//Based on unity builtin shader

Shader "MK/Glow/Luminance/UI/Unlit/Detail"
{
    Properties
    {
        [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
        _Color ("Main Color", Color) = (1,1,1,1)

        _DetailTex ("Detail (RGB)", 2D) = "white" {}
        _Strength ("Detail Strength", Range(0.0, 1.0)) = 0.2

        _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

        [Toggle(UNITY_UI_ALPHACLIP)] _UseUIAlphaClip ("Use Alpha Clip", Float) = 0

        [NoScaleOffset] _EmissionMap ("Emission Texture", 2D) = "white" {}
        [HDR] _EmissionColor ("Emission Color", Color) = (1,1,1,1)
    }

    SubShader
    {
        LOD 100

        Tags
        {
            "Queue" = "Transparent"
            "IgnoreProjector" = "True"
            "RenderType" = "Transparent"
            "PreviewType"="Plane"
        }

        Stencil
        {
            Ref [_Stencil]
            Comp [_StencilComp]
            Pass [_StencilOp]
            ReadMask [_StencilReadMask]
            WriteMask [_StencilWriteMask]
        }

        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"

            #pragma multi_compile __ UNITY_UI_CLIP_RECT
            #pragma multi_compile __ UNITY_UI_ALPHACLIP

            struct appdata_t
            {
                float4 vertex : POSITION;
                float2 texcoord : TEXCOORD0;
                float2 texcoord2 : TEXCOORD1;
                fixed4 color : COLOR;
                UNITY_VERTEX_INPUT_INSTANCE_ID
            };

            struct v2f
            {
                float4 vertex : SV_POSITION;
                float2 texcoord : TEXCOORD0;
                float2 texcoord2 : TEXCOORD1;
                float4 worldPosition : TEXCOORD2;
                fixed4 color : COLOR;
                UNITY_VERTEX_OUTPUT_STEREO
            };

            sampler2D _MainTex;
            sampler2D _DetailTex;
            float4 _MainTex_ST;
            float4 _DetailTex_ST;
            float4 _DetailTex_TexelSize;
            fixed4 _Color;
            fixed _Strength;

            fixed4 _TextureSampleAdd;

            bool _UseClipRect;
            float4 _ClipRect;

            bool _UseAlphaClip;

            uniform fixed3 _EmissionColor;
            uniform sampler2D _EmissionMap;

            v2f vert (appdata_t v)
            {
                v2f o;
                UNITY_SETUP_INSTANCE_ID(v);
                UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(o);
                o.worldPosition = v.vertex;
                o.vertex = UnityObjectToClipPos(o.worldPosition);

                o.texcoord = TRANSFORM_TEX(v.texcoord, _MainTex);
                o.texcoord2 = TRANSFORM_TEX(v.texcoord2 * _DetailTex_TexelSize.xy, _DetailTex);
                o.color = v.color * _Color;

                return o;
            }

            fixed4 frag (v2f i) : COLOR
            {
                fixed4 color = (tex2D(_MainTex, i.texcoord) + _TextureSampleAdd) * i.color;
                fixed4 detail = tex2D(_DetailTex, i.texcoord2);
                color.rgb = lerp(color.rgb, color.rgb * detail.rgb, detail.a * _Strength);
                color = color * _Color;

                #ifdef UNITY_UI_CLIP_RECT
                color.a *= UnityGet2DClipping(i.worldPosition.xy, _ClipRect);
                #endif

                #ifdef UNITY_UI_ALPHACLIP
                clip (color.a - 0.001);
                #endif

                color.rgb = tex2D(_EmissionMap, i.texcoord).rgb * _EmissionColor;

                return color;
            }
            ENDCG

        }
    }
}
