85 lines
2.1 KiB
HLSL
85 lines
2.1 KiB
HLSL
#include "snoise.hlsl"
|
|
|
|
/*
|
|
contributors: Patricio Gonzalez Vivo
|
|
description: Fractal Brownian Motion
|
|
use: fbm(<float2|float3> pos)
|
|
options:
|
|
FBM_OCTAVES: numbers of octaves. Default is 4.
|
|
FBM_NOISE_FNC(POS_UV): noise function to use Default 'snoise(POS_UV)' (simplex noise)
|
|
FBM_VALUE_INITIAL: initial value. Default is 0.
|
|
FBM_SCALE_SCALAR: scalar. Defualt is 2.
|
|
FBM_AMPLITUD_INITIAL: initial amplitud value. Default is 0.5
|
|
FBM_AMPLITUD_SCALAR: amplitud scalar. Default is 0.5
|
|
license:
|
|
- Copyright (c) 2021 Patricio Gonzalez Vivo under Prosperity License - https://prosperitylicense.com/versions/3.0.0
|
|
- Copyright (c) 2021 Patricio Gonzalez Vivo under Patron License - https://lygia.xyz/license
|
|
*/
|
|
|
|
#ifndef FBM_OCTAVES
|
|
#define FBM_OCTAVES 4
|
|
#endif
|
|
|
|
#ifndef FBM_NOISE_FNC
|
|
#define FBM_NOISE_FNC(POS_UV) snoise(POS_UV)
|
|
#endif
|
|
|
|
#ifndef FBM_NOISE2_FNC
|
|
#define FBM_NOISE2_FNC(POS_UV) FBM_NOISE_FNC(POS_UV)
|
|
#endif
|
|
|
|
#ifndef FBM_NOISE3_FNC
|
|
#define FBM_NOISE3_FNC(POS_UV) FBM_NOISE_FNC(POS_UV)
|
|
#endif
|
|
|
|
#ifndef FBM_NOISE_TYPE
|
|
#define FBM_NOISE_TYPE float
|
|
#endif
|
|
|
|
|
|
#ifndef FBM_VALUE_INITIAL
|
|
#define FBM_VALUE_INITIAL 0.0
|
|
#endif
|
|
|
|
#ifndef FBM_SCALE_SCALAR
|
|
#define FBM_SCALE_SCALAR 2.0
|
|
#endif
|
|
|
|
#ifndef FBM_AMPLITUD_INITIAL
|
|
#define FBM_AMPLITUD_INITIAL 0.5
|
|
#endif
|
|
|
|
#ifndef FBM_AMPLITUD_SCALAR
|
|
#define FBM_AMPLITUD_SCALAR 0.5
|
|
#endif
|
|
|
|
#ifndef FNC_FBM
|
|
#define FNC_FBM
|
|
FBM_NOISE_TYPE fbm(in float2 st) {
|
|
// Initial values
|
|
FBM_NOISE_TYPE value = FBM_VALUE_INITIAL;
|
|
float amplitud = FBM_AMPLITUD_INITIAL;
|
|
|
|
// Loop of octaves
|
|
for (int i = 0; i < FBM_OCTAVES; i++) {
|
|
value += amplitud * FBM_NOISE2_FNC(st);
|
|
st *= FBM_SCALE_SCALAR;
|
|
amplitud *= FBM_AMPLITUD_SCALAR;
|
|
}
|
|
return value;
|
|
}
|
|
|
|
FBM_NOISE_TYPE fbm(in float3 pos) {
|
|
// Initial values
|
|
FBM_NOISE_TYPE value = FBM_VALUE_INITIAL;
|
|
float amplitud = FBM_AMPLITUD_INITIAL;
|
|
|
|
// Loop of octaves
|
|
for (int i = 0; i < FBM_OCTAVES; i++) {
|
|
value += amplitud * FBM_NOISE3_FNC(pos);
|
|
pos *= FBM_SCALE_SCALAR;
|
|
amplitud *= FBM_AMPLITUD_SCALAR;
|
|
}
|
|
return value;
|
|
}
|
|
#endif
|