Shader "Hidden/InTerra/InTerra-Diffuse-Base" {
    Properties{
        _MainTex("Base (RGB) Smoothness (A)", 2D) = "white" {}
        _TriplanarTex("splat0", 2D) = "white" {}
        
        // used in fallback on old cards
        _Color("Main Color", Color) = (1,1,1,1)

        [HideInInspector] _TerrainHolesTexture("Holes Map (RGB)", 2D) = "white" {}
        [HideInInspector] _TerrainSizeXZPosY("",  Vector) = (0,0,0)
        [HideInInspector] _TriplanarOneToAllSteep("", Float) = 0
        [HideInInspector] _TriplanarSharpness("Triplanar Sharpness",   Range(3,10)) = 8
        _HT_distance_scale("Scale",   Range(0,0.5)) = 0.25
    }

    SubShader{
        Tags {
            "RenderType" = "Opaque"
            "Queue" = "Geometry-100"
        }
        LOD 200

        CGPROGRAM
        #pragma surface surf Lambert vertex:SplatmapVert addshadow fullforwardshadows
        #pragma instancing_options assumeuniformscaling nomatrices nolightprobe nolightmap forwardadd
        #pragma target 3.0

        #define _ALPHATEST_ON

        #pragma shader_feature_local _TERRAIN_TRIPLANAR_ONE
        #pragma shader_feature_local _TERRAIN_DISTANCEBLEND

        #define DIFFUSE
        #define INTERRA_TERRAIN
        #define TERRAIN_BASE_PASS
        #define TERRAIN_INSTANCED_PERPIXEL_NORMAL

        #include "InTerra_DefinedGlobalKeywords.cginc"
        #include "InTerra_InputsAndFunctions.cginc"
        #include "InTerra_Mixing.cginc"

        #include "UnityPBSLighting.cginc"

        sampler2D _MainTex;
        sampler2D _TriplanarTex;


        void surf(Input IN, inout SurfaceOutput o) {
            #ifdef _ALPHATEST_ON
                ClipHoles(IN.tc.xy);
            #endif
            half4 albedo = tex2D(_MainTex, IN.tc.xy);

            #ifdef _TERRAIN_TRIPLANAR_ONE
                float3  weights;
                float3 flipUV = float3(1, 1, -1);
                #if defined(UNITY_INSTANCING_ENABLED) && !defined(SHADER_API_D3D11_9X) 
                    weights = abs(IN.terrainNormals);
                #else
                    weights = abs(IN.worldNormal);
                #endif
                weights = pow(weights, _TriplanarSharpness);
                weights = weights / (weights.x + weights.y + weights.z);

                float2 frontUV = TerrainFrontUV(IN.worldPos, _MainTex_ST, IN.tc.xy, flipUV);
                float2 sideUV = TerrainSideUV(IN.worldPos, _MainTex_ST, IN.tc.xy, flipUV);

                half4 cFront = tex2D(_TriplanarTex, frontUV);
                half4 cSide = tex2D(_TriplanarTex, sideUV);

                TriplanarBase(albedo, cFront, cSide, weights, albedo.a, _TriplanarOneToAllSteep);   
                #ifdef _TERRAIN_TINT_TEXTURE
                    half4 tint = tex2D(_TerrainColorTintTexture, IN.tc.xy * _TerrainColorTintTexture_ST.xy + _TerrainColorTintTexture_ST.zw);
                    albedo.rgb = lerp(albedo.rgb, ((albedo.rgb) * (tint)), _TerrainColorTintStrenght).rgb;
                #endif              
            #endif                                     

            o.Albedo = albedo.rgb;
            o.Alpha = 1;

            #if defined(INSTANCING_ON) && defined(SHADER_TARGET_SURFACE_ANALYSIS) && defined(TERRAIN_INSTANCED_PERPIXEL_NORMAL)
                o.Normal = float3(0, 0, 1); // make sure that surface shader compiler realizes we write to normal, as UNITY_INSTANCING_ENABLED is not defined for SHADER_TARGET_SURFACE_ANALYSIS.
            #endif

            #if defined(UNITY_INSTANCING_ENABLED) && !defined(SHADER_API_D3D11_9X) && defined(TERRAIN_INSTANCED_PERPIXEL_NORMAL)
                o.Normal = normalize(tex2D(_TerrainNormalmapTexture, IN.tc.zw).xyz * 2 - 1).xzy;
            #endif
        }
        ENDCG

        UsePass "Hidden/Nature/Terrain/Utilities/PICKING"
        UsePass "Hidden/Nature/Terrain/Utilities/SELECTION"
    }
    FallBack "Diffuse"
}