/*
- Copyright (C) 2000-2007 Paul Davis
+ Copyright (C) 2000-2007 Paul Davis
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#ifndef __ardour_gtk_log_meter_h__
#define __ardour_gtk_log_meter_h__
+#include "ardour/dB.h"
+
#if 1
-inline float
+static inline float
_log_meter (float power, double lower_db, double upper_db, double non_linearity)
{
return (power < lower_db ? 0.0 : pow((power-lower_db)/(upper_db-lower_db), non_linearity));
}
-inline float
+static inline float
alt_log_meter (float power)
{
return _log_meter (power, -192.0, 0.0, 8.0);
}
#endif
-inline float
+/* prototypes - avoid compiler warning */
+static inline float log_meter (float db);
+static inline float meter_deflect_ppm (float);
+static inline float meter_deflect_din (float);
+static inline float meter_deflect_nordic (float);
+static inline float meter_deflect_vu (float);
+static inline float meter_deflect_k (float, float);
+
+
+
+static inline float
log_meter (float db)
{
gfloat def = 0.0f; /* Meter deflection %age */
-
+
if (db < -70.0f) {
def = 0.0f;
} else if (db < -60.0f) {
} else {
def = 115.0f;
}
-
- /* 115 is the deflection %age that would be
+
+ /* 115 is the deflection %age that would be
when db=6.0. this is an arbitrary
endpoint for our scaling.
*/
return def/115.0f;
}
+static inline float
+log_meter0dB (float db)
+{
+ gfloat def = 0.0f; /* Meter deflection %age */
+
+ if (db < -70.0f) {
+ def = 0.0f;
+ } else if (db < -60.0f) {
+ def = (db + 70.0f) * 0.25f;
+ } else if (db < -50.0f) {
+ def = (db + 60.0f) * 0.5f + 2.5f;
+ } else if (db < -40.0f) {
+ def = (db + 50.0f) * 0.75f + 7.5f;
+ } else if (db < -30.0f) {
+ def = (db + 40.0f) * 1.5f + 15.0f;
+ } else if (db < -20.0f) {
+ def = (db + 30.0f) * 2.0f + 30.0f;
+ } else if (db < 0.0f) {
+ def = (db + 20.0f) * 2.5f + 50.0f;
+ } else {
+ def = 100.0f;
+ }
+ return def/100.0f;
+}
+
+static inline float
+meter_deflect_ppm (float db)
+{
+ if (db < -30) {
+ // 2.258 == ((-30 + 32.0)/ 28.0) / 10^(-30 / 20);
+ return (dB_to_coefficient(db) * 2.258769757f);
+ } else {
+ const float rv = (db + 32.0f) / 28.0f;
+ if (rv < 1.0) {
+ return rv;
+ } else {
+ return 1.0;
+ }
+ }
+}
+
+static inline float
+meter_deflect_din (float db)
+{
+ float rv = dB_to_coefficient(db);
+ rv = sqrtf (sqrtf (2.3676f * rv)) - 0.1803f;
+ if (rv >= 1.0) {
+ return 1.0;
+ } else {
+ return (rv > 0 ? rv : 0.0);
+ }
+}
+
+static inline float
+meter_deflect_nordic (float db)
+{
+ if (db < -60) {
+ return 0.0;
+ } else {
+ const float rv = (db + 60.0f) / 54.0f;
+ if (rv < 1.0) {
+ return rv;
+ } else {
+ return 1.0;
+ }
+ }
+}
+
+static inline float
+meter_deflect_vu (float db)
+{
+ const float rv = 6.77165f * dB_to_coefficient(db);
+ if (rv > 1.0) return 1.0;
+ return rv;
+}
+
+static inline float
+meter_deflect_k (float db, float krange)
+{
+ db+=krange;
+ if (db < -40.0f) {
+ return (dB_to_coefficient(db) * 500.0f / (krange + 45.0f));
+ } else {
+ const float rv = (db + 45.0f) / (krange + 45.0f);
+ if (rv < 1.0) {
+ return rv;
+ } else {
+ return 1.0;
+ }
+ }
+}
+
#endif /* __ardour_gtk_log_meter_h__ */