FactoryCraft-Server/FactoryCraft/NoiseInterpolator.cpp

#include "NoiseInterpolator.h"

#include "Text.h"

using namespace Framework;

NoiseInterpolator::NoiseInterpolator(
    int seed, std::function<Noise*(int)> noiseSupplier, int width, int height)
    : Noise(),
      noiseSize(width, height),
      cache(
          10, [](int k) { return k; }, CacheCleanupStrategy::LONGEST_NOT_USED),
      noiseSupplier(noiseSupplier),
      seed(seed)
{}

double NoiseInterpolator::getRealNoise(double x, double y, double z)
{
    int ix = (int)ceil(x), iy = (int)ceil(y);
    int xOff = ix % noiseSize.x, yOff = iy % noiseSize.y;
    int xI = ix / noiseSize.x, yI = iy / noiseSize.y;
    if (ix < 0) xI--;
    if (iy < 0) yI--;
    int key = ((xI & 0xFFFF) << 16) | (yI & 0xFFFF);
    if (!cache.has(key))
        cache.put(key, RCPointer<Noise>::of(noiseSupplier(key + seed)));
    return cache.get(key)->getNoise(
        (xOff + 1 - (ix - x)), (yOff + 1 - (iy - y)), z);
}

double NoiseInterpolator::getNoise(double x, double y, double z)
{
    const double weights[6] = {0.32, 0.17, 0.09, 0.05, 0.03, 0.02};
    double sum = 0;
    for (int xi = -5; xi <= 5; xi++)
    {
        for (int yi = -5; yi <= 5; yi++)
            sum += getRealNoise(x + xi, y + yi, z) * weights[abs(xi)]
                 * weights[abs(yi)];
    }
    return sum;
}

int NoiseInterpolator::getSeed() const
{
    return seed;
}