using UnityEngine;

namespace UnityStandardAssets.ImageEffects
{
	[ExecuteInEditMode]
	[RequireComponent(typeof(Camera))]
	[AddComponentMenu("Image Effects/Rendering/Screen Space Ambient Obscurance")]
	internal class ScreenSpaceAmbientObscurance : PostEffectsBase
	{
		[Range(0f, 3f)]
		public float intensity = 0.5f;

		[Range(0.1f, 3f)]
		public float radius = 0.2f;

		[Range(0f, 3f)]
		public int blurIterations = 1;

		[Range(0f, 5f)]
		public float blurFilterDistance = 1.25f;

		[Range(0f, 1f)]
		public int downsample;

		public Texture2D rand;

		public Shader aoShader;

		private Material aoMaterial;

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

		private void OnDisable()
		{
			if ((bool)aoMaterial)
			{
				Object.DestroyImmediate(aoMaterial);
			}
			aoMaterial = null;
		}

		[ImageEffectOpaque]
		private void OnRenderImage(RenderTexture source, RenderTexture destination)
		{
			if (!CheckResources())
			{
				Graphics.Blit(source, destination);
				return;
			}
			Matrix4x4 projectionMatrix = GetComponent<Camera>().projectionMatrix;
			Matrix4x4 inverse = projectionMatrix.inverse;
			Vector4 value = new Vector4(-2f / ((float)Screen.width * projectionMatrix[0]), -2f / ((float)Screen.height * projectionMatrix[5]), (1f - projectionMatrix[2]) / projectionMatrix[0], (1f + projectionMatrix[6]) / projectionMatrix[5]);
			aoMaterial.SetVector("_ProjInfo", value);
			aoMaterial.SetMatrix("_ProjectionInv", inverse);
			aoMaterial.SetTexture("_Rand", rand);
			aoMaterial.SetFloat("_Radius", radius);
			aoMaterial.SetFloat("_Radius2", radius * radius);
			aoMaterial.SetFloat("_Intensity", intensity);
			aoMaterial.SetFloat("_BlurFilterDistance", blurFilterDistance);
			int width = source.width;
			int height = source.height;
			RenderTexture renderTexture = RenderTexture.GetTemporary(width >> downsample, height >> downsample);
			Graphics.Blit(source, renderTexture, aoMaterial, 0);
			if (downsample > 0)
			{
				RenderTexture temporary = RenderTexture.GetTemporary(width, height);
				Graphics.Blit(renderTexture, temporary, aoMaterial, 4);
				RenderTexture.ReleaseTemporary(renderTexture);
				renderTexture = temporary;
			}
			for (int i = 0; i < blurIterations; i++)
			{
				aoMaterial.SetVector("_Axis", new Vector2(1f, 0f));
				RenderTexture temporary = RenderTexture.GetTemporary(width, height);
				Graphics.Blit(renderTexture, temporary, aoMaterial, 1);
				RenderTexture.ReleaseTemporary(renderTexture);
				aoMaterial.SetVector("_Axis", new Vector2(0f, 1f));
				renderTexture = RenderTexture.GetTemporary(width, height);
				Graphics.Blit(temporary, renderTexture, aoMaterial, 1);
				RenderTexture.ReleaseTemporary(temporary);
			}
			aoMaterial.SetTexture("_AOTex", renderTexture);
			Graphics.Blit(source, destination, aoMaterial, 2);
			RenderTexture.ReleaseTemporary(renderTexture);
		}
	}
}