axmol/extensions/Particle3D/ParticleUniverse/CCPUParticle3DNoise.cpp

/****************************************************************************
 Copyright (C) 2013 Henry van Merode. All rights reserved.
 Copyright (c) 2015 Chukong Technologies Inc.
 
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 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.
 
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#include "CCPUParticle3DNoise.h"

NS_CC_BEGIN

    static int permutation[] = { 151,160,137,91,90,15,
    131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
    190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
    88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
    77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
    102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
    135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
    5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
    223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
    129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
    251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
    49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
    138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180
};

//-----------------------------------------------------------------------
PUNoise3D::PUNoise3D(void) : 
    _octaves(2),
    _frequency(1.0f),
    _amplitude(1.0f),
    _persistence(1.0f)
{
}
//-----------------------------------------------------------------------
PUNoise3D::~PUNoise3D(void)
{
}
//-----------------------------------------------------------------------
void PUNoise3D::initialise(unsigned short octaves, double frequency, double amplitude, double persistence)
{
    _octaves = octaves;
    _frequency = frequency;
    _amplitude = amplitude;
    _persistence = persistence;

    for (int i = 0; i < 256; ++i)
    {
        _p[i] = permutation[i];
        _p[256+i] = permutation[i];
    }
}
//-----------------------------------------------------------------------
//void Noise3D::noise2img(unsigned short dimension)
//{
//	double x = 0.0;
//	double y = 0.0;
//	double step = 1.0 / (double)dimension;
//	size_t buffSize = 4 * dimension * dimension; // Assume Image of pixelformat 32 bits (i.e. PF_R8G8B8A8)
//	unsigned char* buff = new (std::nothrow) unsigned char[buffSize];
//	size_t p = 0;
//	while (p < buffSize)
//	{
//		unsigned char n = (unsigned char)(255 * noise(x, y, 0.5));
//		buff[p] = n;
//		buff[p+1] = n;
//		buff[p+2] = n;
//		buff[p+3] = n;
//		p += 4;
//
//		x += step;
//		if (x >= 1.0)
//		{
//			x = 0.0;
//			y += step;
//		}
//	}
//	Ogre::Image* image = new (std::nothrow) Ogre::Image();
//	image->loadDynamicImage(buff, dimension, dimension, 0, Ogre::PF_R8G8B8A8 , false, 1, 0);
//	image->save("noise2img.png");
//	delete image;
//	delete [] buff;
//}
//-----------------------------------------------------------------------
double PUNoise3D::noise(const Vec3& position)
{
    return noise(position.x, position.y, position.z);
}
//-----------------------------------------------------------------------
double PUNoise3D::noise(double x, double y, double z)
{
    double n = 0;
    double freq = _frequency;
    double ampl = _amplitude;
    for (unsigned short u = 0; u < _octaves; ++u) 
    { 
        n += genNoise(x * freq, y * freq, z * freq) * ampl;
        freq *= 2;
        ampl *= _persistence;
    }
    return n;
}
//-----------------------------------------------------------------------
double PUNoise3D::genNoise(double x, double y, double z)
{
    int X = (int)floor(x) & 255;
    int Y = (int)floor(y) & 255;
    int Z = (int)floor(z) & 255;
    x -= floor(x);
    y -= floor(y);
    z -= floor(z);
    double u = fade(x);
    double v = fade(y);
    double w = fade(z);
    int A = _p[X  ]+Y, AA = _p[A]+Z, AB = _p[A+1]+Z;
    int B = _p[X+1]+Y, BA = _p[B]+Z, BB = _p[B+1]+Z;

    double lrp = lerp(w,	lerp(v, lerp(u, grad(_p[AA], x, y, z),
        grad(_p[BA], x-1, y, z)),
        lerp(u, grad(_p[AB], x, y-1, z),
        grad(_p[BB], x-1, y-1, z))),
        lerp(v, lerp(u, grad(_p[AA+1], x, y  , z-1),
        grad(_p[BA+1], x-1, y, z-1)),
        lerp(u, grad(_p[AB+1], x, y-1, z-1),
        grad(_p[BB+1], x-1, y-1, z-1))));
    return fabs(lrp); // Use absolute value, because lrp in between [-1, 1]
}
//-----------------------------------------------------------------------
double PUNoise3D::fade(double t)
{
    return t * t * t * (t * (t * 6 - 15) + 10);
}
//-----------------------------------------------------------------------
double PUNoise3D::lerp(double t, double a, double b)
{
    return a + t * (b - a);
}
//-----------------------------------------------------------------------
double PUNoise3D::grad(int hash, double x, double y, double z)
{
    int h = hash & 15;
    double u = h<8 ? x : y;
    double v = h<4 ? y : h==12||h==14 ? x : z;
    return ((h&1) == 0 ? u : -u) + ((h&2) == 0 ? v : -v);
}

NS_CC_END