(svn r5999) -Feature: change the original date format to a 32 bits format based at the year 0.

The game date subsystem now allows someone to start in the year 0 and continue
up to the year 5 000 000. However, you currently cannot build anything before 
1920 as there is no newgrf support for dates before 1920 or after 2090 yet.

1 files changed, 25 insertions, 1 deletions

diff --git a/openttd.c b/openttd.c
index 708bfc317..4a71a589d 100644
--- a/openttd.c
+++ b/openttd.c
@@ -793,7 +793,7 @@ void SwitchMode(int new_mode)
 				}
 			}
 			_generating_world = false;
-			_patches_newgame.starting_year = BASE_YEAR + _cur_year;
+			_patches_newgame.starting_year = ORIGINAL_BASE_YEAR + _cur_year;
 			// delete all stations owned by a player
 			DeleteAllPlayerStations();
 		} else {
@@ -1439,5 +1439,29 @@ bool AfterLoadGame(void)
 
 	if (!CheckSavegameVersion(27)) AfterLoadStations();
 
+	/* Time starts at 0 instead of 1920.
+	 * Account for this in older games by adding an offset */
+	if (CheckSavegameVersion(31)) {
+		Station *st;
+		Waypoint *wp;
+		Engine *e;
+		Player *player;
+		Industry *i;
+		Vehicle *v;
+
+		_date += DAYS_TILL_ORIGINAL_BASE_YEAR;
+
+		FOR_ALL_STATIONS(st)    st->build_date += DAYS_TILL_ORIGINAL_BASE_YEAR;
+		FOR_ALL_WAYPOINTS(wp)   wp->build_date += DAYS_TILL_ORIGINAL_BASE_YEAR;
+		FOR_ALL_ENGINES(e)      e->intro_date  += DAYS_TILL_ORIGINAL_BASE_YEAR;
+		FOR_ALL_PLAYERS(player) player->inaugurated_year += ORIGINAL_BASE_YEAR;
+		FOR_ALL_INDUSTRIES(i)   i->last_prod_year        += ORIGINAL_BASE_YEAR;
+
+		FOR_ALL_VEHICLES(v) {
+			v->date_of_last_service += DAYS_TILL_ORIGINAL_BASE_YEAR;
+			v->build_year += ORIGINAL_BASE_YEAR;
+		}
+	}
+
 	return true;
 }