--- a/rail_cmd.c	Wed Mar 01 06:39:04 2006 +0000
+++ b/rail_cmd.c	Wed Mar 01 08:56:38 2006 +0000
@@ -4,6 +4,7 @@
 #include "openttd.h"
 #include "debug.h"
 #include "functions.h"
+#include "rail_map.h"
 #include "road.h"
 #include "table/sprites.h"
 #include "table/strings.h"
@@ -372,13 +373,7 @@
 			if (CmdFailed(ret)) return ret;
 			cost += ret;
 
-			if (flags & DC_EXEC) {
-				SetTileType(tile, MP_RAILWAY);
-				SetTileOwner(tile, _current_player);
-				_m[tile].m2 = 0; // Bare land
-				_m[tile].m3 = p1; // No signals, rail type
-				_m[tile].m5 = trackbit;
-			}
+			if (flags & DC_EXEC) MakeRailNormal(tile, _current_player, trackbit, p1);
 			break;
 	}
 
@@ -681,12 +676,8 @@
 	if (flags & DC_EXEC) {
 		if (IsLocalPlayer()) _last_built_train_depot_tile = tile;
 
-		ModifyTile(tile,
-			MP_SETTYPE(MP_RAILWAY) |
-			MP_MAP3LO | MP_MAPOWNER_CURRENT | MP_MAP5,
-			p1, /* map3_lo */
-			p2 | RAIL_TYPE_DEPOT_WAYPOINT /* map5 */
-		);
+		MakeRailDepot(tile, _current_player, p2, p1);
+		MarkTileDirtyByTile(tile);
 
 		d->xy = tile;
 		d->town_index = ClosestTownFromTile(tile, (uint)-1)->index;

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rail_map.h	Wed Mar 01 08:56:38 2006 +0000
@@ -0,0 +1,49 @@
+/* $Id$ */
+
+#ifndef RAIL_MAP_H
+#define RAIL_MAP_H
+
+#include "rail.h"
+#include "tile.h"
+#include "waypoint.h"
+
+
+static inline TrackBits GetRailWaypointBits(TileIndex t)
+{
+	return _m[t].m5 & RAIL_WAYPOINT_TRACK_MASK ? TRACK_BIT_DIAG2 : TRACK_BIT_DIAG1;
+}
+
+
+static inline void MakeRailNormal(TileIndex t, Owner o, TrackBits b, RailType r)
+{
+	SetTileType(t, MP_RAILWAY);
+	SetTileOwner(t, o);
+	_m[t].m2 = 0;
+	_m[t].m3 = r;
+	_m[t].m4 = 0;
+	_m[t].m5 = RAIL_TYPE_NORMAL | b;
+}
+
+
+static inline void MakeRailDepot(TileIndex t, Owner o, DiagDirection d, RailType r)
+{
+	SetTileType(t, MP_RAILWAY);
+	SetTileOwner(t, o);
+	_m[t].m2 = 0;
+	_m[t].m3 = r;
+	_m[t].m4 = 0;
+	_m[t].m5 = RAIL_TYPE_DEPOT_WAYPOINT | RAIL_SUBTYPE_DEPOT | d;
+}
+
+
+static inline void MakeRailWaypoint(TileIndex t, Owner o, Axis a, RailType r, uint index)
+{
+	SetTileType(t, MP_RAILWAY);
+	SetTileOwner(t, o);
+	_m[t].m2 = index;
+	_m[t].m3 = r;
+	_m[t].m4 = 0;
+	_m[t].m5 = RAIL_TYPE_DEPOT_WAYPOINT | RAIL_SUBTYPE_WAYPOINT | a;
+}
+
+#endif

--- a/road_cmd.c	Wed Mar 01 06:39:04 2006 +0000
+++ b/road_cmd.c	Wed Mar 01 08:56:38 2006 +0000
@@ -2,6 +2,7 @@
 
 #include "stdafx.h"
 #include "openttd.h"
+#include "rail_map.h"
 #include "road.h"
 #include "table/sprites.h"
 #include "table/strings.h"
@@ -234,26 +235,22 @@
 				}
 
 				case ROAD_CROSSING: {
-					byte c;
+					TrackBits track;
 
 					if (!(ti.map5 & 8)) {
-						c = 2;
 						if (pieces & ROAD_Y) goto return_error;
+						track = TRACK_BIT_DIAG2;
 					} else {
-						c = 1;
 						if (pieces & ROAD_X) goto return_error;
+						track = TRACK_BIT_DIAG1;
 					}
 
 					cost = _price.remove_road * 2;
 					if (flags & DC_EXEC) {
 						ChangeTownRating(t, -road_remove_cost[(byte)edge_road], RATING_ROAD_MINIMUM);
 
-						ModifyTile(tile,
-							MP_SETTYPE(MP_RAILWAY) |
-							MP_MAP2_CLEAR | MP_MAP3LO | MP_MAP3HI_CLEAR | MP_MAP5,
-							_m[tile].m4 & 0xF, /* map3_lo */
-							c											/* map5 */
-						);
+						MakeRailNormal(tile, GetTileOwner(tile), track, GB(_m[tile].m4, 0, 4));
+						MarkTileDirtyByTile(tile);
 					}
 					return cost;
 				}

--- a/waypoint.c	Wed Mar 01 06:39:04 2006 +0000
+++ b/waypoint.c	Wed Mar 01 08:56:38 2006 +0000
@@ -8,6 +8,7 @@
 #include "gfx.h"
 #include "map.h"
 #include "order.h"
+#include "rail_map.h"
 #include "saveload.h"
 #include "station.h"
 #include "tile.h"
@@ -174,15 +175,19 @@
 	TileIndex tile = TileVirtXY(x, y);
 	Waypoint *wp;
 	uint tileh;
-	uint dir;
+	Axis axis;
 
 	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
 
 	/* if custom gfx are used, make sure it is within bounds */
 	if (p1 >= GetNumCustomStations(STAT_CLASS_WAYP)) return CMD_ERROR;
 
-	if (!IsTileType(tile, MP_RAILWAY) || ((dir = 0, _m[tile].m5 != 1) && (dir = 1, _m[tile].m5 != 2)))
+	if (!IsTileType(tile, MP_RAILWAY) || (
+				(axis = AXIS_X, _m[tile].m5 != TRACK_BIT_DIAG1) &&
+				(axis = AXIS_Y, _m[tile].m5 != TRACK_BIT_DIAG2)
+			)) {
 		return_cmd_error(STR_1005_NO_SUITABLE_RAILROAD_TRACK);
+	}
 
 	if (!CheckTileOwnership(tile))
 		return CMD_ERROR;
@@ -191,7 +196,7 @@
 
 	tileh = GetTileSlope(tile, NULL);
 	if (tileh != 0) {
-		if (!_patches.build_on_slopes || IsSteepTileh(tileh) || !(tileh & (0x3 << dir)) || !(tileh & ~(0x3 << dir)))
+		if (!_patches.build_on_slopes || IsSteepTileh(tileh) || !(tileh & (0x3 << axis)) || !(tileh & ~(0x3 << axis)))
 			return_cmd_error(STR_0007_FLAT_LAND_REQUIRED);
 	}
 
@@ -208,7 +213,8 @@
 
 	if (flags & DC_EXEC) {
 		const StationSpec *spec = NULL;
-		ModifyTile(tile, MP_MAP2 | MP_MAP5, wp->index, RAIL_TYPE_WAYPOINT | dir);
+		MakeRailWaypoint(tile, GetTileOwner(tile), axis, GB(_m[tile].m3, 0, 4), wp->index);
+		MarkTileDirtyByTile(tile);
 
 		if (GB(p1, 0, 8) < GetNumCustomStations(STAT_CLASS_WAYP))
 			spec = GetCustomStation(STAT_CLASS_WAYP, GB(p1, 0, 8));
@@ -294,9 +300,8 @@
 		RedrawWaypointSign(wp);
 
 		if (justremove) {
-			ModifyTile(tile, MP_MAP2_CLEAR | MP_MAP5, 1<<direction);
-			CLRBIT(_m[tile].m3, 4);
-			_m[tile].m4 = 0;
+			MakeRailNormal(tile, GetTileOwner(tile), GetRailWaypointBits(tile), GB(_m[tile].m3, 0, 4));
+			MarkTileDirtyByTile(tile);
 		} else {
 			DoClearSquare(tile);
 			SetSignalsOnBothDir(tile, direction);