From 487ada663027eadb91fe8e98c2d79917a7df15de Mon Sep 17 00:00:00 2001
From: Ben Loftis <ben@harrisonconsoles.com>
Date: Wed, 25 Nov 2015 14:52:58 -0600
Subject: [PATCH] handle encoder changes.  shift+knob = input trim.  ToDo: 
 panner control

---
 libs/surfaces/faderport/faderport.cc | 45 ++++++++++++++++++++++++++++
 libs/surfaces/faderport/faderport.h  |  4 +++
 2 files changed, 49 insertions(+)

diff --git a/libs/surfaces/faderport/faderport.cc b/libs/surfaces/faderport/faderport.cc
index 8bf93572e3..859b69abe4 100644
--- a/libs/surfaces/faderport/faderport.cc
+++ b/libs/surfaces/faderport/faderport.cc
@@ -38,6 +38,7 @@
 
 #include "ardour/async_midi_port.h"
 #include "ardour/audioengine.h"
+#include "ardour/amp.h"
 #include "ardour/debug.h"
 #include "ardour/filesystem_paths.h"
 #include "ardour/midi_port.h"
@@ -71,6 +72,8 @@ FaderPort::FaderPort (Session& s)
 	, button_state (ButtonState (0))
 	, blink_state (false)
 {
+	last_encoder_time = 0;
+	
 	boost::shared_ptr<ARDOUR::Port> inp;
 	boost::shared_ptr<ARDOUR::Port> outp;
 
@@ -285,11 +288,53 @@ FaderPort::switch_handler (MIDI::Parser &, MIDI::EventTwoBytes* tb)
 void
 FaderPort::encoder_handler (MIDI::Parser &, MIDI::pitchbend_t pb)
 {
+	int delta = 1;
 	if (pb < 8192) {
 		cerr << "Encoder right\n";
 	} else {
+		delta = -1;
 		cerr << "Encoder left\n";
 	}
+
+	//knob debouncing and hysteresis.  The presonus encoder often sends bursts of events, or goes the wrong direction
+	{
+		last_last_encoder_delta = last_encoder_delta;
+		last_encoder_delta = delta;
+		microseconds_t now = get_microseconds ();
+		if ((now - last_encoder_time) < 10*1000) { //require at least 10ms interval between changes, because the device sometimes sends multiple deltas
+			return;
+		}
+		if ((now - last_encoder_time) < 100*1000) { //avoid directional changes while "spinning", 100ms window
+			if ( (delta == last_encoder_delta) && (delta == last_last_encoder_delta) ) {
+				last_good_encoder_delta = delta;  //3 in a row, grudgingly accept this as the new direction
+			}
+			if (delta != last_good_encoder_delta) {  //otherwise ensure we keep going the same way
+				delta = last_good_encoder_delta;
+			}
+		} else {  //we aren't yet in a spin window, just assume this move is really what we want
+			//NOTE:  if you are worried about where these get initialized, here it is.
+			last_last_encoder_delta = delta;
+			last_encoder_delta = delta;
+		}
+		last_encoder_time = now;
+		last_good_encoder_delta = delta;
+	}
+	
+	if (_current_route) {
+
+		if ( (button_state & ShiftDown) == ShiftDown ) {    //shift+encoder = input trim
+			boost::shared_ptr<AutomationControl> gain = _current_route->trim()->gain_control ();
+			if (gain) {
+				float val = gain->get_user();  //for gain elements, the "user" value is in dB
+				val += delta;
+				gain->set_user(val);
+			}
+		} else {  //pan / balance
+			//ToDo
+		}
+		
+	}
+	
 }
 
 void
diff --git a/libs/surfaces/faderport/faderport.h b/libs/surfaces/faderport/faderport.h
index 471c0ab4d8..3635070d9b 100644
--- a/libs/surfaces/faderport/faderport.h
+++ b/libs/surfaces/faderport/faderport.h
@@ -128,6 +128,10 @@ class FaderPort : public ARDOUR::ControlProtocol, public AbstractUI<FaderPortReq
 	int fader_lsb;
 	bool fader_is_touched;
 
+	ARDOUR::microseconds_t last_encoder_time;
+	int last_good_encoder_delta;
+	int last_encoder_delta, last_last_encoder_delta;
+
 	void sysex_handler (MIDI::Parser &p, MIDI::byte *, size_t);
 	void switch_handler (MIDI::Parser &, MIDI::EventTwoBytes* tb);
 	void encoder_handler (MIDI::Parser &, MIDI::pitchbend_t pb);