Shader "Unlit/RimShaderPlus"
{
    Properties
    {
        _MainTex("Base 2D", 2D) = "white"{}
        _InSideRimColor ("InSideRimColor", Color) = (1,1,1,1)
        _InSideRimPower("InSideRimPower", Range(0.0,5)) = 0
        _InSideRimIntensity("InSideRimIntensity", Range(0.0, 10)) = 0
    }
    SubShader
    {
        Tags
        {
            "RenderType"="Opaque"
        }
        LOD 100
        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"
            #include "Lighting.cginc"

            sampler2D _MainTex;
            float4 _MainTex_ST;
            uniform float4 _MainColor;
            uniform float4 _InSideRimColor;
            uniform float _InSideRimPower;
            uniform float _InSideRimIntensity;

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
                float3 normal : NORMAL;
                float4 tangent : TANGENT;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float3 normal : TEXCOORD1;
                float4 vertex : SV_POSITION;
                float4 vertexWorld : TEXCOORD2;
            };

            v2f vert(appdata v)
            {
                v2f o;
                o.normal = mul(unity_ObjectToWorld, float4(v.normal, 0)).xyz;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.vertexWorld = mul(unity_ObjectToWorld, v.vertex);
                o.uv = v.uv;
                return o;
            }

            fixed4 frag(v2f i) : SV_Target
            {
                i.normal = normalize(i.normal);
                float3 worldViewDir = normalize(_WorldSpaceCameraPos.xyz - i.vertexWorld.xyz);
                half NdotV = max(0, dot(i.normal, worldViewDir));
                NdotV = 1.0 - NdotV;
                float fresnel = pow(NdotV, _InSideRimPower) * _InSideRimIntensity;
                fresnel *= i.normal.x;
                fresnel = max(0, fresnel);
                float3 Emissive = _InSideRimColor.rgb * fresnel;
                return tex2D(_MainTex, i.uv) + float4(Emissive, 1);
            }
            ENDCG
        }

    }
}