Fix #2051 by keeping a copy of the timer in the SktTimer class.

src/main.cpp

@@ -1085,6 +1085,7 @@ void initRest()
     stk_config->load(file_manager->getAsset("stk_config.xml"));
 
     irr_driver = new IrrDriver();
+    StkTime::init();   // grabs the timer object from the irrlicht device
 
     // Now create the actual non-null device in the irrlicht driver
     irr_driver->initDevice();

src/utils/time.cpp

@@ -22,13 +22,31 @@
 
 #include <ctime>
 
+irr::ITimer *StkTime::m_timer = NULL;
+
+/** Init function for the timer. It grabs a copy of the timer of the
+ *  current irrlicht device (which is the NULL device). This way the
+ *  irrlicht time routine can be used even if no device exists. This
+ *  situation can happen when the window resolution is changed - if the
+ *  sfx manager (in a separate thread) would access the timer while the
+ *  device does not exist, stk crashes.
+ */
+void StkTime::init()
+{
+    assert(!m_timer);
+    m_timer = irr_driver->getDevice()->getTimer();
+    m_timer->grab();
+}   // init
+
+// ----------------------------------------------------------------------------
 /** Returns a time based on an arbitrary 'epoch' (e.g. could be start
  *  time of the application, 1.1.1970, ...).
  *  The value is a double precision floating point value in seconds.
  */
 double StkTime::getRealTime(long startAt)
 {
-    return irr_driver->getRealTime()/1000.0;
+    assert(m_timer);
+    return m_timer->getRealTime()/1000.0;
 }   // getTimeSinceEpoch
 
 // ----------------------------------------------------------------------------

src/utils/time.hpp

@@ -18,6 +18,9 @@
 
 #ifndef HEADER_TIME_HPP
 #define HEADER_TIME_HPP
+
+#include "ITimer.h"
+
 #include <stdexcept>
 
 #ifdef WIN32
@@ -36,9 +39,16 @@
 
 class StkTime
 {
+private:
+    /** This objects keeps a copy of irrlicht's null-device timer. This is
+    *  important otherwise we can't get the time when resolution is switched
+    *  (and the sfx threads needs real time at that time). */
+    static irr::ITimer *m_timer;
+
 public:
     typedef time_t TimeType;
 
+    static void init();
     static void getDate(int *day=NULL, int *month=NULL, int *year=NULL);
 
         /** Converts the time in this object to a human readable string. */