X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;ds=sidebyside;f=libs%2Fardour%2Fparameter_descriptor.cc;h=67ea267bfaf157d3d7ee29249e837ffedb29a2e8;hb=6584a89c4eb5024fe89a15acd8e4fa4697e606be;hp=5d988583cb5b7acad638d907e51fe0051329035b;hpb=24727e65befc310f24196d11a56ec7b269977c16;p=ardour.git

diff --git a/libs/ardour/parameter_descriptor.cc b/libs/ardour/parameter_descriptor.cc
index 5d988583cb..67ea267bfa 100644
--- a/libs/ardour/parameter_descriptor.cc
+++ b/libs/ardour/parameter_descriptor.cc
@@ -48,6 +48,11 @@ ParameterDescriptor::ParameterDescriptor(const Evoral::Parameter& parameter)
 		upper  = Config->get_max_gain();
 		normal = 1.0f;
 		break;
+	case TrimAutomation:
+		upper  = 10; // +20dB
+		lower  = .1; // -20dB
+		normal = 1.0f;
+		break;
 	case PanAzimuthAutomation:
 		normal = 0.5f; // there really is no _normal but this works for stereo, sort of
 		upper  = 1.0f;
@@ -116,7 +121,7 @@ ParameterDescriptor::update_steps()
 	if (unit == ParameterDescriptor::MIDI_NOTE) {
 		step      = smallstep = 1;  // semitone
 		largestep = 12;             // octave
-	} else if (type == GainAutomation) {
+	} else if (type == GainAutomation || type == TrimAutomation) {
 		/* dB_coeff_step gives a step normalized for [0, max_gain].  This is
 		   like "slider position", so we convert from "slider position" to gain
 		   to have the correct unit here. */
@@ -132,11 +137,17 @@ ParameterDescriptor::update_steps()
 		largestep = (delta / 30.0f);
 
 		if (logarithmic) {
-			/* Compensate for internal_to_interface's pow so we get roughly the
-			   desired number of steps. */
-			smallstep = pow(smallstep, 1.5f);
-			step      = pow(step, 1.5f);
-			largestep = pow(largestep, 1.5f);
+			/* Steps are linear, but we map them with pow like values (in
+			   internal_to_interface).  Thus, they are applied exponentially,
+			   which means too few steps.  So, divide to get roughly the
+			   desired number of steps (30).  This is not mathematically
+			   precise but seems to be about right for the controls I tried.
+			   If you're reading this, you've probably found a case where that
+			   isn't true, and somebody needs to sit down with a piece of paper
+			   and actually do the math. */
+			smallstep = smallstep / logf(30.0f);
+			step      = step      / logf(30.0f);
+			largestep = largestep / logf(30.0f);
 		} else if (integer_step) {
 			smallstep = std::max(1.0, rint(smallstep));
 			step      = std::max(1.0, rint(step));