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

// Upgrade NOTE: replaced '_Object2World' with 'unity_ObjectToWorld'

Shader "Unlit/ShaderTest4"
{
	Properties
	{
		_Color("Color Tint",Color) = (1,1,1,1)
		_RampTex("Ramp Tex",2D) = "white" {}
		_Specular("Specular",Color) = (1,1,1,1)
		_Gloss("Gloss",Range(8.0,256)) = 20
	}
	SubShader
	{
		Tags { "RenderType"="Opaque"
				"LightMode"="ForwardBase"}
		LOD 100

		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			// make fog work
			#pragma multi_compile_fog
			
			#include "UnityCG.cginc"
			#include "Lighting.cginc"


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

			struct v2f
			{
				float4 pos : SV_POSITION;
				float3 worldNormal : TEXCOORD0;
				float3 worldPos : TEXCOORD1;
				float2 uv : TEXCOORD2;
				UNITY_FOG_COORDS(1)
				
			};

			fixed4 _Color;
			sampler2D _RampTex;
			float4 _RampTex_ST;
			float4 _Specular;
			float _Gloss;

			v2f vert (appdata v)
			{
				v2f o;
				//o.pos = UnityObjectToClipPos(v.vertex);
				o.pos = UnityObjectToClipPos(v.vertex);
				o.worldNormal = UnityObjectToWorldNormal(v.normal);
				o.worldPos = mul(unity_ObjectToWorld,v.vertex).xyz;
				o.uv = TRANSFORM_TEX(v.texcoord, _RampTex);
				UNITY_TRANSFER_FOG(o,o.vertex);
				return o;
			}
			
			fixed4 frag (v2f i) : SV_Target
			{
				fixed3 worldNormal = normalize(i.worldNormal);
				fixed3 worldLightDir = normalize(UnityWorldSpaceLightDir(i.worldPos));
				fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;
				fixed halfLambert = 0.5 * dot(worldNormal,worldLightDir)+0.5;
				fixed3 diffuseColor = tex2D(_RampTex,fixed2(halfLambert,halfLambert)).rgb;
				fixed3 diffuse = _LightColor0.rgb * diffuseColor;
				fixed3 viewDir = normalize(UnityWorldSpaceViewDir(i.worldPos));
				fixed3 halfDir = normalize(worldLightDir + viewDir);
				fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(max(0,dot(worldNormal,halfDir)),_Gloss);

				// sample the texture
				//fixed4 col = tex2D(_MainTex, i.uv);
				// apply fog
				UNITY_APPLY_FOG(i.fogCoord, col);
				return fixed4(ambient + diffuse + specular,1.0);
			}
			ENDCG
		}
	}
	FallBack "Specular"
}