Support KBM Files (surge-synthesizer#1462)

Addresses surge-synthesizer#1041

This larger diff supports KBM files inside the surge engine
but doesn't include the workflow to load them in the UI or display
them at tuning time yet. Rather it sets up the ability to parse
KBM files and push them onto the storage and note architecture
and uses the Unit Test frameowrk to show that the synth is properly
retuned and remapped.

- Unit tests confirm we parse valid KBM files properly
- Add SurgeStorage hooks for a current mapping
- Confirm tuning and mapping for full-keyboard mappings works
- Allow users to pick a KBM file

Still work to do on persisting and showing.

src/common/SurgeStorage.cpp

@@ -1291,38 +1291,113 @@ bool SurgeStorage::retuneToScale(const Surge::Storage::Scale& s)
    isStandardTuning = false;
 
    float pitches[512];
-   int pos0 = 256 + scaleConstantNote();
+   int posPitch0 = 256 + scaleConstantNote();
+   int posScale0 = 256 + currentMapping.middleNote;
    float pitchMod = log(scaleConstantPitch())/log(2) - 1;
-   pitches[pos0] = 1.0;
+
+   int scalePositionOfStartNote = 0;
+   int scalePositionOfTuningNote = currentMapping.keys[currentMapping.tuningConstantNote - currentMapping.middleNote];
+   float tuningCenterPitchOffset;
+   if( scalePositionOfTuningNote == 0 )
+      tuningCenterPitchOffset = 0;
+   else
+      tuningCenterPitchOffset = s.tones[scalePositionOfTuningNote-1].floatValue - 1.0;
+
+   pitches[posPitch0] = 1.0;
    for (int i=0; i<512; ++i)
    {
-       int distanceFromScale0 = i - pos0;
+      // TODO: ScaleCenter and PitchCenter are now two different notes.
+       int distanceFromPitch0 = i - posPitch0;
+       int distanceFromScale0 = i - posScale0;
 
-       if( distanceFromScale0 == 0 )
+       if( distanceFromPitch0 == 0 )
        {
+          table_pitch[i] = pow( 2.0, pitches[i] + pitchMod );
+#if DEBUG_SCALES
+           if( i > 296 && i < 340 )
+               std::cout << "PITCH: i=" << i << " n=" << i - 256 
+                         << " p=" << pitches[i]
+                         << " tp=" << table_pitch[i]
+                         << " fr=" << table_pitch[i] * 8.175798915
+                         << std::endl;
+#endif           
        }
        else 
        {
+          /*
+            We used to have this which assumed 1-12
+            Now we have our note number, our distance from the 
+            center note, and the key remapping
            int rounds = (distanceFromScale0-1) / s.count;
            int thisRound = (distanceFromScale0-1) % s.count;
+          */
+
+          int rounds;
+          int thisRound;
+          int disable = false;
+          if( currentMapping.isStandardMapping )
+          {
+             rounds = (distanceFromScale0-1) / s.count;
+             thisRound = (distanceFromScale0-1) % s.count;
+          }
+          else
+          {
+             /*
+             ** Now we have this situation. We are at note i so we
+             ** are m away from the center note which is distanceFromScale0
+             **
+             ** If we mod that by the mapping size we know which note we are on
+             */
+             int mappingKey = distanceFromScale0 % currentMapping.count;
+             if( mappingKey < 0 )
+                mappingKey += currentMapping.count;
+             int cm = currentMapping.keys[mappingKey];
+             int push = 0;
+             if( cm < 0 )
+             {
+                disable = true;
+             }
+             else
+             {
+                push = mappingKey - cm;
+             }
+             rounds = (distanceFromScale0 - push - 1) / s.count;
+             thisRound = (distanceFromScale0 - push - 1) % s.count;
+#ifdef DEBUG_SCALES
+             if( i > 296 && i < 340 )
+                std::cout << "MAPPING n=" << i - 256 << " pushes ds0=" << distanceFromScale0 << " cmc=" << currentMapping.count << " tr=" << thisRound << " r=" << rounds << " mk=" << mappingKey << " cm=" << cm << " push=" << push << " dis=" << disable << " mk-p-1=" << mappingKey - push - 1 << std::endl;
+#endif
+
+
+          }
 
            if( thisRound < 0 )
            {
                thisRound += s.count;
                rounds -= 1;
            }
            float mul = pow( s.tones[s.count-1].floatValue, rounds);
-           pitches[i] = s.tones[thisRound].floatValue + rounds * (s.tones[s.count - 1].floatValue - 1.0);
+           if( disable )
+              pitches[i] = 0;
+           else
+              pitches[i] = s.tones[thisRound].floatValue + rounds * (s.tones[s.count - 1].floatValue - 1.0) - tuningCenterPitchOffset;
+
            float otp = table_pitch[i];
            table_pitch[i] = pow( 2.0, pitches[i] + pitchMod );
 
 #if DEBUG_SCALES
            if( i > 296 && i < 340 )
-               std::cout << "PITCH: i=" << i << " n=" << i - 256 << " r=" << rounds << " t=" << thisRound
+               std::cout << "PITCH: i=" << i << " n=" << i - 256
+                         << " ds0=" << distanceFromScale0 
+                         << " dp0=" << distanceFromPitch0
+                         << " r=" << rounds << " t=" << thisRound
                          << " p=" << pitches[i]
-                         << " t=" << s.tones[thisRound].floatValue
+                         << " t=" << s.tones[thisRound].floatValue << " " << s.tones[thisRound ]
+                         << " dis=" << disable
                          << " tp=" << table_pitch[i]
+                         << " fr=" << table_pitch[i] * 8.175798915
                          << " otp=" << otp
+                         << " tcpo=" << tuningCenterPitchOffset
                          << " diff=" << table_pitch[i] - otp
 
                    //<< " l2p=" << log(otp)/log(2.0)
@@ -1345,6 +1420,30 @@ bool SurgeStorage::retuneToScale(const Surge::Storage::Scale& s)
    return true;
 }
 
+bool SurgeStorage::remapToStandardKeyboard()
+{
+   return remapToKeyboard(Surge::Storage::KeyboardMapping());
+}
+
+bool SurgeStorage::remapToKeyboard(const Surge::Storage::KeyboardMapping& k)
+{
+   currentMapping = k;
+   isStandardMapping = k.isStandardMapping;
+   if( isStandardMapping )
+   {
+      tuningPitch = 32.0;
+      tuningPitchInv = 1.0 / 32.0;
+   }
+   else
+   {
+      tuningPitch = k.tuningFrequency / 8.175798915;
+      tuningPitchInv = 1.0 / tuningPitch;
+   }
+   // The mapping will change all the cached pitches
+   retuneToScale(currentScale);
+   return true;
+}
+
 #if TARGET_LV2
 bool SurgeStorage::skipLoadWtAndPatch = false;
 #endif

src/common/SurgeStorage.h

@@ -608,12 +608,18 @@ class alignas(16) SurgeStorage
    void note_to_omega(float, float&, float&);
 
    bool retuneToScale(const Surge::Storage::Scale& s);
-   inline int scaleConstantNote() { return 60; }
-   inline float scaleConstantPitch() { return 32.0; }
-   inline float scaleConstantPitchInv() { return 0.03125; } // Obviously that's the inverse of the above
+   bool remapToKeyboard(const Surge::Storage::KeyboardMapping &k);
+   bool remapToStandardKeyboard(); 
+   inline int scaleConstantNote() { return currentMapping.tuningConstantNote; }
+   inline float scaleConstantPitch() { return tuningPitch; }
+   inline float scaleConstantPitchInv() { return tuningPitchInv; } // Obviously that's the inverse of the above
 
    Surge::Storage::Scale currentScale;
    bool isStandardTuning;
+
+   Surge::Storage::KeyboardMapping currentMapping;
+   bool isStandardMapping = true;
+   float tuningPitch = 32.0f, tuningPitchInv = 0.03125f;
 
 private:
    TiXmlDocument snapshotloader;

src/common/Tunings.cpp

@@ -118,6 +118,97 @@ Surge::Storage::Scale Surge::Storage::parseSCLData(const std::string &d)
     return res;
 }
 
+Surge::Storage::KeyboardMapping keyboardMappingFromStream(std::istream &inf)
+{
+   std::string line;
+   const int read_header = 0, read_count = 1, read_note = 2;
+
+   Surge::Storage::KeyboardMapping res;
+   std::ostringstream rawOSS;
+   res.isStandardMapping = false;
+   res.keys.clear();
+
+   enum parsePosition {
+      map_size = 0,
+      first_midi,
+      last_midi,
+      middle,
+      reference,
+      freq,
+      degree,
+      keys
+   };
+   parsePosition state = map_size;
+
+   while (std::getline(inf, line))
+   {
+      rawOSS << line << "\n";
+      if (line[0] == '!')
+      {
+         continue;
+      }
+
+      if( line == "x" ) line = "-1";
+
+      int i = std::atoi(line.c_str());
+      float v = std::atof(line.c_str());
+
+      switch (state)
+      {
+      case map_size:
+         res.count = i;
+         break;
+      case first_midi:
+         res.firstMidi = i;
+         break;
+      case last_midi:
+         res.lastMidi = i;
+         break;
+      case middle:
+         res.middleNote = i;
+         break;
+      case reference:
+         res.tuningConstantNote = i;
+         break;
+      case freq:
+         res.tuningFrequency = v;
+         break;
+      case degree:
+         res.octaveDegrees = i;
+         break;
+      case keys:
+         res.keys.push_back(i);
+         break;
+      }
+      if( state != keys ) state = (parsePosition)(state + 1);
+   }
+
+   res.rawText = rawOSS.str();
+   return res;
+}
+
+Surge::Storage::KeyboardMapping Surge::Storage::readKBMFile(std::string fname)
+{
+   std::ifstream inf;
+   inf.open(fname);
+   if (!inf.is_open())
+   {
+      return KeyboardMapping();
+   }
+
+   auto res = keyboardMappingFromStream(inf);
+   res.name = fname;
+   return res;
+}
+
+Surge::Storage::KeyboardMapping Surge::Storage::parseKBMData(const std::string &d)
+{
+    std::istringstream iss(d);
+    auto res = keyboardMappingFromStream(iss);
+    res.name = "Mapping from Patch";
+    return res;
+}
+
 std::ostream& Surge::Storage::operator<<(std::ostream& os, const Surge::Storage::Tone& t)
 {
    os << (t.type == Tone::kToneCents ? "cents" : "ratio") << "  ";

src/common/Tunings.h

@@ -45,10 +45,49 @@ struct Scale
    std::string toHtml(SurgeStorage *storage);
 };
 
+struct KeyboardMapping
+{
+   bool isValid;
+   bool isStandardMapping;
+   int count;
+   int firstMidi, lastMidi;
+   int middleNote;
+   int tuningConstantNote;
+   float tuningFrequency;
+   int octaveDegrees;
+   std::vector<int> keys; // rather than an 'x' we use a '-1' for skipped keys
+
+   std::string rawText;
+   std::string name;
+
+   KeyboardMapping() : isValid(true),
+                       isStandardMapping(true),
+                       count(12),
+                       firstMidi(0),
+                       lastMidi(127),
+                       middleNote(60),
+                       tuningConstantNote(60),
+                       tuningFrequency(8.175798915 * 32),
+                       octaveDegrees(12),
+                       rawText( "" ),
+                       name( "" )
+      {
+         for( int i=0; i<12; ++i )
+            keys.push_back(i);
+      }
+
+   // TODO
+   // std::string toHtml(); 
+};
+
 std::ostream& operator<<(std::ostream& os, const Tone& sc);
 std::ostream& operator<<(std::ostream& os, const Scale& sc);
-
+//TODO
+//std::ostream& operator<<(std::ostream& os, const KeyboardMapping& kbm);
+
 Scale readSCLFile(std::string fname);
 Scale parseSCLData(const std::string &sclContents);
+KeyboardMapping readKBMFile(std::string fname);
+KeyboardMapping parseKBMData(const std::string &kbmContents);
 } // namespace Storage
 } // namespace Surge

src/common/gui/SurgeGUIEditor.cpp

@@ -3460,6 +3460,15 @@ VSTGUI::COptionMenu *SurgeGUIEditor::makeTuningMenu(VSTGUI::CRect &menuRect)
         );
     st->setEnabled(! this->synth->storage.isStandardTuning);
     tid++;
+
+    auto *kst = addCallbackMenu(tuningSubMenu, "Set to Standard Keyboard Mapping",
+                    [this]()
+                    {
+                        this->synth->storage.remapToStandardKeyboard();
+                    }
+        );
+    kst->setEnabled(! this->synth->storage.currentMapping.isStandardMapping);
+    tid++;
 
     addCallbackMenu(tuningSubMenu, "Apply .scl file tuning",
                     [this]()
@@ -3491,6 +3500,36 @@ VSTGUI::COptionMenu *SurgeGUIEditor::makeTuningMenu(VSTGUI::CRect &menuRect)
         );
     tid++;
 
+    addCallbackMenu(tuningSubMenu, "Apply .kbm keyboard mapping",
+                    [this]()
+                    {
+                        auto cb = [this](std::string sf)
+                        {
+                            std::string sfx = ".kbm";
+                            if( sf.length() >= sfx.length())
+                            {
+                                if( sf.compare(sf.length() - sfx.length(), sfx.length(), sfx) != 0 )
+                                {
+                                    Surge::UserInteractions::promptError( "Please only select .kbm files", "Invalid Choice" );
+                                    std::cout << "FILE is [" << sf << "]" << std::endl;
+                                    return;
+                                }
+                            }
+                            auto kb = Surge::Storage::readKBMFile(sf);
+
+                            if (!this->synth->storage.remapToKeyboard(kb) )
+                            {
+                               Surge::UserInteractions::promptError( "This .kbm file is not valid", "File format error" );
+                               return;
+                            }
+                        };
+                        Surge::UserInteractions::promptFileOpenDialog(this->synth->storage.userDataPath,
+                                                                      ".scl",
+                                                                      cb);
+                    }
+        );
+    tid++;
+
     auto *sct = addCallbackMenu(tuningSubMenu, "Show current tuning",
                     [this]()
                     {