Shader "Cheng/Mesh_Texture_BlendMod"
{
	Properties
	{
		_MainTex ("底图", 2D) = "white" {}
		_BlendTex ("混合图", 2D) = "white" {}
	}
	
    CGINCLUDE
    #include "UnityCG.cginc"
    struct appdata
    {
    	float4 vertex : POSITION;
    	float2 uv : TEXCOORD0;
    };
    struct v2f
    {
    	float2 uv : TEXCOORD0;
    	UNITY_FOG_COORDS(1)
    	float4 vertex : SV_POSITION;

    };
    sampler2D _MainTex;
    float4 _MainTex_ST;
    sampler2D _BlendTex;
    v2f vert (appdata v)
    {
    	v2f o;
    	o.vertex = UnityObjectToClipPos(v.vertex);
    	o.uv = TRANSFORM_TEX(v.uv, _MainTex);
    	UNITY_TRANSFER_FOG(o,o.vertex);
    	return o;
    }
    fixed4 frag (v2f i) : SV_Target
    {
    	fixed4 A = tex2D(_MainTex, i.uv);  //A为底图rgba 四维向量
        fixed4 B = tex2D(_BlendTex,i.uv);  //B为混合图agba  四维向量

    	//——————只更改此处代码————————

    	//fixed4 C =A*(1-B.a)+B*(B.a);      //正常透明混合
        //fixed4 C =min(A,B);               //变暗
        //fixed4 C =max(A,B);//变亮
        //fixed4 C=1-((1-A)*(1-B));//滤色 A+B-A*B
        //fixed4 C=A-((1-A)*(1-B))/B; //颜色加深
        //fixed4 C= A+(A*B)/(1-B); //颜色减淡
        //fixed4 C=A+B-1;//线性加深
        //fixed4 C=A+B; //线性减淡
        //fixed4 C=A*B; //正片叠底
        //fixed4 ifFlag= step(A,fixed4(0.5,0.5,0.5,0.5));
        //fixed4 C=ifFlag*A*B*2+(1-ifFlag)*(1-(1-A)*(1-B)*2);//叠加
        fixed4 ifFlag= step(B,fixed4(0.5,0.5,0.5,0.5));
        fixed4 C=ifFlag*A*B*2+(1-ifFlag)*(1-(1-A)*(1-B)*2); //强光
        //fixed4 ifFlag= step(B,fixed4(0.5,0.5,0.5,0.5));
        //fixed4 C=ifFlag*(A*B*2+A*A*(1-B*2))+(1-ifFlag)*(A*(1-B)*2+sqrt(A)*(2*B-1)); //柔光
        //fixed4 ifFlag= step(B,fixed4(0.5,0.5,0.5,0.5));
        //fixed4 C=ifFlag*(A-(1-A)*(1-2*B)/(2*B))+(1-ifFlag)*(A+A*(2*B-1)/(2*(1-B))); //亮光
        //fixed4 ifFlag= step(B,fixed4(0.5,0.5,0.5,0.5));
        //fixed4 C=ifFlag*(min(A,2*B))+(1-ifFlag)*(max(A,( B*2-1))); //点光  
        //fixed4 C=A+2*B-1; //线性光
        //fixed4 ifFlag= step(A+B,fixed4(1,1,1,1));
        //fixed4 C=ifFlag*(fixed4(0,0,0,0))+(1-ifFlag)*(fixed4(1,1,1,1)); //实色混合
        //fixed4 C=A+B-A*B*2; //排除
        //fixed4 C=abs(A-B); //差值
        //fixed4 ifFlag= step(B.r+B.g+B.b,A.r+A.g+A.b);
        //fixed4 C=ifFlag*(B)+(1-ifFlag)*(A); //深色
        //fixed4 ifFlag= step(B.r+B.g+B.b,A.r+A.g+A.b);
        //fixed4 C=ifFlag*(A)+(1-ifFlag)*(B); //浅色
        //fixed4 C=A-B; //减去
        //fixed4 C=A/B; //划分
        //---------------------------

    	return C;
    }//混合模式，调整

    ENDCG
    SubShader
    {
    	Tags { "Queue"="Transparent" }

    	Pass
    	{
    		CGPROGRAM
    		#pragma vertex vert
    		#pragma fragment frag
    		// make fog work
    		#pragma multi_compile_fog
    		ENDCG
    	}
    }
}