1 using System;
2 using UnityEngine;
3
4 namespace UnityStandardAssets.ImageEffects
5 {
6 [ExecuteInEditMode]
7 [AddComponentMenu("Image Effects/Blur/Blur")]
8 public class Blur : MonoBehaviour
9 {
10 /// Blur iterations - larger number means more blur.
11 [Range(0,10)]
12 public int iterations = 3;
13
14 /// Blur spread for each iteration. Lower values
15 /// give better looking blur, but require more iterations to
16 /// get large blurs. Value is usually between 0.5 and 1.0.
17 [Range(0.0f,1.0f)]
18 public float blurSpread = 0.6f;
19
20
21 // --------------------------------------------------------
22 // The blur iteration shader.
23 // Basically it just takes 4 texture samples and averages them.
24 // By applying it repeatedly and spreading out sample locations
25 // we get a Gaussian blur approximation.
26
27 public Shader blurShader = null;
28
29 static Material m_Material = null;
30 protected Material material {
31 get {
32 if (m_Material == null) {
33 m_Material = new Material(blurShader);
34 m_Material.hideFlags = HideFlags.DontSave;
35 }
36 return m_Material;
37 }
38 }
39
40 protected void OnDisable() {
41 if ( m_Material ) {
42 DestroyImmediate( m_Material );
43 }
44 }
45
46 // --------------------------------------------------------
47
48 protected void Start()
49 {
50 // Disable if we don't support image effects
51 if (!SystemInfo.supportsImageEffects) {
52 enabled = false;
53 return;
54 }
55 // Disable if the shader can't run on the users graphics card
56 if (!blurShader || !material.shader.isSupported) {
57 enabled = false;
58 return;
59 }
60 }
61
62 // Performs one blur iteration.
63 public void FourTapCone (RenderTexture source, RenderTexture dest, int iteration)
64 {
65 float off = 0.5f + iteration*blurSpread;
66 Graphics.BlitMultiTap (source, dest, material,
67 new Vector2(-off, -off),
68 new Vector2(-off, off),
69 new Vector2( off, off),
70 new Vector2( off, -off)
71 );
72 }
73
74 // Downsamples the texture to a quarter resolution.
75 private void DownSample4x (RenderTexture source, RenderTexture dest)
76 {
77 float off = 1.0f;
78 Graphics.BlitMultiTap (source, dest, material,
79 new Vector2(-off, -off),
80 new Vector2(-off, off),
81 new Vector2( off, off),
82 new Vector2( off, -off)
83 );
84 }
85
86 // Called by the camera to apply the image effect
87 void OnRenderImage (RenderTexture source, RenderTexture destination) {
88 int rtW = source.width/4;
89 int rtH = source.height/4;
90 RenderTexture buffer = RenderTexture.GetTemporary(rtW, rtH, 0);
91
92 // Copy source to the 4x4 smaller texture.
93 DownSample4x (source, buffer);
94
95 // Blur the small texture
96 for(int i = 0; i < iterations; i++)
97 {
98 RenderTexture buffer2 = RenderTexture.GetTemporary(rtW, rtH, 0);
99 FourTapCone (buffer, buffer2, i);
100 RenderTexture.ReleaseTemporary(buffer);
101 buffer = buffer2;
102 }
103 Graphics.Blit(buffer, destination);
104
105 RenderTexture.ReleaseTemporary(buffer);
106 }
107 }
108 }
