(svn r25841) -Codechange: Use NUM_AIRPORTTILES_PER_GRF instead of NUM_AIRPORTTILES to properly distinguish limits per NewGRF and limits of the pool.

-Change: [NewGRF] Lower the limit of airport tile types per NewGRF from 256 to 255 to prevent usage of ID 0xFF in Action3, and thus allowing it to become an extended byte somewhen.

src/airport.h

@@ -20,7 +20,9 @@ static const uint MAX_TERMINALS =   8;                       ///< maximum number
 static const uint MAX_HELIPADS  =   3;                       ///< maximum number of helipads per airport
 static const uint MAX_ELEMENTS  = 255;                       ///< maximum number of aircraft positions at airport
 
-static const uint NUM_AIRPORTTILES       = 256;              ///< total number of airport tiles
+static const uint NUM_AIRPORTTILES_PER_GRF = 255;            ///< Number of airport tiles per NewGRF; limited to 255 to allow extending Action3 with an extended byte later on.
+
+static const uint NUM_AIRPORTTILES       = 256;              ///< Total number of airport tiles.
 static const uint NEW_AIRPORTTILE_OFFSET = 74;               ///< offset of first newgrf airport tile
 static const uint INVALID_AIRPORTTILE    = NUM_AIRPORTTILES; ///< id for an invalid airport tile
 

src/newgrf.cpp

@@ -4118,14 +4118,14 @@ static ChangeInfoResult AirportTilesChangeInfo(uint airtid, int numinfo, int pro
 {
 	ChangeInfoResult ret = CIR_SUCCESS;
 
-	if (airtid + numinfo > NUM_AIRPORTTILES) {
-		grfmsg(1, "AirportTileChangeInfo: Too many airport tiles loaded (%u), max (%u). Ignoring.", airtid + numinfo, NUM_AIRPORTTILES);
+	if (airtid + numinfo > NUM_AIRPORTTILES_PER_GRF) {
+		grfmsg(1, "AirportTileChangeInfo: Too many airport tiles loaded (%u), max (%u). Ignoring.", airtid + numinfo, NUM_AIRPORTTILES_PER_GRF);
 		return CIR_INVALID_ID;
 	}
 
 	/* Allocate airport tile specs if they haven't been allocated already. */
 	if (_cur.grffile->airtspec == NULL) {
-		_cur.grffile->airtspec = CallocT<AirportTileSpec*>(NUM_AIRPORTTILES);
+		_cur.grffile->airtspec = CallocT<AirportTileSpec*>(NUM_AIRPORTTILES_PER_GRF);
 	}
 
 	for (int i = 0; i < numinfo; i++) {
@@ -7826,7 +7826,7 @@ static void ResetCustomAirports()
 
 		AirportTileSpec **&airporttilespec = (*file)->airtspec;
 		if (airporttilespec != NULL) {
-			for (uint i = 0; i < NUM_AIRPORTTILES; i++) {
+			for (uint i = 0; i < NUM_AIRPORTTILES_PER_GRF; i++) {
 				free(airporttilespec[i]);
 			}
 			free(airporttilespec);
@@ -8581,7 +8581,7 @@ static void FinaliseAirportsArray()
 
 		AirportTileSpec **&airporttilespec = (*file)->airtspec;
 		if (airporttilespec != NULL) {
-			for (uint i = 0; i < NUM_AIRPORTTILES; i++) {
+			for (uint i = 0; i < NUM_AIRPORTTILES_PER_GRF; i++) {
 				if (airporttilespec[i] != NULL && airporttilespec[i]->enabled) {
 					_airporttile_mngr.SetEntitySpec(airporttilespec[i]);
 				}