// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)

#ifndef AUTOLIGHT_INCLUDED
#define AUTOLIGHT_INCLUDED

#include "HLSLSupport.cginc"
#include "UnityShadowLibrary.cginc"

// ----------------
//  Shadow helpers
// ----------------

// If none of the keywords are defined, assume directional?
#if !defined(POINT) && !defined(SPOT) && !defined(DIRECTIONAL) && !defined(POINT_COOKIE) && !defined(DIRECTIONAL_COOKIE)
    #define DIRECTIONAL
#endif

// ---- Screen space direction light shadows helpers (any version)
#if defined (SHADOWS_SCREEN)

    #if defined(UNITY_NO_SCREENSPACE_SHADOWS)
        UNITY_DECLARE_SHADOWMAP(_ShadowMapTexture);
        #define TRANSFER_SHADOW(a) a._ShadowCoord = mul( unity_WorldToShadow[0], mul( unity_ObjectToWorld, v.vertex ) );
        inline fixed unitySampleShadow (unityShadowCoord4 shadowCoord)
        {
            #if defined(SHADOWS_NATIVE)
                fixed shadow = UNITY_SAMPLE_SHADOW(_ShadowMapTexture, shadowCoord.xyz);
                shadow = _LightShadowData.r + shadow * (1-_LightShadowData.r);
                return shadow;
            #else
                unityShadowCoord dist = SAMPLE_DEPTH_TEXTURE(_ShadowMapTexture, shadowCoord.xy);
                // tegra is confused if we use _LightShadowData.x directly
                // with "ambiguous overloaded function reference max(mediump float, float)"
                unityShadowCoord lightShadowDataX = _LightShadowData.x;
                unityShadowCoord threshold = shadowCoord.z;
                return max(dist > threshold, lightShadowDataX);
            #endif
        }

    #else // UNITY_NO_SCREENSPACE_SHADOWS
        UNITY_DECLARE_SCREENSPACE_SHADOWMAP(_ShadowMapTexture);
        #define TRANSFER_SHADOW(a) a._ShadowCoord = ComputeScreenPos(a.pos);
        inline fixed unitySampleShadow (unityShadowCoord4 shadowCoord)
        {
            fixed shadow = UNITY_SAMPLE_SCREEN_SHADOW(_ShadowMapTexture, shadowCoord);
            return shadow;
        }

    #endif

    #define SHADOW_COORDS(idx1) unityShadowCoord4 _ShadowCoord : TEXCOORD##idx1;
    #define SHADOW_ATTENUATION(a) unitySampleShadow(a._ShadowCoord)
#endif

// -----------------------------
//  Shadow helpers (5.6+ version)
// -----------------------------
// This version depends on having worldPos available in the fragment shader and using that to compute light coordinates.
// if also supports ShadowMask (separately baked shadows for lightmapped objects)

half UnityComputeForwardShadows(float2 lightmapUV, float3 worldPos, float4 screenPos)
{
    //fade value
    float zDist = dot(_WorldSpaceCameraPos - worldPos, UNITY_MATRIX_V[2].xyz);
    float fadeDist = UnityComputeShadowFadeDistance(worldPos, zDist);
    half  realtimeToBakedShadowFade = UnityComputeShadowFade(fadeDist);

    //baked occlusion if any
    half shadowMaskAttenuation = UnitySampleBakedOcclusion(lightmapUV, worldPos);

    half realtimeShadowAttenuation = 1.0f;
    //directional realtime shadow
    #if defined (SHADOWS_SCREEN)
        #if defined(UNITY_NO_SCREENSPACE_SHADOWS) && !defined(UNITY_HALF_PRECISION_FRAGMENT_SHADER_REGISTERS)
            realtimeShadowAttenuation = unitySampleShadow(mul(unity_WorldToShadow[0], unityShadowCoord4(worldPos, 1)));
        #else
            //Only reached when LIGHTMAP_ON is NOT defined (and thus we use interpolator for screenPos rather than lightmap UVs). See HANDLE_SHADOWS_BLENDING_IN_GI below.
            realtimeShadowAttenuation = unitySampleShadow(screenPos);
        #endif
    #endif

    #if defined(UNITY_FAST_COHERENT_DYNAMIC_BRANCHING) && defined(SHADOWS_SOFT) && !defined(LIGHTMAP_SHADOW_MIXING)
    //avoid expensive shadows fetches in the distance where coherency will be good
    UNITY_BRANCH
    if (realtimeToBakedShadowFade < (1.0f - 1e-2f))
    {
    #endif

        //spot realtime shadow
        #if (defined (SHADOWS_DEPTH) && defined (SPOT))
            #if !defined(UNITY_HALF_PRECISION_FRAGMENT_SHADER_REGISTERS)
                unityShadowCoord4 spotShadowCoord = mul(unity_WorldToShadow[0], unityShadowCoord4(worldPos, 1));
            #else
                unityShadowCoord4 spotShadowCoord = screenPos;
            #endif
            realtimeShadowAttenuation = UnitySampleShadowmap(spotShadowCoord);
        #endif

        //point realtime shadow
        #if defined (SHADOWS_CUBE)
            realtimeShadowAttenuation = UnitySampleShadowmap(worldPos - _LightPositionRange.xyz);
        #endif

    #if defined(UNITY_FAST_COHERENT_DYNAMIC_BRANCHING) && defined(SHADOWS_SOFT) && !defined(LIGHTMAP_SHADOW_MIXING)
    }
    #endif

    return UnityMixRealtimeAndBakedShadows(realtimeShadowAttenuation, shadowMaskAttenuation, realtimeToBakedShadowFade);
}

#if defined(SHADER_API_D3D11) || defined(SHADER_API_D3D12) || defined(SHADER_API_XBOXONE) || defined(SHADER_API_PSSL)
#   define UNITY_SHADOW_W(_w) _w
#else
#   define UNITY_SHADOW_W(_w) (1.0/_w)
#endif

#if !defined(UNITY_HALF_PRECISION_FRAGMENT_SHADER_REGISTERS)
#    define UNITY_READ_SHADOW_COORDS(input) 0
#else
#    define UNITY_READ_SHADOW_COORDS(input) READ_SHADOW_COORDS(input)
#endif

#if defined(HANDLE_SHADOWS_BLENDING_IN_GI) // handles shadows in the depths of the GI function for performance reasons
#   define UNITY_SHADOW_COORDS(idx1) SHADOW_COORDS(idx1)
#   define UNITY_TRANSFER_SHADOW(a, coord) TRANSFER_SHADOW(a)
#   define UNITY_SHADOW_ATTENUATION(a, worldPos) SHADOW_ATTENUATION(a)
#elif defined(SHADOWS_SCREEN) && !defined(LIGHTMAP_ON) && !defined(UNITY_NO_SCREENSPACE_SHADOWS) // no lightmap uv thus store screenPos instead
    // can happen if we have two directional lights. main light gets handled in GI code, but 2nd dir light can have shadow screen and mask.
    // - Disabled on ES2 because WebGL 1.0 seems to have junk in .w (even though it shouldn't)
#   if defined(SHADOWS_SHADOWMASK) && !defined(SHADER_API_GLES)
#       define UNITY_SHADOW_COORDS(idx1) unityShadowCoord4 _ShadowCoord : TEXCOORD##idx1;
#       define UNITY_TRANSFER_SHADOW(a, coord) {a._ShadowCoord.xy = coord * unity_LightmapST.xy + unity_LightmapST.zw; a._ShadowCoord.zw = ComputeScreenPos(a.pos).xy;}
#       define UNITY_SHADOW_ATTENUATION(a, worldPos) UnityComputeForwardShadows(a._ShadowCoord.xy, worldPos, float4(a._ShadowCoord.zw, 0.0, UNITY_SHADOW_W(a.pos.w)));
#   else
#       define UNITY_SHADOW_COORDS(idx1) SHADOW_COORDS(idx1)
#       define UNITY_TRANSFER_SHADOW(a, coord) TRANSFER_SHADOW(a)
#       define UNITY_SHADOW_ATTENUATION(a, worldPos) UnityComputeForwardShadows(0, worldPos, a._ShadowCoord)
#   endif
#else
#   define UNITY_SHADOW_COORDS(idx1) unityShadowCoord4 _ShadowCoord : TEXCOORD##idx1;
#   if defined(SHADOWS_SHADOWMASK)
#       define UNITY_TRANSFER_SHADOW(a, coord) a._ShadowCoord.xy = coord.xy * unity_LightmapST.xy + unity_LightmapST.zw;
#       if (defined(SHADOWS_DEPTH) || defined(SHADOWS_SCREEN) || defined(SHADOWS_CUBE) || UNITY_LIGHT_PROBE_PROXY_VOLUME)
#           define UNITY_SHADOW_ATTENUATION(a, worldPos) UnityComputeForwardShadows(a._ShadowCoord.xy, worldPos, UNITY_READ_SHADOW_COORDS(a))
#       else
#           define UNITY_SHADOW_ATTENUATION(a, worldPos) UnityComputeForwardShadows(a._ShadowCoord.xy, 0, 0)
#       endif
#   else
#       if !defined(UNITY_HALF_PRECISION_FRAGMENT_SHADER_REGISTERS)
#           define UNITY_TRANSFER_SHADOW(a, coord)
#       else
#           define UNITY_TRANSFER_SHADOW(a, coord) TRANSFER_SHADOW(a)
#       endif
#       if (defined(SHADOWS_DEPTH) || defined(SHADOWS_SCREEN) || defined(SHADOWS_CUBE))
#           define UNITY_SHADOW_ATTENUATION(a, worldPos) UnityComputeForwardShadows(0, worldPos, UNITY_READ_SHADOW_COORDS(a))
#       else
#           if UNITY_LIGHT_PROBE_PROXY_VOLUME
#               define UNITY_SHADOW_ATTENUATION(a, worldPos) UnityComputeForwardShadows(0, worldPos, UNITY_READ_SHADOW_COORDS(a))
#           else
#               define UNITY_SHADOW_ATTENUATION(a, worldPos) UnityComputeForwardShadows(0, 0, 0)
#           endif
#       endif
#   endif
#endif

#ifdef POINT
sampler2D_float _LightTexture0;
unityShadowCoord4x4 unity_WorldToLight;
#   define UNITY_LIGHT_ATTENUATION(destName, input, worldPos) \
        unityShadowCoord3 lightCoord = mul(unity_WorldToLight, unityShadowCoord4(worldPos, 1)).xyz; \
        fixed shadow = UNITY_SHADOW_ATTENUATION(input, worldPos); \
        fixed destName = tex2D(_LightTexture0, dot(lightCoord, lightCoord).rr).r * shadow;
#endif

#ifdef SPOT
sampler2D_float _LightTexture0;
unityShadowCoord4x4 unity_WorldToLight;
sampler2D_float _LightTextureB0;
inline fixed UnitySpotCookie(unityShadowCoord4 LightCoord)
{
    return tex2D(_LightTexture0, LightCoord.xy / LightCoord.w + 0.5).w;
}
inline fixed UnitySpotAttenuate(unityShadowCoord3 LightCoord)
{
    return tex2D(_LightTextureB0, dot(LightCoord, LightCoord).xx).r;
}
#if !defined(UNITY_HALF_PRECISION_FRAGMENT_SHADER_REGISTERS)
#define DECLARE_LIGHT_COORD(input, worldPos) unityShadowCoord4 lightCoord = mul(unity_WorldToLight, unityShadowCoord4(worldPos, 1))
#else
#define DECLARE_LIGHT_COORD(input, worldPos) unityShadowCoord4 lightCoord = input._LightCoord
#endif
#   define UNITY_LIGHT_ATTENUATION(destName, input, worldPos) \
        DECLARE_LIGHT_COORD(input, worldPos); \
        fixed shadow = UNITY_SHADOW_ATTENUATION(input, worldPos); \
        fixed destName = (lightCoord.z > 0) * UnitySpotCookie(lightCoord) * UnitySpotAttenuate(lightCoord.xyz) * shadow;
#endif

#ifdef DIRECTIONAL
#   define UNITY_LIGHT_ATTENUATION(destName, input, worldPos) fixed destName = UNITY_SHADOW_ATTENUATION(input, worldPos);
#endif

#ifdef POINT_COOKIE
samplerCUBE_float _LightTexture0;
unityShadowCoord4x4 unity_WorldToLight;
sampler2D_float _LightTextureB0;
#   if !defined(UNITY_HALF_PRECISION_FRAGMENT_SHADER_REGISTERS)
#       define DECLARE_LIGHT_COORD(input, worldPos) unityShadowCoord3 lightCoord = mul(unity_WorldToLight, unityShadowCoord4(worldPos, 1)).xyz
#   else
#       define DECLARE_LIGHT_COORD(input, worldPos) unityShadowCoord3 lightCoord = input._LightCoord
#   endif
#   define UNITY_LIGHT_ATTENUATION(destName, input, worldPos) \
        DECLARE_LIGHT_COORD(input, worldPos); \
        fixed shadow = UNITY_SHADOW_ATTENUATION(input, worldPos); \
        fixed destName = tex2D(_LightTextureB0, dot(lightCoord, lightCoord).rr).r * texCUBE(_LightTexture0, lightCoord).w * shadow;
#endif

#ifdef DIRECTIONAL_COOKIE
sampler2D_float _LightTexture0;
unityShadowCoord4x4 unity_WorldToLight;
#   if !defined(UNITY_HALF_PRECISION_FRAGMENT_SHADER_REGISTERS)
#       define DECLARE_LIGHT_COORD(input, worldPos) unityShadowCoord2 lightCoord = mul(unity_WorldToLight, unityShadowCoord4(worldPos, 1)).xy
#   else
#       define DECLARE_LIGHT_COORD(input, worldPos) unityShadowCoord2 lightCoord = input._LightCoord
#   endif
#   define UNITY_LIGHT_ATTENUATION(destName, input, worldPos) \
        DECLARE_LIGHT_COORD(input, worldPos); \
        fixed shadow = UNITY_SHADOW_ATTENUATION(input, worldPos); \
        fixed destName = tex2D(_LightTexture0, lightCoord).w * shadow;
#endif


// -----------------------------
//  Light/Shadow helpers (4.x version)
// -----------------------------
// This version computes light coordinates in the vertex shader and passes them to the fragment shader.

// ---- Spot light shadows
#if defined (SHADOWS_DEPTH) && defined (SPOT)
#define SHADOW_COORDS(idx1) unityShadowCoord4 _ShadowCoord : TEXCOORD##idx1;
#define TRANSFER_SHADOW(a) a._ShadowCoord = mul (unity_WorldToShadow[0], mul(unity_ObjectToWorld,v.vertex));
#define SHADOW_ATTENUATION(a) UnitySampleShadowmap(a._ShadowCoord)
#endif

// ---- Point light shadows
#if defined (SHADOWS_CUBE)
#define SHADOW_COORDS(idx1) unityShadowCoord3 _ShadowCoord : TEXCOORD##idx1;
#define TRANSFER_SHADOW(a) a._ShadowCoord.xyz = mul(unity_ObjectToWorld, v.vertex).xyz - _LightPositionRange.xyz;
#define SHADOW_ATTENUATION(a) UnitySampleShadowmap(a._ShadowCoord)
#define READ_SHADOW_COORDS(a) unityShadowCoord4(a._ShadowCoord.xyz, 1.0)
#endif

// ---- Shadows off
#if !defined (SHADOWS_SCREEN) && !defined (SHADOWS_DEPTH) && !defined (SHADOWS_CUBE)
#define SHADOW_COORDS(idx1)
#define TRANSFER_SHADOW(a)
#define SHADOW_ATTENUATION(a) 1.0
#define READ_SHADOW_COORDS(a) 0
#else
#ifndef READ_SHADOW_COORDS
#define READ_SHADOW_COORDS(a) a._ShadowCoord
#endif
#endif

#ifdef POINT
#   define DECLARE_LIGHT_COORDS(idx) unityShadowCoord3 _LightCoord : TEXCOORD##idx;
#   define COMPUTE_LIGHT_COORDS(a) a._LightCoord = mul(unity_WorldToLight, mul(unity_ObjectToWorld, v.vertex)).xyz;
#   define LIGHT_ATTENUATION(a)    (tex2D(_LightTexture0, dot(a._LightCoord,a._LightCoord).rr).r * SHADOW_ATTENUATION(a))
#endif

#ifdef SPOT
#   define DECLARE_LIGHT_COORDS(idx) unityShadowCoord4 _LightCoord : TEXCOORD##idx;
#   define COMPUTE_LIGHT_COORDS(a) a._LightCoord = mul(unity_WorldToLight, mul(unity_ObjectToWorld, v.vertex));
#   define LIGHT_ATTENUATION(a)    ( (a._LightCoord.z > 0) * UnitySpotCookie(a._LightCoord) * UnitySpotAttenuate(a._LightCoord.xyz) * SHADOW_ATTENUATION(a) )
#endif

#ifdef DIRECTIONAL
#   define DECLARE_LIGHT_COORDS(idx)
#   define COMPUTE_LIGHT_COORDS(a)
#   define LIGHT_ATTENUATION(a) SHADOW_ATTENUATION(a)
#endif

#ifdef POINT_COOKIE
#   define DECLARE_LIGHT_COORDS(idx) unityShadowCoord3 _LightCoord : TEXCOORD##idx;
#   define COMPUTE_LIGHT_COORDS(a) a._LightCoord = mul(unity_WorldToLight, mul(unity_ObjectToWorld, v.vertex)).xyz;
#   define LIGHT_ATTENUATION(a)    (tex2D(_LightTextureB0, dot(a._LightCoord,a._LightCoord).rr).r * texCUBE(_LightTexture0, a._LightCoord).w * SHADOW_ATTENUATION(a))
#endif

#ifdef DIRECTIONAL_COOKIE
#   define DECLARE_LIGHT_COORDS(idx) unityShadowCoord2 _LightCoord : TEXCOORD##idx;
#   define COMPUTE_LIGHT_COORDS(a) a._LightCoord = mul(unity_WorldToLight, mul(unity_ObjectToWorld, v.vertex)).xy;
#   define LIGHT_ATTENUATION(a)    (tex2D(_LightTexture0, a._LightCoord).w * SHADOW_ATTENUATION(a))
#endif

#define UNITY_LIGHTING_COORDS(idx1, idx2) DECLARE_LIGHT_COORDS(idx1) UNITY_SHADOW_COORDS(idx2)
#define LIGHTING_COORDS(idx1, idx2) DECLARE_LIGHT_COORDS(idx1) SHADOW_COORDS(idx2)
#define UNITY_TRANSFER_LIGHTING(a, coord) COMPUTE_LIGHT_COORDS(a) UNITY_TRANSFER_SHADOW(a, coord)
#define TRANSFER_VERTEX_TO_FRAGMENT(a) COMPUTE_LIGHT_COORDS(a) TRANSFER_SHADOW(a)

#endif