Generic Damage Component

using UnityEngine;
using System.Collections;

public class Damage : MonoBehaviour {

    public float currentShield;
    public float maxShield = 1;
    public Explosion.ExplosionType explosionType = Explosion.ExplosionType.Medium;
    [HideInInspector] public float lastExplosionDamage;
    [HideInInspector] public Vector3 lastVelocity;
    [HideInInspector] public float factor;
    public float slideDamage = 1;
    public DieType dieType = DieType.Destroy;

    public enum DieType {
        None,
        Unfreeze,
        Destroy
    }

    public void Start()
    {
        currentShield = maxShield;
        lastExplosionDamage = currentShield;
    }

    void FixedUpdate()
    {
        if (rigidbody != null) {
            lastVelocity = rigidbody.velocity;
        }
    }


    public void Add(float amount, Vector3 pos)
    {
        if (currentShield > 0) {
            currentShield = Mathf.Clamp(currentShield - amount, 0, maxShield);

            if (currentShield == 0 )
            {
                Explode();
            } else {


                // small explosions for gradual damage
                if (currentShield < lastExplosionDamage - 0.1f) {
                    if (amount >= 0.3f) {
                        Explosion.Explode(pos,lastVelocity,Explosion.ExplosionType.Medium);
                    } else if (amount >= 0.05f) {
                        Explosion.Explode(pos,lastVelocity,Explosion.ExplosionType.Small);
                    }
                    lastExplosionDamage = currentShield;
                }

                factor = Mathf.InverseLerp(maxShield,0,currentShield);

            }
        }

    }

    public void Explode()
    {
        Explosion e = Explosion.Explode(transform.position,lastVelocity,explosionType);

        Collider[] myColliders = GetComponentsInChildren<Collider>();

        foreach (Collider c in e.GetComponentsInChildren<Collider>())
        {
            foreach (Collider c2 in myColliders) {
                Physics.IgnoreCollision(c,c2);
            }
        }

        switch (dieType) {
            case DieType.Destroy: Destroy(gameObject); break;
            case DieType.Unfreeze: rigidbody.constraints = RigidbodyConstraints.None; break;
        }

        CameraMovement mainCam = Camera.main.GetComponent<CameraMovement>();

        // if camera was watching this object, now watch the explosion instead
        if (mainCam.target == transform)
        {
            Time.timeScale = 0.1f;
            mainCam.target = e.transform;
        }


    }


    void OnCollisionEnter(Collision c)
    {
        if (rigidbody != null)
        {
            float velocityChangeFactor = Mathf.InverseLerp(0,90,Vector3.Angle(rigidbody.velocity,lastVelocity));
            Add( c.impactForceSum.magnitude * 0.01f * velocityChangeFactor, c.contacts[0].point);
        } else {
            // this is a static object - be damaged by impact of other moving object
            Add( c.impactForceSum.magnitude * 0.01f, c.contacts[0].point);
        }

    }

    void OnCollisionStay(Collision c)
    {
        //Debug.Log(slideDamage);
        Add( c.impactForceSum.magnitude * 0.00001f * slideDamage, c.contacts[0].point);

    }



}