XCEngine/project/Assets/Shaders/XCCharacterToon.shader

Shader "XC Character Toon"
{
    Properties
    {
        _BaseMap ("Base Map", 2D) = "white" [Semantic(BaseColorTexture)]
        _BaseColor ("Base Color", Color) = (1,1,1,1) [Semantic(BaseColor)]
        _Cutoff ("Alpha Cutoff", Range) = 0.5 [Semantic(AlphaCutoff)]
        _IsDay ("Is Day", Float) = 1
        _DoubleSided ("Double Sided", Float) = 0
        _LightMap ("Light Map", 2D) = "white"
        _LightDirectionMultiplier ("Light Direction Multiplier", Vector) = (1,0.5,1,0)
        _ShadowOffset ("Shadow Offset", Float) = 0.1
        _ShadowSmoothness ("Shadow Smoothness", Float) = 0.4
        _ShadowColor ("Shadow Color", Color) = (1.1,1.1,1.1,1)
        _ShadowRamp ("Shadow Ramp", 2D) = "white"
        _UseCustomMaterialType ("Use Custom Material Type", Float) = 0
        _CustomMaterialType ("Custom Material Type", Float) = 1
        _UseEmission ("Use Emission", Float) = 0
        _EmissionIntensity ("Emission Intensity", Float) = 0.2
        _UseNormalMap ("Use Normal Map", Float) = 0
        _NormalMap ("Normal Map", 2D) = "bump"
        _IsFace ("Is Face", Float) = 0
        _FaceDirection ("Face Direction", Vector) = (0,0,1,0)
        _FaceShadowOffset ("Face Shadow Offset", Float) = 0
        _FaceBlushColor ("Face Blush Color", Color) = (1,0.72156864,0.69803923,1)
        _FaceBlushStrength ("Face Blush Strength", Float) = 0
        _FaceLightMap ("Face Light Map", 2D) = "white"
        _FaceShadow ("Face Shadow", 2D) = "white"
        _UseSpecular ("Use Specular", Float) = 0
        _SpecularSmoothness ("Specular Smoothness", Float) = 5
        _NonmetallicIntensity ("Nonmetallic Intensity", Float) = 0.3
        _MetallicIntensity ("Metallic Intensity", Float) = 8
        _MetalMap ("Metal Map", 2D) = "white"
        _UseRim ("Use Rim", Float) = 0
        _RimOffset ("Rim Offset", Float) = 5
        _RimThreshold ("Rim Threshold", Float) = 0.5
        _RimIntensity ("Rim Intensity", Float) = 0.5
        _UseSmoothNormal ("Use Smooth Normal", Float) = 0
        _OutlineWidth ("Outline Width", Float) = 1.6
        _OutlineWidthParams ("Outline Width Params", Vector) = (0,6,0.1,0.6)
        _OutlineZOffset ("Outline Z Offset", Float) = 0.1
        _ScreenOffset ("Screen Offset", Vector) = (0,0,0,0)
        _OutlineColor ("Outline Color", Color) = (0.5176471,0.35686275,0.34117648,1)
        _OutlineColor2 ("Outline Color 2", Color) = (0.3529412,0.3529412,0.3529412,1)
        _OutlineColor3 ("Outline Color 3", Color) = (0.47058824,0.47058824,0.5647059,1)
        _OutlineColor4 ("Outline Color 4", Color) = (0.5176471,0.35686275,0.34117648,1)
        _OutlineColor5 ("Outline Color 5", Color) = (0.35,0.35,0.35,1)
    }
    HLSLINCLUDE
    cbuffer PerObjectConstants
    {
        float4x4 gProjectionMatrix;
        float4x4 gViewMatrix;
        float4x4 gModelMatrix;
        float4x4 gNormalMatrix;
    };

    static const int XC_MAX_ADDITIONAL_LIGHTS = 8;

    struct AdditionalLightData
    {
        float4 colorAndIntensity;
        float4 positionAndRange;
        float4 directionAndType;
        float4 spotAnglesAndFlags;
    };

    cbuffer LightingConstants
    {
        float4 gMainLightDirectionAndIntensity;
        float4 gMainLightColorAndFlags;
        float4 gLightingParams;
        AdditionalLightData gAdditionalLights[XC_MAX_ADDITIONAL_LIGHTS];
    };

    cbuffer MaterialConstants
    {
        float4 _BaseColor;
        float4 _Cutoff;
        float4 _IsDay;
        float4 _DoubleSided;
        float4 _LightDirectionMultiplier;
        float4 _ShadowOffset;
        float4 _ShadowSmoothness;
        float4 _ShadowColor;
        float4 _UseCustomMaterialType;
        float4 _CustomMaterialType;
        float4 _UseEmission;
        float4 _EmissionIntensity;
        float4 _UseNormalMap;
        float4 _IsFace;
        float4 _FaceDirection;
        float4 _FaceShadowOffset;
        float4 _FaceBlushColor;
        float4 _FaceBlushStrength;
        float4 _UseSpecular;
        float4 _SpecularSmoothness;
        float4 _NonmetallicIntensity;
        float4 _MetallicIntensity;
        float4 _UseRim;
        float4 _RimOffset;
        float4 _RimThreshold;
        float4 _RimIntensity;
        float4 _UseSmoothNormal;
        float4 _OutlineWidth;
        float4 _OutlineWidthParams;
        float4 _OutlineZOffset;
        float4 _ScreenOffset;
        float4 _OutlineColor;
        float4 _OutlineColor2;
        float4 _OutlineColor3;
        float4 _OutlineColor4;
        float4 _OutlineColor5;
    };

    cbuffer ShadowReceiverConstants
    {
        float4x4 gWorldToShadowMatrix;
        float4 gShadowBiasAndTexelSize;
        float4 gShadowOptions;
    };

    Texture2D BaseColorTexture;
    Texture2D _LightMap;
    Texture2D _ShadowRamp;
    Texture2D _NormalMap;
    Texture2D _FaceLightMap;
    Texture2D _FaceShadow;
    Texture2D _MetalMap;
    SamplerState LinearClampSampler;
    Texture2D ShadowMapTexture;
    SamplerState ShadowMapSampler;

    struct VSInput
    {
        float3 position : POSITION;
        float3 normal : NORMAL;
        float4 color : COLOR;
        float2 texcoord : TEXCOORD0;
        float2 backTexcoord : TEXCOORD1;
        float3 tangent : TEXCOORD2;
        float3 bitangent : TEXCOORD3;
    };

    struct PSInput
    {
        float4 position : SV_POSITION;
        float2 texcoord : TEXCOORD0;
        float2 backTexcoord : TEXCOORD1;
        float3 positionWS : TEXCOORD2;
        float3 positionVS : TEXCOORD3;
        float3 normalWS : TEXCOORD4;
        float3 tangentWS : TEXCOORD5;
        float3 bitangentWS : TEXCOORD6;
        float4 color : COLOR;
    };

    float3 NormalizeSafe(float3 value, float3 fallbackValue)
    {
        const float lengthSq = dot(value, value);
        if (lengthSq <= 1e-6f) {
            return fallbackValue;
        }

        return value * rsqrt(lengthSq);
    }

    bool UseEmissionFeature()
    {
    #ifdef _EMISSION
        return true;
    #else
        return _UseEmission.x > 0.5f;
    #endif
    }

    bool UseNormalMapFeature()
    {
    #ifdef _NORMAL_MAP
        return true;
    #else
        return _UseNormalMap.x > 0.5f;
    #endif
    }

    bool UseFaceFeature()
    {
    #ifdef _IS_FACE
        return true;
    #else
        return _IsFace.x > 0.5f;
    #endif
    }

    bool UseSpecularFeature()
    {
    #ifdef _SPECULAR
        return true;
    #else
        return _UseSpecular.x > 0.5f;
    #endif
    }

    bool UseRimFeature()
    {
    #ifdef _RIM
        return true;
    #else
        return _UseRim.x > 0.5f;
    #endif
    }

    bool UseDoubleSidedFeature()
    {
    #ifdef _DOUBLE_SIDED
        return true;
    #else
        return _DoubleSided.x > 0.5f;
    #endif
    }

    float2 ResolveMaterialTexcoord(PSInput input, bool isFrontFace)
    {
        if (!UseDoubleSidedFeature()) {
            return input.texcoord;
        }

        return lerp(input.texcoord, input.backTexcoord, isFrontFace ? 0.0f : 1.0f);
    }

    PSInput MainVS(VSInput input)
    {
        PSInput output;
        const float4 positionWS = mul(gModelMatrix, float4(input.position, 1.0f));
        const float4 positionVS = mul(gViewMatrix, positionWS);
        output.position = mul(gProjectionMatrix, positionVS);
        output.texcoord = input.texcoord;
        output.backTexcoord = input.backTexcoord;
        output.positionWS = positionWS.xyz;
        output.positionVS = positionVS.xyz;
        output.normalWS = normalize(mul((float3x3)gNormalMatrix, input.normal));
        output.tangentWS = normalize(mul((float3x3)gNormalMatrix, input.tangent));
        output.bitangentWS = normalize(mul((float3x3)gNormalMatrix, input.bitangent));
        output.color = input.color;
        return output;
    }

    float ComputeShadowAttenuation(float3 positionWS, float3 normalWS, float3 lightDirectionWS)
    {
    #ifndef XC_MAIN_LIGHT_SHADOWS
        return 1.0f;
    #else
        if (gShadowOptions.x < 0.5f) {
            return 1.0f;
        }

        const float3 resolvedNormalWS = NormalizeSafe(normalWS, float3(0.0f, 1.0f, 0.0f));
        const float3 resolvedLightDirectionWS =
            NormalizeSafe(lightDirectionWS, float3(0.0f, -1.0f, 0.0f));
        const float nDotL = saturate(dot(resolvedNormalWS, resolvedLightDirectionWS));
        const float normalBiasWorld = gShadowOptions.y * gShadowOptions.z * (1.0f - nDotL);
        const float3 shadowPositionWS = positionWS + resolvedNormalWS * normalBiasWorld;
        const float4 shadowClip = mul(gWorldToShadowMatrix, float4(shadowPositionWS, 1.0f));
        if (shadowClip.w <= 0.0f) {
            return 1.0f;
        }

        const float3 shadowNdc = shadowClip.xyz / shadowClip.w;
    #if UNITY_UV_STARTS_AT_TOP
        const float shadowUvY = shadowNdc.y * -0.5f + 0.5f;
    #else
        const float shadowUvY = shadowNdc.y * 0.5f + 0.5f;
    #endif
        const float2 shadowUv = float2(shadowNdc.x * 0.5f + 0.5f, shadowUvY);
    #if UNITY_NEAR_CLIP_VALUE < 0
        if (shadowUv.x < 0.0f || shadowUv.x > 1.0f ||
            shadowUv.y < 0.0f || shadowUv.y > 1.0f ||
            shadowNdc.z < -1.0f || shadowNdc.z > 1.0f) {
            return 1.0f;
        }

        const float receiverDepth = shadowNdc.z * 0.5f + 0.5f - gShadowBiasAndTexelSize.x;
    #else
        if (shadowUv.x < 0.0f || shadowUv.x > 1.0f ||
            shadowUv.y < 0.0f || shadowUv.y > 1.0f ||
            shadowNdc.z < 0.0f || shadowNdc.z > 1.0f) {
            return 1.0f;
        }

        const float receiverDepth = shadowNdc.z - gShadowBiasAndTexelSize.x;
    #endif
        const float2 shadowTexelSize = gShadowBiasAndTexelSize.yz;
        float visibility = 0.0f;
        [unroll]
        for (int offsetY = -1; offsetY <= 1; ++offsetY) {
            [unroll]
            for (int offsetX = -1; offsetX <= 1; ++offsetX) {
                const float2 sampleUv =
                    shadowUv + float2((float)offsetX, (float)offsetY) * shadowTexelSize;
                if (sampleUv.x < 0.0f || sampleUv.x > 1.0f ||
                    sampleUv.y < 0.0f || sampleUv.y > 1.0f) {
                    visibility += 1.0f;
                    continue;
                }

                const float shadowDepth = ShadowMapTexture.Sample(ShadowMapSampler, sampleUv).r;
                visibility += receiverDepth <= shadowDepth ? 1.0f : 0.0f;
            }
        }

        visibility *= (1.0f / 9.0f);
        const float shadowStrength = saturate(gShadowBiasAndTexelSize.w);
        return lerp(1.0f - shadowStrength, 1.0f, visibility);
    #endif
    }

    float ComputeRangeAttenuation(float distanceSq, float range)
    {
        if (range <= 0.0f) {
            return 0.0f;
        }

        const float clampedRange = max(range, 0.0001f);
        const float rangeSq = clampedRange * clampedRange;
        if (distanceSq >= rangeSq) {
            return 0.0f;
        }

        const float distance = sqrt(max(distanceSq, 0.0f));
        const float normalized = saturate(1.0f - distance / clampedRange);
        return normalized * normalized;
    }

    float ComputeSpotAttenuation(AdditionalLightData light, float3 directionToLightWS)
    {
        const float cosOuter = light.spotAnglesAndFlags.x;
        const float cosInner = light.spotAnglesAndFlags.y;
        const float3 spotAxisToLightWS = NormalizeSafe(light.directionAndType.xyz, float3(0.0f, -1.0f, 0.0f));
        const float cosTheta = dot(spotAxisToLightWS, directionToLightWS);
        return saturate((cosTheta - cosOuter) / max(cosInner - cosOuter, 1e-4f));
    }

    float3 EvaluateAdditionalLight(AdditionalLightData light, float3 normalWS, float3 positionWS)
    {
        const float lightType = light.directionAndType.w;
        const float3 lightColor = light.colorAndIntensity.rgb;
        const float lightIntensity = light.colorAndIntensity.w;

        float3 directionToLightWS = float3(0.0f, 0.0f, 0.0f);
        float attenuation = 1.0f;

        if (lightType < 0.5f) {
            directionToLightWS = NormalizeSafe(light.directionAndType.xyz, float3(0.0f, -1.0f, 0.0f));
        } else {
            const float3 lightVectorWS = light.positionAndRange.xyz - positionWS;
            const float distanceSq = dot(lightVectorWS, lightVectorWS);
            if (distanceSq <= 1e-6f) {
                return float3(0.0f, 0.0f, 0.0f);
            }

            directionToLightWS = lightVectorWS * rsqrt(distanceSq);
            attenuation = ComputeRangeAttenuation(distanceSq, light.positionAndRange.w);
            if (attenuation <= 0.0f) {
                return float3(0.0f, 0.0f, 0.0f);
            }

            if (lightType > 1.5f) {
                attenuation *= ComputeSpotAttenuation(light, directionToLightWS);
                if (attenuation <= 0.0f) {
                    return float3(0.0f, 0.0f, 0.0f);
                }
            }
        }

        const float diffuse = saturate(dot(normalWS, directionToLightWS));
        if (diffuse <= 0.0f) {
            return float3(0.0f, 0.0f, 0.0f);
        }

        return lightColor * (diffuse * lightIntensity * attenuation);
    }

    float3 ComputeSurfaceNormalWS(PSInput input, float2 texcoord)
    {
        float3 normalWS = NormalizeSafe(input.normalWS, float3(0.0f, 1.0f, 0.0f));
        if (!UseNormalMapFeature()) {
            return normalWS;
        }

        const float3 tangentWS = NormalizeSafe(input.tangentWS, float3(1.0f, 0.0f, 0.0f));
        const float3 bitangentWS = NormalizeSafe(input.bitangentWS, float3(0.0f, 0.0f, 1.0f));
        const float3 normalTS = _NormalMap.Sample(LinearClampSampler, texcoord).xyz * 2.0f - 1.0f;
        const float3 mappedNormalWS =
            tangentWS * normalTS.x +
            bitangentWS * normalTS.y +
            normalWS * normalTS.z;
        return NormalizeSafe(mappedNormalWS, normalWS);
    }

    float3 GetAdjustedMainLightDirection()
    {
        const float3 scaledDirection =
            gMainLightDirectionAndIntensity.xyz * _LightDirectionMultiplier.xyz;
        return NormalizeSafe(
            scaledDirection,
            NormalizeSafe(gMainLightDirectionAndIntensity.xyz, float3(0.0f, -1.0f, 0.0f)));
    }

    float ResolveMaterialSelector(float lightMapAlpha)
    {
        const float useCustomMaterialType = _UseCustomMaterialType.x > 0.5f ? 1.0f : 0.0f;
        return lerp(lightMapAlpha, _CustomMaterialType.x, useCustomMaterialType);
    }

    float GetGenericShadow(float3 normalWS, float3 lightDirectionWS, float aoFactor)
    {
        const float ndotl = dot(normalWS, lightDirectionWS);
        const float halfLambert = ndotl * 0.5f + 0.5f;
        const float shadow = saturate(2.0f * halfLambert * aoFactor);
        return lerp(shadow, 1.0f, step(0.9f, aoFactor));
    }

    float GetFaceShadow(PSInput input, float2 texcoord, float3 lightDirectionWS)
    {
        const float3 faceDirection = NormalizeSafe(
            float3(_FaceDirection.x, 0.0f, _FaceDirection.z),
            float3(0.0f, 0.0f, 1.0f));
        const float3 flatLightDirection = NormalizeSafe(
            float3(lightDirectionWS.x, 0.0f, lightDirectionWS.z),
            float3(0.0f, 0.0f, 1.0f));
        const float faceDotLight = dot(faceDirection, flatLightDirection);
        const float faceCrossLight = cross(faceDirection, flatLightDirection).y;

        float2 shadowUv = texcoord;
        shadowUv.x = lerp(shadowUv.x, 1.0f - shadowUv.x, step(0.0f, faceCrossLight));

        const float faceShadowMap = _FaceLightMap.Sample(LinearClampSampler, shadowUv).r;
        const float faceShadow = step(-0.5f * faceDotLight + 0.5f + _FaceShadowOffset.x, faceShadowMap);
        const float faceMask = _FaceShadow.Sample(LinearClampSampler, texcoord).a;
        return lerp(faceShadow, 1.0f, faceMask);
    }

    float3 GetShadowColor(float shadow, float materialSelector)
    {
        float rampIndex = 4.0f;
        rampIndex = lerp(rampIndex, 1.0f, step(0.2f, materialSelector));
        rampIndex = lerp(rampIndex, 2.0f, step(0.4f, materialSelector));
        rampIndex = lerp(rampIndex, 0.0f, step(0.6f, materialSelector));
        rampIndex = lerp(rampIndex, 3.0f, step(0.8f, materialSelector));

        const float rangeMin = 0.5f + _ShadowOffset.x - _ShadowSmoothness.x;
        const float rangeMax = 0.5f + _ShadowOffset.x;
        const float2 rampUv = float2(
            smoothstep(rangeMin, rangeMax, shadow),
            rampIndex / 10.0f + 0.5f * saturate(_IsDay.x) + 0.05f);
        const float3 shadowRamp = _ShadowRamp.Sample(LinearClampSampler, rampUv).rgb;

        float3 shadowColor =
            shadowRamp * lerp(_ShadowColor.rgb, float3(1.0f, 1.0f, 1.0f), smoothstep(0.9f, 1.0f, rampUv.x));
        shadowColor = lerp(shadowColor, float3(1.0f, 1.0f, 1.0f), step(rangeMax, shadow));
        return shadowColor;
    }

    float3 GetSpecular(
        PSInput input,
        float3 normalWS,
        float3 lightDirectionWS,
        float3 albedo,
        float3 lightMap)
    {
        const float3 viewDirectionVS = NormalizeSafe(-input.positionVS, float3(0.0f, 0.0f, 1.0f));
        const float3 lightDirectionVS = NormalizeSafe(
            mul((float3x3)gViewMatrix, lightDirectionWS),
            float3(0.0f, 0.0f, 1.0f));
        const float3 normalVS = NormalizeSafe(mul((float3x3)gViewMatrix, normalWS), float3(0.0f, 0.0f, 1.0f));
        const float3 halfDirectionVS = NormalizeSafe(lightDirectionVS + viewDirectionVS, lightDirectionVS);
        const float nDotH = dot(normalVS, halfDirectionVS);
        const float blinnPhong = pow(saturate(nDotH), max(_SpecularSmoothness.x, 1.0f));

        const float2 matcapUv = normalVS.xy * 0.5f + 0.5f;
        const float3 metalMap = _MetalMap.Sample(LinearClampSampler, matcapUv).rgb;

        const float3 nonMetallic =
            step(1.1f, lightMap.b + blinnPhong) * lightMap.r * _NonmetallicIntensity.x;
        const float3 metallic =
            blinnPhong * lightMap.b * albedo * metalMap * _MetallicIntensity.x;
        return lerp(nonMetallic, metallic, step(0.9f, lightMap.r));
    }

    float GetRim(PSInput input, float3 normalWS)
    {
        const float3 viewDirectionVS = NormalizeSafe(-input.positionVS, float3(0.0f, 0.0f, 1.0f));
        const float3 normalVS = NormalizeSafe(mul((float3x3)gViewMatrix, normalWS), float3(0.0f, 0.0f, 1.0f));
        const float nDotV = dot(normalVS, viewDirectionVS);
        const float fresnel = pow(saturate(1.0f - nDotV), max(_RimOffset.x, 0.001f));
        return smoothstep(0.0f, max(_RimThreshold.x, 0.001f), fresnel) * _RimIntensity.x;
    }

    float4 MainPS(PSInput input, bool isFrontFace : SV_IsFrontFace) : SV_TARGET
    {
        const float2 texcoord = ResolveMaterialTexcoord(input, isFrontFace);
        float4 baseMap = BaseColorTexture.Sample(LinearClampSampler, texcoord);
        float3 albedo = baseMap.rgb * _BaseColor.rgb;
        const float alphaMask = baseMap.a;

        if (UseFaceFeature()) {
            albedo = lerp(albedo, _FaceBlushColor.rgb, _FaceBlushStrength.x * alphaMask);
        }

        const float3 normalWS = ComputeSurfaceNormalWS(input, texcoord);

        float3 color = albedo;
        if (gMainLightColorAndFlags.a >= 0.5f) {
            const float3 lightDirectionWS = GetAdjustedMainLightDirection();
            const float4 lightMap = _LightMap.Sample(LinearClampSampler, texcoord);
            const float materialSelector = ResolveMaterialSelector(lightMap.a);
            float shadow = UseFaceFeature()
                ? GetFaceShadow(input, texcoord, lightDirectionWS)
                : GetGenericShadow(normalWS, lightDirectionWS, lightMap.g * input.color.x);
            shadow *= ComputeShadowAttenuation(input.positionWS, normalWS, lightDirectionWS);

            const float3 shadowColor = GetShadowColor(shadow, materialSelector);

            float3 specular = float3(0.0f, 0.0f, 0.0f);
            if (UseSpecularFeature()) {
                specular = GetSpecular(input, normalWS, lightDirectionWS, albedo, lightMap.rgb);
            }

            float3 emission = float3(0.0f, 0.0f, 0.0f);
            if (UseEmissionFeature()) {
                emission = albedo * _EmissionIntensity.x * alphaMask;
            }

            float3 rim = float3(0.0f, 0.0f, 0.0f);
            if (UseRimFeature()) {
                rim = albedo * GetRim(input, normalWS);
            }

            color = albedo * shadowColor + specular + emission + rim;
        }

        const int additionalLightCount = min((int)gLightingParams.x, XC_MAX_ADDITIONAL_LIGHTS);
        [unroll]
        for (int lightIndex = 0; lightIndex < XC_MAX_ADDITIONAL_LIGHTS; ++lightIndex) {
            if (lightIndex >= additionalLightCount) {
                break;
            }

            color +=
                albedo *
                EvaluateAdditionalLight(gAdditionalLights[lightIndex], normalWS, input.positionWS) *
                0.15f;
        }

        return float4(saturate(color), 1.0f);
    }
    ENDHLSL
    SubShader
    {
        Cull Back
        ZWrite On
        ZTest LEqual
        Pass
        {
            Name "ForwardLit"
            Tags { "LightMode" = "ForwardLit" }
            HLSLPROGRAM
            #pragma target 4.5
            #pragma vertex MainVS
            #pragma fragment MainPS
            #pragma multi_compile _ XC_MAIN_LIGHT_SHADOWS
            #pragma shader_feature_local _ XC_ALPHA_TEST
            #pragma shader_feature_local _ _EMISSION
            #pragma shader_feature_local _ _NORMAL_MAP
            #pragma shader_feature_local _ _IS_FACE
            #pragma shader_feature_local _ _SPECULAR
            #pragma shader_feature_local _ _RIM
            ENDHLSL
        }
        UsePass "Builtin Depth Only/DepthOnly"
        UsePass "Builtin Shadow Caster/ShadowCaster"
    }
}