libcruft-util/noise/fractal/hmf.ipp

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/*
* 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>
*/
#ifdef __UTIL_NOISE_FRACTAL_HMF_IPP
#error
#endif
#define __UTIL_NOISE_FRACTAL_HMF_IPP
namespace util { namespace noise { namespace fractal {
///////////////////////////////////////////////////////////////////////////
template <typename T, typename B>
hmf<T,B>::hmf (seed_t _seed,
unsigned _octaves,
T _H,
T _frequency,
T _lacunarity,
T _amplitude,
T _gain,
T _offset):
base<T,B> (_seed,
_octaves,
_H,
_frequency,
_lacunarity,
_amplitude,
_gain),
m_offset (_offset)
{ ; }
//-------------------------------------------------------------------------
template <typename T, typename B>
hmf<T,B>::hmf (seed_t _seed):
hmf<T,B> (_seed,
DEFAULT_OCTAVES,
DEFAULT_H,
DEFAULT_FREQUENCY,
DEFAULT_LACUNARITY,
DEFAULT_AMPLITUDE,
DEFAULT_GAIN,
DEFAULT_OFFSET)
{ ; }
///////////////////////////////////////////////////////////////////////////
template <typename T, typename B>
T
hmf<T,B>::operator() (util::point<2,T> p) const
{
T scale = this->m_invAH;
T result = 0;
T signal = 0;
T weight = 1;
p *= this->m_frequency;
for (size_t i = 0; i < this->m_octaves; ++i) {
signal = (this->m_basis (p) + m_offset) * scale;
result += signal * weight;
weight *= signal;
weight = min (weight, T{1});
scale *= this->m_invGH;
p += T{1};
p *= this->m_lacunarity;
}
return result;
}
} } }