using UnityEngine;

namespace UnityStandardAssets.ImageEffects
{
	[ExecuteInEditMode]
	[AddComponentMenu("Image Effects/Blur/Blur")]
	public class Blur : MonoBehaviour
	{
		[Range(0f, 10f)]
		public int iterations = 3;

		[Range(0f, 1f)]
		public float blurSpread = 0.6f;

		public Shader blurShader;

		private static Material m_Material;

		protected Material material
		{
			get
			{
				if (m_Material == null)
				{
					m_Material = new Material(blurShader);
					m_Material.hideFlags = HideFlags.DontSave;
				}
				return m_Material;
			}
		}

		protected void OnDisable()
		{
			if ((bool)m_Material)
			{
				Object.DestroyImmediate(m_Material);
			}
		}

		protected void Start()
		{
			if (!SystemInfo.supportsImageEffects)
			{
				base.enabled = false;
			}
			else if (!blurShader || !material.shader.isSupported)
			{
				base.enabled = false;
			}
		}

		public void FourTapCone(RenderTexture source, RenderTexture dest, int iteration)
		{
			float num = 0.5f + (float)iteration * blurSpread;
			Graphics.BlitMultiTap(source, dest, material, new Vector2(0f - num, 0f - num), new Vector2(0f - num, num), new Vector2(num, num), new Vector2(num, 0f - num));
		}

		private void DownSample4x(RenderTexture source, RenderTexture dest)
		{
			float num = 1f;
			Graphics.BlitMultiTap(source, dest, material, new Vector2(0f - num, 0f - num), new Vector2(0f - num, num), new Vector2(num, num), new Vector2(num, 0f - num));
		}

		private void OnRenderImage(RenderTexture source, RenderTexture destination)
		{
			int width = source.width / 4;
			int height = source.height / 4;
			RenderTexture renderTexture = RenderTexture.GetTemporary(width, height, 0);
			DownSample4x(source, renderTexture);
			for (int i = 0; i < iterations; i++)
			{
				RenderTexture temporary = RenderTexture.GetTemporary(width, height, 0);
				FourTapCone(renderTexture, temporary, i);
				RenderTexture.ReleaseTemporary(renderTexture);
				renderTexture = temporary;
			}
			Graphics.Blit(renderTexture, destination);
			RenderTexture.ReleaseTemporary(renderTexture);
		}
	}
}