libcruft-util/noise/fractal/rmf.cpp

114 lines
3.8 KiB
C++

/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2012-2015 Danny Robson <danny@nerdcruft.net>
*/
#include "rmf.hpp"
#include "../basis/constant.hpp"
#include "../basis/perlin.hpp"
#include "../basis/value.hpp"
#include "../basis/worley.hpp"
#include "../lerp.hpp"
using util::noise::fractal::rmf;
///////////////////////////////////////////////////////////////////////////////
template <typename T, typename B>
rmf<T,B>::rmf (unsigned _octaves,
T _frequency,
T _lacunarity,
T _amplitude,
T _gain,
seed_t _seed):
seed (_seed),
octaves (_octaves),
frequency (_frequency),
lacunarity (_lacunarity),
amplitude (_amplitude),
gain (_gain),
basis (_seed)
{ ; }
//-----------------------------------------------------------------------------
template <typename T, typename B>
rmf<T,B>::rmf ():
rmf<T,B> (DEFAULT_OCTAVES,
DEFAULT_FREQUENCY,
DEFAULT_LACUNARITY,
DEFAULT_AMPLITUDE,
DEFAULT_GAIN,
rand ())
{ ; }
//-----------------------------------------------------------------------------
template <typename T, typename B>
T
rmf<T,B>::operator() (util::point<2,T> p) const {
const T offset = 1;
const T H = 1.f;
T exponents[octaves];
for (size_t i = 0; i < octaves; ++i)
exponents[i] = std::pow (std::pow (lacunarity, float (i)), -H);
T signal = 0;
T result = 0;
T weight = 1;
p *= frequency;
for (size_t i = 0; i < octaves; ++i) {
// generates ridged noise
signal = basis (p);
signal = std::fabs (signal);
signal = offset - signal;
// sharpens the ridges
signal *= signal;
// influence by sharpness of previous iteration
signal *= weight;
// contribute to the weight
weight = signal * gain;
weight = limit (weight, 0, 1);
// record and continue
result += signal * exponents[i];
p *= lacunarity;
}
return result;
}
//-----------------------------------------------------------------------------
template struct util::noise::fractal::rmf<float, util::noise::basis::worley<float>>;
template struct util::noise::fractal::rmf<float, util::noise::basis::perlin<float,util::lerp::linear>>;
template struct util::noise::fractal::rmf<float, util::noise::basis::perlin<float,util::lerp::cubic>>;
template struct util::noise::fractal::rmf<float, util::noise::basis::perlin<float,util::lerp::quintic>>;
template struct util::noise::fractal::rmf<float, util::noise::basis::value<float,util::lerp::linear>>;
template struct util::noise::fractal::rmf<float, util::noise::basis::value<float,util::lerp::quintic>>;
template struct util::noise::fractal::rmf<double, util::noise::basis::worley<double>>;
template struct util::noise::fractal::rmf<double, util::noise::basis::perlin<double,util::lerp::linear>>;
template struct util::noise::fractal::rmf<double, util::noise::basis::perlin<double,util::lerp::quintic>>;
template struct util::noise::fractal::rmf<double, util::noise::basis::value<double,util::lerp::linear>>;
template struct util::noise::fractal::rmf<double, util::noise::basis::value<double,util::lerp::quintic>>;