mobileWaterToon.shader

//https://gist.github.com/fangzhangmnm/38eeeca077db38d0e0b7af53a620947b

//Credit: Inspired by noriben's work https://booth.pm/ja/items/1671087

//reference https://docs.unity3d.com/Manual/SL-VertexFragmentShaderExamples.html

Shader "fzmnm/mobileWaterToon"
{
    Properties
    {
		[Header(Scatter)]
		_ShallowColor ("ShallowColor", Color) = (0.7, 0.95, 1)
		_DeepColor ("DeepColor", Color) = (0, 0.5, 0.75)
		_ScatterStrength ("ScatterStrength", Range(0, 10)) = 1
		[PowerSlider(2)]_ScatterDepth("ScatterDepth",Range(0,10))=.5
		[PowerSlider(2)]_DeepDepth("DeepDepth",Range(0,10))=5

		[Space]
		[Header(Reflection)]
		_ReflectionColor ("ReflectionColor", Color) = (0.8, 0.9, 1)
		_ReflectionStrength ("ReflectionStrength", Range(0, 10)) = 5
		[PowerSlider(2)]_FresnelCoeff ("FresnelCoeff", Range(0, 128)) = 10
		[PowerSlider(2)]_ReflectionDistortion ("ReflectionDistortion", Range(0, 2)) = 0.05
        
		[Space]
		[Header(Specular)]
		_SpecularColor ("SpecularColor", Color) = (1, 1, 1)
		_SpecularStrength ("SpecularStrength", Range(0, 5)) = 3
        _SpecularLightDir ("SpecularLightDir",Vector)=(.1,.5,-1)
		[PowerSlider(2)]_SpecularCoeff ("SpecularCoeff", Range(0, 128)) = 32
		[PowerSlider(2)]_SpecularDistortion ("SpecularDistortion", Range(0, 2)) = 2
        
		[Space]
		[Header(Foam)]
		_FoamColor ("FoamColor", Color) = (1, 1, 1,.8)
        _FoamDepth("FoamDepth",Range(0,1))=.1
        _FoamTexture("FoamTexture",2D)="white"{}
		[PowerSlider(2)]_FoamScale ("FoamScale", Range(0, 1000)) = 100
		_FoamScroll ("FoamScroll" , Vector) = (0,0.0005,0)
        
        
		[Space]
		[Header(Distortion)]
		[Normal]_DistortionTexture ("DistortionTexture", 2D) = "blue" {}
		[PowerSlider(2)]_DistortionScale ("DistortionScale", Range(0, 100)) = 10
		_DistortionScroll ("DistortionScroll" , Vector) = (0,0.002,0)

        [Space]
        [Header(Displacement)]
        _DisplacementTexture("DisplacementTexture",2D)="black"{}
		[PowerSlider(2)]_DisplacementStrength ("DisplacementStrength", Range(0, 5)) = 0.1
		[PowerSlider(2)]_DisplacementScale ("DisplacementScale", Range(0, 100)) = 20
		_DisplacementScroll ("DisplacementScroll" , Vector) = (0,0.003,0)

		[Space]
		[Header(Color Correction)]
		[PowerSlider(2)]_Gamma ("Gamma", Range(0, 5)) = 1.1
    }
    SubShader
    {
		Tags { "RenderType"="Transparent" "Queue" = "Transparent" "LightMode" = "ForwardBase"}
        LOD 100
        Cull Back
		Blend SrcAlpha OneMinusSrcAlpha
        ZWrite On

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #pragma multi_compile_fog

            #include "UnityCG.cginc"
            #include "UnityLightingCommon.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
				half3 normal : NORMAL;
				half3 tangent : TANGENT;
				half4 vertColor : COLOR;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                UNITY_FOG_COORDS(1)
                float4 vertex : SV_POSITION;
                // TANGENT, BINORMAL, NORMAL semantics are only available for input of vertex shader
                half3 normal: TEXCOORD2; 
                half3 tangent: TEXCOORD3;
				half3 worldPos : TEXCOORD4;
                half4 vertColor:COLOR;
            };

            fixed3 _ShallowColor,_DeepColor;
            half _ScatterStrength,_ScatterDepth,_DeepDepth;

            fixed3 _ReflectionColor;
            half _ReflectionStrength,_FresnelCoeff,_ReflectionDistortion;

            fixed3 _SpecularColor,_SpecularLightDir;
            half _SpecularStrength,_SpecularCoeff,_SpecularDistortion;

            sampler2D _FoamTexture;
            float _FoamScale;
            float2 _FoamScroll;
            fixed4 _FoamColor;
            half _FoamDepth;

            half _Gamma;
            
			sampler2D _DistortionTexture;
            float _DistortionScale;
            float2 _DistortionScroll;

            sampler2D _DisplacementTexture;
            float _DisplacementScale,_DisplacementStrength;
            float2 _DisplacementScroll;




            v2f vert (appdata v)
            {
                v2f o;

                float2 displacementTextureUV=(v.uv+_Time.y*_DisplacementScroll)*_DisplacementScale;
                float h=tex2Dlod(_DisplacementTexture,float4(displacementTextureUV,0,0))*2-1;
                v.vertex.xyz+=v.normal*h*_DisplacementStrength;

                o.vertex = UnityObjectToClipPos(v.vertex);
                UNITY_TRANSFER_FOG(o,o.vertex);

                o.uv=v.uv;

                o.normal=UnityObjectToWorldNormal(v.normal);
                o.tangent=UnityObjectToWorldDir(v.tangent);

                o.vertColor=v.vertColor;

                o.worldPos=mul(unity_ObjectToWorld,v.vertex);

                return o;
            }

            fixed4 frag (v2f i) : SV_Target
            {
                i.normal=normalize(i.normal);
                half3 viewDir=normalize(UnityWorldSpaceViewDir(i.worldPos));
                float3x3 TBN=transpose(float3x3(normalize(i.tangent),normalize(cross(i.normal,i.tangent)),i.normal));
                half3 normal=normalize(mul(TBN,UnpackNormal(tex2D(_DistortionTexture,(i.uv+_Time.y*_DistortionScroll)*_DistortionScale))));

                half depth=i.vertColor.r/saturate(dot(i.normal,viewDir));
                
                half transmissive=exp(-depth/_ScatterDepth);

                half3 scatteredLight=lerp(_DeepColor,_ShallowColor,exp(-depth/_DeepDepth))*_ScatterStrength;
                
                half3 normalReflection=normalize(lerp(i.normal,normal,_ReflectionDistortion));
                half3 reflectionDir=reflect(-viewDir,normalReflection);
                reflectionDir.y*=reflectionDir.y<0?-1:1;
                half fresnelStrength=pow(1-saturate(dot(normalReflection,viewDir)),_FresnelCoeff);
                half3 reflectedLight=UNITY_SAMPLE_TEXCUBE_LOD(unity_SpecCube0,reflectionDir,0)*_ReflectionColor*_ReflectionStrength*fresnelStrength;
                
                half3 normalSpecular=normalize(lerp(i.normal,normal,_SpecularDistortion));
                half3 halfDir=normalize(normalize(_SpecularLightDir)+viewDir);
                half3 specularLight=_SpecularColor*pow(saturate(dot(normalSpecular,halfDir)),_SpecularCoeff)*_SpecularStrength*fresnelStrength;

                half3 light=scatteredLight+reflectedLight+specularLight;

                half foam=saturate(1-i.vertColor.r/_FoamDepth);
                half foamTex=tex2D(_FoamTexture,(i.uv+_Time.y*_FoamScroll)*_FoamScale);
                foam=saturate(2*foam+foamTex-1);

                light=lerp(light,_FoamColor.rgb,foam);
                transmissive=lerp(transmissive,1-_FoamColor.a,foam);

                light=pow(light,_Gamma);
                
                //return fixed4(fixed3(1,1,1)*foam,1);
                return fixed4(light,1-transmissive);
            }
            ENDCG
        }
    }
}