godot/servers/audio/effects/eq.h
2017-01-21 19:01:00 -03:00

107 lines
1.3 KiB
C++

//
// C++ Interface: eq
//
// Description:
//
//
// Author: reduzio@gmail.com (C) 2006
//
// Copyright: See COPYING file that comes with this distribution
//
//
#ifndef EQ_FILTER_H
#define EQ_FILTER_H
#include "typedefs.h"
#include "vector.h"
/**
@author Juan Linietsky
*/
class EQ {
public:
enum Preset {
PRESET_6_BANDS,
PRESET_8_BANDS,
PRESET_10_BANDS,
PRESET_21_BANDS,
PRESET_31_BANDS
};
class BandProcess {
friend class EQ;
float c1,c2,c3;
struct History {
float a1,a2,a3;
float b1,b2,b3;
} history;
public:
inline void process_one(float & p_data);
BandProcess();
};
private:
struct Band {
float freq;
float c1,c2,c3;
};
Vector<Band> band;
float mix_rate;
void recalculate_band_coefficients();
public:
void set_mix_rate(float p_mix_rate);
int get_band_count() const;
void set_preset_band_mode(Preset p_preset);
void set_bands(const Vector<float>& p_bands);
BandProcess get_band_processor(int p_band) const;
float get_band_frequency(int p_band);
EQ();
~EQ();
};
/* Inline Function */
inline void EQ::BandProcess::process_one(float & p_data) {
history.a1=p_data;
history.b1= c1 * ( history.a1 - history.a3 )
+ c3 * history.b2
- c2 * history.b3;
p_data = history.b1;
history.a3=history.a2;
history.a2=history.a1;
history.b3=history.b2;
history.b2=history.b1;
}
#endif