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

//Somehow achieves an effect similar to this:
 //#define BlendOverlayf(base, blend)     (base < 0.5 ? (2.0 * base * blend) : (1.0 - 2.0 * (1.0 - base) * (1.0 - blend)))

Shader "Photoshop/Overlay"
{
    Properties
    {
        _MainTex("Base (RGB) Trans (A)", 2D) = "white" {}
    }

        SubShader
    {
        Tags {"Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent"}
        ZWrite Off Lighting Off Cull Off Fog { Mode Off } Blend DstColor SrcColor
        LOD 110

        Pass
        {
            CGPROGRAM
            #pragma vertex vert_vct
            #pragma fragment frag_mult 
            #pragma fragmentoption ARB_precision_hint_fastest
            #include "UnityCG.cginc"

            sampler2D _MainTex;
            float4 _MainTex_ST;

            struct vin_vct
            {
                float4 vertex : POSITION;
                float4 color : COLOR;
                float2 texcoord : TEXCOORD0;
            };

            struct v2f_vct
            {
                float4 vertex : POSITION;
                fixed4 color : COLOR;
                half2 texcoord : TEXCOORD0;
            };

            v2f_vct vert_vct(vin_vct v)
            {
                v2f_vct o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.color = v.color;
                o.texcoord = v.texcoord;
                return o;
            }

            float4 frag_mult(v2f_vct i) : COLOR
            {
                float4 tex = tex2D(_MainTex, i.texcoord);

                float4 final;
                final.rgb = i.color.rgb * tex.rgb * 2;
                final.a = i.color.a * tex.a;
                return lerp(float4(0.5f,0.5f,0.5f,0.5f), final, final.a);

            }

            ENDCG

        }


    }

}