add log file writing

src/engine/configEngine.cpp

@@ -23,6 +23,7 @@
 #ifdef _WIN32
 #include "winStuff.h"
 #define CONFIG_FILE "\\furnace.cfg"
+#define LOG_FILE "\\furnace.log"
 #else
 #ifdef __HAIKU__
 #include <support/SupportDefs.h>

src/engine/engine.cpp

@@ -4221,7 +4221,7 @@ bool DivEngine::deinitAudioBackend(bool dueToSwitchMaster) {
   return true;
 }
 
-bool DivEngine::init() {
+void DivEngine::preInit() {
   // register systems
   if (!systemsRegistered) registerSystems();
 
@@ -4229,8 +4229,13 @@ bool DivEngine::init() {
   initConfDir();
   logD("config path: %s",configPath.c_str());
 
+  String logPath=configPath+DIR_SEPARATOR_STR+"furnace.log";
+  startLogFile(logPath.c_str());
+  
   loadConf();
+}
 
+bool DivEngine::init() {
   loadSampleROMs();
 
   // set default system preset

src/engine/engine.h

@@ -1012,6 +1012,9 @@ class DivEngine {
     // quit dispatch
     void quitDispatch();
 
+    // pre-initialize the engine.
+    void preInit();
+
     // initialize the engine.
     bool init();