automatic safe mode!

to-do: test on Windows...

src/engine/engine.cpp

@@ -3634,14 +3634,22 @@ bool DivEngine::deinitAudioBackend(bool dueToSwitchMaster) {
   return true;
 }
 
-void DivEngine::preInit() {
+bool DivEngine::preInit(bool noSafeMode) {
+  bool wantSafe=false;
   // register systems
   if (!systemsRegistered) registerSystems();
 
   // init config
   initConfDir();
   logD("config path: %s",configPath.c_str());
 
+  if (!noSafeMode) {
+    String safeModePath=configPath+DIR_SEPARATOR_STR+"safemode";
+    if (touchFile(safeModePath.c_str())==-EEXIST) {
+      wantSafe=true;
+    }
+  }
+
   String logPath=configPath+DIR_SEPARATOR_STR+"furnace.log";
   startLogFile(logPath.c_str());
 
@@ -3655,6 +3663,17 @@ void DivEngine::preInit() {
     SDL_SetHint("SDL_HINT_AUDIODRIVER",audioDriver.c_str());
   }
 #endif
+
+  if (wantSafe) {
+    logW("requesting safe mode.");
+  }
+
+  return wantSafe;
+}
+
+void DivEngine::everythingOK() {
+  String safeModePath=configPath+DIR_SEPARATOR_STR+"safemode";
+  deleteFile(safeModePath.c_str());
 }
 
 bool DivEngine::init() {

src/engine/engine.h

@@ -1196,12 +1196,15 @@ class DivEngine {
     // quit dispatch
     void quitDispatch();
 
-    // pre-initialize the engine.
-    void preInit();
+    // pre-initialize the engine. returns whether Furnace should run in safe mode.
+    bool preInit(bool noSafeMode=true);
 
     // initialize the engine.
     bool init();
 
+    // confirm that the engine is running (delete safe mode file).
+    void everythingOK();
+
     // terminate the engine.
     bool quit();
 

src/fileutils.cpp

@@ -25,6 +25,7 @@
 #include <shlwapi.h>
 #else
 #include <unistd.h>
+#include <fcntl.h>
 #include <errno.h>
 #include <sys/stat.h>
 #endif
@@ -100,3 +101,26 @@ bool makeDir(const char* path) {
   return (mkdir(path,0755)==0);
 #endif
 }
+
+int touchFile(const char* path) {
+#ifdef _WIN32
+  HANDLE h=CreateFileW(utf8To16(path).c_str(),GENERIC_WRITE,FILE_SHARE_DELETE|FILE_SHARE_READ|FILE_SHARE_WRITE,NULL,CREATE_NEW,FILE_ATTRIBUTE_TEMPORARY,NULL);
+  if (h==INVALID_HANDLE_VALUE) {
+    switch (GetLastError()) {
+      case ERROR_FILE_EXISTS:
+        return -EEXIST;
+        break;
+    }
+    return -EPERM;
+  }
+  if (CloseHandle(h)==0) {
+    return -EBADF;
+  }
+  return 0;
+#else
+  int fd=open(path,O_CREAT|O_WRONLY|O_TRUNC|O_EXCL,0666);
+  if (fd<0) return -errno;
+  close(fd);
+  return 0;
+#endif
+}

src/fileutils.h

@@ -28,5 +28,6 @@ bool deleteFile(const char* path);
 int fileExists(const char* path);
 bool dirExists(const char* what);
 bool makeDir(const char* path);
+int touchFile(const char* path);
 
 #endif

src/gui/gui.cpp

@@ -3455,6 +3455,11 @@ bool FurnaceGUI::loop() {
     logD("key input: main thread");
   }
 
+  if (safeMode) {
+    showError("Furnace has been started in Safe Mode.\nthis means that:\n\n- software rendering is being used\n- audio output may not work\n- font loading is disabled\n\ncheck any settings which may have made Furnace start up in this mode.\nfont loading is one of these.");
+    settingsOpen=true;
+  }
+
   while (!quit) {
     SDL_Event ev;
     if (e->isPlaying()) {
@@ -6244,6 +6249,7 @@ bool FurnaceGUI::loop() {
     if (mustClear) {
       rend->clear(ImVec4(0,0,0,0));
       mustClear--;
+      if (mustClear==0) e->everythingOK();
     } else {
       if (initialScreenWipe>0.0f && !settings.disableFadeIn) {
         WAKE_UP;

src/main.cpp

@@ -131,14 +131,24 @@ TAParamResult pConsole(String val) {
 }
 
 TAParamResult pSafeMode(String val) {
+#ifdef HAVE_GUI
   safeMode=true;
   return TA_PARAM_SUCCESS;
+#else
+  logE("Furnace was compiled without the GUI. safe mode is pointless.");
+  return TA_PARAM_ERROR;
+#endif
 }
 
 TAParamResult pSafeModeAudio(String val) {
+#ifdef HAVE_GUI
   safeMode=true;
   safeModeWithAudio=true;
   return TA_PARAM_SUCCESS;
+#else
+  logE("Furnace was compiled without the GUI. safe mode is pointless.");
+  return TA_PARAM_ERROR;
+#endif
 }
 
 TAParamResult pBinary(String val) {
@@ -515,7 +525,24 @@ int main(int argc, char** argv) {
     return 1;
   }
 
-  e.preInit();
+#ifdef HAVE_GUI
+  if (e.preInit(false)) {
+    if (consoleMode || benchMode || outName!="" || vgmOutName!="" || cmdOutName!="") {
+      logW("engine wants safe mode, but Furnace GUI is not going to start.");
+    } else {
+      safeMode=true;
+    }
+  }
+#else
+  if (e.preInit(true)) {
+    logW("engine wants safe mode, but Furnace GUI is not available.");
+  }
+#endif
+
+  if (safeMode && (consoleMode || benchMode || outName!="" || vgmOutName!="" || cmdOutName!="")) {
+    logE("you can't use safe mode and console/export mode together.");
+    return 0;
+  }
 
   if (safeMode && !safeModeWithAudio) {
     e.setAudio(DIV_AUDIO_DUMMY);
@@ -684,6 +711,7 @@ int main(int argc, char** argv) {
   if (!g.init()) {
     reportError(g.getLastError());
     finishLogFile();
+    e.everythingOK();
     return 1;
   }
 
@@ -720,5 +748,6 @@ int main(int argc, char** argv) {
     CoUninitialize();
   }
 #endif
+  e.everythingOK();
   return 0;
 }