Unity Shader 图片模糊效果实现

Unity Shader 图片模糊效果实现

shader源码如下

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Custom/GaussianBlur"
{
	Properties
	{
		_MainTex("Texture", 2D) = "white" {}
		_StencilComp("Stencil Comparison", Float) = 8
		_Stencil("Stencil ID", Float) = 0
		_StencilOp("Stencil Operation", Float) = 0
		_StencilWriteMask("Stencil Write Mask", Float) = 255
		_StencilReadMask("Stencil Read Mask", Float) = 255

		_ColorMask("Color Mask", Float) = 15

		_BlurSize("Blur Size", Float) = 2  //调整模糊强度
	}

		CGINCLUDE

#include "UnityCG.cginc"

		sampler2D _MainTex;
		uniform half4 _MainTex_TexelSize;
		uniform float _BlurSize;

		static const half weight[4] = { 0.0205, 0.0855, 0.232, 0.324 };
		static const half4 coordOffset = half4(1.0h, 1.0h, -1.0h, -1.0h);

		struct v2f_blurSGX
		{
			float4 pos:SV_POSITION;
			half2 uv:TEXCOORD0;
			half4 uvoff[3]:TEXCOORD1;
		};

		v2f_blurSGX vert_BlurHorizontal(appdata_img v)
		{
			v2f_blurSGX o;
			o.pos = UnityObjectToClipPos(v.vertex);
			o.uv = v.texcoord.xy;
			half2 offs = _MainTex_TexelSize.xy*half2(1, 0)*_BlurSize;
			o.uvoff[0] = v.texcoord.xyxy + offs.xyxy*coordOffset * 3;
			o.uvoff[1] = v.texcoord.xyxy + offs.xyxy*coordOffset * 2;
			o.uvoff[2] = v.texcoord.xyxy + offs.xyxy*coordOffset;

			return o;
		}

		v2f_blurSGX vert_BlurVertical(appdata_img v)
		{
			v2f_blurSGX o;
			o.pos = UnityObjectToClipPos(v.vertex);
			o.uv = v.texcoord.xy;

			half2 offs = _MainTex_TexelSize.xy*half2(0, 1)*_BlurSize;
			o.uvoff[0] = v.texcoord.xyxy + offs.xyxy*coordOffset * 3;
			o.uvoff[1] = v.texcoord.xyxy + offs.xyxy*coordOffset * 2;
			o.uvoff[2] = v.texcoord.xyxy + offs.xyxy*coordOffset;

			return o;
		}

		fixed4 frag_Blur(v2f_blurSGX i) :SV_Target
		{

			fixed4 c = tex2D(_MainTex,i.uv)*weight[3];
			for (int idx = 0; idx < 3; idx++)
			{
				c += tex2D(_MainTex,i.uvoff[idx].xy)*weight[idx];
				c += tex2D(_MainTex,i.uvoff[idx].zw)*weight[idx];
			}

			return c;
		}

			ENDCG

			SubShader
		{
			// No culling or depth
			Cull Off ZWrite Off
			Stencil
			{
				Ref[_Stencil]
				Comp[_StencilComp]
				Pass[_StencilOp]
				ReadMask[_StencilReadMask]
				WriteMask[_StencilWriteMask]
			}
			Fog{ Mode Off }
			Blend SrcAlpha OneMinusSrcAlpha
			ColorMask[_ColorMask]

				Pass
			{
				ZTest Always
				CGPROGRAM
				#pragma vertex vert_BlurHorizontal
				#pragma fragment frag_Blur


				ENDCG
			}

				Pass
			{
				ZTest Always
				CGPROGRAM
				#pragma vertex vert_BlurVertical
				#pragma fragment frag_Blur


				ENDCG
			}
		}
}