(svn r3167) - NewGRF: Start moving custom station code to separate files.

          Rewrite handling of station classes.
          Allow for more than 8 station tile layouts.
          Start of code to unload custom stations.

10 files changed, 259 insertions, 179 deletions

diff --git a/Makefile b/Makefile
index f038127b3..8036237c2 100644
--- a/Makefile
+++ b/Makefile
@@ -659,6 +659,7 @@ C_SOURCES += sprite.c
 C_SOURCES += spritecache.c
 C_SOURCES += station_cmd.c
 C_SOURCES += station_gui.c
+C_SOURCES += station_newgrf.c
 C_SOURCES += string.c
 C_SOURCES += strings.c
 C_SOURCES += subsidy_gui.c
diff --git a/newgrf.c b/newgrf.c
index f66cec1f5..0d0ed95cd 100644
--- a/newgrf.c
+++ b/newgrf.c
@@ -800,22 +800,7 @@ static bool StationChangeInfo(uint stid, int numinfo, int prop, byte **bufp, int
 				classid |= *(buf++) << 8;
 				classid |= *(buf++);
 
-				switch (classid) {
-					case 'DFLT':
-						stat->sclass = STAT_CLASS_DFLT;
-						break;
-					case 'WAYP':
-						stat->sclass = STAT_CLASS_WAYP;
-						break;
-					default:
-						/* TODO: No support for custom
-						 * classes for now, so stuff
-						 * everything to the single
-						 * default one. --pasky */
-						stat->sclass = STAT_CLASS_DFLT;
-						//stat->sclass = STAT_CLASS_CUSTOM;
-						break;
-				}
+				stat->sclass = AllocateStationClass(classid);
 			}
 			break;
 		}
@@ -825,24 +810,28 @@ static bool StationChangeInfo(uint stid, int numinfo, int prop, byte **bufp, int
 				StationSpec *stat = &_cur_grffile->stations[stid + i];
 				int t;
 
-				stat->tiles = grf_load_byte(&buf);
+				stat->tiles = grf_load_extended(&buf);
+				stat->renderdata = calloc(stat->tiles, sizeof(*stat->renderdata));
 				for (t = 0; t < stat->tiles; t++) {
 					DrawTileSprites *dts = &stat->renderdata[t];
 					int seq_count = 0;
+					PalSpriteID ground_sprite;
 
-					if (t >= 8) {
-						grfmsg(GMS_WARN, "StationChangeInfo: Sprite %d>=8, skipping.", t);
-						grf_load_dword(&buf); // at least something
-						continue;
-					}
-
-					dts->ground_sprite = grf_load_dword(&buf);
-					if (!dts->ground_sprite) {
+					ground_sprite = grf_load_dword(&buf);
+					if (ground_sprite == 0) {
 						static const DrawTileSeqStruct empty = {0x80, 0, 0, 0, 0, 0, 0};
 						dts->seq = &empty;
 						continue;
 					}
 
+					if (HASBIT(ground_sprite, 31)) {
+						// Bit 31 indicates that we should use a custom sprite.
+						dts->ground_sprite = GB(ground_sprite, 0, 15) - 0x42D;
+						dts->ground_sprite += _cur_grffile->first_spriteset;
+					} else {
+						dts->ground_sprite = ground_sprite;
+					}
+
 					dts->seq = NULL;
 					while (buf < *bufp + len) {
 						DrawTileSeqStruct *dtss;
@@ -873,6 +862,7 @@ static bool StationChangeInfo(uint stid, int numinfo, int prop, byte **bufp, int
 				int t;
 
 				stat->tiles = srcstat->tiles;
+				stat->renderdata = calloc(stat->tiles, sizeof(*stat->renderdata));
 				for (t = 0; t < stat->tiles; t++) {
 					DrawTileSprites *dts = &stat->renderdata[t];
 					const DrawTileSprites *sdts = &srcstat->renderdata[t];
@@ -1548,6 +1538,9 @@ static void NewSpriteGroup(byte *buf, int len)
 	loaded_ptr = buf;
 	loading_ptr = buf + 2 * numloaded;
 
+	if (_cur_grffile->first_spriteset == 0)
+		_cur_grffile->first_spriteset = _cur_grffile->spriteset_start;
+
 	if (numloaded > 16) {
 		grfmsg(GMS_WARN, "NewSpriteGroup: More than 16 sprites in group %x, skipping the rest.", setid);
 		numloaded = 16;
@@ -1688,8 +1681,8 @@ static void NewVehicle_SpriteGroupMapping(byte *buf, int len)
 				stat->spritegroup[0] = _cur_grffile->spritegroups[groupid];
 				stat->spritegroup[0]->ref_count++;
 				stat->grfid = _cur_grffile->grfid;
-				SetCustomStation(stid, stat);
-				stat->sclass = STAT_CLASS_NONE;
+				stat->localidx = stid;
+				SetCustomStation(stat);
 			}
 		}
 		return;
@@ -2396,6 +2389,28 @@ static void ReleaseSpriteGroups(GRFFile *file)
 	file->spritegroups_count = 0;
 }
 
+static void ResetCustomStations(void)
+{
+	GRFFile *file;
+	int i;
+	CargoID c;
+
+	for (file = _first_grffile; file != NULL; file = file->next) {
+		for (i = 0; i < 256; i++) {
+			if (file->stations[i].grfid != file->grfid)
+				continue;
+
+			// TODO: Release renderdata, platforms and layouts
+
+			// Release this stations sprite groups.
+			for (c = 0; c < NUM_GLOBAL_CID; c++) {
+				if (file->stations[i].spritegroup[c] != NULL)
+					UnloadSpriteGroup(&file->stations[i].spritegroup[c]);
+			}
+		}
+	}
+}
+
 /**
  * Reset all NewGRF loaded data
  * TODO
@@ -2433,6 +2448,10 @@ static void ResetNewGRFData(void)
 
 	// Reset price base data
 	ResetPriceBaseMultipliers();
+
+	// Reset station classes
+	ResetStationClasses();
+	ResetCustomStations();
 }
 
 static void InitNewGRFFile(const char* filename, int sprite_offset)
diff --git a/newgrf.h b/newgrf.h
index 5abc5c95f..50b9ba462 100644
--- a/newgrf.h
+++ b/newgrf.h
@@ -12,6 +12,7 @@ struct GRFFile {
 	uint32 grfid;
 	uint16 flags;
 	uint16 sprite_offset;
+	SpriteID first_spriteset; ///< Holds the first spriteset's sprite offset.
 	GRFFile *next;
 
 	/* A sprite group contains all sprites of a given vehicle (or multiple
diff --git a/rail_gui.c b/rail_gui.c
index 8fee0cfbd..668e797ff 100644
--- a/rail_gui.c
+++ b/rail_gui.c
@@ -127,7 +127,7 @@ static void PlaceRail_Depot(TileIndex tile)
 static void PlaceRail_Waypoint(TileIndex tile)
 {
 	if (!_remove_button_clicked) {
-		DoCommandP(tile, (_waypoint_count > 0) ? (0x100 + _cur_waypoint_type) : 0, 0, CcPlaySound1E, CMD_BUILD_TRAIN_WAYPOINT | CMD_MSG(STR_CANT_BUILD_TRAIN_WAYPOINT));
+		DoCommandP(tile, _cur_waypoint_type, 0, CcPlaySound1E, CMD_BUILD_TRAIN_WAYPOINT | CMD_MSG(STR_CANT_BUILD_TRAIN_WAYPOINT));
 	} else {
 		DoCommandP(tile, 0, 0, CcPlaySound1E, CMD_REMOVE_TRAIN_WAYPOINT | CMD_MSG(STR_CANT_REMOVE_TRAIN_WAYPOINT));
 	}
@@ -257,9 +257,9 @@ static void BuildRailClick_Depot(Window *w)
 
 static void BuildRailClick_Waypoint(Window *w)
 {
-	_waypoint_count = GetCustomStationsCount(STAT_CLASS_WAYP);
+	_waypoint_count = GetNumCustomStations(STAT_CLASS_WAYP);
 	if (HandlePlacePushButton(w, 11, SPR_CURSOR_WAYPOINT, 1, PlaceRail_Waypoint)
-	    && _waypoint_count > 0)
+			&& _waypoint_count > 1)
 		ShowBuildWaypointPicker();
 }
 
@@ -829,14 +829,14 @@ static void BuildWaypointWndProc(Window *w, WindowEvent *e)
 {
 	switch (e->event) {
 	case WE_PAINT: {
+		int i;
 		w->click_state = (1 << 3) << (_cur_waypoint_type - w->hscroll.pos);
 		DrawWindowWidgets(w);
 
-		if(w->hscroll.pos + 0 <= _waypoint_count) DrawWaypointSprite(2,   25, w->hscroll.pos + 0, _cur_railtype);
-		if(w->hscroll.pos + 1 <= _waypoint_count) DrawWaypointSprite(70,  25, w->hscroll.pos + 1, _cur_railtype);
-		if(w->hscroll.pos + 2 <= _waypoint_count) DrawWaypointSprite(138, 25, w->hscroll.pos + 2, _cur_railtype);
-		if(w->hscroll.pos + 3 <= _waypoint_count) DrawWaypointSprite(206, 25, w->hscroll.pos + 3, _cur_railtype);
-		if(w->hscroll.pos + 4 <= _waypoint_count) DrawWaypointSprite(274, 25, w->hscroll.pos + 4, _cur_railtype);
+		for (i = 0; i < 5; i++)
+			if(w->hscroll.pos + i < _waypoint_count)
+				DrawWaypointSprite(2 + i * 68, 25, w->hscroll.pos + i, _cur_railtype);
+
 		break;
 	}
 	case WE_CLICK: {
@@ -889,7 +889,7 @@ static void ShowBuildWaypointPicker(void)
 {
 	Window *w = AllocateWindowDesc(&_build_waypoint_desc);
 	w->hscroll.cap = 5;
-	w->hscroll.count = _waypoint_count + 1;
+	w->hscroll.count = _waypoint_count;
 }
 
 
diff --git a/station.h b/station.h
index 45f88fa9c..6fa329292 100644
--- a/station.h
+++ b/station.h
@@ -8,6 +8,7 @@
 #include "sprite.h"
 #include "tile.h"
 #include "vehicle.h"
+#include "station_newgrf.h"
 
 typedef struct GoodsEntry {
 	uint16 waiting_acceptance;
@@ -195,83 +196,10 @@ uint GetStationPlatforms(const Station *st, TileIndex tile);
 
 void StationPickerDrawSprite(int x, int y, RailType railtype, int image);
 
-
-/* Station layout for given dimensions - it is a two-dimensional array
- * where index is computed as (x * platforms) + platform. */
-typedef byte *StationLayout;
-
-typedef enum StationClass {
-	STAT_CLASS_NONE, // unused station slot or so
-	STAT_CLASS_DFLT, // default station class
-	STAT_CLASS_WAYP, // waypoints
-
-	/* TODO: When we actually support custom classes, they are
-	 * going to be allocated dynamically (with some classid->sclass
-	 * mapping, there's a TTDPatch limit on 16 custom classes in
-	 * the whole game at the same time) with base at
-	 * STAT_CLASS_CUSTOM. --pasky */
-	STAT_CLASS_CUSTOM, // some custom class
-} StationClass;
-
-typedef struct StationSpec {
-	uint32 grfid;
-	int localidx; // per-GRFFile station index + 1; SetCustomStation() takes care of this
-
-	StationClass sclass;
-
-	/* Bitmask of platform numbers/lengths available for the station.  Bits
-	 * 0..6 correspond to 1..7, while bit 7 corresponds to >7 platforms or
-	 * lenght. */
-	byte allowed_platforms;
-	byte allowed_lengths;
-
-	/* Custom sprites */
-	byte tiles;
-	/* 00 = plain platform
-	 * 02 = platform with building
-	 * 04 = platform with roof, left side
-	 * 06 = platform with roof, right side
-	 *
-	 * These numbers are used for stations in NE-SW direction, or these
-	 * numbers plus one for stations in the NW-SE direction.  */
-	DrawTileSprites renderdata[8];
-
-	/* Custom layouts */
-	/* The layout array is organized like [lenghts][platforms], both being
-	 * dynamic arrays, the field itself is length*platforms array containing
-	 * indexes to @renderdata (only even numbers allowed) for the given
-	 * station tile. */
-	/* @lengths is length of the @platforms and @layouts arrays, that is
-	 * number of maximal length for which the layout is defined (since
-	 * arrays are indexed from 0, the length itself is at [length - 1]). */
-	byte lengths;
-	/* @platforms is array of number of platforms defined for each length.
-	 * Zero means no platforms defined. */
-	byte *platforms;
-	/* @layout is @layouts-sized array of @platforms-sized arrays,
-	 * containing pointers to length*platforms-sized arrays or NULL if
-	 * default OTTD station layout should be used for stations of these
-	 * dimensions. */
-	StationLayout **layouts;
-
-	/* Sprite offsets for renderdata->seq->image. spritegroup[0] is default
-	 * whilst spritegroup[1] is "GC_PURCHASE". */
-	SpriteGroup *spritegroup[2];
-} StationSpec;
-
-/* Here, @stid is local per-GRFFile station index. If spec->localidx is not yet
- * set, it gets new dynamically allocated global index and spec->localidx is
- * set to @stid, otherwise we take it as that we are replacing it and try to
- * search for it first (that isn't much fast but we do it only very seldom). */
-void SetCustomStation(byte stid, StationSpec *spec);
-/* Here, @stid is global station index (in continous range 0..GetCustomStationsCount())
- * (lookup is therefore very fast as we do this very frequently). */
-StationSpec *GetCustomStation(StationClass sclass, byte stid);
 /* Get sprite offset for a given custom station and station structure (may be
  * NULL if ctype is set - that means we are in a build dialog). The station
  * structure is used for variational sprite groups. */
 uint32 GetCustomStationRelocation(const StationSpec *spec, const Station *st, byte ctype);
-int GetCustomStationsCount(StationClass sclass);
 
 RoadStop * GetRoadStopByTile(TileIndex tile, RoadStopType type);
 static inline int GetRoadStopType(TileIndex tile)
diff --git a/station_cmd.c b/station_cmd.c
index f46bd19a6..b0c88412c 100644
--- a/station_cmd.c
+++ b/station_cmd.c
@@ -1199,60 +1199,6 @@ uint GetStationPlatforms(const Station *st, TileIndex tile)
 	return len - 1;
 }
 
-
-/* TODO: Custom classes! */
-/* Indexed by class, just STAT_CLASS_DFLT and STAT_CLASS_WAYP supported. */
-static int _statspec_highest_id[2] = {-1, -1};
-static StationSpec _station_spec[2][256];
-
-void SetCustomStation(byte local_stid, StationSpec *spec)
-{
-	StationClass sclass;
-	int stid = -1;
-
-	assert(spec->sclass == STAT_CLASS_DFLT || spec->sclass == STAT_CLASS_WAYP);
-	sclass = spec->sclass - 1;
-
-	if (spec->localidx != 0) {
-		/* Already allocated, try to resolve to global stid */
-		int i;
-
-		for (i = 0; i <= _statspec_highest_id[sclass]; i++) {
-			if (_station_spec[sclass][i].grfid == spec->grfid &&
-					_station_spec[sclass][i].localidx == local_stid + 1) {
-				stid = i;
-				/* FIXME: Release original SpriteGroup to
-				 * prevent leaks. But first we need to
-				 * refcount the SpriteGroup. --pasky */
-				break;
-			}
-		}
-	}
-
-	if (stid == -1) {
-		/* Allocate new one. */
-		if (_statspec_highest_id[sclass] >= 255) {
-			error("Too many custom stations allocated.");
-			return;
-		}
-		stid = ++_statspec_highest_id[sclass];
-		spec->localidx = local_stid + 1;
-	}
-
-	//debug("Registering station #%d of class %d", stid, sclass);
-	memcpy(&_station_spec[sclass][stid], spec, sizeof(*spec));
-}
-
-StationSpec *GetCustomStation(StationClass sclass, byte stid)
-{
-	assert(sclass == STAT_CLASS_DFLT || sclass == STAT_CLASS_WAYP);
-	sclass--;
-	//debug("Asking for station #%d of class %d", stid, sclass);
-	if (stid > _statspec_highest_id[sclass])
-		return NULL;
-	return &_station_spec[sclass][stid];
-}
-
 static const RealSpriteGroup *ResolveStationSpriteGroup(const SpriteGroup *spg, const Station *st)
 {
 	switch (spg->type) {
@@ -1351,14 +1297,6 @@ uint32 GetCustomStationRelocation(const StationSpec *spec, const Station *st, by
 	return SPR_RAIL_PLATFORM_Y_FRONT;
 }
 
-int GetCustomStationsCount(StationClass sclass)
-{
-	assert(sclass == STAT_CLASS_DFLT || sclass == STAT_CLASS_WAYP);
-	sclass--;
-	return _statspec_highest_id[sclass] + 1;
-}
-
-
 static int32 RemoveRailroadStation(Station *st, TileIndex tile, uint32 flags)
 {
 	int w,h;
diff --git a/station_newgrf.c b/station_newgrf.c
new file mode 100644
index 000000000..1150a2376
--- /dev/null
+++ b/station_newgrf.c
@@ -0,0 +1,115 @@
+/* $Id$ */
+
+/** @file station_newgrf.c Functions for dealing with station classes and custom stations. */
+
+#include "stdafx.h"
+#include "openttd.h"
+#include "debug.h"
+#include "sprite.h"
+#include "station_newgrf.h"
+
+static StationClass station_classes[STAT_CLASS_MAX];
+
+/**
+ * Reset station classes to their default state.
+ * This includes initialising the Default and Waypoint classes with an empty
+ * entry, for standard stations and waypoints.
+ */
+void ResetStationClasses(void)
+{
+	StationClassID i;
+	for (i = 0; i < STAT_CLASS_MAX; i++) {
+		station_classes[i].id = 0;
+
+		free(station_classes[i].name);
+		station_classes[i].name = NULL;
+
+		station_classes[i].stations = 0;
+
+		free(station_classes[i].spec);
+		station_classes[i].spec = NULL;
+	}
+
+	// Set up initial data
+	station_classes[0].id = 'DFLT';
+	station_classes[0].name = strdup("Default");
+	station_classes[0].stations = 1;
+	station_classes[0].spec = malloc(sizeof(*station_classes[0].spec));
+	station_classes[0].spec[0] = NULL;
+
+	station_classes[1].id = 'WAYP';
+	station_classes[1].name = strdup("Waypoints");
+	station_classes[1].stations = 1;
+	station_classes[1].spec = malloc(sizeof(*station_classes[1].spec));
+	station_classes[1].spec[0] = NULL;
+}
+
+/**
+ * Allocate a station class for the given class id.
+ * @param classid A 32 bit value identifying the class.
+ * @return Index into station_classes of allocated class.
+ */
+StationClassID AllocateStationClass(uint32 class)
+{
+	StationClassID i;
+
+	for (i = 0; i < STAT_CLASS_MAX; i++) {
+		if (station_classes[i].id == class) {
+			// ClassID is already allocated, so reuse it.
+			return i;
+		} else if (station_classes[i].id == 0) {
+			// This class is empty, so allocate it to the ClassID.
+			station_classes[i].id = class;
+			return i;
+		}
+	}
+
+	DEBUG(grf, 2)("StationClassAllocate: Already allocated %d classes, using default.", STAT_CLASS_MAX);
+	return STAT_CLASS_DFLT;
+}
+
+/**
+ * Return the number of stations for the given station class.
+ * @param sclass Index of the station class.
+ * @return Number of stations in the class.
+ */
+uint GetNumCustomStations(StationClassID sclass)
+{
+	assert(sclass < STAT_CLASS_MAX);
+	return station_classes[sclass].stations;
+}
+
+/**
+ * Tie a station spec to its station class.
+ * @param spec The station spec.
+ */
+void SetCustomStation(StationSpec *spec)
+{
+	StationClass *station_class;
+	int i;
+
+	assert(spec->sclass < STAT_CLASS_MAX);
+	station_class = &station_classes[spec->sclass];
+
+	i = station_class->stations++;
+	station_class->spec = realloc(station_class->spec, station_class->stations * sizeof(*station_class->spec));
+
+	station_class->spec[i] = spec;
+}
+
+/**
+ * Retrieve a station spec from a class.
+ * @param sclass Index of the station class.
+ * @param station The station index with the class.
+ * @return The station spec.
+ */
+const StationSpec *GetCustomStation(StationClassID sclass, uint station)
+{
+	assert(sclass < STAT_CLASS_MAX);
+	if (station < station_classes[sclass].stations)
+		return station_classes[sclass].spec[station];
+
+	// If the custom station isn't defined any more, then the GRF file
+	// probably was not loaded.
+	return NULL;
+}
diff --git a/station_newgrf.h b/station_newgrf.h
new file mode 100644
index 000000000..b4bca4b46
--- /dev/null
+++ b/station_newgrf.h
@@ -0,0 +1,77 @@
+/* $Id$ */
+
+/** @file station_newgrf.h Header file for NewGRF stations */
+
+#ifndef STATION_NEWGRF_H
+#define STATION_NEWGRF_H
+
+#include "engine.h"
+
+typedef enum {
+	STAT_CLASS_DFLT,     ///< Default station class.
+	STAT_CLASS_WAYP,     ///< Waypoint class.
+	STAT_CLASS_MAX = 16, ///< Maximum number of classes.
+} StationClassID;
+
+/* Station layout for given dimensions - it is a two-dimensional array
+ * where index is computed as (x * platforms) + platform. */
+typedef byte *StationLayout;
+
+typedef struct stationspec {
+	uint32 grfid; ///< ID of GRF file station belongs to.
+	int localidx; ///< Index within GRF file of station.
+
+	StationClassID sclass; ///< The class to which this spec belongs.
+
+	/**
+	 * Bitmask of number of platforms available for the station.
+	 * 0..6 correpsond to 1..7, while bit 7 corresponds to >7 platforms.
+	 */
+	byte allowed_platforms;
+	/**
+	 * Bitmask of platform lengths available for the station.
+	 * 0..6 correpsond to 1..7, while bit 7 corresponds to >7 tiles long.
+	 */
+	byte allowed_lengths;
+
+	/** Number of tile layouts.
+	 * A minimum of 8 is required is required for stations.
+	 * 0-1 = plain platform
+	 * 2-3 = platform with building
+	 * 4-5 = platform with roof, left side
+	 * 6-7 = platform with roof, right side
+	 */
+	int tiles;
+	DrawTileSprites *renderdata; ///< Array of tile layouts.
+
+	byte lengths;
+	byte *platforms;
+	StationLayout **layouts;
+
+	/**
+	 * NUM_GLOBAL_CID sprite groups.
+	 * Used for obtaining the sprite offset of custom sprites, and for
+	 * evaluating callbacks.
+	 */
+	SpriteGroup *spritegroup[NUM_GLOBAL_CID];
+} StationSpec;
+
+/**
+ * Struct containing information relating to station classes.
+ */
+typedef struct stationclass {
+	uint32 id;          ///< ID of this class, e.g. 'DFLT', 'WAYP', etc.
+	char *name;         ///< Name of this class.
+	uint stations;      ///< Number of stations in this class.
+	StationSpec **spec; ///< Array of station specifications.
+} StationClass;
+
+void ResetStationClasses(void);
+StationClassID AllocateStationClass(uint32 class);
+void SetStationClassName(StationClassID sclass, const char *name);
+uint GetNumCustomStations(StationClassID sclass);
+
+void SetCustomStation(StationSpec *spec);
+const StationSpec *GetCustomStation(StationClassID sclass, uint station);
+
+#endif /* STATION_NEWGRF_H */
diff --git a/waypoint.c b/waypoint.c
index c93492b7c..fd5c10e75 100644
--- a/waypoint.c
+++ b/waypoint.c
@@ -154,7 +154,7 @@ static Waypoint *FindDeletedWaypointCloseTo(TileIndex tile)
 /** Convert existing rail to waypoint. Eg build a waypoint station over
  * piece of rail
  * @param x,y coordinates where waypoint will be built
- * @param p1 graphics for waypoint type, bit 8 signifies custom waypoint gfx (& 0x100)
+ * @param p1 graphics for waypoint type, 0 indicates standard graphics
  * @param p2 unused
  *
  * @todo When checking for the tile slope,
@@ -170,7 +170,7 @@ int32 CmdBuildTrainWaypoint(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);
 
 	/* if custom gfx are used, make sure it is within bounds */
-	if (p1 > 0x100 + (uint)GetCustomStationsCount(STAT_CLASS_WAYP)) return CMD_ERROR;
+	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)))
 		return_cmd_error(STR_1005_NO_SUITABLE_RAILROAD_TRACK);
@@ -200,10 +200,10 @@ int32 CmdBuildTrainWaypoint(int x, int y, uint32 flags, uint32 p1, uint32 p2)
 	if (flags & DC_EXEC) {
 		bool reserved = PBSTileReserved(tile) != 0;
 		ModifyTile(tile, MP_MAP5, RAIL_TYPE_WAYPOINT | dir);
-		if (--p1 & 0x100) { // waypoint type 0 uses default graphics
+		if (p1 > 0) { // waypoint type 0 uses default graphics
 			// custom graphics
 			_m[tile].m3 |= 16;
-			_m[tile].m4 = p1 & 0xff;
+			_m[tile].m4 = (p1 - 1) & 0xff;
 		}
 		if (reserved) {
 			PBSReserveTrack(tile, dir);
@@ -387,14 +387,14 @@ void DrawWaypointSprite(int x, int y, int stat_id, RailType railtype)
 	x += 33;
 	y += 17;
 
-	/* draw default waypoint graphics of ID 0 */
-	if (stat_id == 0) {
+	stat = GetCustomStation(STAT_CLASS_WAYP, stat_id);
+	if (stat == NULL) {
+		// stat is NULL for default waypoints and when waypoint graphics are
+		// not loaded.
 		DrawDefaultWaypointSprite(x, y, railtype);
 		return;
 	}
 
-	stat = GetCustomStation(STAT_CLASS_WAYP, stat_id - 1);
-	assert(stat);
 	relocation = GetCustomStationRelocation(stat, NULL, 1);
 	// emulate station tile - open with building
 	// add 1 to get the other direction
diff --git a/waypoint.h b/waypoint.h
index 537d86e69..a2b1c28bd 100644
--- a/waypoint.h
+++ b/waypoint.h
@@ -16,6 +16,7 @@ struct Waypoint {
 	ViewportSign sign;
 	uint16 build_date;
 	byte stat_id;
+	uint32 grfid;
 	byte deleted;          // this is a delete counter. when it reaches 0, the waypoint struct is deleted.
 };