using UltimateWater.Internal;
using UnityEngine;
using UnityEngine.Serialization;

namespace UltimateWater
{
	public class WaveParticlesSystemGPU : MonoBehaviour, IOverlaysRenderer
	{
		public struct ParticleData
		{
			public Vector2 Position;

			public Vector2 Direction;

			public float Wavelength;

			public float Amplitude;

			public float InitialLifetime;

			public float Lifetime;

			public float UvOffsetPack;

			public float Foam;

			public float TrailCalming;

			public float TrailFoam;
		}

		[SerializeField]
		[FormerlySerializedAs("maxParticles")]
		private int _MaxParticles = 80000;

		[SerializeField]
		[FormerlySerializedAs("controllerShader")]
		private ComputeShader _ControllerShader;

		[SerializeField]
		[FormerlySerializedAs("particlesRenderShader")]
		private Shader _ParticlesRenderShader;

		[SerializeField]
		[FormerlySerializedAs("foamTexture")]
		private Texture _FoamTexture;

		[SerializeField]
		[FormerlySerializedAs("foamOverlayTexture")]
		private Texture _FoamOverlayTexture;

		[SerializeField]
		[FormerlySerializedAs("foamAtlasWidth")]
		private int _FoamAtlasWidth = 8;

		[SerializeField]
		[FormerlySerializedAs("foamAtlasHeight")]
		private int _FoamAtlasHeight = 4;

		private Material _ParticlesRenderMaterial;

		private ComputeBuffer _ParticlesA;

		private ComputeBuffer _ParticlesB;

		private ComputeBuffer _SpawnBuffer;

		private ComputeBuffer _ParticlesRenderInfo;

		private ComputeBuffer _ParticlesUpdateInfo;

		private Vector2 _LastSurfaceOffset;

		private uint _ParticlesToSpawnCount;

		private Water _Water;

		private readonly ParticleData[] _ParticlesToSpawn = new ParticleData[16];

		private readonly RenderBuffer[] _RenderBuffers = new RenderBuffer[2];

		public ComputeBuffer ParticlesBuffer => _ParticlesA;

		public int FoamAtlasWidth => _FoamAtlasWidth;

		public int FoamAtlasHeight => _FoamAtlasHeight;

		public void EmitParticle(ParticleData particleData)
		{
			if (_ParticlesToSpawnCount != _ParticlesToSpawn.Length)
			{
				_ParticlesToSpawn[_ParticlesToSpawnCount++] = particleData;
			}
		}

		public void RenderOverlays(DynamicWaterCameraData overlays)
		{
			Spray component = GetComponent<Spray>();
			if (component != null && component.ParticlesBuffer != null)
			{
				Graphics.SetRandomWriteTarget(3, component.ParticlesBuffer);
			}
			_RenderBuffers[0] = overlays.DynamicDisplacementMap.colorBuffer;
			_RenderBuffers[1] = overlays.NormalMap.colorBuffer;
			_ParticlesRenderMaterial.SetBuffer("_Particles", _ParticlesA);
			_ParticlesRenderMaterial.SetMatrix("_ParticlesVP", GL.GetGPUProjectionMatrix(overlays.Camera.PlaneProjectorCamera.projectionMatrix, renderIntoTexture: true) * overlays.Camera.PlaneProjectorCamera.worldToCameraMatrix);
			if (_ParticlesRenderMaterial.SetPass(0))
			{
				Graphics.SetRenderTarget(_RenderBuffers, overlays.DynamicDisplacementMap.depthBuffer);
				Graphics.DrawProceduralIndirectNow(MeshTopology.Points, _ParticlesRenderInfo);
				Graphics.ClearRandomWriteTargets();
			}
			if (_ParticlesRenderMaterial.SetPass(2))
			{
				Graphics.SetRenderTarget(overlays.DisplacementsMask);
				Graphics.DrawProceduralIndirectNow(MeshTopology.Points, _ParticlesRenderInfo);
			}
			Graphics.SetRenderTarget(null);
		}

		public void RenderFoam(DynamicWaterCameraData overlays)
		{
			if (_ParticlesRenderMaterial.SetPass(1))
			{
				Graphics.SetRenderTarget(overlays.FoamMap);
				Graphics.DrawProceduralIndirectNow(MeshTopology.Points, _ParticlesRenderInfo);
			}
			if (_ParticlesRenderMaterial.SetPass(3))
			{
				Graphics.DrawProceduralIndirectNow(MeshTopology.Points, _ParticlesRenderInfo);
			}
		}

		private void OnValidate()
		{
			if (_ParticlesRenderShader == null)
			{
				_ParticlesRenderShader = Shader.Find("UltimateWater/Particles/GPU_Render");
			}
			if (_ParticlesRenderMaterial != null)
			{
				SetMaterialProperties();
			}
		}

		private void Update()
		{
			CheckResources();
			UpdateParticles();
			SpawnParticles();
			SwapBuffers();
			ComputeBuffer.CopyCount(_ParticlesA, _ParticlesRenderInfo, 0);
		}

		private void Start()
		{
			_Water = GetComponentInParent<Water>();
			OnValidate();
			_ParticlesRenderMaterial = new Material(_ParticlesRenderShader)
			{
				hideFlags = HideFlags.DontSave
			};
			SetMaterialProperties();
			_LastSurfaceOffset = _Water.SurfaceOffset;
		}

		private void OnDestroy()
		{
			if (_ParticlesA != null)
			{
				_ParticlesA.Release();
				_ParticlesA = null;
			}
			if (_ParticlesB != null)
			{
				_ParticlesB.Release();
				_ParticlesB = null;
			}
			if (_ParticlesRenderInfo != null)
			{
				_ParticlesRenderInfo.Release();
				_ParticlesRenderInfo = null;
			}
			if (_ParticlesUpdateInfo != null)
			{
				_ParticlesUpdateInfo.Release();
				_ParticlesUpdateInfo = null;
			}
			if (_SpawnBuffer != null)
			{
				_SpawnBuffer.Release();
				_SpawnBuffer = null;
			}
		}

		private void UpdateParticles()
		{
			_ParticlesB.SetCounterValue(0u);
			Vector2 surfaceOffset = _Water.SurfaceOffset;
			ComputeBuffer.CopyCount(_ParticlesA, _ParticlesUpdateInfo, 0);
			_ControllerShader.SetFloat("deltaTime", Time.deltaTime);
			_ControllerShader.SetVector("surfaceOffsetDelta", new Vector4(_LastSurfaceOffset.x - surfaceOffset.x, _LastSurfaceOffset.y - surfaceOffset.y, 0f, 0f));
			_ControllerShader.SetBuffer(0, "Particles", _ParticlesB);
			_ControllerShader.SetBuffer(0, "SourceParticles", _ParticlesA);
			_ControllerShader.DispatchIndirect(0, _ParticlesUpdateInfo);
			_LastSurfaceOffset = surfaceOffset;
		}

		private void SpawnParticles()
		{
			if (_ParticlesToSpawnCount != 0)
			{
				_SpawnBuffer.SetData(_ParticlesToSpawn);
				_ControllerShader.SetBuffer(1, "Particles", _ParticlesB);
				_ControllerShader.SetBuffer(1, "SpawnedParticles", _SpawnBuffer);
				_ControllerShader.Dispatch(1, 1, 1, 1);
				for (int i = 0; i < _ParticlesToSpawnCount; i++)
				{
					_ParticlesToSpawn[i].Lifetime = 0f;
				}
				_ParticlesToSpawnCount = 0u;
			}
		}

		private void SwapBuffers()
		{
			ComputeBuffer particlesA = _ParticlesA;
			_ParticlesA = _ParticlesB;
			_ParticlesB = particlesA;
		}

		private void CheckResources()
		{
			if (_ParticlesA == null)
			{
				_ParticlesA = new ComputeBuffer(_MaxParticles, 48, ComputeBufferType.Append);
				_ParticlesA.SetCounterValue(0u);
				_ParticlesB = new ComputeBuffer(_MaxParticles, 48, ComputeBufferType.Append);
				_ParticlesB.SetCounterValue(0u);
				_SpawnBuffer = new ComputeBuffer(16, 48, ComputeBufferType.Default);
			}
			if (_ParticlesRenderInfo == null)
			{
				_ParticlesRenderInfo = new ComputeBuffer(1, 16, ComputeBufferType.IndirectArguments);
				_ParticlesRenderInfo.SetData(new int[4] { 0, 1, 0, 0 });
			}
			if (_ParticlesUpdateInfo == null)
			{
				_ParticlesUpdateInfo = new ComputeBuffer(1, 12, ComputeBufferType.IndirectArguments);
				_ParticlesUpdateInfo.SetData(new int[3] { 0, 1, 1 });
			}
		}

		private void SetMaterialProperties()
		{
			_ParticlesRenderMaterial.SetVector("_FoamAtlasParams", new Vector4(1f / (float)_FoamAtlasWidth, 1f / (float)_FoamAtlasHeight, 0f, 0f));
			_ParticlesRenderMaterial.SetTexture("_FoamAtlas", _FoamTexture);
			_ParticlesRenderMaterial.SetTexture("_FoamOverlayTexture", _FoamOverlayTexture);
		}
	}
}