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

public class CombineMeshNode : MeshProcessor {
    public List<ProceduralMeshData> Source = new List<ProceduralMeshData>();

    public override void Execute(ProceduralMeshData m)
    {
        List<Vector3> vertices = new List<Vector3>();
        List<int[]> indices = new List<int[]>();
        List<Vector3> normals = new List<Vector3>();
        List<Vector4> tangents = new List<Vector4>();
        List<List<Vector4>> uvs = new List<List<Vector4>>();

        //combine 
        foreach (var meshData in Source)
        {
            if (meshData != null)
            {
                //append all indices
                foreach (var submeshIndices in meshData.Indices)
                {
                    var newIndices = new int[submeshIndices.Length];
                    //offset indices
                    for (int i = 0; i < newIndices.Length; ++i)
                    {
                        newIndices[i] = submeshIndices[i] + vertices.Count;
                    }
                    indices.Add(newIndices);
                }


                vertices.AddRange(meshData.Vertices);

                normals.AddRange(meshData.Normals);

                if (meshData.Tangents != null)
                {
                    tangents.AddRange(meshData.Tangents);
                }
               

                while (uvs.Count < meshData.Uvs.Count){
                    uvs.Add(new List<Vector4>());
                }

                for (int i = 0; i < meshData.Uvs.Count; ++i)
                {
                    uvs[i].AddRange(meshData.Uvs[i]);
                }

            }
        }

        m.Vertices = vertices.ToArray();
        m.Indices = indices;
        m.Normals = normals.ToArray();
        m.Tangents = tangents.Count == 0 ? null : tangents.ToArray();
        m.Uvs = uvs;
    }
}