Add LV2 extension to notify host about midi-bank/pgm state.

4 files changed, 84 insertions, 6 deletions

diff --git a/libs/ardour/ardour/lv2_extensions.h b/libs/ardour/ardour/lv2_extensions.h
index 26432b54d7..027eb0391b 100644
--- a/libs/ardour/ardour/lv2_extensions.h
+++ b/libs/ardour/ardour/lv2_extensions.h
@@ -228,4 +228,29 @@ typedef struct {
 /**
    @}
 */
+
+/**
+   @defgroup bankpatch
+
+   @{
+*/
+
+
+#define LV2_BANKPATCH_URI "http://ardour.org/lv2/bankpatch"
+#define LV2_BANKPATCH_PREFIX LV2_BANKPATCH_URI "#"
+#define LV2_BANKPATCH__notify LV2_BANKPATCH_PREFIX "notify"
+
+typedef void* LV2_BankPatch_Handle;
+
+/** a LV2 Feature provided by the Host to the plugin */
+typedef struct {
+	/** Opaque host data */
+	LV2_BankPatch_Handle handle;
+	/** Info from plugin's run(), notify host that bank/program changed */
+	void (*notify)(LV2_BankPatch_Handle handle, uint8_t channel, uint32_t bank, uint8_t pgm);
+} LV2_BankPatch;
+
+/**
+   @}
+*/
 #endif
diff --git a/libs/ardour/ardour/lv2_plugin.h b/libs/ardour/ardour/lv2_plugin.h
index b17de51928..d4b6ca819f 100644
--- a/libs/ardour/ardour/lv2_plugin.h
+++ b/libs/ardour/ardour/lv2_plugin.h
@@ -277,9 +277,23 @@ class LIBARDOUR_API LV2Plugin : public ARDOUR::Plugin, public ARDOUR::Workee
 	Glib::Threads::Mutex _work_mutex;
 
 #ifdef LV2_EXTENDED
+	static void queue_draw (LV2_Inline_Display_Handle);
+	static void midnam_update (LV2_Midnam_Handle);
+	static void bankpatch_notify (LV2_BankPatch_Handle, uint8_t, uint32_t, uint8_t);
+
 	const LV2_Inline_Display_Interface* _display_interface;
 	bool _inline_display_in_gui;
-	const LV2_Midnam_Interface* _midname_interface;
+	const LV2_Midnam_Interface*    _midname_interface;
+
+	uint32_t _bankpatch[16];
+	bool seen_bankpatch;
+	bool knows_bank_patch () { return seen_bankpatch; }
+	uint32_t bank_patch (uint8_t chn) {
+		assert (chn < 16);
+		if (chn > 15) return UINT32_MAX;
+		return _bankpatch[chn];
+	}
+
 #endif
 
 	typedef struct {
@@ -297,6 +311,7 @@ class LIBARDOUR_API LV2Plugin : public ARDOUR::Plugin, public ARDOUR::Workee
 #ifdef LV2_EXTENDED
 	LV2_Feature    _queue_draw_feature;
 	LV2_Feature    _midnam_feature;
+	LV2_Feature    _bankpatch_feature;
 #endif
 
 	// Options passed to plugin
diff --git a/libs/ardour/ardour/plugin.h b/libs/ardour/ardour/plugin.h
index 4e7f45bc8a..419e33e5fa 100644
--- a/libs/ardour/ardour/plugin.h
+++ b/libs/ardour/ardour/plugin.h
@@ -180,6 +180,10 @@ class LIBARDOUR_API Plugin : public PBD::StatefulDestructible, public Latent
 	virtual std::string midnam_model () { return ""; }
 	PBD::Signal0<void> UpdateMidnam;
 
+	virtual bool knows_bank_patch () { return false; }
+	virtual uint32_t bank_patch (uint8_t chn) { return UINT32_MAX; }
+	PBD::Signal1<void, uint8_t> BankPatchChange;
+
 	struct PresetRecord {
 	    PresetRecord () : valid (false) {}
 	    PresetRecord (const std::string& u, const std::string& l, bool s = true) : uri (u), label (l), user (s), valid (true)  {}
diff --git a/libs/ardour/lv2_plugin.cc b/libs/ardour/lv2_plugin.cc
index 5e02997fe9..5311136afc 100644
--- a/libs/ardour/lv2_plugin.cc
+++ b/libs/ardour/lv2_plugin.cc
@@ -230,19 +230,35 @@ work_respond(LV2_Worker_Respond_Handle handle,
 
 #ifdef LV2_EXTENDED
 /* inline display extension */
-static void
-queue_draw (LV2_Inline_Display_Handle handle)
+void
+LV2Plugin::queue_draw (LV2_Inline_Display_Handle handle)
 {
 	LV2Plugin* plugin = (LV2Plugin*)handle;
 	plugin->QueueDraw(); /* EMIT SIGNAL */
 }
 
-static void
-midnam_update (LV2_Midnam_Handle handle)
+void
+LV2Plugin::midnam_update (LV2_Midnam_Handle handle)
 {
 	LV2Plugin* plugin = (LV2Plugin*)handle;
 	plugin->UpdateMidnam (); /* EMIT SIGNAL */
 }
+
+void
+LV2Plugin::bankpatch_notify (LV2_BankPatch_Handle handle, uint8_t chn, uint32_t bank, uint8_t pgm)
+{
+	LV2Plugin* plugin = (LV2Plugin*)handle;
+	if (chn > 15) {
+		return;
+	}
+	plugin->seen_bankpatch = true;
+	if (pgm > 127 || bank > 16383) {
+		plugin->_bankpatch[chn] = UINT32_MAX;
+	} else {
+		plugin->_bankpatch[chn] = (bank << 7) | pgm;
+	}
+	plugin->BankPatchChange (chn); /* EMIT SIGNAL */
+}
 #endif
 
 /* log extension */
@@ -329,6 +345,7 @@ struct LV2Plugin::Impl {
 #ifdef LV2_EXTENDED
 	LV2_Inline_Display*          queue_draw;
 	LV2_Midnam*                  midnam;
+	LV2_BankPatch*               bankpatch;
 #endif
 };
 
@@ -422,7 +439,7 @@ LV2Plugin::init(const void* c_plugin, framecnt_t rate)
 	lilv_node_free(state_uri);
 	lilv_node_free(state_iface_uri);
 
-	_features    = (LV2_Feature**)calloc(13, sizeof(LV2_Feature*));
+	_features    = (LV2_Feature**)calloc(14, sizeof(LV2_Feature*));
 	_features[0] = &_instance_access_feature;
 	_features[1] = &_data_access_feature;
 	_features[2] = &_make_path_feature;
@@ -457,6 +474,15 @@ LV2Plugin::init(const void* c_plugin, framecnt_t rate)
 	_midnam_feature.URI  = LV2_MIDNAM__update;
 	_midnam_feature.data = _impl->midnam;
 	_features[n_features++]  = &_midnam_feature;
+
+	_impl->bankpatch = (LV2_BankPatch*)
+		malloc (sizeof(LV2_BankPatch));
+	_impl->bankpatch->handle = this;
+	_impl->bankpatch->notify = bankpatch_notify;
+
+	_bankpatch_feature.URI  = LV2_BANKPATCH__notify;
+	_bankpatch_feature.data = _impl->bankpatch;
+	_features[n_features++]  = &_bankpatch_feature;
 #endif
 
 #ifdef HAVE_LV2_1_2_0
@@ -490,6 +516,13 @@ LV2Plugin::init(const void* c_plugin, framecnt_t rate)
 	_features[n_features++] = &_options_feature;
 #endif
 
+#ifdef LV2_EXTENDED
+	seen_bankpatch = false;
+	for (uint32_t chn = 0; chn < 16; ++chn) {
+		_bankpatch[chn] = UINT32_MAX;
+	}
+#endif
+
 	LV2_State_Make_Path* make_path = (LV2_State_Make_Path*)malloc(
 		sizeof(LV2_State_Make_Path));
 	make_path->handle = this;
@@ -900,6 +933,7 @@ LV2Plugin::~LV2Plugin ()
 #ifdef LV2_EXTENDED
 	free(_impl->queue_draw);
 	free(_impl->midnam);
+	free(_impl->bankpatch);
 #endif
 
 	free(_features);