v15b: fix CC7 to VSTi (legacy tag kHostMidiCC+cc + volume-param fallback), CC lane grid + 0/+- labels

native_bridge/src/Vst3Instrument.cpp

@@ -76,6 +76,8 @@ using Steinberg::Vst::ParamID;
 using Steinberg::Vst::ParamValue;
 using Steinberg::Vst::IMidiMapping;
 using Steinberg::Vst::IParamValueQueue;
+using Steinberg::Vst::ParameterInfo;
+using Steinberg::Vst::TChar;
 using Steinberg::Vst::kNoParamId;
 using Steinberg::Vst::BusInfo;
 using Steinberg::Vst::kAudio;
@@ -154,6 +156,11 @@ struct Vst3HostState {
     // every overlapping voice gets a unique id and note-off releases them all.
     int32 nextNoteId = 1;
     std::vector<int32> noteIdsByPitch[128];
+    // CC → plugin param tag cache for the no-IMidiMapping volume fallback
+    // (scanVolumeParam). 0 = unresolved; kNoParamId = no matching param.
+    bool ccParamResolved[128] = {};
+    bool ccLogged[128] = {};
+    ParamID ccParamTag[128] = {};
 };
 
 // Resolve the plugin's ParamID for a MIDI CC / pitch-bend, preferring the
@@ -173,6 +180,39 @@ ParamID midiControllerTag(IPtr<IEditController>& controller, int16 channel,
     return legacyTag;
 }
 
+// Case-insensitive substring match of an ASCII token on a UTF-16 SDK string.
+bool titleContains(const TChar* s, const char* token) {
+    for (int i = 0; i < 127 && s[i] != 0; ++i) {
+        int j = 0;
+        for (; token[j]; ++j) {
+            if (i + j >= 127 || s[i + j] == 0) break;
+            char c = (char)(s[i + j] & 0x7F);
+            if (c >= 'A' && c <= 'Z') c += 'a' - 'A';
+            if (c != token[j]) break;
+        }
+        if (token[j] == 0) return true;
+    }
+    return false;
+}
+
+// No-IMidiMapping fallback: scan the controller's parameter list for the
+// first volume/gain/output/level/master param (priority order) and use its
+// tag for CC 7/11. Plugins without mapping ignore the legacy kHostMidiCC
+// tags, so CC volume curves die there without this scan.
+ParamID scanVolumeParam(IPtr<IEditController>& controller) {
+    if (!controller) return kNoParamId;
+    static const char* tokens[] = {"volume", "gain", "output", "level", "master"};
+    int32 count = controller->getParameterCount();
+    for (int32 i = 0; i < count; ++i) {
+        ParameterInfo info = {};
+        if (controller->getParameterInfo(i, info) != kResultOk) continue;
+        for (const char* t : tokens) {
+            if (titleContains(info.title, t)) return info.id;
+        }
+    }
+    return kNoParamId;
+}
+
 }  // namespace
 #endif
 
@@ -474,7 +514,22 @@ void Vst3Instrument::controlChange(uint32_t channel, uint32_t cc, uint32_t value
     auto* s = static_cast<Vst3HostState*>(state_);
     if (!s || !s->controller) return;
     ParamID tag = midiControllerTag(s->controller, 0, (int16)cc,
-                                    kHostMidiCC);
+                                    kHostMidiCC + cc);
+    // IMidiMapping absent (common): plugin cannot resolve kHostMidiCC+cc, so
+    // fall back to a scanned volume param (resolved once per CC).
+    if (cc < 128 && tag == kHostMidiCC + cc && !s->ccParamResolved[cc]) {
+        s->ccParamResolved[cc] = true;
+        s->ccParamTag[cc] = scanVolumeParam(s->controller);
+        std::cerr << "[midi] cc=" << cc << " no IMidiMapping → volume-param tag=0x"
+                  << std::hex << s->ccParamTag[cc] << std::dec << std::endl;
+    }
+    if (cc < 128 && tag == kHostMidiCC + cc) tag = s->ccParamTag[cc];
+    if (cc < 128 && !s->ccLogged[cc]) {
+        s->ccLogged[cc] = true;
+        std::cerr << "[midi] cc=" << cc << " tag=0x" << std::hex << tag
+                  << std::dec << " v=" << value << std::endl;
+    }
+    if (tag == kNoParamId) return;
     ParamValue v = value / 127.0;
     // setParamNormalized covers single-component plugins; the param queue
     // reaches split plugins that read inputParameterChanges inside process().