add ability to select VGM version when exporting

by default it is 1.71 but please tell me if you want this to be changed

src/engine/engine.h

@@ -305,7 +305,7 @@ class DivEngine {
     // specify system to build ROM for.
     SafeWriter* buildROM(int sys);
     // dump to VGM.
-    SafeWriter* saveVGM(bool* sysToExport=NULL, bool loop=true);
+    SafeWriter* saveVGM(bool* sysToExport=NULL, bool loop=true, int version=0x171);
     // export to an audio file
     bool saveAudio(const char* path, int loops, DivAudioExportModes mode);
     // wait for audio export to finish
@@ -317,8 +317,8 @@ class DivEngine {
     // notify wavetable change
     void notifyWaveChange(int wave);
 
-    // returns whether a system is VGM compatible
+    // returns the minimum VGM version which may carry the specified system, or 0 if none.
-    bool isVGMExportable(DivSystem which);
+    int minVGMVersion(DivSystem which);
 
     // save config
     bool saveConf();

src/engine/sysDef.cpp

@@ -1670,41 +1670,44 @@ DivInstrumentType DivEngine::getPreferInsType(int chan) {
   return DIV_INS_FM;
 }
 
-bool DivEngine::isVGMExportable(DivSystem which) {
+int DivEngine::minVGMVersion(DivSystem which) {
   switch (which) {
-    case DIV_SYSTEM_SMS:
-    case DIV_SYSTEM_GB:
-    case DIV_SYSTEM_PCE:
-    case DIV_SYSTEM_NES:
-    case DIV_SYSTEM_YM2151:
     case DIV_SYSTEM_YM2612:
     case DIV_SYSTEM_YM2612_EXT:
+    case DIV_SYSTEM_SMS:
+    case DIV_SYSTEM_OPLL:
+    case DIV_SYSTEM_OPLL_DRUMS:
+    case DIV_SYSTEM_VRC7:
+    case DIV_SYSTEM_YM2151:
+      return 0x150; // due to usage of data blocks
+    case DIV_SYSTEM_SEGAPCM:
+    case DIV_SYSTEM_SEGAPCM_COMPAT:
     case DIV_SYSTEM_YM2610:
     case DIV_SYSTEM_YM2610_EXT:
     case DIV_SYSTEM_YM2610_FULL:
     case DIV_SYSTEM_YM2610_FULL_EXT:
     case DIV_SYSTEM_YM2610B:
     case DIV_SYSTEM_YM2610B_EXT:
-    case DIV_SYSTEM_AY8910:
-    case DIV_SYSTEM_AY8930:
-    case DIV_SYSTEM_SAA1099:
-    case DIV_SYSTEM_QSOUND:
-    case DIV_SYSTEM_SEGAPCM:
-    case DIV_SYSTEM_SEGAPCM_COMPAT:
-    case DIV_SYSTEM_OPLL:
-    case DIV_SYSTEM_OPLL_DRUMS:
-    case DIV_SYSTEM_VRC7:
-    case DIV_SYSTEM_X1_010:
-    case DIV_SYSTEM_SWAN:
     case DIV_SYSTEM_OPL:
     case DIV_SYSTEM_OPL_DRUMS:
     case DIV_SYSTEM_OPL2:
     case DIV_SYSTEM_OPL2_DRUMS:
     case DIV_SYSTEM_OPL3:
     case DIV_SYSTEM_OPL3_DRUMS:
-      return true;
+    case DIV_SYSTEM_AY8910:
+    case DIV_SYSTEM_AY8930:
+      return 0x151;
+    case DIV_SYSTEM_GB:
+    case DIV_SYSTEM_PCE:
+    case DIV_SYSTEM_NES:
+    case DIV_SYSTEM_QSOUND:
+      return 0x161;
+    case DIV_SYSTEM_SAA1099:
+    case DIV_SYSTEM_X1_010:
+    case DIV_SYSTEM_SWAN:
+      return 0x171;
     default:
-      return false;
+      return 0;
   }
-  return false;
+  return 0;
 }

src/engine/vgmOps.cpp

@@ -592,7 +592,11 @@ void DivEngine::performVGMWrite(SafeWriter* w, DivSystem sys, DivRegWrite& write
   }
 }
 
-SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop) {
+SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop, int version) {
+  if (version<0x150) {
+    lastError="VGM version is too low";
+    return NULL;
+  }
   stop();
   repeatPattern=false;
   setOrder(0);
@@ -679,7 +683,7 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop) {
   // write header
   w->write("Vgm ",4);
   w->writeI(0); // will be written later
-  w->writeI(0x171); // VGM 1.71
+  w->writeI(version);
 
   bool willExport[32];
   bool isSecond[32];
@@ -709,6 +713,7 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop) {
     if (sysToExport!=NULL) {
       if (!sysToExport[i]) continue;
     }
+    if (minVGMVersion(song.system[i])>version) continue;
     switch (song.system[i]) {
       case DIV_SYSTEM_SMS:
         if (!hasSN) {
@@ -979,66 +984,138 @@ SafeWriter* DivEngine::saveVGM(bool* sysToExport, bool loop) {
   w->writeI(0); // tick rate
   w->writeS(snNoiseConfig);
   w->writeC(snNoiseSize);
-  w->writeC(snFlags);
+  if (version>=0x151) {
+    w->writeC(snFlags);
+  } else {
+    w->writeC(0);
+  }
   w->writeI(hasOPN2);
   w->writeI(hasOPM);
   w->writeI(0); // data pointer. will be written later
-  w->writeI(hasSegaPCM);
+  if (version>=0x151) {
-  w->writeI(segaPCMOffset);
+    w->writeI(hasSegaPCM);
-  w->writeI(hasRFC);
+    w->writeI(segaPCMOffset);
-  w->writeI(hasOPN);
+    w->writeI(hasRFC);
-  w->writeI(hasOPNA);
+    w->writeI(hasOPN);
-  w->writeI(hasOPNB);
+    w->writeI(hasOPNA);
-  w->writeI(hasOPL2);
+    w->writeI(hasOPNB);
-  w->writeI(hasOPL);
+    w->writeI(hasOPL2);
-  w->writeI(hasY8950);
+    w->writeI(hasOPL);
-  w->writeI(hasOPL3);
+    w->writeI(hasY8950);
-  w->writeI(hasOPL4);
+    w->writeI(hasOPL3);
-  w->writeI(hasOPX);
+    w->writeI(hasOPL4);
-  w->writeI(hasZ280);
+    w->writeI(hasOPX);
-  w->writeI(hasRFC1);
+    w->writeI(hasZ280);
-  w->writeI(hasPWM);
+    w->writeI(hasRFC1);
-  w->writeI(hasAY);
+    w->writeI(hasPWM);
-  w->writeC(ayConfig);
+    w->writeI(hasAY);
-  w->writeC(ayFlags);
+    w->writeC(ayConfig);
-  w->writeC(ayFlags); // OPN
+    w->writeC(ayFlags);
-  w->writeC(ayFlags); // OPNA
+    w->writeC(ayFlags); // OPN
+    w->writeC(ayFlags); // OPNA
+  } else {
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeC(0);
+    w->writeC(0);
+    w->writeC(0); // OPN
+    w->writeC(0); // OPNA
+  }
+  // currently not used but is part of 1.60
   w->writeC(0); // volume
   w->writeC(0); // reserved
   w->writeC(0); // loop count
+  // 1.51
   w->writeC(0); // loop modifier
-  w->writeI(hasGB);
+  
-  w->writeI(hasNES);
+  if (version>=0x161) {
-  w->writeI(hasMultiPCM);
+    w->writeI(hasGB);
-  w->writeI(hasuPD7759);
+    w->writeI(hasNES);
-  w->writeI(hasOKIM6258);
+    w->writeI(hasMultiPCM);
-  w->writeC(0); // flags
+    w->writeI(hasuPD7759);
-  w->writeC(0); // K flags
+    w->writeI(hasOKIM6258);
-  w->writeC(0); // C140 chip type
+    w->writeC(0); // flags
-  w->writeC(0); // reserved
+    w->writeC(0); // K flags
-  w->writeI(hasOKIM6295);
+    w->writeC(0); // C140 chip type
-  w->writeI(hasK051649);
+    w->writeC(0); // reserved
-  w->writeI(hasK054539);
+    w->writeI(hasOKIM6295);
-  w->writeI(hasPCE);
+    w->writeI(hasK051649);
-  w->writeI(hasNamco);
+    w->writeI(hasK054539);
-  w->writeI(hasK053260);
+    w->writeI(hasPCE);
-  w->writeI(hasPOKEY);
+    w->writeI(hasNamco);
-  w->writeI(hasQSound);
+    w->writeI(hasK053260);
-  w->writeI(hasSCSP);
+    w->writeI(hasPOKEY);
+    w->writeI(hasQSound);
+  } else {
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeC(0); // flags
+    w->writeC(0); // K flags
+    w->writeC(0); // C140 chip type
+    w->writeC(0); // reserved
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+  }
+  if (version>=0x171) {
+    w->writeI(hasSCSP);
+  } else {
+    w->writeI(0);
+  }
+  // 1.70
   w->writeI(0); // extra header
-  w->writeI(hasSwan);
+  // 1.71
-  w->writeI(hasVSU);
+  if (version>=0x171) {
-  w->writeI(hasSAA);
+    w->writeI(hasSwan);
-  w->writeI(hasES5503);
+    w->writeI(hasVSU);
-  w->writeI(hasES5505);
+    w->writeI(hasSAA);
-  w->writeC(0); // 5503 chans
+    w->writeI(hasES5503);
-  w->writeC(0); // 5505 chans
+    w->writeI(hasES5505);
-  w->writeC(0); // C352 clock divider
+    w->writeC(0); // 5503 chans
-  w->writeC(0); // reserved
+    w->writeC(0); // 5505 chans
-  w->writeI(hasX1);
+    w->writeC(0); // C352 clock divider
-  w->writeI(hasC352);
+    w->writeC(0); // reserved
-  w->writeI(hasGA20);
+    w->writeI(hasX1);
-  w->writeI(hasLynx);
+    w->writeI(hasC352);
+    w->writeI(hasGA20);
+    w->writeI(hasLynx);
+  } else {
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeC(0); // 5503 chans
+    w->writeC(0); // 5505 chans
+    w->writeC(0); // C352 clock divider
+    w->writeC(0); // reserved
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+    w->writeI(0);
+  }
   for (int i=0; i<6; i++) { // reserved
     w->writeI(0);
   }

src/gui/gui.cpp

@@ -2131,14 +2131,27 @@ bool FurnaceGUI::loop() {
       }
       if (ImGui::BeginMenu("export VGM...")) {
         ImGui::Text("settings:");
+        if (ImGui::BeginCombo("format version",fmt::sprintf("%d.%.2x",vgmExportVersion>>8,vgmExportVersion&0xff).c_str())) {
+          for (int i=0; i<6; i++) {
+            if (ImGui::Selectable(fmt::sprintf("%d.%.2x",vgmVersions[i]>>8,vgmVersions[i]&0xff).c_str(),vgmExportVersion==vgmVersions[i])) {
+              vgmExportVersion=vgmVersions[i];
+            }
+          }
+          ImGui::EndCombo();
+        }
         ImGui::Checkbox("loop",&vgmExportLoop);
-        ImGui::Text("systems to export:");;
+        ImGui::Text("systems to export:");
         bool hasOneAtLeast=false;
         for (int i=0; i<e->song.systemLen; i++) {
-          ImGui::BeginDisabled(!e->isVGMExportable(e->song.system[i]));
+          int minVersion=e->minVGMVersion(e->song.system[i]);
+          ImGui::BeginDisabled(minVersion>vgmExportVersion || minVersion==0);
           ImGui::Checkbox(fmt::sprintf("%d. %s##_SYSV%d",i+1,getSystemName(e->song.system[i]),i).c_str(),&willExport[i]);
           ImGui::EndDisabled();
-          if (!e->isVGMExportable(e->song.system[i])) {
+          if (minVersion>vgmExportVersion) {
+            if (ImGui::IsItemHovered(ImGuiHoveredFlags_AllowWhenDisabled)) {
+              ImGui::SetTooltip("this system is only available in VGM %d.%.2x and higher!",minVersion>>8,minVersion&0xff);
+            }
+          } else if (minVersion==0) {
             if (ImGui::IsItemHovered(ImGuiHoveredFlags_AllowWhenDisabled)) {
               ImGui::SetTooltip("this system is not supported by the VGM format!");
             }
@@ -2147,7 +2160,7 @@ bool FurnaceGUI::loop() {
           }
         }
         ImGui::Text("select the systems you wish to export,");
-        ImGui::Text("but only up to 2 of each type.");
+        ImGui::Text("but only up to %d of each type.",(vgmExportVersion>=0x151)?2:1);
         if (hasOneAtLeast) {
           if (ImGui::MenuItem("click to export")) {
             openFileDialog(GUI_FILE_EXPORT_VGM);
@@ -2504,7 +2517,7 @@ bool FurnaceGUI::loop() {
               MARK_MODIFIED;
               break;
             case GUI_FILE_EXPORT_VGM: {
-              SafeWriter* w=e->saveVGM(willExport,vgmExportLoop);
+              SafeWriter* w=e->saveVGM(willExport,vgmExportLoop,vgmExportVersion);
               if (w!=NULL) {
                 FILE* f=fopen(copyOfName.c_str(),"wb");
                 if (f!=NULL) {
@@ -2519,7 +2532,7 @@ bool FurnaceGUI::loop() {
                   showWarning(e->getWarnings(),GUI_WARN_GENERIC);
                 }
               } else {
-                showError("could not write VGM. dang it.");
+                showError(fmt::sprintf("could not write VGM! (%s)",e->getLastError()));
               }
               break;
             }
@@ -2918,6 +2931,7 @@ FurnaceGUI::FurnaceGUI():
   displayExporting(false),
   vgmExportLoop(true),
   displayNew(false),
+  vgmExportVersion(0x171),
   curFileDialog(GUI_FILE_OPEN),
   warnAction(GUI_WARN_OPEN),
   fileDialog(NULL),

src/gui/gui.h

@@ -643,6 +643,7 @@ class FurnaceGUI {
   bool quit, warnQuit, willCommit, edit, modified, displayError, displayExporting, vgmExportLoop;
   bool displayNew;
   bool willExport[32];
+  int vgmExportVersion;
 
   FurnaceGUIFileDialogs curFileDialog;
   FurnaceGUIWarnings warnAction;

src/gui/guiConst.cpp

@@ -70,6 +70,15 @@ const int altValues[24]={
   0, 10, 1, 11, 2, 3, 12, 4, 13, 5, 14, 6, 7, 15, 8, -1, 9, -1, -1, -1, -1, -1, -1, -1
 };
 
+const int vgmVersions[6]={
+  0x150,
+  0x151,
+  0x160,
+  0x161,
+  0x170,
+  0x171
+};
+
 const char* insTypes[DIV_INS_MAX]={
   "Standard",
   "FM (4-operator)",

src/gui/guiConst.h

@@ -28,4 +28,5 @@ extern const char* sampleDepths[17];
 extern const char* resampleStrats[];
 extern const int availableSystems[];
 extern const char* guiActions[][2];
-extern const int altValues[24];
+extern const int altValues[24];
+extern const int vgmVersions[6];