GrabPassBlur.shader

// Upgrade NOTICE
// replace 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Custom/GrabPassBlur" {
  Properties {
    _Color ("Main Color", Color) = (1, 1, 1, 1)
    _Distortion ("Distortion", Range (0, 128)) = 10
    _MainTex ("Tint Color (RGB)", 2D) = "white" {}
    _BumpMap ("Normalmap", 2D) = "bump" {}
    _Size ("Size", Range(0, 20)) = 1
  }

  Category {
    Tags {
      "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Opaque"
    }

    SubShader {
      // Horizontal blur
      GrabPass {
        Tags {
          "LightMode" = "Always"
        }
      } Pass {
        Tags {
          "LightMode" = "Always"
        }

        CGPROGRAM
        #pragma vertex vert
        #pragma fragment frag
        #pragma fragmentoption ARB_precision_hint_fastest
        #include "UnityCG.cginc"

        struct appdata_t {
          float4 vertex : POSITION;
          float2 texcoord: TEXCOORD0;
        };

        struct v2f {
          float4 vertex : POSITION;
          float4 uvgrab : TEXCOORD0;
        };

        v2f vert(appdata_t v) {
          v2f o;
          o.vertex = UnityObjectToClipPos(v.vertex);
          #if UNITY_UV_STARTS_AT_TOP
            float scale = -1.0;
          #else
            float scale = 1.0;
          #endif
          o.uvgrab.xy = (float2(o.vertex.x, o.vertex.y * scale) + o.vertex.w) * 0.5;
          o.uvgrab.zw = o.vertex.zw;
          return o;
        }

        sampler2D _GrabTexture;
        float4 _GrabTexture_TexelSize;
        float _Size;

        half4 frag(v2f i) : COLOR {
          half4 sum = half4(0, 0, 0, 0);

          #define GRABPIXEL(weight,kernelx) tex2Dproj( _GrabTexture, UNITY_PROJ_COORD(float4(i.uvgrab.x + _GrabTexture_TexelSize.x * kernelx*_Size, i.uvgrab.y, i.uvgrab.z, i.uvgrab.w))) * weight

          sum += GRABPIXEL(0.05, -4.0);
          sum += GRABPIXEL(0.09, -3.0);
          sum += GRABPIXEL(0.12, -2.0);
          sum += GRABPIXEL(0.15, -1.0);
          sum += GRABPIXEL(0.18, 0.0);
          sum += GRABPIXEL(0.15, +1.0);
          sum += GRABPIXEL(0.12, +2.0);
          sum += GRABPIXEL(0.09, +3.0);
          sum += GRABPIXEL(0.05, +4.0);

          return sum;
        }
        ENDCG
      }

      // Vertical blur
      GrabPass {
        Tags {
          "LightMode" = "Always"
        }
      } Pass {
        Tags {
          "LightMode" = "Always"
        }

        CGPROGRAM
        #pragma vertex vert
        #pragma fragment frag
        #pragma fragmentoption ARB_precision_hint_fastest
        #include "UnityCG.cginc"

        struct appdata_t {
          float4 vertex : POSITION;
          float2 texcoord: TEXCOORD0;
        };

        struct v2f {
          float4 vertex : POSITION;
          float4 uvgrab : TEXCOORD0;
        };

        v2f vert(appdata_t v) 
          v2f o;
          o.vertex = UnityObjectToClipPos(v.vertex);
          #if UNITY_UV_STARTS_AT_TOP
            float scale = -1.0;
          #else
            float scale = 1.0;
          #endif
          o.uvgrab.xy = (float2(o.vertex.x, o.vertex.y * scale) + o.vertex.w) * 0.5;
          o.uvgrab.zw = o.vertex.zw;
          return o;
        }

        sampler2D _GrabTexture;
        float4 _GrabTexture_TexelSize;
        float _Size;

        half4 frag(v2f i) : COLOR {
          half4 sum = half4(0, 0, 0, 0);

          #define GRABPIXEL(weight,kernely) tex2Dproj( _GrabTexture, UNITY_PROJ_COORD(float4(i.uvgrab.x, i.uvgrab.y + _GrabTexture_TexelSize.y * kernely*_Size, i.uvgrab.z, i.uvgrab.w))) * weight

          sum += GRABPIXEL(0.05, -4.0);
          sum += GRABPIXEL(0.09, -3.0);
          sum += GRABPIXEL(0.12, -2.0);
          sum += GRABPIXEL(0.15, -1.0);
          sum += GRABPIXEL(0.18, 0.0);
          sum += GRABPIXEL(0.15, +1.0);
          sum += GRABPIXEL(0.12, +2.0);
          sum += GRABPIXEL(0.09, +3.0);
          sum += GRABPIXEL(0.05, +4.0);

          return sum;
        }
        ENDCG
      }

      // Distortion
      GrabPass {
        Tags {
          "LightMode" = "Always"
        }
      } Pass {
        Tags {
          "LightMode" = "Always"
        }

        CGPROGRAM
        #pragma vertex vert
        #pragma fragment frag
        #pragma fragmentoption ARB_precision_hint_fastest
        #include "UnityCG.cginc"

        struct appdata_t {
          float4 vertex : POSITION;
          float2 texcoord: TEXCOORD0;
        };

        struct v2f {
          float4 vertex : POSITION;
          float4 uvgrab : TEXCOORD0;
          float2 uvbump : TEXCOORD1;
          float2 uvmain : TEXCOORD2;
        };

        float _Distortion;
        float4 _BumpMap_ST;
        float4 _MainTex_ST;

        v2f vert(appdata_t v) {
          v2f o;
          o.vertex = UnityObjectToClipPos(v.vertex);
          #if UNITY_UV_STARTS_AT_TOP
            float scale = -1.0;
          #else
            float scale = 1.0;
          #endif
          o.uvgrab.xy = (float2(o.vertex.x, o.vertex.y * scale) + o.vertex.w) * 0.5;
          o.uvgrab.zw = o.vertex.zw;
          o.uvbump = TRANSFORM_TEX(v.texcoord, _BumpMap);
          o.uvmain = TRANSFORM_TEX(v.texcoord, _MainTex);
          return o;
        }

        fixed4 _Color;
        sampler2D _GrabTexture;
        float4 _GrabTexture_TexelSize;
        sampler2D _BumpMap;
        sampler2D _MainTex;

        half4 frag(v2f i) : COLOR {
          half2 bump = UnpackNormal(tex2D(_BumpMap, i.uvbump)).rg;
          float2 offset = bump * _Distortion * _GrabTexture_TexelSize.xy;
          i.uvgrab.xy = offset * i.uvgrab.z + i.uvgrab.xy;

          half4 col = tex2Dproj(_GrabTexture, UNITY_PROJ_COORD(i.uvgrab));
          half4 tint = tex2D(_MainTex, i.uvmain) * _Color;

          return col * tint;
        }
        ENDCG
      }
    }
  }
}