(svn r8759) -Feature: Allow airports to have up to 4 entry points depending on approach direction. Note: they're not yet used, but will be soon

4 files changed, 78 insertions, 23 deletions

diff --git a/src/aircraft_cmd.cpp b/src/aircraft_cmd.cpp
index f3fdd3f1e..4a82b3049 100644
--- a/src/aircraft_cmd.cpp
+++ b/src/aircraft_cmd.cpp
@@ -1443,6 +1443,50 @@ static void AircraftLandAirplane(Vehicle *v)
 	MaybeCrashAirplane(v);
 }
 
+/**
+ * Find the entry point to an airport depending on direction which
+ * the airport is being approached from. Each airport can have up to
+ * four entry points for its approach system so that approaching
+ * aircraft do not fly through each other or are forced to do 180
+ * degree turns during the approach. The arrivals are grouped into
+ * four sectors dependent on the DiagDirection from which the airport
+ * is approached.
+ *
+ * @param v   The vehicle that is approaching the airport
+ * @param apc The Airport Class being approached.
+ * @returns   The index of the entry point
+ */
+static byte AircraftGetEntryPoint(const Vehicle *v, const AirportFTAClass *apc)
+{
+	const Station *st     = NULL;
+	int           delta_x = 0;
+	int           delta_y = 0;
+	TileIndex     tile    = INVALID_TILE;
+
+	assert(v != NULL);
+	assert(apc != NULL);
+
+	st = GetStation(v->u.air.targetairport);
+	/* Make sure we don't go to 0,0 if the airport has been removed. */
+	tile = (st->airport_tile != 0) ? st->airport_tile : st->xy;
+
+	delta_x = v->x_pos - TileX(tile) * TILE_SIZE;
+	delta_y = v->y_pos - TileY(tile) * TILE_SIZE;
+
+	if (abs(delta_y) < abs(delta_x)) {
+		/* We are northeast or southwest of the airport */
+		if (delta_x < 0) return apc->entry_points[DIAGDIR_NE];
+
+		return apc->entry_points[DIAGDIR_SW];
+	}
+
+	/* We're either northwest or southeast of the airport */
+	if (delta_y < 0) return apc->entry_points[DIAGDIR_NW];
+
+	return apc->entry_points[DIAGDIR_SE];
+}
+
+
 // set the right pos when heading to other airports after takeoff
 static void AircraftNextAirportPos_and_Order(Vehicle *v)
 {
@@ -1451,7 +1495,7 @@ static void AircraftNextAirportPos_and_Order(Vehicle *v)
 		v->u.air.targetairport = v->current_order.dest;
 
 	const AirportFTAClass *apc = GetStation(v->u.air.targetairport)->Airport();
-	v->u.air.pos = v->u.air.previous_pos = apc->entry_point;
+	v->u.air.pos = v->u.air.previous_pos = AircraftGetEntryPoint(v, apc);
 }
 
 static void AircraftLeaveHangar(Vehicle *v)
@@ -1817,8 +1861,7 @@ static bool AirportMove(Vehicle *v, const AirportFTAClass *apc)
 		current = current->next;
 	} while (current != NULL);
 
-	DEBUG(misc, 0, "[Ap] cannot move further on Airport! (pos %d state %d)", v->u.air.pos, v->u.air.state);
-	DEBUG(misc, 0, "[Ap] airport entry point: %d, Vehicle: %d", apc->entry_point, v->index);
+	DEBUG(misc, 0, "[Ap] cannot move further on Airport! (pos %d state %d) for vehicle %d", v->u.air.pos, v->u.air.state, v->index);
 	assert(0);
 	return false;
 }
@@ -2118,7 +2161,7 @@ void UpdateAirplanesOnNewStation(Station *st)
 				 *you cannot delete airport, so it doesn't matter
 				 */
 				if (v->u.air.state >= FLYING) { // circle around
-					v->u.air.pos = v->u.air.previous_pos = ap->entry_point;
+					v->u.air.pos = v->u.air.previous_pos = AircraftGetEntryPoint(v, ap);
 					v->u.air.state = FLYING;
 					// landing plane needs to be reset to flying height (only if in pause mode upgrade,
 					// in normal mode, plane is reset in AircraftController. It doesn't hurt for FLYING
diff --git a/src/airport.cpp b/src/airport.cpp
index b020310d2..3155129f9 100644
--- a/src/airport.cpp
+++ b/src/airport.cpp
@@ -36,7 +36,7 @@ void InitializeAirports(void)
 		_airport_moving_data_country,
 		_airport_terminal_country,
 		NULL,
-		16,
+		_airport_entries_country,
 		AirportFTAClass::ALL | AirportFTAClass::SHORT_STRIP,
 		_airport_fta_country,
 		_airport_depots_country,
@@ -49,7 +49,7 @@ void InitializeAirports(void)
 		_airport_moving_data_town,
 		_airport_terminal_city,
 		NULL,
-		19,
+		_airport_entries_city,
 		AirportFTAClass::ALL,
 		_airport_fta_city,
 		_airport_depots_city,
@@ -62,7 +62,7 @@ void InitializeAirports(void)
 		_airport_moving_data_metropolitan,
 		_airport_terminal_metropolitan,
 		NULL,
-		20,
+		_airport_entries_metropolitan,
 		AirportFTAClass::ALL,
 		_airport_fta_metropolitan,
 		_airport_depots_metropolitan,
@@ -75,7 +75,7 @@ void InitializeAirports(void)
 		_airport_moving_data_international,
 		_airport_terminal_international,
 		_airport_helipad_international,
-		37,
+		_airport_entries_international,
 		AirportFTAClass::ALL,
 		_airport_fta_international,
 		_airport_depots_international,
@@ -88,7 +88,7 @@ void InitializeAirports(void)
 		_airport_moving_data_intercontinental,
 		_airport_terminal_intercontinental,
 		_airport_helipad_intercontinental,
-		43,
+		_airport_entries_intercontinental,
 		AirportFTAClass::ALL,
 		_airport_fta_intercontinental,
 		_airport_depots_intercontinental,
@@ -101,7 +101,7 @@ void InitializeAirports(void)
 		_airport_moving_data_heliport,
 		NULL,
 		_airport_helipad_heliport_oilrig,
-		7,
+		_airport_entries_heliport_oilrig,
 		AirportFTAClass::HELICOPTERS,
 		_airport_fta_heliport_oilrig,
 		NULL,
@@ -114,7 +114,7 @@ void InitializeAirports(void)
 		_airport_moving_data_oilrig,
 		NULL,
 		_airport_helipad_heliport_oilrig,
-		7,
+		_airport_entries_heliport_oilrig,
 		AirportFTAClass::HELICOPTERS,
 		_airport_fta_heliport_oilrig,
 		NULL,
@@ -127,7 +127,7 @@ void InitializeAirports(void)
 		_airport_moving_data_commuter,
 		_airport_terminal_commuter,
 		_airport_helipad_commuter,
-		22,
+		_airport_entries_commuter,
 		AirportFTAClass::ALL | AirportFTAClass::SHORT_STRIP,
 		_airport_fta_commuter,
 		_airport_depots_commuter,
@@ -140,7 +140,7 @@ void InitializeAirports(void)
 		_airport_moving_data_helidepot,
 		NULL,
 		_airport_helipad_helidepot,
-		4,
+		_airport_entries_helidepot,
 		AirportFTAClass::HELICOPTERS,
 		_airport_fta_helidepot,
 		_airport_depots_helidepot,
@@ -153,7 +153,7 @@ void InitializeAirports(void)
 		_airport_moving_data_helistation,
 		NULL,
 		_airport_helipad_helistation,
-		25,
+		_airport_entries_helistation,
 		AirportFTAClass::HELICOPTERS,
 		_airport_fta_helistation,
 		_airport_depots_helistation,
@@ -191,7 +191,7 @@ AirportFTAClass::AirportFTAClass(
 	const AirportMovingData *moving_data_,
 	const byte *terminals_,
 	const byte *helipads_,
-	const byte entry_point_,
+	const byte *entry_points_,
 	Flags flags_,
 	const AirportFTAbuildup *apFA,
 	const TileIndexDiffC *depots_,
@@ -207,7 +207,7 @@ AirportFTAClass::AirportFTAClass(
 	flags(flags_),
 	nof_depots(nof_depots_),
 	nofelements(AirportGetNofElements(apFA)),
-	entry_point(entry_point_),
+	entry_points(entry_points_),
 	size_x(size_x_),
 	size_y(size_y_),
 	delta_z(delta_z_)
@@ -232,15 +232,18 @@ AirportFTAClass::AirportFTAClass(
 	/* Get the number of elements from the source table. We also double check this
 	 * with the entry point which must be within bounds and use this information
 	 * later on to build and validate the state machine */
-	if (entry_point >= nofelements) {
-		DEBUG(misc, 0, "[Ap] entry (%d) must be within the airport (maximum %d)", entry_point, nofelements);
-		assert(entry_point < nofelements);
+	for (DiagDirection i = DIAGDIR_BEGIN; i < DIAGDIR_END; i++) {
+		if (entry_points[i] >= nofelements) {
+			DEBUG(misc, 0, "[Ap] entry (%d) must be within the airport (maximum %d)", entry_points[i], nofelements);
+			assert(entry_points[i] < nofelements);
+		}
 	}
 
 	/* Build the state machine itself */
 	layout = AirportBuildAutomata(nofelements, apFA);
-	DEBUG(misc, 2, "[Ap] #count %3d; #term %2d (%dgrp); #helipad %2d (%dgrp); entry %3d",
-		nofelements, nofterminals, nofterminalgroups, nofhelipads, nofhelipadgroups, entry_point);
+	DEBUG(misc, 2, "[Ap] #count %3d; #term %2d (%dgrp); #helipad %2d (%dgrp); entries %3d, %3d, %3d, %3d",
+		nofelements, nofterminals, nofterminalgroups, nofhelipads, nofhelipadgroups,
+		entry_points[DIAGDIR_NE], entry_points[DIAGDIR_SE], entry_points[DIAGDIR_SW], entry_points[DIAGDIR_NW]);
 
 	/* Test if everything went allright. This is only a rude static test checking
 	 * the symantic correctness. By no means does passing the test mean that the
diff --git a/src/airport.h b/src/airport.h
index 83cb4eda3..ce210301d 100644
--- a/src/airport.h
+++ b/src/airport.h
@@ -132,7 +132,7 @@ typedef struct AirportFTAClass {
 			const AirportMovingData *moving_data,
 			const byte *terminals,
 			const byte *helipads,
-			byte entry_point,
+			const byte *entry_points,
 			Flags flags,
 			const AirportFTAbuildup *apFA,
 			const TileIndexDiffC *depots,
@@ -158,7 +158,7 @@ typedef struct AirportFTAClass {
 	Flags flags;
 	byte nof_depots;                      // number of depots this airport has
 	byte nofelements;                     // number of positions the airport consists of
-	byte entry_point;                     // when an airplane arrives at this airport, enter it at position entry_point
+	const byte *entry_points;             ///< when an airplane arrives at this airport, enter it at position entry_point, index depends on direction
 	byte size_x;
 	byte size_y;
 	byte delta_z;                         // Z adjustment for helicopter pads
diff --git a/src/airport_movement.h b/src/airport_movement.h
index 1b225c808..3f5a9622d 100644
--- a/src/airport_movement.h
+++ b/src/airport_movement.h
@@ -373,6 +373,7 @@ static const AirportMovingData _airport_moving_data_oilrig[9] = {
  * this may be changed later when airports are moved to external file  */
 static const TileIndexDiffC _airport_depots_country[] = {{3, 0}};
 static const byte _airport_terminal_country[] = {1, 2};
+static const byte _airport_entries_country[] = {16, 16, 16, 16};
 static const AirportFTAbuildup _airport_fta_country[] = {
 	{  0, HANGAR, NOTHING_block, 1 },
 	{  1, 255, AIRPORT_BUSY_block, 0 }, { 1, HANGAR, 0, 0 }, { 1, TERM1, TERM1_block, 2 }, { 1, TERM2, 0, 4 }, { 1, HELITAKEOFF, 0, 19 }, { 1, 0, 0, 6 },
@@ -405,6 +406,7 @@ static const AirportFTAbuildup _airport_fta_country[] = {
 static const TileIndexDiffC _airport_depots_commuter[] = { { 4, 0 } };
 static const byte _airport_terminal_commuter[] = { 1, 3 };
 static const byte _airport_helipad_commuter[] = { 1, 2 };
+static const byte _airport_entries_commuter[] = {7, 7, 7, 7};
 static const AirportFTAbuildup _airport_fta_commuter[] = {
 	{  0, HANGAR, NOTHING_block, 1 }, { 0, HELITAKEOFF, HELIPAD2_block, 1 }, { 0, 0, 0, 1 },
 	{  1, 255, TAXIWAY_BUSY_block, 0 }, { 1, HANGAR, 0, 0 }, { 1, TAKEOFF, 0, 11 }, { 1, TERM1, TAXIWAY_BUSY_block, 10 }, { 1, TERM2, TAXIWAY_BUSY_block, 10 }, { 1, TERM3, TAXIWAY_BUSY_block, 10 }, { 1, HELIPAD1, TAXIWAY_BUSY_block, 10 }, { 1, HELIPAD2, TAXIWAY_BUSY_block, 10 }, { 1, HELITAKEOFF, TAXIWAY_BUSY_block, 10 }, { 1, 0, 0, 0 },
@@ -454,6 +456,7 @@ static const AirportFTAbuildup _airport_fta_commuter[] = {
 
 static const TileIndexDiffC _airport_depots_city[] = { { 5, 0 } };
 static const byte _airport_terminal_city[] = { 1, 3 };
+static const byte _airport_entries_city[] = {19, 19, 19, 19};
 static const AirportFTAbuildup _airport_fta_city[] = {
 	{  0, HANGAR, NOTHING_block, 1 }, { 0, TAKEOFF, OUT_WAY_block, 1 }, { 0, 0, 0, 1 },
 	{  1, 255, TAXIWAY_BUSY_block, 0 }, { 1, HANGAR, 0, 0 }, { 1, TERM2, 0, 6 }, { 1, TERM3, 0, 6 }, { 1, 0, 0, 7 }, // for all else, go to 7
@@ -489,6 +492,7 @@ static const AirportFTAbuildup _airport_fta_city[] = {
 
 static const TileIndexDiffC _airport_depots_metropolitan[] = { { 5, 0 } };
 static const byte _airport_terminal_metropolitan[] = { 1, 3 };
+static const byte _airport_entries_metropolitan[] = {20, 20, 20, 20};
 static const AirportFTAbuildup _airport_fta_metropolitan[] = {
 	{  0, HANGAR, NOTHING_block, 1 },
 	{  1, 255, TAXIWAY_BUSY_block, 0 }, { 1, HANGAR, 0, 0 }, { 1, TERM2, 0, 6 }, { 1, TERM3, 0, 6 }, { 1, 0, 0, 7 }, // for all else, go to 7
@@ -527,6 +531,7 @@ static const AirportFTAbuildup _airport_fta_metropolitan[] = {
 static const TileIndexDiffC _airport_depots_international[] = { { 0, 3 }, { 6, 1 } };
 static const byte _airport_terminal_international[] = { 2, 3, 3 };
 static const byte _airport_helipad_international[] = { 1, 2 };
+static const byte _airport_entries_international[] = { 37, 37, 37, 37 };
 static const AirportFTAbuildup _airport_fta_international[] = {
 	{  0, HANGAR, NOTHING_block, 2 }, { 0, 255, TERM_GROUP1_block, 0 }, { 0, 255, TERM_GROUP2_ENTER1_block, 1 }, { 0, HELITAKEOFF, HELIPAD1_block, 2 }, { 0, 0, 0, 2 },
 	{  1, HANGAR, NOTHING_block, 3 }, { 1, 255, HANGAR2_AREA_block, 1 }, { 1, HELITAKEOFF, HELIPAD2_block, 3 }, { 1, 0, 0, 3 },
@@ -592,6 +597,7 @@ static const AirportFTAbuildup _airport_fta_international[] = {
 static const TileIndexDiffC _airport_depots_intercontinental[] = { { 0, 5 }, { 8, 4 } };
 static const byte _airport_terminal_intercontinental[] = { 2, 4, 4 };
 static const byte _airport_helipad_intercontinental[] = { 1, 2 };
+static const byte _airport_entries_intercontinental[] = { 43, 43, 43, 43 };
 static const AirportFTAbuildup _airport_fta_intercontinental[] = {
 	{  0, HANGAR, NOTHING_block, 2 }, { 0, 255, HANGAR1_AREA_block | TERM_GROUP1_block, 0 }, { 0, 255, HANGAR1_AREA_block | TERM_GROUP1_block, 1 }, { 0, TAKEOFF, HANGAR1_AREA_block | TERM_GROUP1_block, 2 }, { 0, 0, 0, 2 },
 	{  1, HANGAR, NOTHING_block, 3 }, { 1, 255, HANGAR2_AREA_block, 1 }, { 1, 255, HANGAR2_AREA_block, 0 }, { 1, 0, 0, 3 },
@@ -684,6 +690,7 @@ static const AirportFTAbuildup _airport_fta_intercontinental[] = {
 
 // heliports, oilrigs don't have depots
 static const byte _airport_helipad_heliport_oilrig[] = { 1, 1 };
+static const byte _airport_entries_heliport_oilrig[] = { 7, 7, 7, 7 };
 static const AirportFTAbuildup _airport_fta_heliport_oilrig[] = {
 	{ 0, HELIPAD1, HELIPAD1_block, 1 },
 	{ 1, HELITAKEOFF, NOTHING_block, 0 }, // takeoff
@@ -701,6 +708,7 @@ static const AirportFTAbuildup _airport_fta_heliport_oilrig[] = {
 // helidepots
 static const TileIndexDiffC _airport_depots_helidepot[] = { { 1, 0 } };
 static const byte _airport_helipad_helidepot[] = { 1, 1 };
+static const byte _airport_entries_helidepot[] = { 4, 4, 4, 4 };
 static const AirportFTAbuildup _airport_fta_helidepot[] = {
 	{  0, HANGAR, NOTHING_block, 1 },
 	{  1, 255, HANGAR2_AREA_block, 0 }, { 1, HANGAR, 0, 0 }, { 1, HELIPAD1, HELIPAD1_block, 14 }, { 1, HELITAKEOFF, 0, 15 }, { 1, 0, 0, 0 },
@@ -730,6 +738,7 @@ static const AirportFTAbuildup _airport_fta_helidepot[] = {
 // helistation
 static const TileIndexDiffC _airport_depots_helistation[] = { { 0, 0 } };
 static const byte _airport_helipad_helistation[] = { 1, 3 };
+static const byte _airport_entries_helistation[] = { 25, 25, 25, 25 };
 static const AirportFTAbuildup _airport_fta_helistation[] = {
 	{  0, HANGAR, NOTHING_block, 8 },    { 0, HELIPAD1, 0, 1 }, { 0, HELIPAD2, 0, 1 }, { 0, HELIPAD3, 0, 1 }, { 0, HELITAKEOFF, 0, 1 }, { 0, 0, 0, 0 },
 	{  1, 255, HANGAR2_AREA_block, 0 },  { 1, HANGAR, 0, 0 }, { 1, HELITAKEOFF, 0, 3 }, { 1, 0, 0, 4 },