Shader "Bamboo/RimLight"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
		_RimColor ("Rim Color", color) = (1.0, 0, 0, 1.0)
		_RimPower ("Rim Power", Range(0.0001, 3.0)) = 1.0
		_RimIntensity ("Rim Intensity", Range(0, 100.0)) = 1.0
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 100

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"
			#include "Lighting.cginc"

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

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
				float3 worldNormal : TEXCOORD1;
				float3 worldViewDir : TEXCOORD2;
            };

            sampler2D _MainTex;
            float4 _MainTex_ST;
			fixed4 _RimColor;
			half _RimPower;
			float _RimIntensity;

            v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
				o.worldNormal = UnityObjectToWorldNormal(v.normal);
				o.worldViewDir = WorldSpaceViewDir(v.vertex);
                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
				fixed3 worldNormal = normalize(i.worldNormal);
				fixed3 worldViewDir = normalize(i.worldViewDir);

                fixed4 diffuse = tex2D(_MainTex, i.uv);
				// powÆðË¥¼õ×÷ÓÃ
				fixed4 rimLight = _RimColor * pow(saturate(1.0 - dot(worldNormal, worldViewDir)), 1.0 / _RimPower) * _RimIntensity;
				//fixed4 rimLight = _RimColor * saturate(1.0 - dot(worldNormal, worldViewDir)) * _RimIntensity;

				fixed3 color = diffuse.rgb + rimLight;
                return fixed4(color, 1.0);
            }
            ENDCG
        }
    }
}