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

Shader "Hidden/TerrainEngine/Splatmap/Lightmap-AddPass" {
	Properties {
		_Control ("Control (RGBA)", 2D) = "black" {}
		_Splat3 ("Layer 3 (A)", 2D) = "white" {}
		_Splat2 ("Layer 2 (B)", 2D) = "white" {}
		_Splat1 ("Layer 1 (G)", 2D) = "white" {}
		_Splat0 ("Layer 0 (R)", 2D) = "white" {}
	}
	SubShader {
		Tags {"SplatCount" = "4" "Queue" = "Geometry-99" "IgnoreProjector"="True" "RenderType" = "Opaque"}
		
		CGPROGRAM
			#pragma surface surf Terrain vertex:vert exclude_path:prepass decal:add
			#pragma target 3.0
	
			sampler2D _Control;

			struct SurfaceOutputTerrain {
				fixed3 Albedo;
				fixed3 Normal;
				fixed4 Light;
				fixed3 Emission;
				fixed Specular;
				fixed Alpha;
			};

			inline fixed4 LightingTerrain (SurfaceOutputTerrain s, fixed3 lightDir, fixed3 viewDir, fixed atten)
			{
				float4 result;
				result.rgb = (s.Albedo * s.Light.x) + ( pow(s.Light.y, s.Light.w * 128) * s.Light.z );
				result.rgb *= _LightColor0.rgb * atten * 2;
				result.a = 1.0;
				return result;
			}
									
			struct Input {
				float2	uv_Control;
				float3	worldPos;
				float3	worldNormal;
				float3	lightDir;
				float3	viewDir;
			};
	
			void vert(inout appdata_full v, out Input o) {
				o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
				o.worldNormal = mul(unity_ObjectToWorld, float4(v.normal, 0.0)).xyz;
				o.lightDir = normalize(ObjSpaceLightDir(v.vertex));
				o.viewDir = normalize(ObjSpaceViewDir(v.vertex));
			}
	
			sampler2D _Splat0, _Splat1, _Splat2, _Splat3;
			sampler2D _BumpMap4, _BumpMap5, _BumpMap6, _BumpMap7;
			sampler2D _SpecMap4, _SpecMap5, _SpecMap6, _SpecMap7;
			float _TerrainTexScale4, _TerrainTexScale5, _TerrainTexScale6, _TerrainTexScale7;
	
			void surf (Input IN, inout SurfaceOutputTerrain o) {
			// INITIALISE THE CONTROL SPLAT FOR TERRAIN
				fixed4 splat_control = tex2D(_Control, IN.uv_Control);
				fixed alpha = splat_control.r;
				alpha = lerp ( alpha, 1.0, splat_control.g );
				alpha = lerp ( alpha, 1.0, splat_control.b );
				alpha = lerp ( alpha, 1.0, splat_control.a );
	
			// INITIALISE THE VARIABLES FOR TRIPLANAR PROJECTION
				float3 worldNormal = normalize(IN.worldNormal);
				float3 projNormal = saturate(pow(worldNormal * 1.5, 4));
	
			// INITIALISE VARIABLES WE'LL NEED
				float3 tangent;
				float3 binormal;
				float3x3 rotation;
				float3 lightDirT;
				float3 viewDirT;
				
				float2 uv;
				float2 uv0;
				float2 uv1;
				float2 uv2;
				float2 uv3;
				
				float3 h;
				float4 tempNormal;
				float3 normal;
				
				fixed3 albedoX;
				fixed3 albedoY;
				fixed3 albedoZ;
				fixed4 lightX;
				fixed4 lightY;
				fixed4 lightZ;
	
			// CALCULATE X FOR ALL
			
				// UV
				uv = IN.worldPos.zy;
				uv0 = uv * _TerrainTexScale4;
				uv1 = uv * _TerrainTexScale5;
				uv2 = uv * _TerrainTexScale6;
				uv3 = uv * _TerrainTexScale7;
	
				// Tangent
				tangent = float3(0, 0, 1);
				
				// Light and View Vectors
				binormal = cross(worldNormal, tangent) * (step(worldNormal.x, 0) * 2 - 1);
				rotation = float3x3(tangent, binormal, worldNormal);
				lightDirT = mul(rotation, IN.lightDir);
				viewDirT = mul(rotation, IN.viewDir);
				
				// Albedo
				albedoX = tex2D(_Splat0, uv0).rgb * splat_control.r;
				albedoX += tex2D(_Splat1, uv1).rgb * splat_control.g;
				albedoX += tex2D(_Splat2, uv2).rgb * splat_control.b;
				albedoX += tex2D(_Splat3, uv3).rgb * splat_control.a;
				
				// Normal
				tempNormal = tex2D (_BumpMap4, uv0) * splat_control.r;
				tempNormal += tex2D (_BumpMap5, uv1) * splat_control.g;
				tempNormal += tex2D (_BumpMap6, uv2) * splat_control.b;
				tempNormal += tex2D (_BumpMap7, uv3) * splat_control.a;
				tempNormal = lerp(float4(0.0, 0.5, 0.0, 0.5), tempNormal, alpha);
				normal = UnpackNormal(tempNormal);
				
				// Specular
				lightX.zw = tex2D (_SpecMap4, uv0).rg * splat_control.r;
				lightX.zw += tex2D (_SpecMap5, uv1).rg * splat_control.g;
				lightX.zw += tex2D (_SpecMap6, uv2).rg * splat_control.b;
				lightX.zw += tex2D (_SpecMap7, uv3).rg * splat_control.a;
				lightX.zw = lerp(fixed2(0.0, 0.1), lightX.zw, alpha);
				
				// Lighting Values
				lightX.x = saturate(dot(normal, lightDirT));
				h = normalize(lightDirT + viewDirT);
				lightX.y = saturate(dot(normal, h));
	
			// CALCULATE Y FOR ALL
			
				// UV
				uv = IN.worldPos.xz;
				uv0 = uv * _TerrainTexScale4;
				uv1 = uv * _TerrainTexScale5;
				uv2 = uv * _TerrainTexScale6;
				uv3 = uv * _TerrainTexScale7;
	
				// Tangent
				tangent = float3(1, 0, 0);
				
				// Light and View Vectors
				binormal = cross(worldNormal, tangent) * (step(worldNormal.y, 0) * 2 - 1);
				rotation = float3x3(tangent, binormal, worldNormal);
				lightDirT = mul(rotation, IN.lightDir);
				viewDirT = mul(rotation, IN.viewDir);
				
				// Albedo
				albedoY = tex2D(_Splat0, uv0).rgb * splat_control.r;
				albedoY += tex2D(_Splat1, uv1).rgb * splat_control.g;
				albedoY += tex2D(_Splat2, uv2).rgb * splat_control.b;
				albedoY += tex2D(_Splat3, uv3).rgb * splat_control.a;
				
				// Normal
				tempNormal = tex2D (_BumpMap4, uv0) * splat_control.r;
				tempNormal += tex2D (_BumpMap5, uv1) * splat_control.g;
				tempNormal += tex2D (_BumpMap6, uv2) * splat_control.b;
				tempNormal += tex2D (_BumpMap7, uv3) * splat_control.a;
				tempNormal = lerp(float4(0.0, 0.5, 0.0, 0.5), tempNormal, alpha);
				normal = UnpackNormal(tempNormal);
				
				// Specular
				lightY.zw = tex2D (_SpecMap4, uv0).rg * splat_control.r;
				lightY.zw += tex2D (_SpecMap5, uv1).rg * splat_control.g;
				lightY.zw += tex2D (_SpecMap6, uv2).rg * splat_control.b;
				lightY.zw += tex2D (_SpecMap7, uv3).rg * splat_control.a;
				lightY.zw = lerp(fixed2(0.0, 0.1), lightY.zw, alpha);
				
				// Lighting Values
				lightY.x = saturate(dot(normal, lightDirT));
				h = normalize(lightDirT + viewDirT);
				lightY.y = saturate(dot(normal, h));
	
			// CALCULATE Z FOR ALL
			
				// UV
				uv = IN.worldPos.xy;
				uv.x *= -1;
				uv0 = uv * _TerrainTexScale4;
				uv1 = uv * _TerrainTexScale5;
				uv2 = uv * _TerrainTexScale6;
				uv3 = uv * _TerrainTexScale7;
	
				// Tangent
				tangent = float3(-1, 0, 0);
				
				// Light and View Vectors
				binormal = cross(worldNormal, tangent) * (step(worldNormal.z, 0) * 2 - 1);
				rotation = float3x3(tangent, binormal, worldNormal);
				lightDirT = mul(rotation, IN.lightDir);
				viewDirT = mul(rotation, IN.viewDir);
				
				// Albedo
				albedoZ = tex2D(_Splat0, uv0).rgb * splat_control.r;
				albedoZ += tex2D(_Splat1, uv1).rgb * splat_control.g;
				albedoZ += tex2D(_Splat2, uv2).rgb * splat_control.b;
				albedoZ += tex2D(_Splat3, uv3).rgb * splat_control.a;
				
				// Normal
				tempNormal = tex2D (_BumpMap4, uv0) * splat_control.r;
				tempNormal += tex2D (_BumpMap5, uv1) * splat_control.g;
				tempNormal += tex2D (_BumpMap6, uv2) * splat_control.b;
				tempNormal += tex2D (_BumpMap7, uv3) * splat_control.a;
				tempNormal = lerp(float4(0.0, 0.5, 0.0, 0.5), tempNormal, alpha);
				normal = UnpackNormal(tempNormal);
				
				// Specular
				lightZ.zw = tex2D (_SpecMap4, uv0).rg * splat_control.r;
				lightZ.zw += tex2D (_SpecMap5, uv1).rg * splat_control.g;
				lightZ.zw += tex2D (_SpecMap6, uv2).rg * splat_control.b;
				lightZ.zw += tex2D (_SpecMap7, uv3).rg * splat_control.a;
				lightZ.zw = lerp(fixed2(0.0, 0.1), lightZ.zw, alpha);
				
				// Lighting Values
				lightZ.x = saturate(dot(normal, lightDirT));
				h = normalize(lightDirT + viewDirT);
				lightZ.y = saturate(dot(normal, h));
				
				o.Albedo = albedoZ;
				o.Albedo = lerp(o.Albedo, albedoY, projNormal.y);
				o.Albedo = lerp(o.Albedo, albedoX, projNormal.x);
				
				o.Light = lightZ;
				o.Light = lerp(o.Light, lightY, projNormal.y);
				o.Light = lerp(o.Light, lightX, projNormal.x);
				
				o.Alpha = 0.0;
			}
		ENDCG
	}
	
	Fallback Off
}