libcruft-util/noise/fractal/fbm.hpp

70 lines
2.0 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>
*/
#ifndef __UTIL_NOISE_FRACTAL_FBM_HPP
#define __UTIL_NOISE_FRACTAL_FBM_HPP
#include <cstdint>
#include "../../point.hpp"
namespace util { namespace noise { namespace fractal {
/// Fractal Brownian Motion summation.
///
/// Sum progressive layers of a noise basis with scaling frequency
/// and amplitude.
///
/// octaves: count of layers to be summed
/// frequency: point scaling factor for the base octave
/// lacunarity: per octave frequency scaling factor
/// amplitude: maximum absolute value of the noise
/// gain: per octave amplitude scaling factor. typically 1/f.
template <typename T, typename B>
struct fbm {
using seed_t = uint64_t;
static constexpr unsigned DEFAULT_OCTAVES = 8;
static constexpr T DEFAULT_FREQUENCY = T(0.1);
static constexpr T DEFAULT_LACUNARITY = 2;
static constexpr T DEFAULT_AMPLITUDE = 1;
static constexpr T DEFAULT_GAIN = 1 / T(2);
fbm (unsigned octaves,
T frequency,
T lacunarity,
T amplitude,
T gain,
seed_t seed);
fbm ();
seed_t seed;
unsigned octaves;
T frequency;
T lacunarity;
T amplitude;
T gain;
B basis;
constexpr T operator() (util::point<2,T>) const;
};
} } }
#include "fbm.ipp"
#endif