using System;
using UnityEngine;
using UnityEngine.VFX;

namespace UnityEngine.VFX
{
    class IncrementStripIndexOnStart : VFXSpawnerCallbacks
    {
        public class InputProperties
        {
            [Tooltip("Maximum Strip Count (Used to cycle indices)")]
            public uint StripMaxCount = 8;
        }

        static private readonly int stripMaxCountID = Shader.PropertyToID("StripMaxCount");
        static private readonly int stripIndexID = Shader.PropertyToID("stripIndex");

        uint m_Index = 0;

        public override void OnPlay(VFXSpawnerState state, VFXExpressionValues vfxValues, VisualEffect vfxComponent)
        {
            m_Index = (m_Index + 1) % Math.Max(1, vfxValues.GetUInt(stripMaxCountID));
            state.vfxEventAttribute.SetUint(stripIndexID, m_Index);
        }

        public override void OnStop(VFXSpawnerState state, VFXExpressionValues vfxValues, VisualEffect vfxComponent)
        {
            m_Index = 0;
        }

        public override void OnUpdate(VFXSpawnerState state, VFXExpressionValues vfxValues, VisualEffect vfxComponent)
        {
        }
    }
}