Shader "Custom/CastShadow"
{
    Properties
    {
        _MainTex ("MainTexture", 2D) = "white" {}
        _Color ("Color", Color) = (1,1,1,1)
        _Alpha ("Alpha", Range(0,1)) = 0.5
    }
    SubShader
    {
        Tags { "RenderType"="Opaque"}
        ZWrite Off
        Cull Off
        Pass {
            Blend SrcAlpha OneMinusSrcAlpha

            CGPROGRAM

            #pragma vertex vert
            #pragma fragment frag
            
            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;
            fixed4 _Color;
            float _Alpha;
            
            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                return o;
            }
            
            fixed4 frag (v2f i) : SV_Target
            {
                fixed4 basic = tex2D(_MainTex, i.uv);
                if(basic.a==0){
                    discard;
                }
                fixed3 rgb = (_Color.rgb*(_Alpha*2));
                fixed4 col = float4(rgb,_Alpha);
                return col;
            }
            ENDCG

        }

    }
    FallBack "Diffuse"
}