/*
 * 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_HETERO_IPP
#error
#endif
#define __UTIL_NOISE_FRACTAL_HETERO_IPP

namespace util { namespace noise { namespace fractal {
    ///////////////////////////////////////////////////////////////////////////
    template <typename T, typename B>
    hetero<T,B>::hetero(seed_t _seed,
                        unsigned _octaves,
                        T _H,
                        T _frequency,
                        T _lacunarity,
                        T _amplitude,
                        T _gain):
        hetero<T,B> (_seed,
                     _octaves,
                     _H,
                     _frequency,
                     _lacunarity,
                     _amplitude,
                     _gain,
                     -this->basis ().bounds ().min + this->basis ().bounds ().magnitude () / T{2})
    { ; }


    //-------------------------------------------------------------------------
    template <typename T, typename B>
    hetero<T,B>::hetero(seed_t _seed,
                        unsigned _octaves,
                        T _H,
                        T _frequency,
                        T _lacunarity,
                        T _amplitude,
                        T _gain,
                        T _offset):
        base<T,B> (_seed,
                   _octaves,
                   _H,
                   _frequency,
                   _lacunarity,
                   _amplitude,
                   _gain),
        m_offset (_offset)
    { ; }


    //-------------------------------------------------------------------------
    template <typename T, typename B>
    hetero<T,B>::hetero (seed_t _seed):
        hetero<T,B> (_seed,
                    DEFAULT_OCTAVES,
                    DEFAULT_H,
                    DEFAULT_FREQUENCY,
                    DEFAULT_LACUNARITY,
                    DEFAULT_AMPLITUDE,
                    DEFAULT_GAIN,
                    DEFAULT_OFFSET)
    { ; }


    ///////////////////////////////////////////////////////////////////////////
    template <typename T, typename B>
    constexpr T
    hetero<T,B>::offset (void) const
    {
        return m_offset;
    }


    //-------------------------------------------------------------------------
    template <typename T, typename B>
    T
    hetero<T,B>::offset (T _offset)
    {
        return m_offset = _offset;
    }


    ///////////////////////////////////////////////////////////////////////////
    template <typename T, typename B>
    T
    hetero<T,B>::operator() (util::point<2,T> p) const
    {
        T scale = this->m_invAH;

        p *= this->m_frequency;
        T result = (this->m_basis (p) + m_offset) * scale;
        p *= this->m_lacunarity;

        T increment = 0;

        for (size_t i = 1; i < this->m_octaves; ++i) {
            scale *= this->m_invGH;

            increment  = this->m_basis (p) + m_offset;
            increment *= scale;
            increment *= result;

            result += increment;

            p += T{1};
            p *= this->m_lacunarity;
        }

        return result;
    }
} } }