matrix.js

/*
 *  CSS matrix3d transform API
 *  Simplification of 3d transforms
 *  Matt Roelle
 *  2013
 *
 *  Dependent on the Sylvester math library (http://sylvester.jcoglan.com/)
 */

function Surface() {
  // identity matrix, has no effect
  this.matrix = Matrix.Diagonal([1,1,1,1]);
  this.stack = [];
}

Surface.prototype.push = function() {
  this.stack.push(this.matrix);
  return this;
};

Surface.prototype.pop = function() {
  this.matrix = this.stack.pop();
  return this;
};

Surface.prototype.toCssString = function() {
  var buffer = 'matrix3d(';
  for(var y = 1; y <= 4; y++) {
    for(var x = 1; x <= 4; x++) {
      buffer += (this.matrix.e(y,x)  + ',');
    }
  }
  return (buffer.slice(0, buffer.length-1)+')');
};

Surface.prototype.bindToDomElement = function(element) {
  this.domElement = element;
};

Surface.prototype.updateCSS = function(element) {
  element.style['-webkit-transform'] = this.toCssString();
  element.style['-moz-transform'] = this.toCssString();
  element.style['-ms-transform'] = this.toCssString();
  element.style['-o-transform'] = this.toCssString();
  element.style['transform'] = this.toCssString();
};

Surface.prototype.update = function() {
  if (this.domElement !== undefined) {
    // if the surface is bound to a DOM element, automatically update the CSS
    this.updateCSS(this.domElement);
  }

  /* all transformation functions return `this`, for chainability
  * ie
  * surface
  * .translate(100,100)
  * .rotate(0,Math.PI/2)
  * .scale(2,2);
  */
  return this;
};

Surface.prototype.translate = function(x, y, z) {
  if (x === undefined) {
    x = 0;
  }
  if (y === undefined) {
    y = 0;
  }
  if (z === undefined) {
    z = 0;
  }

  this.matrix = this.matrix.x($M([
    [1,0,0,0],
    [0,1,0,0],
    [0,0,1,0],
    [x,y,z,1]
  ]));

  return this.update();
};

Surface.prototype.scale = function(x, y, z) {
  if (x === undefined) {
    x = 0;
  }
  if (y === undefined) {
    y = 0;
  }
  if (z === undefined) {
    z = 0;
  }

  this.matrix = this.matrix.x($M([
    [x,0,0,0],
    [0,y,0,0],
    [0,0,z,0],
    [0,0,0,1]
  ]));

  return this.update();
};

Surface.prototype.rotate = function(x, y, z) {
  if (x === undefined) {
    x = 0;
  }
  if (y === undefined) {
    y = 0;
  }
  if (z === undefined) {
    z = 0;
  }

  this.matrix = this.matrix.x($M([
    // x-axis rotation
    [1,0,0,0],
    [0,Math.cos(x),Math.sin(-1*x),0],
    [0,Math.sin(x),Math.cos(x),0],
    [0,0,0,1]
  ])).x($M([
    // y-axis rotation
    [Math.cos(y),0,Math.sin(y),0],
    [0,1,0,0],
    [Math.sin(-1*y),0,Math.cos(y),0],
    [0,0,0,1]
  ])).x($M([
    // z-axis rotation
    [Math.cos(z),Math.sin(-1*z),0,0],
    [Math.sin(z),Math.cos(z),0,0],
    [0,0,1,0],
    [0,0,0,1]
  ]));

  return this.update();
};