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

public class GroundEditor : MonoBehaviour {
    public Vector3[] vertices;
    public float speed;
    public float lastDistance = 99999999999999999999999999f;
    void Start () {
        vertices = GetComponent<MeshFilter> ().mesh.vertices;
    }

    void OnMouseDrag()
    {
        FindNearestPoint ();
    }

    void OnMouseUp()
    {
        lastDistance = 99999999999999999999999999f;
    }

    private void FindNearestPoint()
    {
        Ray inputRay = Camera.main.ScreenPointToRay(Input.mousePosition);
        RaycastHit hit;

        int vertNumber =0;
        if (Physics.Raycast(inputRay, out hit)) {
            for(int i=0; i<vertices.Length; i++){
                float distance = GetDistance (hit.point, vertices [i]);
                if (distance < lastDistance) {
                    lastDistance = distance;
                    vertNumber = i;
                }
            }
            EditGround (vertNumber);
        }
    }

    private float GetDistance(Vector3 start, Vector3 end)
    {
        return (start - end).sqrMagnitude;
        //return Mathf.Sqrt (Mathf.Pow((start.x - end.x),2) + Mathf.Pow((start.y - end.y),2)+ Mathf.Pow((start.z - end.z),2));
    }

    private void EditGround(int number){
        vertices [number].z += speed;
        GetComponent<MeshFilter> ().mesh.vertices = vertices;
        GetComponent<MeshFilter> ().mesh.RecalculateBounds();
        GetComponent<MeshFilter> ().mesh.RecalculateNormals();
    }
}