view src/Modules/Output/Graphics/Scale/Scale.h @ 227:73c6d61440ad

- First add of a lot of graphics code from the old version. Not working yet, not even compiling yet.

/*!
 * \file
 * \brief General definition for frequency scale management
 *
 * \author Willem van Engen <[e-mail]>
 * \date created 2006/09/26
 * \version \$Id: Scale.h 576 2008-05-29 12:51:16Z tom $
 */
/* (c) 2006, University of Cambridge, Medical Research Council
 * http://www.pdn.cam.ac.uk/groups/cnbh/aimmanual
 */
#ifndef __MODULE_SCALE_H__
#define __MODULE_SCALE_H__

#include "Support/SignalBank.h"

/*!
 * \class Scale "Modules/Scale/Scale.h"
 * \brief General class for frequency scale management
 *
 * This class
 *   - Converts between a linear and specified scale
 *   - Creates filterbank signals based on that scale
 *   - Creates any of the children filterbanks with Scale::Create.
 * To create a new scale, all you need to do is override ToLinear() and
 * FromLinear(). See existing scales like ScaleERB for example:
 */
class Scale;
class Scale {
public:
	//! \brief A list of possible scales
	enum ScaleType {
		SCALE_LINEAR, SCALE_ERB, SCALE_LOG, SCALE_LOGSCALED
	};
	/*! \brief Create a new scale based on type
	 *  \param iType Scale type to create
	 *  \param min Bottom frequency
	 *  \param max Top frequency
	 *  \param density Density of distribution on the scale (scale-dependent)
	 *  \return Newly created scale, to be freed by the caller.
	 *
	 *  This is on purpose no virtual function, always use it Scale::Create().
	 *  \todo Split into scaling and filterbank creation parts.
	 *        Maybe even a separate ScaleMaker that implements Create().
	 */
	static Scale *Create(ScaleType iType, unsigned int min, unsigned int max, float density);

	/*! \overload
	 *  This function is for scaling-only Scales, you must not create a SignalBank
     *  with the returned Scale.
	 */
	static Scale *Create(ScaleType iType);

	/*! \brief Create a new Scale
	 *  \param min Bottom frequency
	 *  \param max Top frequency
	 *  \param density Density of distribution on the scale (scale-dependent)
	 */
	Scale(unsigned int min, unsigned int max, float density) {
		m_iMin = min;
		m_iMax = max;
		m_fDensity = density;
		m_sName = NULL;
	};

	virtual ~Scale() { };

	/*! \brief Create an exact copy of this Scale
	 *  \return A newly created Scale, to be freed by the caller.
	 */
	virtual Scale *Clone();

	//! \return this Signal's ScaleType
	ScaleType getType() { return m_iType; };
	//! \return this Signal's name
	const char *getName() { return m_sName; };

	/*! \brief Scale a frequency from linear to this scale
	 *  \param fFreq Frequency to scale
	 *  \return Scaled frequency
	 */
	virtual float FromLinear(float fFreq) = 0;

	/*! \brief Scale a frequency from this scale to linear
	 *  \param fFreq Scaled frequency to scale back
	 *  \return Linear frequency
	 */
	virtual float ToLinear(float fFreq) = 0;

	/*! \brief Scale from [fMin..fMax] to [-0.5..0.5]
	 *  \param fVal Value to scale, must be within [fMin..fMax]
	 *  \return Float in [-0.5..0.5] according to this scale
	 *  \sa FromLinearScaledExtrema
	 *
	 *  This is mainly for displaying any value on a scale and to make sure
	 *  that it fits in on screen. Don't use this for any real maths!
	 *
	 *  The default implementation assumes that the scale is monotonic, so the
	 *  FromLinear(fMin) and FromLinear(fMax) are scale's output boundaries.
	 *
	 *  fMin and fMax are set by FromLinearScaledExtrema. Do not use this before
	 *  calling that.
	 */
	float FromLinearScaled(float fVal);
	/*! \brief Update the FromLinearScaled min/max values
	 *  \param fMin Minimum value to be input
	 *  \param fMax Maxmimum value to be input
	 *  \sa FromLinearScaled
	 */
	void FromLinearScaledExtrema(float fMin, float fMax);
	/*! \overload
	 *  \brief Copy min/max values from another Scale
	 *  \param pScale Scale from which to copy min/max values, must not be NULL
	 */
	void FromLinearScaledExtrema(Scale *pScale);

	/*! \brief Create a new signal bank
	 *  \param iChannels Number of audio channels
	 *  \param iBufferlength Length of the buffer in frames
	 *  \param iSamplerate Samplerate in Hz
	 *  Note that the caller must free the signal bank again.
	 */
	virtual SignalBank* CreateSignalBank(unsigned int iChannels, unsigned int iBufferlength, unsigned int iSamplerate);

	/*! \overload
	 *  \brief Create a signal bank based on a Signal's parameters
	 *  \param pSig Signal to get parameters from
	 *  pSig is only used to look at parameters like samplerate, nothing is done
	 *  with its contents.
	 *  Note that the caller must free the signal bank again.
	 */
	virtual SignalBank* CreateSignalBank(/*! \todo const*/ Signal* pSig);


protected:
	//! \brief Bottom frequency
	unsigned int m_iMin;
	//! \brief Top frequency
	unsigned int m_iMax;
	//! \brief Density of distribution on the scale (scale-dependent)
	float m_fDensity;
	//! \brief The type of this scale, used by Clone(); set this in children.
	ScaleType m_iType;
	//! \brief The name of this scale; set this in children.
	const char *m_sName;

	/*! \brief Minimum value for scaling as input
	 *  \sa FromLinearScaled(), FromLinearScaledExtrema() */
	float m_fMin;
	/*! \brief Maximum value for scaling as input
	 *  \sa FromLinearScaled(), FromLinearScaledExtrema() */
	float m_fMax;
	//! \brief Value used in FromLinearScaled
	float m_fScaledCurHalfSum;
	//! \brief Value used in FromLinearScaled
	float m_fScaledCurDiff;
};

#endif /* __MODULE_SCALE_H__ */