Print a square matrix (2x2, 4x4, 16x16, etc) in a clockwise spiral from outside in

printMatrixInSpiral.js

var mat = [ 
    [1, 2, 3, 4], 
    [5, 6, 7, 8], 
    [9, 10, 11, 12], 
    [13, 14, 15, 16]
];

var DIRECTIONS = {
    FORWARD: 1,
    BACKWARD: -1
};

var AXIS = {
    X: 'X',
    Y: 'Y'
};

function spiralMat(mat) {
    // init
    var position = {
        X: -1, //before first step
        Y: 0
    };
    var matLength = mat.length;
    var stepsCount = matLength;
    var direction = DIRECTIONS.FORWARD;
    var axis = AXIS.X;
    
    function takeStep() {
        position[axis] = position[axis] + direction;
    }

    function printLine() {
        var currentSteps = stepsCount;

        while (currentSteps) {
            takeStep();
            console.log(mat[position.Y][position.X]);
            currentSteps--;
        }
    }

    function rotate() {
        if (direction === DIRECTIONS.FORWARD) {
            if (axis === AXIS.X) {
                axis = AXIS.Y;
                stepsCount--;
                return;   
            }

            if (axis === AXIS.Y) {
                axis = AXIS.X;
                direction = DIRECTIONS.BACKWARD;
                return;
            }
        }

        if (direction === DIRECTIONS.BACKWARD) {
            if (axis === AXIS.X) {
                axis = AXIS.Y;
                stepsCount--;
                return;   
            }

            if (axis === AXIS.Y) {
                axis = AXIS.X;
                direction = DIRECTIONS.FORWARD;
            }
        }

    }

    while(stepsCount) {
        printLine();
        rotate();
    }
}

spiralMat(mat); //result: 1, 2, 3, 4, 8, 12, 16, 15, 14, 13, 9, 5, 6, 7, 11, 10