a7f49ac9a1
Happy new year to the wonderful Godot community! We're starting a new decade with a well-established, non-profit, free and open source game engine, and tons of further improvements in the pipeline from hundreds of contributors. Godot will keep getting better, and we're looking forward to all the games that the community will keep developing and releasing with it.
215 lines
6.5 KiB
C++
215 lines
6.5 KiB
C++
/*************************************************************************/
|
|
/* eq.cpp */
|
|
/*************************************************************************/
|
|
/* This file is part of: */
|
|
/* GODOT ENGINE */
|
|
/* https://godotengine.org */
|
|
/*************************************************************************/
|
|
/* Copyright (c) 2007-2020 Juan Linietsky, Ariel Manzur. */
|
|
/* Copyright (c) 2014-2020 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
|
|
|
|
#include "eq.h"
|
|
#include "core/error_macros.h"
|
|
#include "core/math/math_funcs.h"
|
|
#include <math.h>
|
|
|
|
#define POW2(v) ((v) * (v))
|
|
|
|
/* Helper */
|
|
static int solve_quadratic(double a, double b, double c, double *r1, double *r2) {
|
|
//solves quadractic and returns number of roots
|
|
|
|
double base = 2 * a;
|
|
if (base == 0.0f)
|
|
return 0;
|
|
|
|
double squared = b * b - 4 * a * c;
|
|
if (squared < 0.0)
|
|
return 0;
|
|
|
|
squared = sqrt(squared);
|
|
|
|
*r1 = (-b + squared) / base;
|
|
*r2 = (-b - squared) / base;
|
|
|
|
if (*r1 == *r2)
|
|
return 1;
|
|
else
|
|
return 2;
|
|
}
|
|
|
|
EQ::BandProcess::BandProcess() {
|
|
|
|
c1 = c2 = c3 = history.a1 = history.a2 = history.a3 = 0;
|
|
history.b1 = history.b2 = history.b3 = 0;
|
|
}
|
|
|
|
void EQ::recalculate_band_coefficients() {
|
|
|
|
#define BAND_LOG(m_f) (log((m_f)) / log(2.))
|
|
|
|
for (int i = 0; i < band.size(); i++) {
|
|
|
|
double octave_size;
|
|
|
|
double frq = band[i].freq;
|
|
|
|
if (i == 0) {
|
|
|
|
octave_size = BAND_LOG(band[1].freq) - BAND_LOG(frq);
|
|
} else if (i == (band.size() - 1)) {
|
|
|
|
octave_size = BAND_LOG(frq) - BAND_LOG(band[i - 1].freq);
|
|
} else {
|
|
|
|
double next = BAND_LOG(band[i + 1].freq) - BAND_LOG(frq);
|
|
double prev = BAND_LOG(frq) - BAND_LOG(band[i - 1].freq);
|
|
octave_size = (next + prev) / 2.0;
|
|
}
|
|
|
|
double frq_l = round(frq / pow(2.0, octave_size / 2.0));
|
|
|
|
double side_gain2 = POW2(Math_SQRT12);
|
|
double th = 2.0 * Math_PI * frq / mix_rate;
|
|
double th_l = 2.0 * Math_PI * frq_l / mix_rate;
|
|
|
|
double c2a = side_gain2 * POW2(cos(th)) - 2.0 * side_gain2 * cos(th_l) * cos(th) + side_gain2 - POW2(sin(th_l));
|
|
|
|
double c2b = 2.0 * side_gain2 * POW2(cos(th_l)) + side_gain2 * POW2(cos(th)) - 2.0 * side_gain2 * cos(th_l) * cos(th) - side_gain2 + POW2(sin(th_l));
|
|
|
|
double c2c = 0.25 * side_gain2 * POW2(cos(th)) - 0.5 * side_gain2 * cos(th_l) * cos(th) + 0.25 * side_gain2 - 0.25 * POW2(sin(th_l));
|
|
|
|
//printf("band %i, precoefs = %f,%f,%f\n",i,c2a,c2b,c2c);
|
|
|
|
// Default initializing to silence compiler warning about potential uninitialized use.
|
|
// Both variables are properly set in _solve_quadratic before use, or we continue if roots == 0.
|
|
double r1 = 0, r2 = 0; //roots
|
|
int roots = solve_quadratic(c2a, c2b, c2c, &r1, &r2);
|
|
|
|
ERR_CONTINUE(roots == 0);
|
|
|
|
band.write[i].c1 = 2.0 * ((0.5 - r1) / 2.0);
|
|
band.write[i].c2 = 2.0 * r1;
|
|
band.write[i].c3 = 2.0 * (0.5 + r1) * cos(th);
|
|
//printf("band %i, coefs = %f,%f,%f\n",i,(float)bands[i].c1,(float)bands[i].c2,(float)bands[i].c3);
|
|
}
|
|
}
|
|
|
|
void EQ::set_preset_band_mode(Preset p_preset) {
|
|
|
|
band.clear();
|
|
|
|
#define PUSH_BANDS(m_bands) \
|
|
for (int i = 0; i < m_bands; i++) { \
|
|
Band b; \
|
|
b.freq = bands[i]; \
|
|
band.push_back(b); \
|
|
}
|
|
|
|
switch (p_preset) {
|
|
|
|
case PRESET_6_BANDS: {
|
|
|
|
static const double bands[] = { 32, 100, 320, 1e3, 3200, 10e3 };
|
|
PUSH_BANDS(6);
|
|
|
|
} break;
|
|
|
|
case PRESET_8_BANDS: {
|
|
|
|
static const double bands[] = { 32, 72, 192, 512, 1200, 3000, 7500, 16e3 };
|
|
|
|
PUSH_BANDS(8);
|
|
} break;
|
|
|
|
case PRESET_10_BANDS: {
|
|
static const double bands[] = { 31.25, 62.5, 125, 250, 500, 1e3, 2e3, 4e3, 8e3, 16e3 };
|
|
|
|
PUSH_BANDS(10);
|
|
|
|
} break;
|
|
|
|
case PRESET_21_BANDS: {
|
|
|
|
static const double bands[] = { 22, 32, 44, 63, 90, 125, 175, 250, 350, 500, 700, 1e3, 1400, 2e3, 2800, 4e3, 5600, 8e3, 11e3, 16e3, 22e3 };
|
|
PUSH_BANDS(21);
|
|
|
|
} break;
|
|
|
|
case PRESET_31_BANDS: {
|
|
|
|
static const double bands[] = { 20, 25, 31.5, 40, 50, 63, 80, 100, 125, 160, 200, 250, 315, 400, 500, 630, 800, 1e3, 1250, 1600, 2e3, 2500, 3150, 4e3, 5e3, 6300, 8e3, 10e3, 12500, 16e3, 20e3 };
|
|
PUSH_BANDS(31);
|
|
} break;
|
|
};
|
|
|
|
recalculate_band_coefficients();
|
|
}
|
|
|
|
int EQ::get_band_count() const {
|
|
|
|
return band.size();
|
|
}
|
|
float EQ::get_band_frequency(int p_band) {
|
|
|
|
ERR_FAIL_INDEX_V(p_band, band.size(), 0);
|
|
return band[p_band].freq;
|
|
}
|
|
void EQ::set_bands(const Vector<float> &p_bands) {
|
|
|
|
band.resize(p_bands.size());
|
|
for (int i = 0; i < p_bands.size(); i++) {
|
|
|
|
band.write[i].freq = p_bands[i];
|
|
}
|
|
|
|
recalculate_band_coefficients();
|
|
}
|
|
|
|
void EQ::set_mix_rate(float p_mix_rate) {
|
|
|
|
mix_rate = p_mix_rate;
|
|
recalculate_band_coefficients();
|
|
}
|
|
|
|
EQ::BandProcess EQ::get_band_processor(int p_band) const {
|
|
|
|
EQ::BandProcess band_proc;
|
|
|
|
ERR_FAIL_INDEX_V(p_band, band.size(), band_proc);
|
|
|
|
band_proc.c1 = band[p_band].c1;
|
|
band_proc.c2 = band[p_band].c2;
|
|
band_proc.c3 = band[p_band].c3;
|
|
|
|
return band_proc;
|
|
}
|
|
|
|
EQ::EQ() {
|
|
mix_rate = 44100;
|
|
}
|
|
|
|
EQ::~EQ() {
|
|
}
|