using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class DeformationParts : MonoBehaviour {

    public MeshFilter[] deformMeshes;
    Mesh[] meshes;
    public float minVelocity = 5f;
    public float deformRadius = 0.5f;
    public float multiply = 0.05f;

    void Start ()
    {
        meshes = new Mesh[deformMeshes.Length];

        for (int i = 0; i < deformMeshes.Length; i++)
        {
            meshes[i] = deformMeshes[i].mesh;
        }
    }
    
    void Update () {
  
    }

    private void OnCollisionEnter(Collision collision)
    {
        if (collision.relativeVelocity.magnitude > minVelocity)
        {
            bool isDeformated = false;
            Mesh curDamageMesh;

            for(int i = 0; i < meshes.Length; i++)
            {
                curDamageMesh = meshes[i];
                Vector3[] vertices = meshes[i].vertices;

                for (int k = 0; k < curDamageMesh.vertexCount; k++)
                {
                    for (int j = 0; j < collision.contacts.Length; j++)
                    {
                        Vector3 point = transform.InverseTransformPoint(collision.contacts[j].point);
                        Vector3 velocity = transform.InverseTransformVector(collision.relativeVelocity);
                        float distance = Vector3.Distance(point, vertices[k]);
                        if (distance < deformRadius)
                        {
                            Vector3 deformate = velocity * (deformRadius - distance) * multiply;
                            vertices[k] += deformate;
                            isDeformated = true;
                        }
                    }
                }

                if (isDeformated)
                {
                    curDamageMesh.vertices = vertices;
                    curDamageMesh.RecalculateNormals();
                    curDamageMesh.RecalculateBounds();
                    GetComponent<MeshCollider>().sharedMesh = curDamageMesh;
                }
            }
        }
    }
}