Create matrix Transform Class - Node.js Math

Node.js examples for Math:Matrix

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Description

Create matrix Transform Class

Demo Code


Transform = function (matrix) {
  /*//from  w  w  w .j ava2  s  .  co m
  * 0 2 4
  * 1 3 5
  * x x x
  */
  this.m = matrix || [ 1, 0, 0, 1, 0, 0 ];
};

Transform.prototype.copy = function(transform) {
  this.m = transform.m.slice(0);
  return this;
};

Transform.prototype.reset = function() {
  for (var i = this.m.length - 1; i >= 0; i--)
    this.m[i] = 0;
  this.m[0] = this.m[3] = 1;
  return this;
};

Transform.prototype.translate = function(x, y) {
  this.m[4] += x;
  this.m[5] += y;
  return this;
};

Transform.prototype.scale = function(x, y) {
  this.m[0] *= x;
  this.m[2] *= x;
  this.m[4] *= x;
  this.m[1] *= y;
  this.m[3] *= y;
  this.m[5] *= y;
  return this;
};

Transform.prototype.rotate = function(rads) {
  var c = Math.cos(rads);
  var s = Math.sin(rads);
  var m0 = c*this.m[0] - s*this.m[1];
  var m2 = c*this.m[2] - s*this.m[3];
  var m4 = c*this.m[4] - s*this.m[5];
  var m1 = s*this.m[0] + c*this.m[1];
  var m3 = s*this.m[2] + c*this.m[3];
  var m5 = s*this.m[4] + c*this.m[5];
  this.m[0] = m0;
  this.m[1] = m1;
  this.m[2] = m2;
  this.m[3] = m3;
  this.m[4] = m4;
  this.m[5] = m5;
  return this;
};

Transform.prototype.invert = function() {
  var d = 1 / (this.m[0] * this.m[3] - this.m[1] * this.m[2]);
  var m0 = d * this.m[3];
  var m1 = -d * this.m[1];
  var m2 = -d * this.m[2];
  var m3 = d * this.m[0];
  var m4 = d * (this.m[2] * this.m[5] - this.m[3] * this.m[4]);
  var m5 = d * (this.m[1] * this.m[4] - this.m[0] * this.m[5]);
  this.m[0] = m0;
  this.m[1] = m1;
  this.m[2] = m2;
  this.m[3] = m3;
  this.m[4] = m4;
  this.m[5] = m5;
  return this;
};

Transform.prototype.applyToCoords = function(x, y) {
  return [this.m[0]*x + this.m[2]*y + this.m[4], this.m[1]*x + this.m[3]*y + this.m[5]];
};

Transform.prototype.applyToContext = function(ctx) {
  CanvasRenderingContext2D.prototype.transform.apply(ctx, this.m);
};

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