/* Sparx
 * Copyright August Zinsser 2007
 * This program is distributed under the terms of the GNU General Public License
 */


using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Storage;


namespace Pina3D.Particles
{
    public class Directional : Force
    {
        private Vector3 mDirection;

        public Vector3 Direction { set { mDirection = value; ReCalculateForceVector(); } get { return mDirection; } }
        public override float Magnitude { set { mMagnitude = value; ReCalculateForceVector(); } get { return mMagnitude; } }


        public Directional(string name, float lifeSpan, float delay, Vector3 direction, float magnitude)
            : base(name, lifeSpan, delay)
        {
            mDirection = direction;
            mMagnitude = magnitude;
            ReCalculateForceVector();
        }


        public override Object Clone()
        {
            Directional retFo = new Directional(mName + "_clone", mAge, mDelay, mDirection, mMagnitude);
            return retFo;
        }


        public override void Update(Emission emission)
        {
            if (emission != null && emission.Age > mDelay && emission.Age < mLifeExpectancy + mDelay)
                emission.Velocity3D += Vector3.Multiply(mForceVector, Pina.ElapsedSeconds);
        }


        private void ReCalculateForceVector()
        {
            mForceVector = mDirection;
            if (mForceVector != Vector3.Zero)
                mForceVector.Normalize();
            mForceVector = Vector3.Multiply(mForceVector, mMagnitude);
        }
    }
}