(svn r4554) Replace magic numbers by TILE_{HEIGHT,SIZE}

17 files changed, 83 insertions, 83 deletions

diff --git a/clear_cmd.c b/clear_cmd.c
index a680f398a..3a8b69f91 100644
--- a/clear_cmd.c
+++ b/clear_cmd.c
@@ -460,8 +460,8 @@ void DrawClearLandFence(const TileInfo *ti)
 	byte z = ti->z;
 
 	if (ti->tileh & SLOPE_S) {
-		z += 8;
-		if (ti->tileh == SLOPE_STEEP_S) z += 8;
+		z += TILE_HEIGHT;
+		if (ti->tileh == SLOPE_STEEP_S) z += TILE_HEIGHT;
 	}
 
 	if (GetFenceSW(ti->tile) != 0) {
diff --git a/disaster_cmd.c b/disaster_cmd.c
index da4c3e766..ec1301405 100644
--- a/disaster_cmd.c
+++ b/disaster_cmd.c
@@ -516,8 +516,8 @@ static void DisasterTick_4(Vehicle *v)
 	v->tick_counter++;
 
 	if (v->current_order.station == 1) {
-		int x = TileX(v->dest_tile) * TILE_SIZE + 8;
-		int y = TileY(v->dest_tile) * TILE_SIZE + 8;
+		int x = TileX(v->dest_tile) * TILE_SIZE + TILE_SIZE / 2;
+		int y = TileY(v->dest_tile) * TILE_SIZE + TILE_SIZE / 2;
 		if (abs(v->x_pos - x) + abs(v->y_pos - y) >= 8) {
 			v->direction = GetDirectionTowards(v, x, y);
 
@@ -715,7 +715,7 @@ static void Disaster0_Init(void)
 
 	/* Pick a random place, unless we find
 	    a small airport */
-	x = TileX(Random()) * TILE_SIZE + 8;
+	x = TileX(Random()) * TILE_SIZE + TILE_SIZE / 2;
 
 	FOR_ALL_STATIONS(st) {
 		if (st->xy && st->airport_tile != 0 &&
@@ -745,7 +745,7 @@ static void Disaster1_Init(void)
 	if (v == NULL)
 		return;
 
-	x = TileX(Random()) * TILE_SIZE + 8;
+	x = TileX(Random()) * TILE_SIZE + TILE_SIZE / 2;
 
 	InitializeDisasterVehicle(v, x, 0, 135, DIR_SE, 2);
 	v->dest_tile = TileXY(MapSizeX() / 2, MapSizeY() / 2);
@@ -845,7 +845,7 @@ static void Disaster4_Init(void)
 
 	if (v == NULL) return;
 
-	x = TileX(Random()) * TILE_SIZE + 8;
+	x = TileX(Random()) * TILE_SIZE + TILE_SIZE / 2;
 
 	y = MapMaxX() * TILE_SIZE - 1;
 	InitializeDisasterVehicle(v, x, y, 135, DIR_NW, 9);
@@ -872,13 +872,13 @@ static void Disaster5_Init(void)
 	if (v == NULL) return;
 
 	r = Random();
-	x = TileX(r) * TILE_SIZE + 8;
+	x = TileX(r) * TILE_SIZE + TILE_SIZE / 2;
 
 	if (r & 0x80000000) {
-		y = MapMaxX() * TILE_SIZE - 8 - 1;
+		y = MapMaxX() * TILE_SIZE - TILE_SIZE / 2 - 1;
 		dir = DIR_NW;
 	} else {
-		y = 8;
+		y = TILE_SIZE / 2;
 		dir = DIR_SE;
 	}
 	InitializeDisasterVehicle(v, x, y, 0, dir, 13);
@@ -896,13 +896,13 @@ static void Disaster6_Init(void)
 	if (v == NULL) return;
 
 	r = Random();
-	x = TileX(r) * TILE_SIZE + 8;
+	x = TileX(r) * TILE_SIZE + TILE_SIZE / 2;
 
 	if (r & 0x80000000) {
-		y = MapMaxX() * TILE_SIZE - 8 - 1;
+		y = MapMaxX() * TILE_SIZE - TILE_SIZE / 2 - 1;
 		dir = DIR_NW;
 	} else {
-		y = 8;
+		y = TILE_SIZE / 2;
 		dir = DIR_SE;
 	}
 	InitializeDisasterVehicle(v, x, y, 0, dir, 14);
diff --git a/elrail.c b/elrail.c
index 6a1a70580..ada534046 100644
--- a/elrail.c
+++ b/elrail.c
@@ -290,7 +290,7 @@ static void DrawCatenaryRailway(const TileInfo *ti)
 			sss = &CatenarySpriteData[Wires[tileh_selector][t][PCPconfig]];
 
 			AddSortableSpriteToDraw( sss->image, ti->x + sss->x_offset, ti->y + sss->y_offset,
-				sss->x_size, sss->y_size, sss->z_size, GetSlopeZ(ti->x + min(sss->x_offset, 15), ti->y + min(sss->y_offset, 15)) + sss->z_offset);
+				sss->x_size, sss->y_size, sss->z_size, GetSlopeZ(ti->x + min(sss->x_offset, TILE_SIZE - 1), ti->y + min(sss->y_offset, TILE_SIZE - 1)) + sss->z_offset);
 		}
 	}
 }
@@ -325,18 +325,18 @@ static void DrawCatenaryOnBridge(const TileInfo *ti)
 	/* every other tile needs a pylon on the northern end */
 	if (num % 2) {
 		if (axis == AXIS_X) {
-			AddSortableSpriteToDraw( pylons_bridge[0 + HASBIT(tlg, 0)], ti->x, ti->y + 4 + 8 * HASBIT(tlg, 0), 1, 1, 10, GetBridgeHeight(ti->tile) + 8);
+			AddSortableSpriteToDraw( pylons_bridge[0 + HASBIT(tlg, 0)], ti->x, ti->y + 4 + 8 * HASBIT(tlg, 0), 1, 1, 10, GetBridgeHeight(ti->tile) + TILE_HEIGHT);
 		} else {
-			AddSortableSpriteToDraw( pylons_bridge[2 + HASBIT(tlg, 1)], ti->x + 4 + 8 * HASBIT(tlg, 1), ti->y, 1, 1, 10, GetBridgeHeight(ti->tile) + 8);
+			AddSortableSpriteToDraw( pylons_bridge[2 + HASBIT(tlg, 1)], ti->x + 4 + 8 * HASBIT(tlg, 1), ti->y, 1, 1, 10, GetBridgeHeight(ti->tile) + TILE_HEIGHT);
 		}
 	}
 
 	/* need a pylon on the southern end of the bridge */
 	if (DistanceMax(ti->tile, start) == length) {
 		if (axis == AXIS_X) {
-			AddSortableSpriteToDraw( pylons_bridge[0 + HASBIT(tlg, 0)], ti->x + 16, ti->y + 4 + 8 * HASBIT(tlg, 0), 1, 1, 10, GetBridgeHeight(ti->tile) + 8);
+			AddSortableSpriteToDraw( pylons_bridge[0 + HASBIT(tlg, 0)], ti->x + 16, ti->y + 4 + 8 * HASBIT(tlg, 0), 1, 1, 10, GetBridgeHeight(ti->tile) + TILE_HEIGHT);
 		} else {
-			AddSortableSpriteToDraw( pylons_bridge[2 + HASBIT(tlg, 1)], ti->x + 4 + 8 * HASBIT(tlg, 1), ti->y + 16, 1, 1, 10, GetBridgeHeight(ti->tile) + 8);
+			AddSortableSpriteToDraw( pylons_bridge[2 + HASBIT(tlg, 1)], ti->x + 4 + 8 * HASBIT(tlg, 1), ti->y + 16, 1, 1, 10, GetBridgeHeight(ti->tile) + TILE_HEIGHT);
 		}
 	}
 }
diff --git a/industry_cmd.c b/industry_cmd.c
index f4031562d..ff66bfd98 100644
--- a/industry_cmd.c
+++ b/industry_cmd.c
@@ -387,7 +387,7 @@ static void DrawTile_Industry(TileInfo *ti)
 	if (ti->tileh != SLOPE_FLAT) {
 		AddSortableSpriteToDraw(SPR_FOUNDATION_BASE + ti->tileh, ti->x, ti->y, 16, 16, 7, z);
 		AddChildSpriteScreen(image, 31, 1);
-		z += 8;
+		z += TILE_HEIGHT;
 	} else {
 		/* Else draw regular ground */
 		DrawGroundSprite(image);
@@ -420,7 +420,7 @@ static void DrawTile_Industry(TileInfo *ti)
 
 static uint GetSlopeZ_Industry(const TileInfo* ti)
 {
-	return ti->z + (ti->tileh == SLOPE_FLAT ? 0 : 8);
+	return ti->z + (ti->tileh == SLOPE_FLAT ? 0 : TILE_HEIGHT);
 }
 
 static Slope GetSlopeTileh_Industry(TileIndex tile, Slope tileh)
@@ -702,7 +702,7 @@ static void CreateIndustryEffectSmoke(TileIndex tile)
 	tileh = GetTileSlope(tile, &z);
 	x = TileX(tile) * TILE_SIZE;
 	y = TileY(tile) * TILE_SIZE;
-	CreateEffectVehicle(x + 15, y + 14, z + 59 + (tileh != SLOPE_FLAT ? 8 : 0), EV_CHIMNEY_SMOKE);
+	CreateEffectVehicle(x + 15, y + 14, z + 59 + (tileh != SLOPE_FLAT ? TILE_HEIGHT : 0), EV_CHIMNEY_SMOKE);
 }
 
 static void MakeIndustryTileBigger(TileIndex tile)
@@ -1177,7 +1177,7 @@ static bool CheckNewIndustry_NULL(TileIndex tile, IndustryType type)
 static bool CheckNewIndustry_Forest(TileIndex tile, IndustryType type)
 {
 	if (_opt.landscape == LT_HILLY) {
-		if (GetTileZ(tile) < _opt.snow_line + 16U) {
+		if (GetTileZ(tile) < _opt.snow_line + TILE_HEIGHT * 2U) {
 			_error_message = STR_4831_FOREST_CAN_ONLY_BE_PLANTED;
 			return false;
 		}
@@ -1241,7 +1241,7 @@ static bool CheckNewIndustry_Lumbermill(TileIndex tile, IndustryType type)
 
 static bool CheckNewIndustry_BubbleGen(TileIndex tile, IndustryType type)
 {
-	return GetTileZ(tile) <= 32;
+	return GetTileZ(tile) <= TILE_HEIGHT * 4;
 }
 
 typedef bool CheckNewIndustryProc(TileIndex tile, IndustryType type);
diff --git a/landscape.c b/landscape.c
index b5d904275..53c72dfaf 100644
--- a/landscape.c
+++ b/landscape.c
@@ -212,7 +212,7 @@ void DrawFoundation(TileInfo *ti, uint f)
 		if (sprite_base < SPR_SLOPES_BASE) sprite_base = SPR_FOUNDATION_BASE + 1; // use original slope sprites
 
 		AddSortableSpriteToDraw(f - 1 + sprite_base, ti->x, ti->y, 16, 16, 7, ti->z);
-		ti->z += 8;
+		ti->z += TILE_HEIGHT;
 		ti->tileh = SLOPE_FLAT;
 		OffsetGroundSprite(31, 1);
 	} else {
@@ -332,7 +332,7 @@ int32 CmdClearArea(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 				// draw explosion animation...
 				if ((x == sx || x == ex) && (y == sy || y == ey)) {
 					// big explosion in each corner, or small explosion for single tiles
-					CreateEffectVehicleAbove(x * TILE_SIZE + 8, y * TILE_SIZE + 8, 2,
+					CreateEffectVehicleAbove(x * TILE_SIZE + TILE_SIZE / 2, y * TILE_SIZE + TILE_SIZE / 2, 2,
 						sy == ey && sx == ex ? EV_EXPLOSION_SMALL : EV_EXPLOSION_LARGE
 					);
 				}
diff --git a/rail_cmd.c b/rail_cmd.c
index 34f563ec9..5c4dfcf24 100644
--- a/rail_cmd.c
+++ b/rail_cmd.c
@@ -1078,7 +1078,7 @@ static void DrawTrackFence_SE(const TileInfo *ti)
 	uint32 image = 0x515;
 	if (ti->tileh != SLOPE_FLAT) image = (ti->tileh & SLOPE_S) ? 0x519 : 0x51B;
 	AddSortableSpriteToDraw(image | _drawtile_track_palette,
-		ti->x, ti->y + 15, 16, 1, 4, ti->z);
+		ti->x, ti->y + TILE_SIZE - 1, 16, 1, 4, ti->z);
 }
 
 static void DrawTrackFence_NW_SE(const TileInfo *ti)
@@ -1100,7 +1100,7 @@ static void DrawTrackFence_SW(const TileInfo *ti)
 	uint32 image = 0x516;
 	if (ti->tileh != SLOPE_FLAT) image = (ti->tileh & SLOPE_S) ? 0x51A : 0x51C;
 	AddSortableSpriteToDraw(image | _drawtile_track_palette,
-		ti->x + 15, ti->y, 1, 16, 4, ti->z);
+		ti->x + TILE_SIZE - 1, ti->y, 1, 16, 4, ti->z);
 }
 
 static void DrawTrackFence_NE_SW(const TileInfo *ti)
@@ -1112,33 +1112,33 @@ static void DrawTrackFence_NE_SW(const TileInfo *ti)
 static void DrawTrackFence_NS_1(const TileInfo *ti)
 {
 	int z = ti->z;
-	if (ti->tileh & SLOPE_W) z += 8;
+	if (ti->tileh & SLOPE_W) z += TILE_HEIGHT;
 	AddSortableSpriteToDraw(0x517 | _drawtile_track_palette,
-		ti->x + 8, ti->y + 8, 1, 1, 4, z);
+		ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
 }
 
 static void DrawTrackFence_NS_2(const TileInfo *ti)
 {
 	int z = ti->z;
-	if (ti->tileh & SLOPE_E) z += 8;
+	if (ti->tileh & SLOPE_E) z += TILE_HEIGHT;
 	AddSortableSpriteToDraw(0x517 | _drawtile_track_palette,
-		ti->x + 8, ti->y + 8, 1, 1, 4, z);
+		ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
 }
 
 static void DrawTrackFence_WE_1(const TileInfo *ti)
 {
 	int z = ti->z;
-	if (ti->tileh & SLOPE_N) z += 8;
+	if (ti->tileh & SLOPE_N) z += TILE_HEIGHT;
 	AddSortableSpriteToDraw(0x518 | _drawtile_track_palette,
-		ti->x + 8, ti->y + 8, 1, 1, 4, z);
+		ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
 }
 
 static void DrawTrackFence_WE_2(const TileInfo *ti)
 {
 	int z = ti->z;
-	if (ti->tileh & SLOPE_S) z += 8;
+	if (ti->tileh & SLOPE_S) z += TILE_HEIGHT;
 	AddSortableSpriteToDraw(0x518 | _drawtile_track_palette,
-		ti->x + 8, ti->y + 8, 1, 1, 4, z);
+		ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 4, z);
 }
 
 static void DetTrackDrawProc_Null(const TileInfo *ti)
@@ -1703,12 +1703,12 @@ static uint GetSlopeZ_Track(const TileInfo* ti)
 
 	if (tileh == SLOPE_FLAT) return z;
 	if (GetRailTileType(ti->tile) == RAIL_TYPE_DEPOT_WAYPOINT) {
-		return z + 8;
+		return z + TILE_HEIGHT;
 	} else {
 		uint f = GetRailFoundation(ti->tileh, GetTrackBits(ti->tile));
 
 		if (f != 0) {
-			if (f < 15) return z + 8; // leveled foundation
+			if (f < 15) return z + TILE_HEIGHT; // leveled foundation
 			tileh = _inclined_tileh[f - 15]; // inclined foundation
 		}
 		return z + GetPartialZ(ti->x & 0xF, ti->y & 0xF, tileh);
diff --git a/road_cmd.c b/road_cmd.c
index b4bf40578..b94d58d3e 100644
--- a/road_cmd.c
+++ b/road_cmd.c
@@ -831,12 +831,12 @@ static uint GetSlopeZ_Road(const TileInfo* ti)
 		uint f = GetRoadFoundation(tileh, GetRoadBits(ti->tile));
 
 		if (f != 0) {
-			if (f < 15) return z + 8; // leveled foundation
+			if (f < 15) return z + TILE_HEIGHT; // leveled foundation
 			tileh = _inclined_tileh[f - 15]; // inclined foundation
 		}
 		return z + GetPartialZ(ti->x & 0xF, ti->y & 0xF, tileh);
 	} else {
-		return z + 8;
+		return z + TILE_HEIGHT;
 	}
 }
 
diff --git a/roadveh_cmd.c b/roadveh_cmd.c
index fbe1e454f..64efce814 100644
--- a/roadveh_cmd.c
+++ b/roadveh_cmd.c
@@ -144,8 +144,8 @@ int32 CmdBuildRoadVeh(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 		v->owner = _current_player;
 
 		v->tile = tile;
-		x = TileX(tile) * TILE_SIZE + 8;
-		y = TileY(tile) * TILE_SIZE + 8;
+		x = TileX(tile) * TILE_SIZE + TILE_SIZE / 2;
+		y = TileY(tile) * TILE_SIZE + TILE_SIZE / 2;
 		v->x_pos = x;
 		v->y_pos = y;
 		v->z_pos = GetSlopeZ(x,y);
diff --git a/ship_cmd.c b/ship_cmd.c
index 302f58018..3cb66e430 100644
--- a/ship_cmd.c
+++ b/ship_cmd.c
@@ -847,8 +847,8 @@ int32 CmdBuildShip(TileIndex tile, uint32 flags, uint32 p1, uint32 p2)
 
 		v->owner = _current_player;
 		v->tile = tile;
-		x = TileX(tile) * TILE_SIZE + 8;
-		y = TileY(tile) * TILE_SIZE + 8;
+		x = TileX(tile) * TILE_SIZE + TILE_SIZE / 2;
+		y = TileY(tile) * TILE_SIZE + TILE_SIZE / 2;
 		v->x_pos = x;
 		v->y_pos = y;
 		v->z_pos = GetSlopeZ(x,y);
diff --git a/sound.c b/sound.c
index 0c63825e2..30898cdaf 100644
--- a/sound.c
+++ b/sound.c
@@ -207,9 +207,9 @@ static void SndPlayScreenCoordFx(SoundFx sound, int x, int y)
 
 void SndPlayTileFx(SoundFx sound, TileIndex tile)
 {
-	/* emits sound from center (+ 8) of the tile */
-	int x = TileX(tile) * TILE_SIZE + 8;
-	int y = TileY(tile) * TILE_SIZE + 8;
+	/* emits sound from center of the tile */
+	int x = TileX(tile) * TILE_SIZE + TILE_SIZE / 2;
+	int y = TileY(tile) * TILE_SIZE + TILE_SIZE / 2;
 	Point pt = RemapCoords(x, y, GetSlopeZ(x, y));
 	SndPlayScreenCoordFx(sound, pt.x, pt.y);
 }
diff --git a/station_cmd.c b/station_cmd.c
index 08edf3eb3..801b292d8 100644
--- a/station_cmd.c
+++ b/station_cmd.c
@@ -809,7 +809,7 @@ int32 CheckFlatLandBelow(TileIndex tile, uint w, uint h, uint flags, uint invali
 				return_cmd_error(STR_0007_FLAT_LAND_REQUIRED);
 			}
 			cost += _price.terraform;
-			flat_z += 8;
+			flat_z += TILE_HEIGHT;
 		}
 
 		// get corresponding flat level and make sure that all parts of the station have the same level.
@@ -2032,7 +2032,7 @@ void StationPickerDrawSprite(int x, int y, RailType railtype, int image)
 
 static uint GetSlopeZ_Station(const TileInfo* ti)
 {
-	return ti->z + (ti->tileh == SLOPE_FLAT ? 0 : 8);
+	return ti->z + (ti->tileh == SLOPE_FLAT ? 0 : TILE_HEIGHT);
 }
 
 static Slope GetSlopeTileh_Station(TileIndex tile, Slope tileh)
@@ -2190,8 +2190,8 @@ static uint32 VehicleEnter_Station(Vehicle *v, TileIndex tile, int x, int y)
 					y &= 0xF;
 
 					if (DiagDirToAxis(dir) != AXIS_X) intswap(x, y);
-					if (y == 8) {
-						if (dir != DIAGDIR_SE && dir != DIAGDIR_SW) x = ~x & 0xF;
+					if (y == TILE_SIZE / 2) {
+						if (dir != DIAGDIR_SE && dir != DIAGDIR_SW) x = TILE_SIZE - 1 - x;
 						if (x == 12) return 2 | (station_id << 8); /* enter station */
 						if (x < 12) {
 							uint16 spd;
diff --git a/town_cmd.c b/town_cmd.c
index 277fd06b9..359c780b7 100644
--- a/town_cmd.c
+++ b/town_cmd.c
@@ -106,7 +106,7 @@ static void DrawTile_Town(TileInfo *ti)
 	if (ti->tileh != SLOPE_FLAT) {
 		AddSortableSpriteToDraw(SPR_FOUNDATION_BASE + ti->tileh, ti->x, ti->y, 16, 16, 7, z);
 		AddChildSpriteScreen(dcts->sprite_1, 31, 1);
-		z += 8;
+		z += TILE_HEIGHT;
 	} else {
 		/* Else draw regular ground */
 		DrawGroundSprite(dcts->sprite_1);
@@ -137,7 +137,7 @@ static void DrawTile_Town(TileInfo *ti)
 
 static uint GetSlopeZ_Town(const TileInfo* ti)
 {
-	return ti->z + (ti->tileh == SLOPE_FLAT ? 0 : 8);
+	return ti->z + (ti->tileh == SLOPE_FLAT ? 0 : TILE_HEIGHT);
 }
 
 static Slope GetSlopeTileh_Town(TileIndex tile, Slope tileh)
diff --git a/train_cmd.c b/train_cmd.c
index f29426ced..0567cee0d 100644
--- a/train_cmd.c
+++ b/train_cmd.c
@@ -2615,7 +2615,7 @@ static bool CheckCompatibleRail(const Vehicle *v, TileIndex tile)
 				Slope tileh = GetTileSlope(tile, &height);
 
 				// correct Z position of a train going under a bridge on slopes
-				if (CorrectZ(tileh)) height += 8;
+				if (CorrectZ(tileh)) height += TILE_HEIGHT;
 
 				if (v->z_pos != height) return true; // train is going over bridge
 			}
@@ -3236,7 +3236,7 @@ static bool TrainCheckIfLineEnds(Vehicle *v)
 
 	if (GB(ts, 0, 16) != 0) {
 		/* If we approach a rail-piece which we can't enter, or the back of a depot, don't enter it! */
-		if (x + 4 > 15 &&
+		if (x + 4 >= TILE_SIZE &&
 				(!CheckCompatibleRail(v, tile) ||
 				(IsTileDepotType(tile, TRANSPORT_RAIL) &&
 				GetRailDepotDirection(tile) == dir))) {
@@ -3255,7 +3255,7 @@ static bool TrainCheckIfLineEnds(Vehicle *v)
 			}
 			return true;
 		}
-	} else if (x + 4 > 15) {
+	} else if (x + 4 >= TILE_SIZE) {
 		v->cur_speed = 0;
 		ReverseTrainDirection(v);
 		return false;
diff --git a/tunnelbridge_cmd.c b/tunnelbridge_cmd.c
index da9e84ab2..fc644f20b 100644
--- a/tunnelbridge_cmd.c
+++ b/tunnelbridge_cmd.c
@@ -254,12 +254,12 @@ int32 CmdBuildBridge(TileIndex end_tile, uint32 flags, uint32 p1, uint32 p2)
 	tileh_end = GetTileSlope(tile_end, &z_end);
 
 	if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh_start)) {
-		z_start += 8;
+		z_start += TILE_HEIGHT;
 		tileh_start = SLOPE_FLAT;
 	}
 
 	if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh_end)) {
-		z_end += 8;
+		z_end += TILE_HEIGHT;
 		tileh_end = SLOPE_FLAT;
 	}
 
@@ -650,7 +650,7 @@ static int32 DoClearBridge(TileIndex tile, uint32 flags)
 	v = FindVehicleBetween(
 		tile    + delta,
 		endtile - delta,
-		TilePixelHeight(tile) + 8 + GetCorrectTileHeight(tile)
+		TilePixelHeight(tile) + TILE_HEIGHT + GetCorrectTileHeight(tile)
 	);
 	if (v != NULL) {
 		VehicleInTheWayErrMsg(v);
@@ -758,7 +758,7 @@ int32 DoConvertTunnelBridgeRail(TileIndex tile, RailType totype, bool exec)
 		int32 cost;
 		uint z = TilePixelHeight(tile);
 
-		z += 8;
+		z += TILE_HEIGHT;
 
 		if (!CheckTileOwnership(tile)) return CMD_ERROR;
 
@@ -807,7 +807,7 @@ uint GetBridgeHeight(TileIndex t)
 	/* Return the height there (the height of the NORTH CORNER)
 	 * If the end of the bridge is on a tile with all corners except the north corner raised,
 	 * the z coordinate is 1 height level too low. Compensate for that */
-	return TilePixelHeight(tile) + (GetTileSlope(tile, NULL) == SLOPE_WSE ? 8 : 0);
+	return TilePixelHeight(tile) + (GetTileSlope(tile, NULL) == SLOPE_WSE ? TILE_HEIGHT : 0);
 }
 
 static const byte _bridge_foundations[2][16] = {
@@ -837,20 +837,20 @@ static void DrawBridgePillars(PalSpriteID image, const TileInfo *ti, int x, int
 		if (_display_opt & DO_TRANS_BUILDINGS) MAKE_TRANSPARENT(image);
 
 		p = _tileh_bits[(image & 1) * 2 + (axis == AXIS_X ? 0 : 1)];
-		front_height = ti->z + ((ti->tileh & p[0])?8:0);
-		back_height = ti->z + ((ti->tileh & p[1])?8:0);
+		front_height = ti->z + (ti->tileh & p[0] ? TILE_HEIGHT : 0);
+		back_height  = ti->z + (ti->tileh & p[1] ? TILE_HEIGHT : 0);
 
 		if (IsSteepSlope(ti->tileh)) {
-			if (!(ti->tileh & p[2])) front_height += 8;
-			if (!(ti->tileh & p[3])) back_height += 8;
+			if (!(ti->tileh & p[2])) front_height += TILE_HEIGHT;
+			if (!(ti->tileh & p[3])) back_height  += TILE_HEIGHT;
 		}
 
-		for (; z >= front_height || z >= back_height; z = z - 8) {
+		for (; z >= front_height || z >= back_height; z -= TILE_HEIGHT) {
 			if (z >= front_height) { // front facing pillar
 				AddSortableSpriteToDraw(image, x,y, p[4], p[5], 0x28, z);
 			}
 
-			if (drawfarpillar && z >= back_height && z < i - 8) { // back facing pillar
+			if (drawfarpillar && z >= back_height && z < i - TILE_HEIGHT) { // back facing pillar
 				AddSortableSpriteToDraw(image, x - p[6], y - p[7], p[4], p[5], 0x28, z);
 			}
 		}
@@ -914,7 +914,7 @@ static void DrawTile_TunnelBridge(TileInfo *ti)
 		DrawGroundSprite(image);
 		if (GetRailType(ti->tile) == RAILTYPE_ELECTRIC) DrawCatenary(ti);
 
-		AddSortableSpriteToDraw(image+1, ti->x + 15, ti->y + 15, 1, 1, 8, (byte)ti->z);
+		AddSortableSpriteToDraw(image+1, ti->x + TILE_SIZE - 1, ti->y + TILE_SIZE - 1, 1, 1, 8, (byte)ti->z);
 	} else if (IsBridge(ti->tile)) { // XXX is this necessary?
 		int base_offset;
 
@@ -1076,34 +1076,34 @@ static uint GetSlopeZ_TunnelBridge(const TileInfo* ti)
 			if (5 <= pos && pos <= 10) {
 				uint delta;
 
-				if (HASBIT(BRIDGE_HORZ_RAMP, tileh)) return z + 8;
+				if (HASBIT(BRIDGE_HORZ_RAMP, tileh)) return z + TILE_HEIGHT;
 
-				if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh)) z += 8;
+				if (HASBIT(BRIDGE_FULL_LEVELED_FOUNDATION, tileh)) z += TILE_HEIGHT;
 				switch (dir) {
 					default:
-					case DIAGDIR_NE: delta = (15 - x) / 2; break;
+					case DIAGDIR_NE: delta = (TILE_SIZE - 1 - x) / 2; break;
 					case DIAGDIR_SE: delta = y / 2; break;
 					case DIAGDIR_SW: delta = x / 2; break;
-					case DIAGDIR_NW: delta = (15 - y) / 2; break;
+					case DIAGDIR_NW: delta = (TILE_SIZE - 1 - y) / 2; break;
 				}
 				return z + 1 + delta;
 			} else {
 				uint f = GetBridgeFoundation(tileh, DiagDirToAxis(dir));
 
 				if (f != 0) {
-					if (f < 15) return z + 8;
+					if (f < 15) return z + TILE_HEIGHT;
 					tileh = _inclined_tileh[f - 15];
 				}
 			}
 		} else {
 			// HACK on the bridge?
-			if (_get_z_hint >= z + 8 + (tileh == SLOPE_FLAT ? 0 : 8)) return _get_z_hint;
+			if (_get_z_hint >= z + TILE_HEIGHT + (tileh == SLOPE_FLAT ? 0 : TILE_HEIGHT)) return _get_z_hint;
 
 			if (IsTransportUnderBridge(tile)) {
 				uint f = _bridge_foundations[GetBridgeAxis(tile)][tileh];
 
 				if (f != 0) {
-					if (f < 15) return z + 8;
+					if (f < 15) return z + TILE_HEIGHT;
 					tileh = _inclined_tileh[f - 15];
 				}
 			}
@@ -1360,7 +1360,7 @@ static uint32 VehicleEnter_TunnelBridge(Vehicle *v, TileIndex tile, int x, int y
 			uint h;
 
 			// Compensate for possible foundation
-			if (GetTileSlope(tile, &h) != SLOPE_FLAT) h += 8;
+			if (GetTileSlope(tile, &h) != SLOPE_FLAT) h += TILE_HEIGHT;
 			if (IsBridgeRamp(tile) ||
 					myabs(h - v->z_pos) > 2) { // high above the ground -> on the bridge
 				/* modify speed of vehicle */
diff --git a/unmovable_cmd.c b/unmovable_cmd.c
index 067af3ecc..e6faf9a6b 100644
--- a/unmovable_cmd.c
+++ b/unmovable_cmd.c
@@ -165,7 +165,7 @@ static void DrawTile_Unmovable(TileInfo *ti)
 
 			AddSortableSpriteToDraw(
 				PLAYER_SPRITE_COLOR(GetTileOwner(ti->tile)) + PALETTE_MODIFIER_COLOR + SPR_BOUGHT_LAND,
-				ti->x+8, ti->y+8, 1, 1, 10, GetSlopeZ(ti->x+8, ti->y+8)
+				ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2, 1, 1, 10, GetSlopeZ(ti->x + TILE_SIZE / 2, ti->y + TILE_SIZE / 2)
 			);
 
 			break;
@@ -201,7 +201,7 @@ static uint GetSlopeZ_Unmovable(const TileInfo* ti)
 	if (IsOwnedLand(ti->tile)) {
 		return ti->z + GetPartialZ(ti->x & 0xF, ti->y & 0xF, ti->tileh);
 	} else {
-		return ti->z + (ti->tileh == SLOPE_FLAT ? 0 : 8);
+		return ti->z + (ti->tileh == SLOPE_FLAT ? 0 : TILE_HEIGHT);
 	}
 }
 
@@ -341,7 +341,7 @@ void GenerateUnmovables(void)
 	j = ScaleByMapSize(40); // maximum number of radio towers on the map
 	do {
 		tile = RandomTile();
-		if (IsTileType(tile, MP_CLEAR) && GetTileSlope(tile, &h) == SLOPE_FLAT && h >= 32) {
+		if (IsTileType(tile, MP_CLEAR) && GetTileSlope(tile, &h) == SLOPE_FLAT && h >= TILE_HEIGHT * 4) {
 			if (!checkRadioTowerNearby(tile)) continue;
 			MakeTransmitter(tile);
 			if (--j == 0) break;
diff --git a/vehicle.c b/vehicle.c
index 9ab50af98..e2d19b081 100644
--- a/vehicle.c
+++ b/vehicle.c
@@ -131,7 +131,7 @@ static void *EnsureNoVehicleProcZ(Vehicle *v, void *data)
 	const TileInfo *ti = data;
 
 	if (v->tile != ti->tile || v->type == VEH_Disaster) return NULL;
-	if (!IS_INT_INSIDE(ti->z - v->z_pos, 0, 8 + 1)) return NULL;
+	if (!IS_INT_INSIDE(ti->z - v->z_pos, 0, TILE_HEIGHT + 1)) return NULL;
 
 	VehicleInTheWayErrMsg(v);
 	return v;
@@ -140,7 +140,7 @@ static void *EnsureNoVehicleProcZ(Vehicle *v, void *data)
 static inline uint Correct_Z(Slope tileh)
 {
 	// needs z correction for slope-type graphics that have the NORTHERN tile lowered
-	return CorrectZ(tileh) ? 8 : 0;
+	return CorrectZ(tileh) ? TILE_HEIGHT : 0;
 }
 
 uint GetCorrectTileHeight(TileIndex tile)
diff --git a/viewport.c b/viewport.c
index cc3863cde..239a77d14 100644
--- a/viewport.c
+++ b/viewport.c
@@ -611,8 +611,8 @@ static void DrawTileSelection(const TileInfo *ti)
 			// Figure out the Z coordinate for the single dot.
 			byte z = ti->z;
 			if (ti->tileh & SLOPE_N) {
-				z += 8;
-				if (ti->tileh == SLOPE_STEEP_N) z += 8;
+				z += TILE_HEIGHT;
+				if (ti->tileh == SLOPE_STEEP_N) z += TILE_HEIGHT;
 			}
 			DrawGroundSpriteAt(_cur_dpi->zoom != 2 ? SPR_DOT : SPR_DOT_SMALL, ti->x, ti->y, z);
 		} else if (_thd.drawstyle & HT_RAIL /*&& _thd.place_mode == VHM_RAIL*/) {
@@ -1759,7 +1759,7 @@ bool ScrollMainWindowTo(int x, int y)
 
 bool ScrollMainWindowToTile(TileIndex tile)
 {
-	return ScrollMainWindowTo(TileX(tile) * TILE_SIZE + 8, TileY(tile) * TILE_SIZE + 8);
+	return ScrollMainWindowTo(TileX(tile) * TILE_SIZE + TILE_SIZE / 2, TileY(tile) * TILE_SIZE + TILE_SIZE / 2);
 }
 
 void SetRedErrorSquare(TileIndex tile)