Noise-1.0.0: libnoise/noise/src/module/perlin.h
// perlin.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_PERLIN_H
#define NOISE_MODULE_PERLIN_H
#include "modulebase.h"
namespace noise
{
namespace module
{
/// @addtogroup libnoise
/// @{
/// @addtogroup modules
/// @{
/// @addtogroup generatormodules
/// @{
/// Default frequency for the noise::module::Perlin noise module.
const double DEFAULT_PERLIN_FREQUENCY = 1.0;
/// Default lacunarity for the noise::module::Perlin noise module.
const double DEFAULT_PERLIN_LACUNARITY = 2.0;
/// Default number of octaves for the noise::module::Perlin noise module.
const int DEFAULT_PERLIN_OCTAVE_COUNT = 6;
/// Default persistence value for the noise::module::Perlin noise module.
const double DEFAULT_PERLIN_PERSISTENCE = 0.5;
/// Default noise quality for the noise::module::Perlin noise module.
const noise::NoiseQuality DEFAULT_PERLIN_QUALITY = QUALITY_STD;
/// Default noise seed for the noise::module::Perlin noise module.
const int DEFAULT_PERLIN_SEED = 0;
/// Maximum number of octaves for the noise::module::Perlin noise module.
const int PERLIN_MAX_OCTAVE = 30;
/// Noise module that outputs 3-dimensional Perlin noise.
///
/// @image html moduleperlin.png
///
/// Perlin noise is the sum of several coherent-noise functions of
/// ever-increasing frequencies and ever-decreasing amplitudes.
///
/// An important property of Perlin noise is that a small change in the
/// input value will produce a small change in the output value, while a
/// large change in the input value will produce a random change in the
/// output value.
///
/// This noise module outputs Perlin-noise values that usually range from
/// -1.0 to +1.0, but there are no guarantees that all output values will
/// exist within that range.
///
/// For a better description of Perlin noise, see the links in the
/// <i>References and Acknowledgments</i> section.
///
/// This noise module does not require any source modules.
///
/// <b>Octaves</b>
///
/// The number of octaves control the <i>amount of detail</i> of the
/// Perlin noise. Adding more octaves increases the detail of the Perlin
/// noise, but with the drawback of increasing the calculation time.
///
/// An octave is one of the coherent-noise functions in a series of
/// coherent-noise functions that are added together to form Perlin
/// noise.
///
/// An application may specify the frequency of the first octave by
/// calling the SetFrequency() method.
///
/// An application may specify the number of octaves that generate Perlin
/// noise by calling the SetOctaveCount() method.
///
/// These coherent-noise functions are called octaves because each octave
/// has, by default, double the frequency of the previous octave. Musical
/// tones have this property as well; a musical C tone that is one octave
/// higher than the previous C tone has double its frequency.
///
/// <b>Frequency</b>
///
/// An application may specify the frequency of the first octave by
/// calling the SetFrequency() method.
///
/// <b>Persistence</b>
///
/// The persistence value controls the <i>roughness</i> of the Perlin
/// noise. Larger values produce rougher noise.
///
/// The persistence value determines how quickly the amplitudes diminish
/// for successive octaves. The amplitude of the first octave is 1.0.
/// The amplitude of each subsequent octave is equal to the product of the
/// previous octave's amplitude and the persistence value. So a
/// persistence value of 0.5 sets the amplitude of the first octave to
/// 1.0; the second, 0.5; the third, 0.25; etc.
///
/// An application may specify the persistence value by calling the
/// SetPersistence() method.
///
/// <b>Lacunarity</b>
///
/// The lacunarity specifies the frequency multipler between successive
/// octaves.
///
/// The effect of modifying the lacunarity is subtle; you may need to play
/// with the lacunarity value to determine the effects. For best results,
/// set the lacunarity to a number between 1.5 and 3.5.
///
/// <b>References & acknowledgments</b>
///
/// <a href=http://www.noisemachine.com/talk1/>The Noise Machine</a> -
/// From the master, Ken Perlin himself. This page contains a
/// presentation that describes Perlin noise and some of its variants.
/// He won an Oscar for creating the Perlin noise algorithm!
///
/// <a
/// href=http://freespace.virgin.net/hugo.elias/models/m_perlin.htm>
/// Perlin Noise</a> - Hugo Elias's webpage contains a very good
/// description of Perlin noise and describes its many applications. This
/// page gave me the inspiration to create libnoise in the first place.
/// Now that I know how to generate Perlin noise, I will never again use
/// cheesy subdivision algorithms to create terrain (unless I absolutely
/// need the speed.)
///
/// <a
/// href=http://www.robo-murito.net/code/perlin-noise-math-faq.html>The
/// Perlin noise math FAQ</a> - A good page that describes Perlin noise in
/// plain English with only a minor amount of math. During development of
/// libnoise, I noticed that my coherent-noise function generated terrain
/// with some "regularity" to the terrain features. This page describes a
/// better coherent-noise function called <i>gradient noise</i>. This
/// version of noise::module::Perlin uses gradient coherent noise to
/// generate Perlin noise.
class Perlin: public Module
{
public:
/// Constructor.
///
/// The default frequency is set to
/// noise::module::DEFAULT_PERLIN_FREQUENCY.
///
/// The default lacunarity is set to
/// noise::module::DEFAULT_PERLIN_LACUNARITY.
///
/// The default number of octaves is set to
/// noise::module::DEFAULT_PERLIN_OCTAVE_COUNT.
///
/// The default persistence value is set to
/// noise::module::DEFAULT_PERLIN_PERSISTENCE.
///
/// The default seed value is set to
/// noise::module::DEFAULT_PERLIN_SEED.
Perlin ();
/// Returns the frequency of the first octave.
///
/// @returns The frequency of the first octave.
double GetFrequency () const
{
return m_frequency;
}
/// Returns the lacunarity of the Perlin noise.
///
/// @returns The lacunarity of the Perlin noise.
///
/// The lacunarity is the frequency multiplier between successive
/// octaves.
double GetLacunarity () const
{
return m_lacunarity;
}
/// Returns the quality of the Perlin noise.
///
/// @returns The quality of the Perlin noise.
///
/// See noise::NoiseQuality for definitions of the various
/// coherent-noise qualities.
noise::NoiseQuality GetNoiseQuality () const
{
return m_noiseQuality;
}
/// Returns the number of octaves that generate the Perlin noise.
///
/// @returns The number of octaves that generate the Perlin noise.
///
/// The number of octaves controls the amount of detail in the Perlin
/// noise.
int GetOctaveCount () const
{
return m_octaveCount;
}
/// Returns the persistence value of the Perlin noise.
///
/// @returns The persistence value of the Perlin noise.
///
/// The persistence value controls the roughness of the Perlin noise.
double GetPersistence () const
{
return m_persistence;
}
/// Returns the seed value used by the Perlin-noise function.
///
/// @returns The seed value.
int GetSeed () const
{
return m_seed;
}
virtual int GetSourceModuleCount () const
{
return 0;
}
virtual double GetValue (double x, double y, double z) const;
/// Sets the frequency of the first octave.
///
/// @param frequency The frequency of the first octave.
void SetFrequency (double frequency)
{
m_frequency = frequency;
}
/// Sets the lacunarity of the Perlin noise.
///
/// @param lacunarity The lacunarity of the Perlin noise.
///
/// The lacunarity is the frequency multiplier between successive
/// octaves.
///
/// For best results, set the lacunarity to a number between 1.5 and
/// 3.5.
void SetLacunarity (double lacunarity)
{
m_lacunarity = lacunarity;
}
/// Sets the quality of the Perlin noise.
///
/// @param noiseQuality The quality of the Perlin noise.
///
/// See noise::NoiseQuality for definitions of the various
/// coherent-noise qualities.
void SetNoiseQuality (noise::NoiseQuality noiseQuality)
{
m_noiseQuality = noiseQuality;
}
/// Sets the number of octaves that generate the Perlin noise.
///
/// @param octaveCount The number of octaves that generate the Perlin
/// noise.
///
/// @pre The number of octaves ranges from 1 to
/// noise::module::PERLIN_MAX_OCTAVE.
///
/// @throw noise::ExceptionInvalidParam An invalid parameter was
/// specified; see the preconditions for more information.
///
/// The number of octaves controls the amount of detail in the Perlin
/// noise.
///
/// The larger the number of octaves, the more time required to
/// calculate the Perlin-noise value.
void SetOctaveCount (int octaveCount)
{
if (octaveCount < 1 || octaveCount > PERLIN_MAX_OCTAVE) {
throw noise::ExceptionInvalidParam ();
}
m_octaveCount = octaveCount;
}
/// Sets the persistence value of the Perlin noise.
///
/// @param persistence The persistence value of the Perlin noise.
///
/// The persistence value controls the roughness of the Perlin noise.
///
/// For best results, set the persistence to a number between 0.0 and
/// 1.0.
void SetPersistence (double persistence)
{
m_persistence = persistence;
}
/// Sets the seed value used by the Perlin-noise function.
///
/// @param seed The seed value.
void SetSeed (int seed)
{
m_seed = seed;
}
protected:
/// Frequency of the first octave.
double m_frequency;
/// Frequency multiplier between successive octaves.
double m_lacunarity;
/// Quality of the Perlin noise.
noise::NoiseQuality m_noiseQuality;
/// Total number of octaves that generate the Perlin noise.
int m_octaveCount;
/// Persistence of the Perlin noise.
double m_persistence;
/// Seed value used by the Perlin-noise function.
int m_seed;
};
/// @}
/// @}
/// @}
}
}
#endif