GUI: add option to add more systems

src/engine/engine.cpp

@@ -485,7 +485,12 @@ bool DivEngine::loadDMF(unsigned char* file, size_t len) {
     if (ds.version>0x0a) {
       String hz=reader.readString(3);
       if (ds.customTempo) {
-        ds.hz=std::stoi(hz);
+        try {
+          ds.hz=std::stoi(hz);
+        } catch (std::exception& e) {
+          logW("invalid custom Hz!\n");
+          ds.hz=60;
+        }
       }
     }
     // TODO
@@ -1516,6 +1521,28 @@ void DivEngine::changeSystem(int index, DivSystem which) {
   isBusy.unlock();
 }
 
+bool DivEngine::addSystem(DivSystem which) {
+  if (song.systemLen>32) {
+    lastError="cannot add more than 32 systems";
+    return false;
+  }
+  if (chans+getChannelCount(which)>DIV_MAX_CHANS) {
+    lastError="max number of total channels is 128";
+    return false;
+  }
+  quitDispatch();
+  isBusy.lock();
+  song.system[song.systemLen++]=which;
+  recalcChans();
+  isBusy.unlock();
+  initDispatch();
+  isBusy.lock();
+  renderSamples();
+  reset();
+  isBusy.unlock();
+  return true;
+}
+
 String DivEngine::getLastError() {
   return lastError;
 }

src/engine/engine.h

@@ -402,10 +402,10 @@ class DivEngine {
     void changeSystem(int index, DivSystem which);
 
     // add system
-    void addSystem(DivSystem which);
+    bool addSystem(DivSystem which);
 
     // remove system
-    void removeSystem(int index);
+    bool removeSystem(int index);
 
     // get last error
     String getLastError();

src/gui/gui.cpp

@@ -2555,6 +2555,14 @@ void FurnaceGUI::processDrags(int dragX, int dragY) {
   }
 }
 
+#define sysAddOption(x) \
+  if (ImGui::MenuItem(e->getSystemName(x))) { \
+    if (!e->addSystem(x)) { \
+      showError("cannot add system! ("+e->getLastError()+")"); \
+    } \
+    updateWindowTitle(); \
+  }
+
 #define sysChangeOption(x) \
   if (ImGui::MenuItem(e->getSystemName(x),NULL,e->song.system[0]==x)) { \
     e->changeSystem(0,x); \
@@ -2664,7 +2672,21 @@ bool FurnaceGUI::loop() {
         openFileDialog(GUI_FILE_SAVE);
       }
       ImGui::Separator();
-      if (ImGui::BeginMenu("change platform...")) {
+      if (ImGui::BeginMenu("add platform...")) {
+        sysAddOption(DIV_SYSTEM_GENESIS);
+        sysAddOption(DIV_SYSTEM_GENESIS_EXT);
+        sysAddOption(DIV_SYSTEM_SMS);
+        sysAddOption(DIV_SYSTEM_GB);
+        sysAddOption(DIV_SYSTEM_PCE);
+        sysAddOption(DIV_SYSTEM_NES);
+        sysAddOption(DIV_SYSTEM_C64_8580);
+        sysAddOption(DIV_SYSTEM_C64_6581);
+        sysAddOption(DIV_SYSTEM_ARCADE);
+        sysAddOption(DIV_SYSTEM_YM2610);
+        sysAddOption(DIV_SYSTEM_YM2610_EXT);
+        ImGui::EndMenu();
+      }
+      if (ImGui::BeginMenu("change first platform...")) {
         sysChangeOption(DIV_SYSTEM_GENESIS);
         sysChangeOption(DIV_SYSTEM_GENESIS_EXT);
         sysChangeOption(DIV_SYSTEM_SMS);