Shader "Zhanyou/Mobile/DiffuseMetal"
{
	Properties
	{
		_MainTex ("Base (RGB)", 2D) = "white" {}
		[NoScaleOffset]_BumpMap ("Normal Map", 2D) = "white" {}
		[NoScaleOffset]_ChannelTex("Channel（R = Specular Gloss, G = Specular Power)", 2D) = "white" {}
		
		_BumpLerp ("Normal Strength", Range(0, 5)) = 1
		_Emission ("Emission", Range(0, 1)) = 0
		_Specular ("Specular", Range(0, 2)) = 0.25
		_Gloss ("Gloss", Range(0, 2)) = 1
	}
	SubShader
	{
		Tags { "RenderType"="Opaque" }

		// Forward Base
		Pass
		{
			Name "FORWARD"
			Tags { "LightMode" = "ForwardBase" }

			CGPROGRAM
			#define UNITY_PASS_FORWARDBASE
			#include "UnityGiBase.cginc"
			#pragma multi_compile_fwdbase
			#pragma multi_compile_fog
			#pragma multi_compile __ PLAYER_HALO_ON
            #pragma multi_compile __ T4M_NORMAL_OFF
			#pragma multi_compile __ T4M_UNITY_GI_OFF
			#pragma vertex vert_Base
			#pragma fragment frag

			uniform sampler2D _MainTex;
			uniform float4 _MainTex_ST;
			uniform half _Emission;
			#if !T4M_NORMAL_OFF
				uniform sampler2D _BumpMap;
				uniform half _BumpLerp;
			#endif
			#if !T4M_UNITY_GI_OFF
				uniform half _Specular;
				uniform half _Gloss;
			#endif
			uniform sampler2D _ChannelTex;
			
			fixed4 frag(v2f_Base i) : SV_TARGET
			{
				float2 uv =  TRANSFORM_TEX(i.uv, _MainTex);
				fixed4 c = tex2D(_MainTex, uv);				
#if T4M_NORMAL_OFF
					fixed3 worldNormal = fixed3(i.tSpace0.z, i.tSpace1.z, i.tSpace2.z);
#else
				    half3 normal = UnpackNormal(tex2D(_BumpMap, uv));
				    // 世界法线
				    fixed3 worldNormal;
				    worldNormal.x = dot(i.tSpace0.xyz, normal);
				    worldNormal.y = dot(i.tSpace1.xyz, normal);
				    worldNormal.z = dot(i.tSpace2.xyz, normal);
					worldNormal = normalize(worldNormal);
#endif
					// 标准UnityGi流程
					GET_UNITY_GI_COLOR;
					fixed4 channel = tex2D(_ChannelTex, uv);
#if !T4M_NORMAL_OFF
				    // 法线强度调整功能
				    fixed ndotlVert = LambertTerm(fixed3(i.tSpace0.z, i.tSpace1.z, i.tSpace2.z), lightDir);
				    giColor += (ndotl - ndotlVert) * _BumpLerp * SIM_LIGHT_COLOR;
#endif
#if !T4M_UNITY_GI_OFF
					// 虚拟光源高光反射
					fixed3 worldViewDir = normalize(UnityWorldSpaceViewDir(worldPos));
					half3 h = normalize (_SpecularLight.xyz + worldViewDir);
					half nh = max (0, dot (worldNormal, h));
					half specular = pow (nh, _Specular * channel.g * 128.0) * channel.r * _Gloss * c.a;					
					giColor += specular * atten * c.rgb;
#endif
#if PLAYER_HALO_ON
				    giColor += _DirectionalLightColor * LightColorFromWorld(worldPos);
#endif
				// 自发光功能
				c.rgb = giColor + c.rgb * _Emission;
				UNITY_APPLY_FOG(i.fogCoord, c);
				UNITY_OPAQUE_ALPHA(c.a);
				return c;
			}
			ENDCG
		}
	}
	Fallback "Zhanyou/Mobile/DiffuseBumpedEmit"
}