float Noise::Turb(Point3 p, float lev) {
float sum = 0.0f;
float l,f = 1.0f;
float ml = levels;
for (l = lev; l >= 1.0f; l-=1.0f, ml-=1.0f) {
sum += (float)fabs(noise4(p*f,phase))/f;
f *= 2.0f;
}
if (l>0.0f)
sum += l*(float)fabs(noise4(p*f,phase))/f;
#ifdef DOAA
if (filter&&(ml>l)) {
float r = 0;
if (ml<1.0f) {
r += (ml-l)/f;
}
else {
r += (1.0f-l)/f;
ml -= 1.0f;
f *= 2.0f;
for (l = ml; l >=1.0f; l-=1.0f) {
r += 1.0f/f;
f *= 2.0f;
}
if (l>0.0f)
r+= l/f;
sum += r*avgAbsNs;
}
}
#endif
return sum;
}
static PyObject *
py_noise4(PyObject *self, PyObject *args, PyObject *kwargs)
{
float x, y, z, w;
int octaves = 1;
float persistence = 0.5f;
float lacunarity = 2.0f;
static char *kwlist[] = {"x", "y", "z", "w", "octaves", "persistence", "lacunarity", NULL};
if (!PyArg_ParseTupleAndKeywords(args, kwargs, "ffff|iff:snoise4", kwlist,
&x, &y, &z, &w, &octaves, &persistence))
return NULL;
if (octaves == 1) {
// Single octave, return simple noise
return (PyObject *) PyFloat_FromDouble((double) noise4(x, y, z, w));
} else if (octaves > 1) {
return (PyObject *) PyFloat_FromDouble(
(double) fbm_noise4(x, y, z, w, octaves, persistence, lacunarity));
} else {
PyErr_SetString(PyExc_ValueError, "Expected octaves value > 0");
return NULL;
}
}
inline float
fbm_noise4(float x, float y, float z, float w, int octaves, float persistence, float lacunarity) {
float freq = 1.0f;
float amp = 1.0f;
float max = 1.0f;
float total = noise4(x, y, z, w);
int i;
for (i = 1; i < octaves; ++i) {
freq *= lacunarity;
amp *= persistence;
max += amp;
total += noise4(x * freq, y * freq, z * freq, w * freq) * amp;
}
return total / max;
}
void Noise::ComputeAvgValue() {
#ifdef DOAA
srand(1345);
Point3 p;
int i;
float sum = 0.0f;
filter = FALSE;
for (i=0; i<NAVG; i++) {
p.x = float(rand())/100.0f;
p.y = float(rand())/100.0f;
p.z = float(rand())/100.0f;
sum += NoiseFunction(p,levels,0.0f);
}
avgValue = sum/float(NAVG);
sum = 0.0f;
if (avgAbsNs<0.0f) {
#define NAVGNS 10000
float phase;
for (i=0; i<NAVGNS; i++) {
p.x = float(rand())/100.0f;
p.y = float(rand())/100.0f;
p.z = float(rand())/100.0f;
phase = float(rand())/100.0f;
sum += (float)fabs(noise4(p,phase));
}
avgAbsNs = sum/float(NAVGNS);
}
#endif
}
float Noise::NoiseFunction(Point3 p, float limitLev, float smWidth) {
float res(0.0f);
float lev = limitLev;
if (limitLev<(1.0f-BLENDBAND)) return avgValue;
if (lev<1.0f) lev = 1.0f;
switch (noiseType) {
case NOISE_TURB:
res = Turb(p,lev);
break;
case NOISE_REGULAR:
res = NOISE01(p);
break;
case NOISE_FRACTAL:
{
float sum = 0.0f;
float l, f = 1.0f;
for (l = lev; l >= 1.0f; l-=1.0f) {
sum += noise4(p*f,phase)/f;
f *= 2.0f;
}
if (l>0.0f)
sum += l*noise4(p*f,phase)/f;
res = 0.5f*(sum+1.0f);
}
break;
}
if (low<high) {
//res = threshold(res,low,high);
res = filter? SmoothThresh(res,low,high, smWidth): threshold(res,low,high);
}
if (res<0.0f) res = 0.0f;
else if (res>1.0f) res = 1.0f;
if (filter) {
if (limitLev<1.0f) {
float u = (limitLev+BLENDBAND-1.0f)/BLENDBAND;
res = u*res + (1.0f-u)*avgValue;
}
}
return res;
}
