libcruft-util/noise/fractal/rmf.hpp
Danny Robson 6278902e3e n/fractal: use a common base class
some working variables need to be precomputed. it makes sense to do this
in a base class.
2015-06-02 16:13:12 +10:00

68 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_RMF_HPP
#define __UTIL_NOISE_FRACTAL_RMF_HPP
#include <cstdint>
#include "base.hpp"
#include "../../point.hpp"
namespace util { namespace noise { namespace fractal {
/// Rigid Multifractal summation, based on Musgrave's algorithm
///
/// octaves: count of layers to be summed
/// H: hurst parameter (~roughness)
/// offset: TODO
/// frequency: point scaling factor for the base octave
/// lacunarity: incremental octave frequency scaling factor
/// amplitude: value scaling factor for the base octave
/// gain: incremental octave value scaling factor
template <typename T, typename B>
struct rmf : public base<T,B> {
using seed_t = typename base<T,B>::seed_t;
static constexpr unsigned DEFAULT_OCTAVES = 5;
static constexpr T DEFAULT_H = 1;
static constexpr T DEFAULT_OFFSET = 1;
static constexpr T DEFAULT_FREQUENCY = 1;
static constexpr T DEFAULT_LACUNARITY = 2;
static constexpr T DEFAULT_AMPLITUDE = 2;
static constexpr T DEFAULT_GAIN = 1 / DEFAULT_LACUNARITY;
rmf (seed_t,
unsigned octaves,
T H,
T frequency,
T lacunarity,
T amplitude,
T gain,
T offset);
rmf (seed_t);
constexpr T operator() (util::point<2,T>) const;
private:
T m_offset;
};
} } }
#include "rmf.ipp"
#endif