using System;
using UnityEngine;

[AddComponentMenu("Enviro/Effects/Fog Image Effect")]
[ExecuteInEditMode]
[RequireComponent(typeof(Camera))]
public class EnviroFog : EnviroEffects
{
	public bool distanceFog = true;

	public bool useRadialDistance;

	public bool heightFog = true;

	public float height = 1f;

	[Range(0.001f, 10f)]
	public float heightDensity = 2f;

	public float startDistance;

	public Shader fogShader;

	public Material fogMaterial;

	private Texture3D _noiseTexture;

	public override bool CheckResources()
	{
		CheckSupport(true);
		fogMaterial = CheckShaderAndCreateMaterial(fogShader, fogMaterial);
		if (!isSupported)
		{
			ReportAutoDisable();
		}
		return isSupported;
	}

	private new void Start()
	{
		LoadNoise3dTexture();
	}

	private void OnRenderImage(RenderTexture source, RenderTexture destination)
	{
		if (!CheckResources() || (!distanceFog && !heightFog))
		{
			Graphics.Blit(source, destination);
			return;
		}
		Camera component = GetComponent<Camera>();
		Transform transform = component.transform;
		float nearClipPlane = component.nearClipPlane;
		float farClipPlane = component.farClipPlane;
		float fieldOfView = component.fieldOfView;
		float aspect = component.aspect;
		Matrix4x4 identity = Matrix4x4.identity;
		float num = fieldOfView * 0.5f;
		Vector3 vector = transform.right * nearClipPlane * Mathf.Tan(num * ((float)Math.PI / 180f)) * aspect;
		Vector3 vector2 = transform.up * nearClipPlane * Mathf.Tan(num * ((float)Math.PI / 180f));
		Vector3 vector3 = transform.forward * nearClipPlane - vector + vector2;
		float num2 = vector3.magnitude * farClipPlane / nearClipPlane;
		vector3.Normalize();
		vector3 *= num2;
		Vector3 vector4 = transform.forward * nearClipPlane + vector + vector2;
		vector4.Normalize();
		vector4 *= num2;
		Vector3 vector5 = transform.forward * nearClipPlane + vector - vector2;
		vector5.Normalize();
		vector5 *= num2;
		Vector3 vector6 = transform.forward * nearClipPlane - vector - vector2;
		vector6.Normalize();
		vector6 *= num2;
		identity.SetRow(0, vector3);
		identity.SetRow(1, vector4);
		identity.SetRow(2, vector5);
		identity.SetRow(3, vector6);
		Vector3 position = transform.position;
		float num3 = position.y - height;
		float z = ((!(num3 <= 0f)) ? 0f : 1f);
		fogMaterial.SetMatrix("_FrustumCornersWS", identity);
		fogMaterial.SetVector("_CameraWS", position);
		fogMaterial.SetVector("_HeightParams", new Vector4(height, num3, z, heightDensity * 0.5f));
		fogMaterial.SetVector("_DistanceParams", new Vector4(0f - Mathf.Max(startDistance, 0f), 0f, 0f, 0f));
		fogMaterial.SetTexture("_NoiseTexture", _noiseTexture);
		FogMode fogMode = RenderSettings.fogMode;
		float fogDensity = RenderSettings.fogDensity;
		float fogStartDistance = RenderSettings.fogStartDistance;
		float fogEndDistance = RenderSettings.fogEndDistance;
		bool flag = fogMode == FogMode.Linear;
		float num4 = ((!flag) ? 0f : (fogEndDistance - fogStartDistance));
		float num5 = ((!(Mathf.Abs(num4) > 0.0001f)) ? 0f : (1f / num4));
		Vector4 value = default(Vector4);
		value.x = fogDensity * 1.2011224f;
		value.y = fogDensity * 1.442695f;
		value.z = ((!flag) ? 0f : (0f - num5));
		value.w = ((!flag) ? 0f : (fogEndDistance * num5));
		fogMaterial.SetVector("_SceneFogParams", value);
		fogMaterial.SetVector("_SceneFogMode", new Vector4((float)fogMode, useRadialDistance ? 1 : 0, 0f, 0f));
		int num6 = 0;
		CustomGraphicsBlit(passNr: (!distanceFog || !heightFog) ? (distanceFog ? 1 : 2) : 0, source: source, dest: destination, fxMaterial: fogMaterial);
	}

	private static void CustomGraphicsBlit(RenderTexture source, RenderTexture dest, Material fxMaterial, int passNr)
	{
		RenderTexture.active = dest;
		fxMaterial.SetTexture("_MainTex", source);
		GL.PushMatrix();
		GL.LoadOrtho();
		fxMaterial.SetPass(passNr);
		GL.Begin(7);
		GL.MultiTexCoord2(0, 0f, 0f);
		GL.Vertex3(0f, 0f, 3f);
		GL.MultiTexCoord2(0, 1f, 0f);
		GL.Vertex3(1f, 0f, 2f);
		GL.MultiTexCoord2(0, 1f, 1f);
		GL.Vertex3(1f, 1f, 1f);
		GL.MultiTexCoord2(0, 0f, 1f);
		GL.Vertex3(0f, 1f, 0f);
		GL.End();
		GL.PopMatrix();
	}

	private void LoadNoise3dTexture()
	{
		TextAsset textAsset = Resources.Load("NoiseVolume") as TextAsset;
		byte[] bytes = textAsset.bytes;
		uint num = BitConverter.ToUInt32(textAsset.bytes, 12);
		uint num2 = BitConverter.ToUInt32(textAsset.bytes, 16);
		uint num3 = BitConverter.ToUInt32(textAsset.bytes, 20);
		uint num4 = BitConverter.ToUInt32(textAsset.bytes, 24);
		uint num5 = BitConverter.ToUInt32(textAsset.bytes, 80);
		uint num6 = BitConverter.ToUInt32(textAsset.bytes, 88);
		if (num6 == 0)
		{
			num6 = num3 / num2 * 8;
		}
		_noiseTexture = new Texture3D((int)num2, (int)num, (int)num4, TextureFormat.RGBA32, false);
		_noiseTexture.name = "3D Noise";
		Color[] array = new Color[num2 * num * num4];
		uint num7 = 128u;
		if (textAsset.bytes[84] == 68 && textAsset.bytes[85] == 88 && textAsset.bytes[86] == 49 && textAsset.bytes[87] == 48 && (num5 & 4) != 0)
		{
			uint num8 = BitConverter.ToUInt32(textAsset.bytes, (int)num7);
			if (num8 >= 60 && num8 <= 65)
			{
				num6 = 8u;
			}
			else if (num8 >= 48 && num8 <= 52)
			{
				num6 = 16u;
			}
			else if (num8 >= 27 && num8 <= 32)
			{
				num6 = 32u;
			}
			num7 += 20;
		}
		uint num9 = num6 / 8;
		num3 = (num2 * num6 + 7) / 8;
		for (int i = 0; i < num4; i++)
		{
			for (int j = 0; j < num; j++)
			{
				for (int k = 0; k < num2; k++)
				{
					float num10 = (float)(int)bytes[num7 + k * num9] / 255f;
					array[k + j * num2 + i * num2 * num] = new Color(num10, num10, num10, num10);
				}
				num7 += num3;
			}
		}
		_noiseTexture.SetPixels(array);
		_noiseTexture.Apply();
	}
}