66 lines
1.8 KiB
C++
66 lines
1.8 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>
|
|
*/
|
|
|
|
#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 ():
|
|
H (0.25f),
|
|
octaves (6),
|
|
frequency (0.1f),
|
|
lacunarity (2),
|
|
offset (0.7f),
|
|
amplitude (1),
|
|
gain (1)
|
|
{ ; }
|
|
|
|
|
|
//-------------------------------------------------------------------------
|
|
template <typename T, typename B>
|
|
constexpr T
|
|
hmf<T,B>::operator() (util::point<2,T> p) const
|
|
{
|
|
T exponents[octaves];
|
|
for (size_t i = 0; i < octaves; ++i)
|
|
exponents[i] = std::pow (std::pow (lacunarity, float (i)), -H);
|
|
|
|
T result = 0;
|
|
T signal = 0;
|
|
T weight = 1;
|
|
|
|
p *= frequency;
|
|
|
|
for (size_t i = 0; i < octaves; ++i) {
|
|
signal = (basis (p) + offset) * exponents[i];
|
|
result += weight * signal;
|
|
|
|
weight *= gain * signal;
|
|
if (weight > 1)
|
|
weight = 1;
|
|
|
|
p *= lacunarity;
|
|
}
|
|
|
|
return result;
|
|
}
|
|
} } }
|