Rasagar/Library/PackageCache/com.unity.terrain-tools/Shaders/NoiseLib/Fbm/Perlin.hlsl

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//
//      DO NOT EDIT THIS FILE!! THIS IS AUTOMATICALLY GENERATED!!
//      DO NOT EDIT THIS FILE!! THIS IS AUTOMATICALLY GENERATED!!
//      DO NOT EDIT THIS FILE!! THIS IS AUTOMATICALLY GENERATED!!
//
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#ifndef UNITY_TERRAIN_TOOL_NOISE_FbmPerlin_INC
#define UNITY_TERRAIN_TOOL_NOISE_FbmPerlin_INC

/*=========================================================================

    Includes

=========================================================================*/

#include "Packages/com.unity.terrain-tools/Shaders/NoiseLib/Implementation/PerlinImpl.hlsl"
#include "Packages/com.unity.terrain-tools/Shaders/NoiseLib/NoiseCommon.hlsl"





#ifndef FBMFRACTALINPUT_DEF // [ FBMFRACTALINPUT_DEF
#define FBMFRACTALINPUT_DEF

struct FbmFractalInput
{
	float octaves;
	float amplitude;
	float persistence;
	float frequency;
	float lacunarity;
	float warpIterations;
	float warpStrength;
	float4 warpOffsets;
};



FbmFractalInput GetDefaultFbmFractalInput()
{
	FbmFractalInput ret;

	ret.octaves = 8;
	ret.amplitude = 0.5;
	ret.persistence = 0.5;
	ret.frequency = 1;
	ret.lacunarity = 2;
	ret.warpIterations = 0;
	ret.warpStrength = 0.5;
	ret.warpOffsets = float4(2.5, 1.4, 3.2, 2.7);

	return ret;
}




float _FbmOctaves;
float _FbmAmplitude;
float _FbmPersistence;
float _FbmFrequency;
float _FbmLacunarity;
float _FbmWarpIterations;
float _FbmWarpStrength;
float4 _FbmWarpOffsets;

FbmFractalInput GetFbmFractalInput()
{
	FbmFractalInput ret;

	ret.octaves = _FbmOctaves;
	ret.amplitude = _FbmAmplitude;
	ret.persistence = _FbmPersistence;
	ret.frequency = _FbmFrequency;
	ret.lacunarity = _FbmLacunarity;
	ret.warpIterations = _FbmWarpIterations;
	ret.warpStrength = _FbmWarpStrength;
	ret.warpOffsets = _FbmWarpOffsets;

	return ret;
}



#endif // ] FBMFRACTALINPUT_DEF



/*=========================================================================

    Fractal Functions

=========================================================================*/

float noise_FbmPerlin_Raw( float pos, FbmFractalInput fractalInput )
{
    float prev = 0;
    float n = 0;

    float octaves = ceil(fractalInput.octaves) + (1 - sign(frac(fractalInput.octaves)));

    for( float i = 0; i < octaves; ++i )
    {
        prev = n;
        n += fractalInput.amplitude * get_noise_Perlin( pos * fractalInput.frequency );
        fractalInput.frequency *= fractalInput.lacunarity;
        fractalInput.amplitude *= fractalInput.persistence;
    }

    n = lerp(prev, n, frac(fractalInput.octaves));

    return n;
}

float noise_FbmPerlin_Raw( float2 pos, FbmFractalInput fractalInput )
{
    float prev = 0;
    float n = 0;

    float octaves = ceil(fractalInput.octaves) + (1 - sign(frac(fractalInput.octaves)));

    for( float i = 0; i < octaves; ++i )
    {
        prev = n;
        n += fractalInput.amplitude * get_noise_Perlin( pos * fractalInput.frequency );
        fractalInput.frequency *= fractalInput.lacunarity;
        fractalInput.amplitude *= fractalInput.persistence;
    }

    n = lerp(prev, n, frac(fractalInput.octaves));

    return n;
}

float noise_FbmPerlin_Raw( float3 pos, FbmFractalInput fractalInput )
{
    float prev = 0;
    float n = 0;

    float octaves = ceil(fractalInput.octaves) + (1 - sign(frac(fractalInput.octaves)));

    for( float i = 0; i < octaves; ++i )
    {
        prev = n;
        n += fractalInput.amplitude * get_noise_Perlin( pos * fractalInput.frequency );
        fractalInput.frequency *= fractalInput.lacunarity;
        fractalInput.amplitude *= fractalInput.persistence;
    }

    n = lerp(prev, n, frac(fractalInput.octaves));

    return n;
}

float noise_FbmPerlin_Raw( float4 pos, FbmFractalInput fractalInput )
{
    float prev = 0;
    float n = 0;

    float octaves = ceil(fractalInput.octaves) + (1 - sign(frac(fractalInput.octaves)));

    for( float i = 0; i < octaves; ++i )
    {
        prev = n;
        n += fractalInput.amplitude * get_noise_Perlin( pos * fractalInput.frequency );
        fractalInput.frequency *= fractalInput.lacunarity;
        fractalInput.amplitude *= fractalInput.persistence;
    }

    n = lerp(prev, n, frac(fractalInput.octaves));

    return n;
}

/*=========================================================================

    FbmPerlin Noise Functions - Fractal, Warped

=========================================================================*/

float noise_FbmPerlin( float pos, FbmFractalInput fractalInput )
{
    if(fractalInput.warpIterations > 0)
    {
        float prev = 0;
        float warpIterations = ceil(fractalInput.warpIterations) + (1 - sign(frac(fractalInput.warpIterations)));

        // do warping
        for ( float i = 0; i < warpIterations; ++i )
        {
            float q = noise_FbmPerlin_Raw( pos + fractalInput.warpOffsets.x, fractalInput );
            prev = pos;
            pos = pos + fractalInput.warpStrength * q;
        }

        pos = lerp(prev, pos, frac(fractalInput.warpIterations));
    }

    float f = noise_FbmPerlin_Raw( pos, fractalInput );

    return f;
}

float noise_FbmPerlin( float2 pos, FbmFractalInput fractalInput )
{
    if(fractalInput.warpIterations > 0)
    {
        float2 prev = 0;
        float warpIterations = ceil(fractalInput.warpIterations) + (1 - sign(frac(fractalInput.warpIterations)));

        // do warping
        for ( float i = 0; i < warpIterations; ++i )
        {
            float2 q = float2( noise_FbmPerlin_Raw( pos, fractalInput ),
                            noise_FbmPerlin_Raw( pos + fractalInput.warpOffsets.xy, fractalInput ) );
            prev = pos;

            pos = pos + fractalInput.warpStrength * q;
        }
        
        pos = lerp(prev, pos, frac(fractalInput.warpIterations));
    }

    float f = noise_FbmPerlin_Raw( pos, fractalInput );

    return f;
}

float noise_FbmPerlin( float3 pos, FbmFractalInput fractalInput )
{
    if(fractalInput.warpIterations > 0)
    {
        float3 prev = 0;
        float warpIterations = ceil(fractalInput.warpIterations) + (1 - sign(frac(fractalInput.warpIterations)));

        // do warping
        for ( float i = 0; i < warpIterations; ++i )
        {
            float3 q = float3( noise_FbmPerlin_Raw( pos.xyz, fractalInput ),
                        noise_FbmPerlin_Raw( pos.xyz + fractalInput.warpOffsets.xyz, fractalInput ),
                        noise_FbmPerlin_Raw( pos.xyz + float3( fractalInput.warpOffsets.x, fractalInput.warpOffsets.y, 0 ), fractalInput ) );
            prev = pos;
            pos = pos + fractalInput.warpStrength * q;
        }
        
        pos = lerp(prev, pos, frac(fractalInput.warpIterations));
    }
    
    float f = noise_FbmPerlin_Raw( pos, fractalInput );

    return f;
}

float noise_FbmPerlin( float4 pos, FbmFractalInput fractalInput )
{
    float f = noise_FbmPerlin_Raw( pos, fractalInput );

    return f;
}

#endif // UNITY_TERRAIN_TOOL_NOISE_FbmPerlin_INC