source: other-projects/playing-in-the-street/summer-2013/trunk/Playing-in-the-Street-WPF/Content/Web/mrdoob-three.js-4862f5f/test/unit/math/Matrix3.js@ 28897

/**
 * @author bhouston / http://exocortex.com
 */

module( "Matrix3" );

var matrixEquals3 = 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;
};


var toMatrix4 = function( m3 ) {
    var result = new THREE.Matrix4();
    var re = result.elements;
    var me = m3.elements;
    re[0] = me[0];
    re[1] = me[1];
    re[2] = me[2];
    re[4] = me[3];
    re[5] = me[4];
    re[6] = me[5];
    re[8] = me[6];
    re[9] = me[7];
    re[10] = me[8];

    return result;
};

test( "constructor", function() {
    var a = new THREE.Matrix3();
    ok( a.determinant() == 1, "Passed!" );

    var b = new THREE.Matrix3( 0, 1, 2, 3, 4, 5, 6, 7, 8 );
    ok( b.elements[0] == 0 );
    ok( b.elements[1] == 3 );
    ok( b.elements[2] == 6 );
    ok( b.elements[3] == 1 );
    ok( b.elements[4] == 4 );
    ok( b.elements[5] == 7 );
    ok( b.elements[6] == 2 );
    ok( b.elements[7] == 5 );
    ok( b.elements[8] == 8 );

    ok( ! matrixEquals3( a, b ), "Passed!" );
});

test( "copy", function() {
    var a = new THREE.Matrix3( 0, 1, 2, 3, 4, 5, 6, 7, 8 );
    var b = new THREE.Matrix3().copy( a );

    ok( matrixEquals3( a, b ), "Passed!" );

    // ensure that it is a true copy
    a.elements[0] = 2;
    ok( ! matrixEquals3( a, b ), "Passed!" );
});

test( "set", function() {
    var b = new THREE.Matrix3();
    ok( b.determinant() == 1, "Passed!" );

    b.set( 0, 1, 2, 3, 4, 5, 6, 7, 8 );
    ok( b.elements[0] == 0 );
    ok( b.elements[1] == 3 );
    ok( b.elements[2] == 6 );
    ok( b.elements[3] == 1 );
    ok( b.elements[4] == 4 );
    ok( b.elements[5] == 7 );
    ok( b.elements[6] == 2 );
    ok( b.elements[7] == 5 );
    ok( b.elements[8] == 8 );
});

test( "identity", function() {
    var b = new THREE.Matrix3( 0, 1, 2, 3, 4, 5, 6, 7, 8 );
    ok( b.elements[0] == 0 );
    ok( b.elements[1] == 3 );
    ok( b.elements[2] == 6 );
    ok( b.elements[3] == 1 );
    ok( b.elements[4] == 4 );
    ok( b.elements[5] == 7 );
    ok( b.elements[6] == 2 );
    ok( b.elements[7] == 5 );
    ok( b.elements[8] == 8 );

    var a = new THREE.Matrix3();
    ok( ! matrixEquals3( a, b ), "Passed!" );

    b.identity();
    ok( matrixEquals3( a, b ), "Passed!" );
});

test( "multiplyScalar", function() {
    var b = new THREE.Matrix3( 0, 1, 2, 3, 4, 5, 6, 7, 8 );
    ok( b.elements[0] == 0 );
    ok( b.elements[1] == 3 );
    ok( b.elements[2] == 6 );
    ok( b.elements[3] == 1 );
    ok( b.elements[4] == 4 );
    ok( b.elements[5] == 7 );
    ok( b.elements[6] == 2 );
    ok( b.elements[7] == 5 );
    ok( b.elements[8] == 8 );

    b.multiplyScalar( 2 );
    ok( b.elements[0] == 0*2 );
    ok( b.elements[1] == 3*2 );
    ok( b.elements[2] == 6*2 );
    ok( b.elements[3] == 1*2 );
    ok( b.elements[4] == 4*2 );
    ok( b.elements[5] == 7*2 );
    ok( b.elements[6] == 2*2 );
    ok( b.elements[7] == 5*2 );
    ok( b.elements[8] == 8*2 );
});

test( "determinant", function() {
    var a = new THREE.Matrix3();
    ok( a.determinant() == 1, "Passed!" );

    a.elements[0] = 2;
    ok( a.determinant() == 2, "Passed!" );

    a.elements[0] = 0;
    ok( a.determinant() == 0, "Passed!" );

    // calculated via http://www.euclideanspace.com/maths/algebra/matrix/functions/determinant/threeD/index.htm
    a.set( 2, 3, 4, 5, 13, 7, 8, 9, 11 );
    ok( a.determinant() == -73, "Passed!" );
});


test( "getInverse", function() {
    var identity = new THREE.Matrix4();
    var a = new THREE.Matrix4();
    var b = new THREE.Matrix3( 0, 0, 0, 0, 0, 0, 0, 0, 0 );
    var c = new THREE.Matrix4( 0, 0, 0, 0, 0, 0, 0, 0, 0 );

    ok( ! matrixEquals3( a, b ), "Passed!" );
    b.getInverse( a, false );
    ok( matrixEquals3( b, new THREE.Matrix3() ), "Passed!" );

    try { 
        b.getInverse( c, true );
        ok( false, "Passed!" ); // should never get here.
    }
    catch( err ) {
        ok( true, "Passed!" );
    }

    var testMatrices = [
        new THREE.Matrix4().makeRotationX( 0.3 ),
        new THREE.Matrix4().makeRotationX( -0.3 ),
        new THREE.Matrix4().makeRotationY( 0.3 ),
        new THREE.Matrix4().makeRotationY( -0.3 ),
        new THREE.Matrix4().makeRotationZ( 0.3 ),
        new THREE.Matrix4().makeRotationZ( -0.3 ),
        new THREE.Matrix4().makeScale( 1, 2, 3 ),
        new THREE.Matrix4().makeScale( 1/8, 1/2, 1/3 )
        ];

    for( var i = 0, il = testMatrices.length; i < il; i ++ ) {
        var m = testMatrices[i];
        var mInverse3 = new THREE.Matrix3().getInverse( m );

        var mInverse = toMatrix4( mInverse3 );

        // the determinant of the inverse should be the reciprocal
        ok( Math.abs( m.determinant() * mInverse3.determinant() - 1 ) < 0.0001, "Passed!" );
        ok( Math.abs( m.determinant() * mInverse.determinant() - 1 ) < 0.0001, "Passed!" );

        var mProduct = new THREE.Matrix4().multiplyMatrices( m, mInverse );
        ok( Math.abs( mProduct.determinant() - 1 ) < 0.0001, "Passed!" );
        ok( matrixEquals3( mProduct, identity ), "Passed!" );
    }
});

test( "transpose", function() {
    var a = new THREE.Matrix3();
    var b = a.clone().transpose();
    ok( matrixEquals3( a, b ), "Passed!" );

    b = new THREE.Matrix3( 0, 1, 2, 3, 4, 5, 6, 7, 8 );
    var c = b.clone().transpose();
    ok( ! matrixEquals3( b, c ), "Passed!" ); 
    c.transpose();
    ok( matrixEquals3( b, c ), "Passed!" ); 
});

test( "clone", function() {
    var a = new THREE.Matrix3( 0, 1, 2, 3, 4, 5, 6, 7, 8 );
    var b = a.clone();

    ok( matrixEquals3( a, b ), "Passed!" );

    // ensure that it is a true copy
    a.elements[0] = 2;
    ok( ! matrixEquals3( a, b ), "Passed!" );
});