Shader "FresnelGradient" {
    Properties {
        _FrontColor ("FrontColor", Color) = (1,0,0,1)
        _BackColor ("Back Color", Color) = (0,0,1,1)
        _GradientPower ("GradientPower", Range(0, 10)) = 1
        _Metallic ("Metallic", Range(0, 1)) = 0
        _Roughness ("Roughness", Range(0, 1)) = 0
        _FresnelColor ("Fresnel Color", Color) = (0,0.9568628,1,1)
        _FresnelPower ("Fresnel Power", Range(0, 10)) = 1
    }
    SubShader {
        Tags {
            "RenderType"="Opaque"
        }
        Pass {
            Name "FORWARD"
            Tags {
                "LightMode"="ForwardBase"
            }


            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #define UNITY_PASS_FORWARDBASE
            #define SHOULD_SAMPLE_SH ( defined (LIGHTMAP_OFF) && defined(DYNAMICLIGHTMAP_OFF) )
            #define _GLOSSYENV 1
            #include "UnityCG.cginc"
            #include "AutoLight.cginc"
            #include "Lighting.cginc"
            #include "UnityPBSLighting.cginc"
            #include "UnityStandardBRDF.cginc"
            #pragma multi_compile_fwdbase_fullshadows
            #pragma multi_compile LIGHTMAP_OFF LIGHTMAP_ON
            #pragma multi_compile DIRLIGHTMAP_OFF DIRLIGHTMAP_COMBINED DIRLIGHTMAP_SEPARATE
            #pragma multi_compile DYNAMICLIGHTMAP_OFF DYNAMICLIGHTMAP_ON
            #pragma multi_compile_fog
            #pragma only_renderers d3d9 d3d11 glcore gles
            #pragma target 3.0
            uniform float4 _BackColor;
            uniform float _FresnelPower;
            uniform float4 _FresnelColor;
            uniform float _Metallic;
            uniform float _Roughness;
            uniform float4 _FrontColor;
            uniform float _GradientPower;
            struct VertexInput {
                float4 vertex : POSITION;
                float3 normal : NORMAL;
                float4 tangent : TANGENT;
                float2 texcoord1 : TEXCOORD1;
                float2 texcoord2 : TEXCOORD2;
            };
            struct VertexOutput {
                float4 pos : SV_POSITION;
                float2 uv1 : TEXCOORD0;
                float2 uv2 : TEXCOORD1;
                float4 posWorld : TEXCOORD2;
                float3 normalDir : TEXCOORD3;
                float3 tangentDir : TEXCOORD4;
                float3 bitangentDir : TEXCOORD5;
                LIGHTING_COORDS(6,7)
                UNITY_FOG_COORDS(8)
                #if defined(LIGHTMAP_ON) || defined(UNITY_SHOULD_SAMPLE_SH)
                    float4 ambientOrLightmapUV : TEXCOORD9;
                #endif
            };
            VertexOutput vert (VertexInput v) {
                VertexOutput o = (VertexOutput)0;
                o.uv1 = v.texcoord1;
                o.uv2 = v.texcoord2;
                #ifdef LIGHTMAP_ON
                    o.ambientOrLightmapUV.xy = v.texcoord1.xy * unity_LightmapST.xy + unity_LightmapST.zw;
                    o.ambientOrLightmapUV.zw = 0;
                #elif UNITY_SHOULD_SAMPLE_SH
                #endif
                #ifdef DYNAMICLIGHTMAP_ON
                    o.ambientOrLightmapUV.zw = v.texcoord2.xy * unity_DynamicLightmapST.xy + unity_DynamicLightmapST.zw;
                #endif
                o.normalDir = UnityObjectToWorldNormal(v.normal);
                o.tangentDir = normalize( mul( unity_ObjectToWorld, float4( v.tangent.xyz, 0.0 ) ).xyz );
                o.bitangentDir = normalize(cross(o.normalDir, o.tangentDir) * v.tangent.w);
                o.posWorld = mul(unity_ObjectToWorld, v.vertex);
                float3 lightColor = _LightColor0.rgb;
                o.pos = UnityObjectToClipPos( v.vertex );
                UNITY_TRANSFER_FOG(o,o.pos);
                TRANSFER_VERTEX_TO_FRAGMENT(o)
                return o;
            }
            float4 frag(VertexOutput i) : COLOR {
                i.normalDir = normalize(i.normalDir);
                float3x3 tangentTransform = float3x3( i.tangentDir, i.bitangentDir, i.normalDir);
                float3 viewDirection = normalize(_WorldSpaceCameraPos.xyz - i.posWorld.xyz);
                float3 normalDirection = i.normalDir;
                float3 viewReflectDirection = reflect( -viewDirection, normalDirection );
                float3 lightDirection = normalize(_WorldSpaceLightPos0.xyz);
                float3 lightColor = _LightColor0.rgb;
                float3 halfDirection = normalize(viewDirection+lightDirection);
////// Lighting:
                float attenuation = LIGHT_ATTENUATION(i);
                float3 attenColor = attenuation * _LightColor0.xyz;
                float Pi = 3.141592654;
                float InvPi = 0.31830988618;
///////// Gloss:
                float gloss = _Roughness;
                float perceptualRoughness = 1.0 - _Roughness;
                float roughness = perceptualRoughness * perceptualRoughness;
                float specPow = exp2( gloss * 10.0 + 1.0 );
/////// GI Data:
                UnityLight light;
                #ifdef LIGHTMAP_OFF
                    light.color = lightColor;
                    light.dir = lightDirection;
                    light.ndotl = LambertTerm (normalDirection, light.dir);
                #else
                    light.color = half3(0.f, 0.f, 0.f);
                    light.ndotl = 0.0f;
                    light.dir = half3(0.f, 0.f, 0.f);
                #endif
                UnityGIInput d;
                d.light = light;
                d.worldPos = i.posWorld.xyz;
                d.worldViewDir = viewDirection;
                d.atten = attenuation;
                #if defined(LIGHTMAP_ON) || defined(DYNAMICLIGHTMAP_ON)
                    d.ambient = 0;
                    d.lightmapUV = i.ambientOrLightmapUV;
                #else
                    d.ambient = i.ambientOrLightmapUV;
                #endif
                #if UNITY_SPECCUBE_BLENDING || UNITY_SPECCUBE_BOX_PROJECTION
                    d.boxMin[0] = unity_SpecCube0_BoxMin;
                    d.boxMin[1] = unity_SpecCube1_BoxMin;
                #endif
                #if UNITY_SPECCUBE_BOX_PROJECTION
                    d.boxMax[0] = unity_SpecCube0_BoxMax;
                    d.boxMax[1] = unity_SpecCube1_BoxMax;
                    d.probePosition[0] = unity_SpecCube0_ProbePosition;
                    d.probePosition[1] = unity_SpecCube1_ProbePosition;
                #endif
                d.probeHDR[0] = unity_SpecCube0_HDR;
                d.probeHDR[1] = unity_SpecCube1_HDR;
                Unity_GlossyEnvironmentData ugls_en_data;
                ugls_en_data.roughness = 1.0 - gloss;
                ugls_en_data.reflUVW = viewReflectDirection;
                UnityGI gi = UnityGlobalIllumination(d, 1, normalDirection, ugls_en_data );
                lightDirection = gi.light.dir;
                lightColor = gi.light.color;
////// Specular:
                float NdotL = saturate(dot( normalDirection, lightDirection ));
                float LdotH = saturate(dot(lightDirection, halfDirection));
                float3 specularColor = _Metallic;
                float specularMonochrome;
                float3 diffuseColor = lerp(_FrontColor.rgb,_BackColor.rgb,(1.0 - pow(1.0-max(0,dot(normalDirection, viewDirection)),_GradientPower))); // Need this for specular when using metallic
                diffuseColor = DiffuseAndSpecularFromMetallic( diffuseColor, specularColor, specularColor, specularMonochrome );
                specularMonochrome = 1.0-specularMonochrome;
                float NdotV = abs(dot( normalDirection, viewDirection ));
                float NdotH = saturate(dot( normalDirection, halfDirection ));
                float VdotH = saturate(dot( viewDirection, halfDirection ));
                float visTerm = SmithJointGGXVisibilityTerm( NdotL, NdotV, roughness );
                float normTerm = GGXTerm(NdotH, roughness);
                float specularPBL = (visTerm*normTerm) * UNITY_PI;
                #ifdef UNITY_COLORSPACE_GAMMA
                    specularPBL = sqrt(max(1e-4h, specularPBL));
                #endif
                specularPBL = max(0, specularPBL * NdotL);
                #if defined(_SPECULARHIGHLIGHTS_OFF)
                    specularPBL = 0.0;
                #endif
                half surfaceReduction;
                #ifdef UNITY_COLORSPACE_GAMMA
                    surfaceReduction = 1.0-0.28*roughness*perceptualRoughness;
                #else
                    surfaceReduction = 1.0/(roughness*roughness + 1.0);
                #endif
                specularPBL *= any(specularColor) ? 1.0 : 0.0;
                float3 directSpecular = attenColor*specularPBL*FresnelTerm(specularColor, LdotH);
                half grazingTerm = saturate( gloss + specularMonochrome );
                float3 indirectSpecular = (gi.indirect.specular);
                indirectSpecular *= FresnelLerp (specularColor, grazingTerm, NdotV);
                indirectSpecular *= surfaceReduction;
                float3 specular = (directSpecular + indirectSpecular);
/////// Diffuse:
                NdotL = max(0.0,dot( normalDirection, lightDirection ));
                half fd90 = 0.5 + 2 * LdotH * LdotH * (1-gloss);
                float nlPow5 = Pow5(1-NdotL);
                float nvPow5 = Pow5(1-NdotV);
                float3 directDiffuse = ((1 +(fd90 - 1)*nlPow5) * (1 + (fd90 - 1)*nvPow5) * NdotL) * attenColor;
                float3 indirectDiffuse = float3(0,0,0);
                indirectDiffuse += gi.indirect.diffuse;
                float3 diffuse = (directDiffuse + indirectDiffuse) * diffuseColor;
////// Emissive:
                float3 emissive = (_FresnelColor.rgb*pow(1.0-max(0,dot(normalDirection, viewDirection)),_FresnelPower));
/// Final Color:
                float3 finalColor = diffuse + specular + emissive;
                fixed4 finalRGBA = fixed4(finalColor,1);
                UNITY_APPLY_FOG(i.fogCoord, finalRGBA);
                return finalRGBA;
            }
            ENDCG
        }
        Pass {
            Name "FORWARD_DELTA"
            Tags {
                "LightMode"="ForwardAdd"
            }
            Blend One One


            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #define UNITY_PASS_FORWARDADD
            #define SHOULD_SAMPLE_SH ( defined (LIGHTMAP_OFF) && defined(DYNAMICLIGHTMAP_OFF) )
            #define _GLOSSYENV 1
            #include "UnityCG.cginc"
            #include "AutoLight.cginc"
            #include "Lighting.cginc"
            #include "UnityPBSLighting.cginc"
            #include "UnityStandardBRDF.cginc"
            #pragma multi_compile_fwdadd_fullshadows
            #pragma multi_compile LIGHTMAP_OFF LIGHTMAP_ON
            #pragma multi_compile DIRLIGHTMAP_OFF DIRLIGHTMAP_COMBINED DIRLIGHTMAP_SEPARATE
            #pragma multi_compile DYNAMICLIGHTMAP_OFF DYNAMICLIGHTMAP_ON
            #pragma multi_compile_fog
            #pragma only_renderers d3d9 d3d11 glcore gles
            #pragma target 3.0
            uniform float4 _BackColor;
            uniform float _FresnelPower;
            uniform float4 _FresnelColor;
            uniform float _Metallic;
            uniform float _Roughness;
            uniform float4 _FrontColor;
            uniform float _GradientPower;
            struct VertexInput {
                float4 vertex : POSITION;
                float3 normal : NORMAL;
                float4 tangent : TANGENT;
                float2 texcoord1 : TEXCOORD1;
                float2 texcoord2 : TEXCOORD2;
            };
            struct VertexOutput {
                float4 pos : SV_POSITION;
                float2 uv1 : TEXCOORD0;
                float2 uv2 : TEXCOORD1;
                float4 posWorld : TEXCOORD2;
                float3 normalDir : TEXCOORD3;
                float3 tangentDir : TEXCOORD4;
                float3 bitangentDir : TEXCOORD5;
                LIGHTING_COORDS(6,7)
                UNITY_FOG_COORDS(8)
            };
            VertexOutput vert (VertexInput v) {
                VertexOutput o = (VertexOutput)0;
                o.uv1 = v.texcoord1;
                o.uv2 = v.texcoord2;
                o.normalDir = UnityObjectToWorldNormal(v.normal);
                o.tangentDir = normalize( mul( unity_ObjectToWorld, float4( v.tangent.xyz, 0.0 ) ).xyz );
                o.bitangentDir = normalize(cross(o.normalDir, o.tangentDir) * v.tangent.w);
                o.posWorld = mul(unity_ObjectToWorld, v.vertex);
                float3 lightColor = _LightColor0.rgb;
                o.pos = UnityObjectToClipPos( v.vertex );
                UNITY_TRANSFER_FOG(o,o.pos);
                TRANSFER_VERTEX_TO_FRAGMENT(o)
                return o;
            }
            float4 frag(VertexOutput i) : COLOR {
                i.normalDir = normalize(i.normalDir);
                float3x3 tangentTransform = float3x3( i.tangentDir, i.bitangentDir, i.normalDir);
                float3 viewDirection = normalize(_WorldSpaceCameraPos.xyz - i.posWorld.xyz);
                float3 normalDirection = i.normalDir;
                float3 lightDirection = normalize(lerp(_WorldSpaceLightPos0.xyz, _WorldSpaceLightPos0.xyz - i.posWorld.xyz,_WorldSpaceLightPos0.w));
                float3 lightColor = _LightColor0.rgb;
                float3 halfDirection = normalize(viewDirection+lightDirection);
////// Lighting:
                float attenuation = LIGHT_ATTENUATION(i);
                float3 attenColor = attenuation * _LightColor0.xyz;
                float Pi = 3.141592654;
                float InvPi = 0.31830988618;
///////// Gloss:
                float gloss = _Roughness;
                float perceptualRoughness = 1.0 - _Roughness;
                float roughness = perceptualRoughness * perceptualRoughness;
                float specPow = exp2( gloss * 10.0 + 1.0 );
////// Specular:
                float NdotL = saturate(dot( normalDirection, lightDirection ));
                float LdotH = saturate(dot(lightDirection, halfDirection));
                float3 specularColor = _Metallic;
                float specularMonochrome;
                float3 diffuseColor = lerp(_FrontColor.rgb,_BackColor.rgb,(1.0 - pow(1.0-max(0,dot(normalDirection, viewDirection)),_GradientPower))); // Need this for specular when using metallic
                diffuseColor = DiffuseAndSpecularFromMetallic( diffuseColor, specularColor, specularColor, specularMonochrome );
                specularMonochrome = 1.0-specularMonochrome;
                float NdotV = abs(dot( normalDirection, viewDirection ));
                float NdotH = saturate(dot( normalDirection, halfDirection ));
                float VdotH = saturate(dot( viewDirection, halfDirection ));
                float visTerm = SmithJointGGXVisibilityTerm( NdotL, NdotV, roughness );
                float normTerm = GGXTerm(NdotH, roughness);
                float specularPBL = (visTerm*normTerm) * UNITY_PI;
                #ifdef UNITY_COLORSPACE_GAMMA
                    specularPBL = sqrt(max(1e-4h, specularPBL));
                #endif
                specularPBL = max(0, specularPBL * NdotL);
                #if defined(_SPECULARHIGHLIGHTS_OFF)
                    specularPBL = 0.0;
                #endif
                specularPBL *= any(specularColor) ? 1.0 : 0.0;
                float3 directSpecular = attenColor*specularPBL*FresnelTerm(specularColor, LdotH);
                float3 specular = directSpecular;
/////// Diffuse:
                NdotL = max(0.0,dot( normalDirection, lightDirection ));
                half fd90 = 0.5 + 2 * LdotH * LdotH * (1-gloss);
                float nlPow5 = Pow5(1-NdotL);
                float nvPow5 = Pow5(1-NdotV);
                float3 directDiffuse = ((1 +(fd90 - 1)*nlPow5) * (1 + (fd90 - 1)*nvPow5) * NdotL) * attenColor;
                float3 diffuse = directDiffuse * diffuseColor;
/// Final Color:
                float3 finalColor = diffuse + specular;
                fixed4 finalRGBA = fixed4(finalColor * 1,0);
                UNITY_APPLY_FOG(i.fogCoord, finalRGBA);
                return finalRGBA;
            }
            ENDCG
        }
        Pass {
            Name "Meta"
            Tags {
                "LightMode"="Meta"
            }
            Cull Off

            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #define UNITY_PASS_META 1
            #define SHOULD_SAMPLE_SH ( defined (LIGHTMAP_OFF) && defined(DYNAMICLIGHTMAP_OFF) )
            #define _GLOSSYENV 1
            #include "UnityCG.cginc"
            #include "Lighting.cginc"
            #include "UnityPBSLighting.cginc"
            #include "UnityStandardBRDF.cginc"
            #include "UnityMetaPass.cginc"
            #pragma fragmentoption ARB_precision_hint_fastest
            #pragma multi_compile_shadowcaster
            #pragma multi_compile LIGHTMAP_OFF LIGHTMAP_ON
            #pragma multi_compile DIRLIGHTMAP_OFF DIRLIGHTMAP_COMBINED DIRLIGHTMAP_SEPARATE
            #pragma multi_compile DYNAMICLIGHTMAP_OFF DYNAMICLIGHTMAP_ON
            #pragma multi_compile_fog
            #pragma only_renderers d3d9 d3d11 glcore gles
            #pragma target 3.0
            uniform float4 _BackColor;
            uniform float _FresnelPower;
            uniform float4 _FresnelColor;
            uniform float _Metallic;
            uniform float _Roughness;
            uniform float4 _FrontColor;
            uniform float _GradientPower;
            struct VertexInput {
                float4 vertex : POSITION;
                float3 normal : NORMAL;
                float2 texcoord1 : TEXCOORD1;
                float2 texcoord2 : TEXCOORD2;
            };
            struct VertexOutput {
                float4 pos : SV_POSITION;
                float2 uv1 : TEXCOORD0;
                float2 uv2 : TEXCOORD1;
                float4 posWorld : TEXCOORD2;
                float3 normalDir : TEXCOORD3;
            };
            VertexOutput vert (VertexInput v) {
                VertexOutput o = (VertexOutput)0;
                o.uv1 = v.texcoord1;
                o.uv2 = v.texcoord2;
                o.normalDir = UnityObjectToWorldNormal(v.normal);
                o.posWorld = mul(unity_ObjectToWorld, v.vertex);
                o.pos = UnityMetaVertexPosition(v.vertex, v.texcoord1.xy, v.texcoord2.xy, unity_LightmapST, unity_DynamicLightmapST );
                return o;
            }
            float4 frag(VertexOutput i) : SV_Target {
                i.normalDir = normalize(i.normalDir);
                float3 viewDirection = normalize(_WorldSpaceCameraPos.xyz - i.posWorld.xyz);
                float3 normalDirection = i.normalDir;
                UnityMetaInput o;
                UNITY_INITIALIZE_OUTPUT( UnityMetaInput, o );

                o.Emission = (_FresnelColor.rgb*pow(1.0-max(0,dot(normalDirection, viewDirection)),_FresnelPower));

                float3 diffColor = lerp(_FrontColor.rgb,_BackColor.rgb,(1.0 - pow(1.0-max(0,dot(normalDirection, viewDirection)),_GradientPower)));
                float specularMonochrome;
                float3 specColor;
                diffColor = DiffuseAndSpecularFromMetallic( diffColor, _Metallic, specColor, specularMonochrome );
                float roughness = 1.0 - _Roughness;
                o.Albedo = diffColor + specColor * roughness * roughness * 0.5;

                return UnityMetaFragment( o );
            }
            ENDCG
        }
    }
    FallBack "Diffuse"
    CustomEditor "ShaderForgeMaterialInspector"
}