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/*************************************************************************/
/* eq.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2019 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2019 Godot Engine contributors (cf. AUTHORS.md) */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
// Author: reduzio@gmail.com (C) 2006
#ifndef EQ_FILTER_H
#define EQ_FILTER_H
#include "core/typedefs.h"
#include "core/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
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