Coordinate Transformation

rotation.js

/*****************************************
 * credit to                             *
 * http://www.solitaryroad.com/c308.html *
 *****************************************/
function Location(x, y) {
  this.x = x;
  this.y = y;
  this.flip_h = function(max) {
    return new Location(max - this.x, this.y);
  };

  this.flip_v = function(max) {
    return new Location(this.x, max - this.y);
  };

  this.flip_24 = function() {
    return new Location(this.y, this.x);
  };

  this.flip_13 = function(max) {
    return this.flip_v(max).turn_90(max);
  };

  this.turn_90 = function(max) {
    return this.flip_v(max).flip_24();
  };

  this.turn_180 = function(max) {
    return this.turn_90(max).turn_90(max);
  };

  this.turn_270 = function(max) {
    return this.turn_90(max).turn_90(max).turn_90(max);
  };
}