From 2839b297d5d4545a606fb98c2e8a504f2256d197 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Sun, 2 May 2021 11:57:10 +0200
Subject: [PATCH] Implement the VST keyswitch interface

---
 plugins/vst/SfizzVstController.cpp | 55 ++++++++++++++++++++++++++++--
 plugins/vst/SfizzVstController.h   |  9 ++++-
 2 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/plugins/vst/SfizzVstController.cpp b/plugins/vst/SfizzVstController.cpp
index 9b5458d9..4ba9aa6b 100644
--- a/plugins/vst/SfizzVstController.cpp
+++ b/plugins/vst/SfizzVstController.cpp
@@ -167,6 +167,30 @@ tresult PLUGIN_API SfizzVstControllerNoUi::getMidiControllerAssignment(int32 bus
     return kResultTrue;
 }
 
+int32 PLUGIN_API SfizzVstControllerNoUi::getKeyswitchCount(int32 busIndex, int16 channel)
+{
+    (void)channel;
+
+    if (busIndex != 0)
+        return 0;
+
+    return keyswitches_.size();
+}
+
+tresult PLUGIN_API SfizzVstControllerNoUi::getKeyswitchInfo(int32 busIndex, int16 channel, int32 keySwitchIndex, Vst::KeyswitchInfo& info)
+{
+    (void)channel;
+
+    if (busIndex != 0)
+        return kResultFalse;
+
+    if (keySwitchIndex < 0 || keySwitchIndex >= keyswitches_.size())
+        return kResultFalse;
+
+    info = keyswitches_[keySwitchIndex];
+    return kResultTrue;
+}
+
 tresult PLUGIN_API SfizzVstControllerNoUi::getParamStringByValue(Vst::ParamID tag, Vst::ParamValue valueNormalized, Vst::String128 string)
 {
     switch (tag) {
@@ -291,9 +315,9 @@ tresult SfizzVstControllerNoUi::notify(Vst::IMessage* message)
             static_cast<Vst::ProgramListWithPitchNames*>(getProgramList(kProgramListID));
         for (int16 pitch = 0; pitch < 128; ++pitch) {
             Steinberg::String pitchName;
-            if (!desc.keyLabel[pitch].empty())
+            if (desc.keyUsed.test(pitch) && !desc.keyLabel[pitch].empty())
                 pitchName = Steinberg::String(desc.keyLabel[pitch].c_str());
-            else if (!desc.keyswitchLabel[pitch].empty())
+            else if (desc.keyswitchUsed.test(pitch) && !desc.keyswitchLabel[pitch].empty())
                 pitchName = Steinberg::String(desc.keyswitchLabel[pitch].c_str());
 
             list->setPitchName(0, pitch, pitchName);
@@ -303,6 +327,33 @@ tresult SfizzVstControllerNoUi::notify(Vst::IMessage* message)
         if (unitHandler)
             unitHandler->notifyProgramListChange(kProgramListID, 0);
 
+        // update the key switches and notify
+        size_t idKeyswitch = 0;
+        for (int16 pitch = 0; pitch < 128; ++pitch)
+            idKeyswitch += desc.keyswitchUsed.test(pitch);
+        keyswitches_.resize(idKeyswitch);
+
+        idKeyswitch = 0;
+        for (int16 pitch = 0; pitch < 128; ++pitch) {
+            if (!desc.keyswitchUsed.test(pitch))
+                continue;
+            Vst::KeyswitchInfo info {};
+            info.typeId = Vst::kNoteOnKeyswitchTypeID;
+            Steinberg::String(desc.keyswitchLabel[pitch].c_str()).copyTo(info.title);
+            Steinberg::String(desc.keyswitchLabel[pitch].c_str()).copyTo(info.shortTitle);
+            info.keyswitchMin = pitch; // TODO reexamine this when supporting keyswitch groups
+            info.keyswitchMax = pitch; // TODO reexamine this when supporting keyswitch groups
+            info.keyRemapped = pitch;
+            info.unitId = Vst::kRootUnitId;
+            info.flags = 0;
+            keyswitches_[idKeyswitch++] = info;
+        }
+
+        Vst::IComponentHandler* componentHandler = getComponentHandler();
+        if (componentHandler)
+            // NOTE(jpc) I think that's the right one, but it needs confirmation
+            componentHandler->restartComponent(Vst::kNoteExpressionChanged);
+
         //
         sfzDescriptionUpdate_->deferUpdate();
     }
diff --git a/plugins/vst/SfizzVstController.h b/plugins/vst/SfizzVstController.h
index f976d7e9..cf0b0d7f 100644
--- a/plugins/vst/SfizzVstController.h
+++ b/plugins/vst/SfizzVstController.h
@@ -11,6 +11,7 @@
 #include "public.sdk/source/vst/vstparameters.h"
 #include "public.sdk/source/common/threadchecker.h"
 #include "pluginterfaces/vst/ivstmidicontrollers.h"
+#include "pluginterfaces/vst/ivstnoteexpression.h"
 #include "vstgui/plugin-bindings/vst3editor.h"
 #include <sfizz_message.h>
 #include <mutex>
@@ -21,7 +22,8 @@ using namespace Steinberg;
 using namespace VSTGUI;
 
 class SfizzVstControllerNoUi : public Vst::EditControllerEx1,
-                               public Vst::IMidiMapping {
+                               public Vst::IMidiMapping,
+                               public Vst::IKeyswitchController {
 public:
     virtual ~SfizzVstControllerNoUi() {}
 
@@ -30,6 +32,9 @@ public:
 
     tresult PLUGIN_API getMidiControllerAssignment(int32 busIndex, int16 channel, Vst::CtrlNumber midiControllerNumber, Vst::ParamID& id) override;
 
+    int32 PLUGIN_API getKeyswitchCount (int32 busIndex, int16 channel) override;
+    tresult PLUGIN_API getKeyswitchInfo (int32 busIndex, int16 channel, int32 keySwitchIndex, Vst::KeyswitchInfo& info) override;
+
     tresult PLUGIN_API getParamStringByValue(Vst::ParamID tag, Vst::ParamValue valueNormalized, Vst::String128 string) override;
     tresult PLUGIN_API getParamValueByString(Vst::ParamID tag, Vst::TChar* string, Vst::ParamValue& valueNormalized) override;
 
@@ -41,6 +46,7 @@ public:
     OBJ_METHODS(SfizzVstControllerNoUi, Vst::EditControllerEx1)
     DEFINE_INTERFACES
     DEF_INTERFACE(Vst::IMidiMapping)
+    DEF_INTERFACE(Vst::IKeyswitchController)
     END_DEFINE_INTERFACES(Vst::EditControllerEx1)
     REFCOUNT_METHODS(Vst::EditControllerEx1)
 
@@ -52,6 +58,7 @@ protected:
     Steinberg::IPtr<ScalaUpdate> scalaUpdate_;
     Steinberg::IPtr<PlayStateUpdate> playStateUpdate_;
     Vst::ParamID midiMapping_[Vst::kCountCtrlNumber] {};
+    std::vector<Vst::KeyswitchInfo> keyswitches_;
 };
 
 class SfizzVstController : public SfizzVstControllerNoUi, public VSTGUI::VST3EditorDelegate {