using UnityEngine;

public class VoxelRaycastGPU : MonoBehaviour
{
    public VoxelRaycastGPU(ComputeShader computeShader)
    {
        raycastShader = computeShader;
    }

    public ComputeShader raycastShader;

    public struct Ray
    {
        public float pad;
        public Vector3 direction;
    }

    public struct BatchData
    {
        public Vector3 origin;
        public float maxDistance;
    };

    public struct Hit
    {
        public float penetrationFactor;
        public float reflexionFactor;
        public float lastDistance;
        private float _pad1;
        public Vector3 origin;
        private float _pad2;
        public Vector3 position;
        private float _pad3;
        public float distance;
        public uint hit;
        private float _pad4;
        private float _pad5;
    }

    public void Init( ComputeShader computeShader )
    {
        raycastShader = computeShader;
    }

    public void Raycast( in Ray[] rays, float maxDistance, ref ComputeBuffer rayBuffer, ref ComputeBuffer hitBuffer )
    {
        int kernel = raycastShader.FindKernel("CSMain");

        rayBuffer.SetData(rays);
        raycastShader.SetBuffer(kernel, "rays", rayBuffer);
        raycastShader.SetBuffer(kernel, "hits", hitBuffer);
        raycastShader.SetFloat("maxDistance", maxDistance);

        int threadGroups = Mathf.CeilToInt(rays.Length / 64f);
        raycastShader.Dispatch(kernel, threadGroups, 1, 1);

        Hit[] hits = new Hit[rays.Length];
        hitBuffer.GetData(hits);
    }
}