Unity Stencil buffer Alpha 처리 Shader

    Shader "multiply2D"
    {
        Properties
        {
            [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}

           // UI가 아닐경우는 texture를 입력받아 sampling하게 변경할 것.

            _Color ("Tint", Color) = (1,1,1,1)
            _MainTex ("Base (RGB), Alpha (A)", 2D) = "white" {}
            _Stencil ("Stencil ID", Float) = 0
            _ColorMask ("Color Mask", Float) = 15
            _ClipAlpha ("ClipAlpha", Float) = 0.2
        }
    
        SubShader
        {
            Tags
            {
                "Queue"="Transparent"
                "IgnoreProjector"="True"
                "RenderType"="Transparent"
                "PreviewType"="Plane"
                "CanUseSpriteAtlas"="True"
            }
        
            Stencil
            {
                Ref [_Stencil]
                Comp NotEqual
                Pass Replace
            }
    

            Cull Off
            Lighting Off
            ZWrite Off
            ZTest [unity_GUIZTestMode]
            Blend SrcAlpha OneMinusSrcAlpha
            ColorMask [_ColorMask]
    
            Pass
            {
            CGPROGRAM
                #pragma vertex vert
                #pragma fragment frag
    
                #include "UnityCG.cginc"
                #include "UnityUI.cginc"
            
                struct appdata_t
                {
                    float4 vertex   : POSITION;
                    float4 color    : COLOR;
                    float2 texcoord : TEXCOORD0;
                };
    
                struct v2f
                {
                    float4 vertex   : SV_POSITION;
                    fixed4 color    : COLOR;
                    half2 texcoord  : TEXCOORD0;
                    float4 worldPosition : TEXCOORD1;
                };
            
                fixed4 _Color;
                fixed4 _TextureSampleAdd;
                fixed _ClipAlpha;
    
                v2f vert(appdata_t IN)
                {
                    v2f OUT;
                    OUT.worldPosition = IN.vertex;
                    OUT.vertex = mul(UNITY_MATRIX_MVP, OUT.worldPosition);
    
                    OUT.texcoord = IN.texcoord;
                
                    #ifdef UNITY_HALF_TEXEL_OFFSET
                    OUT.vertex.xy += (_ScreenParams.zw-1.0) * float2(-1,1);
                    #endif
                
                    OUT.color = IN.color * _Color;
                    return OUT;
                }
    
                sampler2D _MainTex;
    
                fixed4 frag(v2f IN) : SV_Target
                {
                    half4 color = (tex2D(_MainTex, IN.texcoord) );
                    color.rgb=_Color.rgb;
                    color.a*=_Color.a;
                    clip (color.a - _ClipAlpha);
                    return color;
                }
            ENDCG
            }
        }
    }