Q.component('WalkAround', {
    added: function () {
        var entity = this.entity;
        Q._defaults(entity.p, {
            vx: 0,
            vy: 0,
            direction: 2,
            collisionMask: Q.SPRITE_DEFAULT
        });
        entity.on('step', this, "step");
        entity.on('hit', this, 'collision');
    },

    collision: function (col, last) {
        var entity = this.entity,
            p = entity.p;
        if (col.normalX > 0) { // bump left;
            p.vy = -Math.abs(p.vy);
            p.vx = -Math.abs(p.vx);
        }
        if (col.normalY > 0) { // bump top;
            p.vy = -Math.abs(p.vy);
            p.vx = Math.abs(p.vx);
        }
        if (col.normalX < 0) { // bump right;
            p.vy = Math.abs(p.vy);
            p.vx = Math.abs(p.vx);
        }
        if (col.normalY < 0) { // bump bottom;
            p.vy = Math.abs(p.vy);
            p.vx = -Math.abs(p.vx);
        }
    },

    step: function (dt) {
        var p = this.entity.p;
        p.x += p.vx * dt;
        p.y += p.vy * dt;
        this.entity.stage.collide(this.entity);
    }
});