Automatically updating MapHud if you have Celestials running

This is a consolidation of the original thread posted here.

NOTE: This mod is designed for those that have the Day/Night Cycles with Seasons working in their current code, and want to have the MapHud update periodically based on the current lighting.

It requires all the things that Day/Night does--specifically, the Celestials object defined in your mission file, and SunFlare objects as well in your mission file (these are what trigger the updateSunPosition if you have the resource implemented).

You need to change Celestial.h:

after the line: (approx line 99)
U32 mTimeOfYear; // Number of days since the last winter equinox

add

U32 mLastHudImpulse; // last time we told the RTS gui hud to rebuild

in Celestial.cc, in void Celestials::UpdateSunPosition()

change

if(prevTime > mTimeOfDay)
    mTimeOfYear = (++mTimeOfYear) % mYearLen;

to

if(prevTime > mTimeOfDay)
  {
  	// this is the day turnover
    mTimeOfYear = (++mTimeOfYear) % mYearLen;
    mLastHudImpulse = 0; // we know we need an impulse since this turnover happens only at midnight
  }
  // loose tracking of hours. used to impulse the HudMap to rebuild itself
  if ( ( (mTimeOfDay >= (mDayLen/24) ) &&
         (mTimeOfDay - (mDayLen/24) > mLastHudImpulse) ) ||
       (mLastHudImpulse == 0)  )
  {
  	// it has been a game hour
  	mLastHudImpulse = mTimeOfDay;
    // trigger RTS MapHud relight/rebuild
    SimObject * guiMapHudObj = Sim::findObject("MapHud");
  	Con::printf("Celestials::updateSunPosition: Pinging MapHud to update based on every hour, using %s. Time of day is %i", 
  	  guiMapHudObj ? guiMapHudObj->getName() : "GuiMapHud not found!",
  	  mTimeOfDay); 
  	Con::executef(guiMapHudObj, 4, "schedule", "10", "rebuildMap", "true" );
  }

  // calculate sun decline and meridian angle (in radians)