// Curved World <http://u3d.as/1W8h>
// Copyright (c) Amazing Assets <https://amazingassets.world>
 
#ifndef UNIVERSAL_SHADOW_CASTER_PASS_INCLUDED
#define UNIVERSAL_SHADOW_CASTER_PASS_INCLUDED

#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Shadows.hlsl"
#if defined(LOD_FADE_CROSSFADE)
    #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/LODCrossFade.hlsl"
#endif

// Shadow Casting Light geometric parameters. These variables are used when applying the shadow Normal Bias and are set by UnityEngine.Rendering.Universal.ShadowUtils.SetupShadowCasterConstantBuffer in com.unity.render-pipelines.universal/Runtime/ShadowUtils.cs
// For Directional lights, _LightDirection is used when applying shadow Normal Bias.
// For Spot lights and Point lights, _LightPosition is used to compute the actual light direction because it is different at each shadow caster geometry vertex.
float3 _LightDirection;
float3 _LightPosition;

struct Attributes
{
    float4 positionOS   : POSITION;
    float3 normalOS     : NORMAL;
    float4 tangentOS    : TANGENT;		//Curved World
    float2 texcoord     : TEXCOORD0;
    UNITY_VERTEX_INPUT_INSTANCE_ID
};

struct Varyings
{
    #if defined(_ALPHATEST_ON)
    	float2 uv           : TEXCOORD0;
    #endif
    float4 positionCS   : SV_POSITION;
    UNITY_VERTEX_INPUT_INSTANCE_ID
};

float4 GetShadowPositionHClip(Attributes input)
{
    float3 positionWS = TransformObjectToWorld(input.positionOS.xyz);
    float3 normalWS = TransformObjectToWorldNormal(input.normalOS);

#if _CASTING_PUNCTUAL_LIGHT_SHADOW
    float3 lightDirectionWS = normalize(_LightPosition - positionWS);
#else
    float3 lightDirectionWS = _LightDirection;
#endif

    float4 positionCS = TransformWorldToHClip(ApplyShadowBias(positionWS, normalWS, lightDirectionWS));
    positionCS = ApplyShadowClamping(positionCS);
    return positionCS;
}

Varyings ShadowPassVertex(Attributes input)
{
    Varyings output;
    UNITY_SETUP_INSTANCE_ID(input);
    UNITY_TRANSFER_INSTANCE_ID(input, output);


#if defined(CURVEDWORLD_IS_INSTALLED) && !defined(CURVEDWORLD_DISABLED_ON)
   #ifdef CURVEDWORLD_NORMAL_TRANSFORMATION_ON
      CURVEDWORLD_TRANSFORM_VERTEX_AND_NORMAL(input.positionOS, input.normalOS, input.tangentOS)
   #else
      CURVEDWORLD_TRANSFORM_VERTEX(input.positionOS)
   #endif
#endif


    #if defined(_ALPHATEST_ON)
        output.uv = TRANSFORM_TEX(input.texcoord, _BaseMap);
    #endif
    
    output.positionCS = GetShadowPositionHClip(input);
    return output;
}

half4 ShadowPassFragment(Varyings input) : SV_TARGET
{
    UNITY_SETUP_INSTANCE_ID(input);

    #if defined(_ALPHATEST_ON)
    	Alpha(SampleAlbedoAlpha(input.uv, TEXTURE2D_ARGS(_BaseMap, sampler_BaseMap)).a, _BaseColor, _Cutoff);
    #endif

    #if defined(LOD_FADE_CROSSFADE)
    	LODFadeCrossFade(input.positionCS);
	#endif

    return 0;
}

#endif
