scale || 1;
  27                 return new L.Point(
  28                         (point.x/scale - this._b) / this._a,
  29                         (point.y/scale - this._d) / this._c);
  30         }
  31 });