implement new meter types

1 files changed, 77 insertions, 0 deletions

diff --git a/gtk2_ardour/logmeter.h b/gtk2_ardour/logmeter.h
index d861509080..c7b18ea6b9 100644
--- a/gtk2_ardour/logmeter.h
+++ b/gtk2_ardour/logmeter.h
@@ -34,6 +34,16 @@ alt_log_meter (float power)
 }
 #endif
 
+/* prototypes - avoid compiler warning */
+inline float log_meter (float db);
+inline float meter_deflect_ppm (float);
+inline float meter_deflect_din (float);
+inline float meter_deflect_nordic (float);
+inline float meter_deflect_vu (float);
+inline float meter_deflect_k (float, float);
+
+
+
 inline float
 log_meter (float db)
 {
@@ -65,4 +75,71 @@ log_meter (float db)
          return def/115.0f;
 }
 
+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;
+		}
+	}
+}
+
+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);
+	}
+}
+
+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;
+		}
+	}
+}
+
+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;
+}
+
+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__ */