From c51e3ac7c783f30d8e465ef937fcaf49f4d28aeb Mon Sep 17 00:00:00 2001
From: Robin Gareus <robin@gareus.org>
Date: Thu, 24 Sep 2020 15:57:14 +0200
Subject: [PATCH] VST3: support non-integer indexed presets

---
 libs/ardour/ardour/vst3_plugin.h |  6 +++++-
 libs/ardour/vst3_plugin.cc       | 34 ++++++++++++++++++++++++--------
 2 files changed, 31 insertions(+), 9 deletions(-)

diff --git a/libs/ardour/ardour/vst3_plugin.h b/libs/ardour/ardour/vst3_plugin.h
index 8f666dc475..4e38dc23b2 100644
--- a/libs/ardour/ardour/vst3_plugin.h
+++ b/libs/ardour/ardour/vst3_plugin.h
@@ -86,6 +86,7 @@ public:
 	Vst::IUnitInfo* unit_info ();
 	FUID const& fuid() const { return _fuid; }
 	Vst::ParameterInfo const& program_change_port() const { return  _program_change_port; }
+	void set_n_factory_presets (size_t n) { _n_factory_presets = n; }
 
 	/* API for Ardour -- Ports */
 	uint32_t    designated_bypass_port () const { return _port_id_bypass; }
@@ -97,7 +98,7 @@ public:
 	void        get_parameter_descriptor (uint32_t, ARDOUR::ParameterDescriptor&) const;
 	std::string print_parameter (uint32_t p) const;
 	std::string print_parameter (Vst::ParamID, Vst::ParamValue) const;
-	bool        set_program (float p, int32 sample_off, bool normalized);
+	bool        set_program (int p, int32 sample_off);
 
 	ARDOUR::Plugin::IOPortDescription describe_io_port (ARDOUR::DataType dt, bool input, uint32_t id) const;
 
@@ -217,6 +218,7 @@ private:
 	int _n_aux_outputs;
 	int _n_midi_inputs;
 	int _n_midi_outputs;
+	int _n_factory_presets;
 };
 
 } // namespace Steinberg
@@ -297,6 +299,8 @@ private:
 
 	Steinberg::VST3PI* _plug;
 	PBD::ScopedConnectionList _connections;
+
+	int32_t _factory_preset_count;
 	std::map <std::string, std::string> _preset_uri_map;
 
 	std::vector<bool> _connected_inputs;
diff --git a/libs/ardour/vst3_plugin.cc b/libs/ardour/vst3_plugin.cc
index 7909b1c0ae..e57fd22fe0 100644
--- a/libs/ardour/vst3_plugin.cc
+++ b/libs/ardour/vst3_plugin.cc
@@ -325,7 +325,7 @@ VST3PI::evoral_to_vst3 (Vst::Event& e, Evoral::Event<samplepos_t> const& ev, int
 				return false;
 			case MIDI_CMD_PGM_CHANGE:
 				assert (size == 2);
-				set_program (data2 / 127.f, ev.time (), true); // TODO map to available programs ?!
+				set_program (data2, ev.time ());
 				return false;
 			case MIDI_CMD_CHANNEL_PRESSURE:
 				assert (size == 2);
@@ -687,7 +687,7 @@ VST3Plugin::load_preset (PresetRecord r)
 	if (tmp[0] == "VST3-P") {
 		int program = PBD::atoi (tmp[2]);
 		assert (!r.user);
-		if (!_plug->set_program (program, 0, false)) {
+		if (!_plug->set_program (program, 0)) {
 #ifndef NDEBUG
 			std::cerr << "set_program failed\n";
 #endif
@@ -764,7 +764,6 @@ static bool vst3_preset_filter (const std::string& str, void*)
 void
 VST3Plugin::find_presets ()
 {
-
 	_presets.clear ();
 	_preset_uri_map.clear ();
 
@@ -828,6 +827,8 @@ VST3Plugin::find_presets ()
 		}
 	}
 
+	_plug->set_n_factory_presets (_presets.size ());
+
 	// TODO check _plug->unit_data()
 	// IUnitData: programDataSupported -> setUnitProgramData (IBStream)
 
@@ -947,6 +948,7 @@ VST3PI::VST3PI (boost::shared_ptr<ARDOUR::VST3PluginModule> m, std::string uniqu
 	, _is_processing (false)
 	, _block_size (0)
 	, _port_id_bypass (UINT32_MAX)
+	, _n_factory_presets (0)
 {
 	using namespace std;
 
@@ -1530,16 +1532,32 @@ VST3PI::set_parameter (uint32_t p, float value, int32 sample_off)
 }
 
 bool
-VST3PI::set_program (float value, int32 sample_off, bool normalized)
+VST3PI::set_program (int pgm, int32 sample_off)
 {
 	if (_program_change_port.id == Vst::kNoParamId) {
 		return false;
 	}
-	Vst::ParamID id = _program_change_port.id;
-
-	if (!normalized) {
-		value = _controller->plainParamToNormalized (id, value);
+	if (_n_factory_presets < 1) {
+		return false;
 	}
+
+	if (pgm < 0 || pgm >= _n_factory_presets) {
+		return false;
+	}
+
+	Vst::ParamID id = _program_change_port.id;
+#if 0
+	/* This fails with some plugins (e.g. waves.vst3),
+	 * that do not use integer indexed presets.
+	 */
+	float value = _controller->plainParamToNormalized (id, pgm);
+#else
+	float value = pgm;
+	if (_n_factory_presets > 1) {
+		value /= (_n_factory_presets - 1.f);
+	}
+#endif
+
 	int32 index;
 	_input_param_changes.addParameterData (id, index)->addPoint (sample_off, value, index);
 	_controller->setParamNormalized (id, value);