using System.Collections.Generic;
using UnityEngine;

namespace UltimateWater.Internal
{
	public class UtilityShaderVariants
	{
		private readonly Dictionary<int, Material> _Materials;

		private static UtilityShaderVariants _Instance;

		public static UtilityShaderVariants Instance
		{
			get
			{
				return (_Instance != null) ? _Instance : (_Instance = new UtilityShaderVariants());
			}
		}

		private UtilityShaderVariants()
		{
			_Materials = new Dictionary<int, Material>();
		}

		public Material GetVariant(Shader shader, string keywords)
		{
			int key = shader.GetInstanceID() ^ keywords.GetHashCode();
			Material value;
			if (!_Materials.TryGetValue(key, out value))
			{
				Material material = new Material(shader);
				material.hideFlags = HideFlags.DontSave;
				material.shaderKeywords = keywords.Split(' ');
				value = material;
				_Materials[key] = value;
			}
			return value;
		}
	}
}