add ability to duplicate sub-songs

src/engine/engine.cpp

@@ -1678,6 +1678,51 @@ int DivEngine::addSubSong() {
   return song.subsong.size()-1;
 }
 
+int DivEngine::duplicateSubSong(int index) {
+  if (song.subsong.size()>=127) return -1;
+  BUSY_BEGIN;
+  saveLock.lock();
+  DivSubSong* theCopy=new DivSubSong;
+  DivSubSong* theOrig=song.subsong[index];
+
+  theCopy->name=theOrig->name;
+  theCopy->notes=theOrig->notes;
+  theCopy->hilightA=theOrig->hilightA;
+  theCopy->hilightB=theOrig->hilightB;
+  theCopy->timeBase=theOrig->timeBase;
+  theCopy->arpLen=theOrig->arpLen;
+  theCopy->speeds=theOrig->speeds;
+  theCopy->virtualTempoN=theOrig->virtualTempoN;
+  theCopy->virtualTempoD=theOrig->virtualTempoD;
+  theCopy->hz=theOrig->hz;
+  theCopy->patLen=theOrig->patLen;
+  theCopy->ordersLen=theOrig->ordersLen;
+  theCopy->orders=theOrig->orders;
+  
+  memcpy(theCopy->chanShow,theOrig->chanShow,DIV_MAX_CHANS*sizeof(bool));
+  memcpy(theCopy->chanCollapse,theOrig->chanCollapse,DIV_MAX_CHANS);
+
+  for (int i=0; i<DIV_MAX_CHANS; i++) {
+    theCopy->chanName[i]=theOrig->chanName[i];
+    theCopy->chanShortName[i]=theOrig->chanShortName[i];
+
+    theCopy->pat[i].effectCols=theOrig->pat[i].effectCols;
+
+    for (int j=0; j<DIV_MAX_PATTERNS; j++) {
+      if (theOrig->pat[i].data[j]==NULL) continue;
+      DivPattern* origPat=theOrig->pat[i].getPattern(j,false);
+      DivPattern* copyPat=theCopy->pat[i].getPattern(j,true);
+      origPat->copyOn(copyPat);
+    }
+  }
+
+  song.subsong.push_back(theCopy);
+  
+  saveLock.unlock();
+  BUSY_END;
+  return song.subsong.size()-1;
+}
+
 bool DivEngine::removeSubSong(int index) {
   if (song.subsong.size()<=1) return false;
   stop();

src/engine/engine.h

@@ -1052,6 +1052,9 @@ class DivEngine {
     // add subsong
     int addSubSong();
 
+    // duplicate subsong
+    int duplicateSubSong(int index);
+
     // remove subsong
     bool removeSubSong(int index);
 

src/gui/subSongs.cpp

@@ -17,7 +17,7 @@ void FurnaceGUI::drawSubSongs(bool asChild) {
   bool began=asChild?ImGui::BeginChild("Subsongs"):ImGui::Begin("Subsongs",&subSongsOpen,globalWinFlags);
   if (began) {
     char id[1024];
-    ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x-ImGui::GetFrameHeightWithSpacing()*2.0f-ImGui::GetStyle().ItemSpacing.x);
+    ImGui::SetNextItemWidth(ImGui::GetContentRegionAvail().x-ImGui::GetFrameHeightWithSpacing()*3.0f-ImGui::GetStyle().ItemSpacing.x*2.0f);
     if (e->curSubSong->name.empty()) {
       snprintf(id,1023,"%d. <no name>",(int)e->getCurrentSubSong()+1);
     } else {
@@ -92,6 +92,28 @@ void FurnaceGUI::drawSubSongs(bool asChild) {
       ImGui::SetTooltip("Add");
     }
     ImGui::SameLine();
+    if (ImGui::Button(ICON_FA_FILES_O "##SubSongDuplicate")) {
+      if (!e->duplicateSubSong(e->getCurrentSubSong())) {
+        showError("too many subsongs!");
+      } else {
+        e->changeSongP(e->song.subsong.size()-1);
+        updateScroll(0);
+        oldOrder=0;
+        oldOrder1=0;
+        oldRow=0;
+        cursor.xCoarse=0;
+        cursor.xFine=0;
+        cursor.y=0;
+        selStart=cursor;
+        selEnd=cursor;
+        curOrder=0;
+        MARK_MODIFIED;
+      }
+    }
+    if (ImGui::IsItemHovered()) {
+      ImGui::SetTooltip("Duplicate");
+    }
+    ImGui::SameLine();
     pushDestColor();
     if (ImGui::Button(ICON_FA_MINUS "##SubSongDel")) {
       if (e->song.subsong.size()<=1) {