#ifndef SAND_INCLUDED
#define SAND_INCLUDED

//#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Lighting.hlsl"
#include "Assets/_Content/Shaders/Include/Noises.hlsl"

void Sand_float
(
    float Progression,
    float3 PositionWS,
    float3 NormalWS,
    out float3 Position,
    out float Height,
    out float Alpha
)
{
    //float t = frac(_Time.y / 20);
    float t = Progression;
    t -= RidgedNoise3D(PositionWS, .3, 1, 2, .5) * .3;
    
    
    float depth = length(PositionWS - _WorldSpaceCameraPos.xyz);
    //Light mainLight = GetMainLight(0);
    //float3 mainLightDir = normalize(mainLight.direction);
    //float lightGradient = dot(normalize(NormalWS), normalize(mainLightDir));
    //lightGradient = smoothstep(-.5, 1, lightGradient);
    //float ao = GetScreenSpaceAmbientOcclusion(ScreenUV).directAmbientOcclusion;
    
    // Arks
    
    /*float arkMask = abs(frac(PositionWS.z * .5) * 2 - 1);
    arkMask = pow(smoothstep(.7, 0, arkMask), 2);
    arkMask += smoothstep(2.8, 3.2, abs(PositionWS.x));
    arkMask = saturate(arkMask);*/
    float arkMask = 0;
    
    // Sand
    
    float sandLayers = 6;
    
    float sandDirection = cos(t * sandLayers * 3.14);
    
    //float sandDensity = smoothstep(1.5, 0, abs(PositionWS.x));
    //sandDensity = saturate(sandDensity + arkMask);
    
    float sandPatern = RidgedNoise3D(PositionWS + float3(sandDirection, 0, 0), .6, 1, 2, .5) * .8;
    sandPatern += 1 - RidgedNoise3D(PositionWS + float3(0, 0, t * sandLayers * 2), .8, 2, 2, .5) * .2;
    
    float sandDensity = sqrt(smoothstep(0, 2, abs(PositionWS.x) + sandPatern));
    
    float sandGradientSign = (floor(t * sandLayers) % 2 == 0) ? 1 : -1;
    float sandGradient = smoothstep(2 * -sandGradientSign, 2 * sandGradientSign, PositionWS.x);
    float sandPhase = frac(t * sandLayers);
    float sandFlow = smoothstep(sandPhase * 2, sandPhase * 2 - 1, sandGradient);
    sandFlow = (sandFlow + floor(t * sandLayers)) / sandLayers;
    
    float sandMask = sandFlow * 1.5 - t * .8 + (sandPatern * 2 - 1) * sandDensity * t * .3;
    sandMask *= sandDensity * .7 + .3;
    
    // Test

    //float test = ValueNoise3D(PositionWS, 40);
    //float test = PerlinNoise3D(PositionWS, 40);
    //float test = PerlinNoise3DLOD(PositionWS, 100, 3.5);
    //float test = SimplexNoise3D(PositionWS, 40);
    //float test = WorleyNoise3D(PositionWS, 40, 1);
    //float id;
    //float test = VoronoiNoise3D(PositionWS, 10, 1, .05, id);
    //float test = FBMNoise3D(PositionWS, 10, 2, 2, .5);
    //float test = RidgedNoise3D(PositionWS, 10, 2, 2, .5);
    
    // Output

    Position = PositionWS;
    Position.y += sandMask;
    
    Height = sandMask;
    
    Alpha = smoothstep(1, .5, abs(smoothstep(-20, 20, PositionWS.x) * 2 - 1));
    //Debug = sandFlow;
}

#endif