Shader "_MyShader/4_Texture/3_RampTexture/Ramp"
{
Properties
{
_RampTex ("RampTex", 2D) = "white" {}
_Color ("Color", COLOR) = (1,1,1,1)
_SpecularColor ("SpecularColor", COLOR) = (1,1,1,1)
_SpecularScale ("SpecularScale", Range(-2,50)) = 5
}
SubShader
{

    Pass
    {
    Tags {"LightMode" = "ForwardBase"}
        CGPROGRAM
        #pragma vertex vert
        #pragma fragment frag
        #include "UnityCG.cginc"
        #include "Lighting.cginc"


        sampler2D _RampTex;
        float4 _RampTex_ST;
        fixed4 _Color;
        fixed4 _SpecularColor;
        float _SpecularScale;


        struct a2v
        {
            float4 ver : POSITION;
            float3 norm : NORMAL;
            float4 texc : TEXCOORD0;
        };

        struct v2f
        {
            float4 pos : SV_POSITION;
            float3 worldNormalDir : POSITION1;
            float3 worldLightDir : POSITION2;
            float3 Blinn_PhongDir : POSITION3;
            float2 uv : TEXCOORD1;
        };

        sampler2D _MainTex;
        float4 _MainTex_ST;
        
        v2f vert (a2v v)
        {
            v2f o;
            o.pos = mul(UNITY_MATRIX_MVP,v.ver);
            
            float3 worldViewDir = normalize(WorldSpaceViewDir(v.ver));
            o.worldLightDir = normalize(WorldSpaceLightDir (v.ver));
            o.worldNormalDir = normalize(UnityObjectToWorldNormal (v.norm));
            o.Blinn_PhongDir = normalize(worldViewDir + o.worldLightDir);

            o.uv = TRANSFORM_TEX(v.texc,_RampTex);

            return o;
        }
        
        fixed4 frag (v2f i) : SV_Target
        {
            fixed halfLambert = 0.5 * dot(i.worldLightDir,i.worldNormalDir) + 0.5;

            fixed3 diffuseC = tex2D(_RampTex,fixed2(halfLambert,halfLambert)).rgb * _Color.rgb * _LightColor0.rgb;

            fixed3 specularC = pow(saturate(dot(i.worldNormalDir,i.Blinn_PhongDir)),_SpecularScale) * _SpecularColor.rgb * _LightColor0.rgb;

            fixed3 ambC = UNITY_LIGHTMODEL_AMBIENT.xyz;

            fixed4 col = fixed4(diffuseC + specularC + ambC,1);

            return col;
        }
        ENDCG
    }
}
FallBack "Specular"

}