matrices.js

{
  translation: function(tx, ty) {
    return [
      1, 0, 0,
      0, 1, 0,
      tx, ty, 1,
    ];
  },

  rotation: function(angleInRadians) {
    var c = Math.cos(angleInRadians);
    var s = Math.sin(angleInRadians);
    return [
      c, -s, 0,
      s, c, 0,
      0, 0, 1,
    ];
  },

  scaling: function(sx, sy) {

    return [
      sx, 0, 0,
      0, sy, 0,
      0, 0, 1,
    ];

  }

}