// exponent.h
//
// Copyright (C) 2003, 2004 Jason Bevins
//
// This library is free software; you can redistribute it and/or modify it
// under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation; either version 2.1 of the License, or (at
// your option) any later version.
//
// This library is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
// License (COPYING.txt) for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this library; if not, write to the Free Software Foundation,
// Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
// The developer's email is jlbezigvins@gmzigail.com (for great email, take
// off every 'zig'.)
//

#ifndef NOISE_MODULE_EXPONENT_H
#define NOISE_MODULE_EXPONENT_H

#include "modulebase.h"

namespace noise
{

    namespace module
    {

        /// @addtogroup libnoise
        /// @{

        /// @addtogroup modules
        /// @{

        /// @addtogroup modifiermodules
        /// @{

        /// Default exponent for the noise::module::Exponent noise module.
        const double DEFAULT_EXPONENT = 1.0;

        /// Noise module that maps the output value from a source module onto an
        /// exponential curve.
        ///
        /// @image html moduleexponent.png
        ///
        /// Because most noise modules will output values that range from -1.0 to
        /// +1.0, this noise module first normalizes this output value (the range
        /// becomes 0.0 to 1.0), maps that value onto an exponential curve, then
        /// rescales that value back to the original range.
        ///
        /// This noise module requires one source module.
        class Exponent : public ModuleBase
        {

        public:
            /// Constructor.
            ///
            /// The default exponent is set to noise::module::DEFAULT_EXPONENT.
            Exponent();

            /// Returns the exponent value to apply to the output value from the
            /// source module.
            ///
            /// @returns The exponent value.
            ///
            /// Because most noise modules will output values that range from -1.0
            /// to +1.0, this noise module first normalizes this output value (the
            /// range becomes 0.0 to 1.0), maps that value onto an exponential
            /// curve, then rescales that value back to the original range.
            double GetExponent() const
            {
                return m_exponent;
            }

            virtual double getValue(double x, double y, double z) const;

            /// Sets the exponent value to apply to the output value from the
            /// source module.
            ///
            /// @param exponent The exponent value.
            ///
            /// Because most noise modules will output values that range from -1.0
            /// to +1.0, this noise module first normalizes this output value (the
            /// range becomes 0.0 to 1.0), maps that value onto an exponential
            /// curve, then rescales that value back to the original range.
            void SetExponent(double exponent)
            {
                m_exponent = exponent;
            }

        protected:
            /// Exponent to apply to the output value from the source module.
            double m_exponent;
        };

        /// @}

        /// @}

        /// @}

    } // namespace module

} // namespace noise

#endif
