libcruft-util/noise/fractal/fbm.ipp

/*
 * 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,
 * WITHOUvalue_t 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_FBM_IPP
#error
#endif
#define __UTIL_NOISE_FRACTAL_FBM_IPP

#include "../../debug.hpp"

namespace util { namespace noise { namespace fractal {
    ///////////////////////////////////////////////////////////////////////////
    template <class B>
    fbm<B>::fbm (seed_t _seed,
                 unsigned _octaves,
                 value_t        _H,
                 value_t        _frequency,
                 value_t        _lacunarity,
                 value_t        _amplitude,
                 value_t        _gain):
        base<B> (_seed,
                 _octaves,
                 _H,
                 _frequency,
                 _lacunarity,
                 _amplitude,
                 _gain)
    { ; }


    //-------------------------------------------------------------------------
    template <class B>
    fbm<B>::fbm (seed_t _seed):
        fbm<B> (_seed,
                DEFAULT_OCTAVES,
                DEFAULT_H,
                DEFAULT_FREQUENCY,
                DEFAULT_LACUNARITY,
                DEFAULT_AMPLITUDE,
                DEFAULT_GAIN)
    { ; }


    ///////////////////////////////////////////////////////////////////////////
    template <class B>
    typename fbm<B>::value_t
    fbm<B>::operator() (point_t p) const noexcept
    {
        value_t total = 0;
        value_t scale = this->m_invAH;

        p *= this->m_frequency;

        for (size_t i = 0; i < this->m_octaves; ++i) {
            total += this->m_basis (p) * scale;

            p += PI<value_t>;
            p *= this->m_lacunarity;
            scale *= this->m_invGH;
        }

        return total;
    }
} } }