FLOAT32 CFrmPerlin::TileableNoise2(const FLOAT32 x, const FLOAT32 y, const FLOAT32 w, const FLOAT32 h)
{
return ( Noise2( x, y ) * ( w - x )* ( h - y ) +
Noise2( x - w, y ) * x * ( h - y ) +
Noise2( x, y - h ) * ( w - x )* y +
Noise2( x - w, y - h ) * x * y ) / ( w * h );
}
/*!
* Multiband Noise 2D
* @param[in] p[2] 2D座標
* @param[in] s
* @param[in] firstBand 最初のバンド
* @param[in] nbands バンド数
* @param[in] w 重み
* @return
*/
RXREAL rxWaveletNoise::MultibandNoise2(RXREAL p[2], int first, int nbands, RXREAL *w0)
{
// HACK:WMultibandNoise2
RXREAL result = 0;
RXREAL w = pow((RXREAL)2.0, (RXREAL)first);
RXREAL q[2];
for(int b = 0; b < nbands; ++b){
q[0] = p[0]*w;
q[1] = p[1]*w;
result += w0[b]*Noise2(q);
w *= 2.0;
}
RXREAL sigma_m = 0;
for(int b = 0; b < nbands; ++b){
sigma_m += w0[b]*w0[b];
}
// B-Splineの平均分散σNは2Dで0.265，3Dで0.210，2D上へ投影した3Dノイズで0.296
RXREAL sigma_n = 0.265;
sigma_m = sqrt(sigma_n*sigma_m);
// 分散が1になるようにノイズを調整
if(sigma_m) result /= sigma_m;
return result;
}
float InterpolatedNoise2(float x, float y) {
int integer_X = int(x);
float fractional_X = x - integer_X;
int integer_Y = int(y);
float fractional_Y = y - integer_Y;
float v1 = Noise2(integer_X, integer_Y);
float v2 = Noise2(integer_X + 1, integer_Y);
float v3 = Noise2(integer_X, integer_Y + 1);
float v4 = Noise2(integer_X + 1, integer_Y + 1);
float i1 = Interpolate(v1, v2, fractional_X);
float i2 = Interpolate(v3, v4, fractional_X);
return Interpolate(i1, i2, fractional_Y);
}
//[-------------------------------------------------------]
//[ Public static functions ]
//[-------------------------------------------------------]
float PerlinNoiseTurbulence::Turbulence2(float fX, float fY, float fFreq)
{
float t = 0.0f;
do {
t += Noise2(fFreq*fX, fFreq*fY)/fFreq;
fFreq *= 0.5f;
} while (fFreq >= 1.0f);
return t;
}
FLOAT32 CFrmPerlin::Turbulence2( const FLOAT32 x, const FLOAT32 y, FLOAT32 fFreq )
{
FLOAT32 t = 0.0f;
do
{
t += Noise2(fFreq * x, fFreq * y) / fFreq;
fFreq *= 0.5f;
} while (fFreq >= 1.0f);
return t;
}
float GNoise::Noise(float vec[], int len)
{
switch (len)
{
case 0:
return 0.;
case 1:
return Noise1(vec[0]);
case 2:
return Noise2(vec);
default:
return Noise3(vec);
}
}
float GNoise::Perlin_Noise_2D(float vec[2])
{
int terms = m_iOctaves;
float freq = m_fFrequency;
float result = 0.0f;
float amp = m_fAmplitude;
vec[0]*=m_fFrequency;
vec[1]*=m_fFrequency; for( int i=0; i<terms; i++ )
{
result += Noise2(vec)*amp;
vec[0] *= 2.0f;
vec[1] *= 2.0f;
amp*=0.5f;
}
return result;
}
//----------------------------------------------------------------------------
float FvPerlinNoise::SumHarmonics2(const FvVector2& kVector,
float fPersistence, float fFrequency, float fIterations)
{
FvVector2 kCurrent(kVector);
kCurrent *= fFrequency;
FvVector2 kNormal(kVector);
kNormal.Normalise();
kNormal *= fFrequency;
float fSum = 0.f;
float fScale = 1.f;
float i = 0.f;
while (i < fIterations)
{
fSum += (fScale * Noise2(kCurrent));
fScale *= fPersistence;
kNormal += kNormal;
i += 1.f;
kCurrent += kNormal;
}
return fSum + 0.5f;
}
float SmoothNoise2(int x, int y) {
return (Noise2(x-1, y-1) + Noise2(x+1, y-1) + Noise2(x-1, y+1) + Noise2(x+1, y+1)) / 16.0f +
(Noise2(x-1, y) + Noise2(x, y-1) + Noise2(x+1, y) + Noise2(x, y+1)) / 8.0f +
Noise2(x, y) / 4.0f;
}
double
SVGFETurbulenceElement::Turbulence(int aColorChannel, double* aPoint,
double aBaseFreqX, double aBaseFreqY,
int aNumOctaves, bool aFractalSum,
bool aDoStitching,
double aTileX, double aTileY,
double aTileWidth, double aTileHeight)
{
StitchInfo stitch;
StitchInfo *stitchInfo = NULL; // Not stitching when NULL.
// Adjust the base frequencies if necessary for stitching.
if (aDoStitching) {
// When stitching tiled turbulence, the frequencies must be adjusted
// so that the tile borders will be continuous.
if (aBaseFreqX != 0.0) {
double loFreq = double (floor(aTileWidth * aBaseFreqX)) / aTileWidth;
double hiFreq = double (ceil(aTileWidth * aBaseFreqX)) / aTileWidth;
if (aBaseFreqX / loFreq < hiFreq / aBaseFreqX)
aBaseFreqX = loFreq;
else
aBaseFreqX = hiFreq;
}
if (aBaseFreqY != 0.0) {
double loFreq = double (floor(aTileHeight * aBaseFreqY)) / aTileHeight;
double hiFreq = double (ceil(aTileHeight * aBaseFreqY)) / aTileHeight;
if (aBaseFreqY / loFreq < hiFreq / aBaseFreqY)
aBaseFreqY = loFreq;
else
aBaseFreqY = hiFreq;
}
// Set up initial stitch values.
stitchInfo = &stitch;
stitch.mWidth = int (aTileWidth * aBaseFreqX + 0.5f);
stitch.mWrapX = int (aTileX * aBaseFreqX + sPerlinN + stitch.mWidth);
stitch.mHeight = int (aTileHeight * aBaseFreqY + 0.5f);
stitch.mWrapY = int (aTileY * aBaseFreqY + sPerlinN + stitch.mHeight);
}
double sum = 0.0f;
double vec[2];
vec[0] = aPoint[0] * aBaseFreqX;
vec[1] = aPoint[1] * aBaseFreqY;
double ratio = 1;
for (int octave = 0; octave < aNumOctaves; octave++) {
if (aFractalSum)
sum += double (Noise2(aColorChannel, vec, stitchInfo) / ratio);
else
sum += double (fabs(Noise2(aColorChannel, vec, stitchInfo)) / ratio);
vec[0] *= 2;
vec[1] *= 2;
ratio *= 2;
if (stitchInfo != NULL) {
// Update stitch values. Subtracting sPerlinN before the multiplication
// and adding it afterward simplifies to subtracting it once.
stitch.mWidth *= 2;
stitch.mWrapX = 2 * stitch.mWrapX - sPerlinN;
stitch.mHeight *= 2;
stitch.mWrapY = 2 * stitch.mWrapY - sPerlinN;
}
}
return sum;
}
inline double Smooth(int i, int j)
{
return (double)(Noise2(i, j)+Noise2(i+1, j)+Noise2(i, j+1)+Noise2(i+1, j+1))/4;
}