(svn r3816) Use existing accessors

ai/default/default.c

@@ -3659,7 +3659,7 @@ pos_3:
 				return;
 			}
 
-			dir = _m[tile].m5 & 3;
+			dir = GetRoadDepotDirection(tile);
 
 			DoCommandByTile(tile, 0, 0, DC_EXEC, CMD_LANDSCAPE_CLEAR);
 			DoCommandByTile(

ai/trolly/pathfinder.c

@@ -9,6 +9,7 @@
 #include "../../command.h"
 #include "trolly.h"
 #include "../../depot.h"
+#include "../../tunnel_map.h"
 #include "../../variables.h"
 #include "../ai.h"
 
@@ -236,7 +237,7 @@ static void AyStar_AiPathFinder_GetNeighbours(AyStar *aystar, OpenListNode *curr
 					// This problem only is valid for tunnels:
 					// When the last tile was not yet a tunnel, check if we enter from the right side..
 					if ((_m[atile].m5 & 0x80) == 0) {
-						if (i != (_m[atile].m5 & 3U)) continue;
+						if (GetTunnelDirection(atile) != i) continue;
 					}
 				}
 			}

ai/trolly/trolly.c

@@ -798,7 +798,7 @@ static void AiNew_State_FindDepot(Player *p)
 			if (IsTileType(t, MP_STREET) &&
 					GetRoadType(t) == ROAD_DEPOT &&
 					IsTileOwner(t, _current_player) &&
-					GB(_m[t].m5, 0, 2) == ReverseDiagDir(j)) { // right direction?
+					GetRoadDepotDirection(t) == ReverseDiagDir(j)) {
 				p->ainew.depot_tile = t;
 				p->ainew.depot_direction = ReverseDiagDir(j);
 				p->ainew.state = AI_STATE_VERIFY_ROUTE;