using System;
using System.Collections.Generic;
using System.Linq;
using System.Numerics;
using System.Text;
using System.Threading.Tasks;

namespace StgSharp.Geometries
{
    public class PlainInstancingBuffer<T> where T : IInstancing<T>
    {
        private List<Vector4> coordList;
        private List<float> scalingList;
        private List<IInstancing<T>> instanceList;

        public PlainInstancingBuffer()
        {
            coordList = new List<Vector4>();
            instanceList = new List<IInstancing<T>>();
            scalingList = new List<float>();
        }

        internal List<Vector4> CoordList 
        {
            get => coordList;
        }

        internal List<float> ScalingList
        {
            get => scalingList;
        }

        public int CreateInstanceID()
        {
            int ret = instanceList.Count;
            coordList.Add(new Vector4());
            scalingList.Add(0);
            return ret;
        }

        public void Remove(T instance)
        {
            if (instance.GlobalBuffer != this)
            {
                throw new ArgumentException();
            }
            int index = instance.BufferId;
            IInstancing<T> temp = instanceList[instanceList.Count - 1];
            instanceList[instance.BufferId] = temp;
            temp.BufferId = instance.BufferId;
            
            coordList[instance.BufferId] = coordList[coordList.Count - 1];
            scalingList[instance.BufferId] = scalingList[scalingList.Count - 1];

            instanceList.RemoveAt(instanceList.Count - 1);
            coordList.RemoveAt(coordList.Count - 1);
            scalingList.RemoveAt(scalingList.Count - 1);
        }

        

    }
}