#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 = Progression;
    t -= RidgedNoise3D(PositionWS, .3, 1, 2, .5) * .3;
    
    
    float depth = length(PositionWS - _WorldSpaceCameraPos.xyz);
    float arkMask = 0;
    
    // Sand
    
    float sandLayers = 6;
    
    float sandDirection = cos(t * sandLayers * 3.14);
    
    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;
    
    // Output

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

#endif