WIP new AudioServer, with buses, effects, etc.

1 files changed, 218 insertions, 0 deletions

diff --git a/servers/audio/effects/eq.cpp b/servers/audio/effects/eq.cpp
new file mode 100644
index 0000000000..14659585b8
--- /dev/null
+++ b/servers/audio/effects/eq.cpp
@@ -0,0 +1,218 @@
+//
+// C++ Interface: eq
+//
+// Description:
+//
+//
+// Author: reduzio@gmail.com (C) 2006
+//
+// Copyright: See COPYING file that comes with this distribution
+//
+//
+#include "eq.h"
+#include <math.h>
+#include "error_macros.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(1.0/M_SQRT2);
+		double th=2.0*M_PI*frq/mix_rate;
+		double th_l=2.0*M_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);
+
+		double r1,r2; //roots
+		int roots=solve_quadratic(c2a,c2b,c2c,&r1,&r2);
+
+		ERR_CONTINUE( roots==0 );
+
+		band[i].c1=2.0 * ((0.5-r1)/2.0);
+		band[i].c2=2.0 * r1;
+		band[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[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()
+{
+}
+
+