97 lines
2.8 KiB
Plaintext
97 lines
2.8 KiB
Plaintext
|
/*
|
||
|
|
* 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_RMF_IPP
|
||
|
|
#error
|
||
|
|
#endif
|
||
|
|
#define __UTIL_NOISE_FRACTAL_RMF_IPP
|
||
|
|
|
||
|
|
|
||
|
|
namespace util { namespace noise { namespace fractal {
|
||
|
|
///////////////////////////////////////////////////////////////////////////
|
||
|
|
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;
|
||
|
|
}
|
||
|
|
} } }
|