text: /**
   * @author simonThiele / https://github.com/simonThiele
   */
  
  QUnit.module( "PerspectiveCamera" );
  
  // see e.g. math/Matrix4.js
  var matrixEquals4 = function ( a, b, tolerance ) {
  
  	tolerance = tolerance || 0.0001;
  	if ( a.elements.length != b.elements.length ) {
  
  		return false;
  
  	}
  	for ( var i = 0, il = a.elements.length; i < il; i ++ ) {
  
  		var delta = a.elements[ i ] - b.elements[ i ];
  		if ( delta > tolerance ) {
  
  			return false;
  
  		}
  
  	}
  
  	return true;
  
  };
  
  QUnit.test( "updateProjectionMatrix", function ( assert ) {
  
  	var cam = new THREE.PerspectiveCamera( 75, 16 / 9, 0.1, 300.0 );
  
  	// updateProjectionMatrix is called in contructor
  	var m = cam.projectionMatrix;
  
  	// perspective projection is given my the 4x4 Matrix
  	// 2n/r-l		0			l+r/r-l				 0
  	//   0		2n/t-b	t+b/t-b				 0
  	//   0			0		-(f+n/f-n)	-(2fn/f-n)
  	//   0			0				-1					 0
  
  	// this matrix was calculated by hand via glMatrix.perspective(75, 16 / 9, 0.1, 300.0, pMatrix)
  	// to get a reference matrix from plain WebGL
  	var reference = new THREE.Matrix4().set(
  		0.7330642938613892, 0, 0, 0,
  		0, 1.3032253980636597, 0, 0,
  		0, 0, - 1.000666856765747, - 0.2000666856765747,
  		0, 0, - 1, 0
  	);
  
  	// assert.ok( reference.equals(m) );
  	assert.ok( matrixEquals4( reference, m, 0.000001 ) );
  
  } );
  
  QUnit.test( "clone" , function( assert ) {
  	var near = 1,
  			far = 3,
  			bottom = -1,
  			top = 1,
  			aspect = 16 / 9,
  			fov = 90;
  
  	var cam = new THREE.PerspectiveCamera( fov, aspect, near, far );
  
  	var clonedCam = cam.clone();
  
  	assert.ok( cam.fov === clonedCam.fov , "fov is equal" );
  	assert.ok( cam.aspect === clonedCam.aspect , "aspect is equal" );
  	assert.ok( cam.near === clonedCam.near , "near is equal" );
  	assert.ok( cam.far === clonedCam.far , "far is equal" );
  	assert.ok( cam.zoom === clonedCam.zoom , "zoom is equal" );
  	assert.ok( cam.projectionMatrix.equals(clonedCam.projectionMatrix) , "projectionMatrix is equal" );
  });
  