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

public class trackGen : MonoBehaviour
{
    public int sectionNum = 20;
    public float minWidth = 5;
    public float MaxWidth = 10;
    public float sectionLenth = 5;

    public float noiseOffset;

    [Range(0,10)]
    public float curveyFactor = 1;

    public MeshFilter meshFilter;

    [System.NonSerialized]
    public List<Vector3> newVerts = new List<Vector3>();
    [System.NonSerialized]
    public List<int> newTris = new List<int>();

    MeshCollider meshCollider;

    public void GenerateTrack()
    {
        Mesh mesh = new Mesh();

        meshCollider = GetComponent<MeshCollider>();
        meshFilter.mesh = mesh;

        mesh.Clear();

        newVerts.Clear();
        newTris.Clear();

        Vector3 pos = Vector3.zero;
        Vector3 lastPos = Vector3.zero;

        float initialOffset = (Mathf.PerlinNoise(0, 0 * 0.1f) * 15) + (Mathf.PerlinNoise(0, 0 * 0.05f) * 60);
        float roadWidth = 10;
        float lastRoadWidth = 10;

        meshCollider.sharedMesh = mesh;

        for (int i = 0; i < sectionNum; i++)
        {
            pos = new Vector3((Mathf.PerlinNoise( noiseOffset, i * 0.1f) * 15) + (Mathf.PerlinNoise(noiseOffset, i * 0.05f) * 60) - initialOffset, 0, sectionLenth * i);
            roadWidth = Mathf.PerlinNoise(i * 0.2f, noiseOffset)  * (MaxWidth-minWidth) + minWidth;
           // roadWidth = 10;
            addSection((pos.x) * curveyFactor - roadWidth, (pos.x) * curveyFactor + roadWidth,( lastPos.x) * curveyFactor - lastRoadWidth,( lastPos.x) * curveyFactor + lastRoadWidth, pos.z);

            lastRoadWidth = roadWidth;
            lastPos = pos;
        }



        mesh.vertices = newVerts.ToArray();
        mesh.triangles = newTris.ToArray();
        mesh.RecalculateNormals();
    }

    void addSection(float frontleft, float frontright, float backleft, float backright,float z) {

        AddQuad(new Vector3(frontleft, 0, 5 + z), new Vector3(frontright, 0, 5 + z), new Vector3(backleft, 0, 0 + z), new Vector3(backright, 0, 0 + z));
        AddQuad(new Vector3(backleft,5, 0 + z), new Vector3(frontleft, 5, 5 + z), new Vector3(backleft, 0, 0 + z), new Vector3(frontleft, 0, 5 + z));
        AddQuad(  new Vector3(backright, 0, 0 + z), new Vector3(frontright, 0, 5 + z), new Vector3(backright, 5, 0 + z), new Vector3(frontright, 5, 5 + z));

    }

    // quad orientation vv

    //------------//
    // A        B //
    //         /  //
    //        /   //
    //     /      //
    // C/       D //
    //------------//

    void AddQuad(Vector3 a, Vector3 b, Vector3 c, Vector3 d) {

        AddTri(a, b, c);
        AddTri(b, d, c);
    }

    void AddTri(Vector3 a, Vector3 b, Vector3 c)
    {
        int vertsLength = newVerts.Count;

        newVerts.Add(a);
        newVerts.Add(b);
        newVerts.Add(c);

        newTris.Add(vertsLength + 0);
        newTris.Add(vertsLength + 1);
        newTris.Add(vertsLength + 2);
    }

    // Update is called once per frame
    void Update()
    {
        
    }
}