(svn r12534) -Feature: Add a new type of town road layouts - random for each town

4 files changed, 87 insertions, 31 deletions

diff --git a/src/lang/english.txt b/src/lang/english.txt
index 5d08b9a81..ffe0ec08c 100644
--- a/src/lang/english.txt
+++ b/src/lang/english.txt
@@ -1173,6 +1173,7 @@ STR_CONFIG_PATCHES_TOWN_LAYOUT_DEFAULT                          :default
 STR_CONFIG_PATCHES_TOWN_LAYOUT_BETTER_ROADS                     :better roads
 STR_CONFIG_PATCHES_TOWN_LAYOUT_2X2_GRID                         :2x2 grid
 STR_CONFIG_PATCHES_TOWN_LAYOUT_3X3_GRID                         :3x3 grid
+STR_CONFIG_PATCHES_TOWN_LAYOUT_RANDOM                           :random
 
 STR_CONFIG_PATCHES_TOOLBAR_POS                                  :{LTBLUE}Position of main toolbar: {ORANGE}{STRING1}
 STR_CONFIG_PATCHES_TOOLBAR_POS_LEFT                             :Left
diff --git a/src/town.h b/src/town.h
index cbbc76371..3f5f2bd84 100644
--- a/src/town.h
+++ b/src/town.h
@@ -6,6 +6,7 @@
 #define TOWN_H
 
 #include "oldpool.h"
+#include "core/bitmath_func.hpp"
 #include "core/random_func.hpp"
 #include "cargo_type.h"
 #include "tile_type.h"
@@ -13,6 +14,7 @@
 #include "town_type.h"
 #include "player_type.h"
 #include "newgrf_string_type.h"
+#include "settings_type.h"
 
 enum {
 	HOUSE_NO_CLASS   = 0,
@@ -161,6 +163,9 @@ struct Town : PoolItem<Town, TownID, &_Town_pool> {
 	/* NOSAVE: The number of each type of building in the town. */
 	BuildingCounts building_counts;
 
+	/* NOSAVE: The town specific road layout */
+	TownLayout layout;
+
 	/**
 	 * Creates a new town
 	 */
@@ -170,8 +175,21 @@ struct Town : PoolItem<Town, TownID, &_Town_pool> {
 	~Town();
 
 	inline bool IsValid() const { return this->xy != 0; }
+
+	void InitializeLayout();
+
+	inline TownLayout GetActiveLayout() const;
 };
 
+/**
+ * Get the current valid layout for the town
+ * @return the active layout for this town
+ */
+inline TownLayout Town::GetActiveLayout() const
+{
+	return (_patches.town_layout == TL_RANDOM) ? this->layout : _patches.town_layout;
+}
+
 struct HouseSpec {
 	/* Standard properties */
 	Year min_date;                     ///< introduction year of the house
@@ -314,7 +332,6 @@ extern const Town **_town_sort;
 extern Town *_cleared_town;
 extern int _cleared_town_rating;
 
-uint TileHash2Bit(uint x, uint y);
 void ResetHouses();
 
 void ClearTownHouse(Town *t, TileIndex tile);
@@ -327,4 +344,34 @@ void ChangeTownRating(Town *t, int add, int max);
 HouseZonesBits GetTownRadiusGroup(const Town* t, TileIndex tile);
 void SetTownRatingTestMode(bool mode);
 
+/**
+ * Calculate a hash value from a tile position
+ *
+ * @param x The X coordinate
+ * @param y The Y coordinate
+ * @return The hash of the tile
+ */
+static inline uint TileHash(uint x, uint y)
+{
+	uint hash = x >> 4;
+	hash ^= x >> 6;
+	hash ^= y >> 4;
+	hash -= y >> 6;
+	return hash;
+}
+
+/**
+ * Get the last two bits of the TileHash
+ *  from a tile position.
+ *
+ * @see TileHash()
+ * @param x The X coordinate
+ * @param y The Y coordinate
+ * @return The last two bits from hash of the tile
+ */
+static inline uint TileHash2Bit(uint x, uint y)
+{
+	return GB(TileHash(x, y), 0, 2);
+}
+
 #endif /* TOWN_H */
diff --git a/src/town_cmd.cpp b/src/town_cmd.cpp
index 6d4c1bec3..041f9bddd 100644
--- a/src/town_cmd.cpp
+++ b/src/town_cmd.cpp
@@ -107,6 +107,23 @@ Town::~Town()
 	this->xy = 0;
 }
 
+/**
+ * Generate a random town road layout.
+ *
+ * The layout is based on the TileHash.
+ */
+void Town::InitializeLayout()
+{
+	this->layout = (TownLayout)(TileHash(TileX(this->xy), TileY(this->xy)) % NUM_TLS);
+
+	/* Set invalid layouts to valid ones */
+	switch (this->layout) {
+		default: break;
+		case TL_RANDOM: this->layout = TL_ORIGINAL; break;
+		case TL_NO_ROADS: this->layout = TL_BETTER_ROADS; break;
+	}
+}
+
 // Local
 static int _grow_town_result;
 
@@ -130,23 +147,6 @@ static TownDrawTileProc * const _town_draw_tile_procs[1] = {
 };
 
 /**
- * Calculate a hash value from a tile position
- *
- * @param x The X coordinate
- * @param y The Y coordinate
- * @return The hash of the tile
- */
-uint TileHash2Bit(uint x, uint y)
-{
-	uint hash = x >> 4;
-	hash ^= x >> 6;
-	hash ^= y >> 4;
-	hash -= y >> 6;
-	hash &= 3;
-	return hash;
-}
-
-/**
  * Return a random direction
  *
  * @return a random direction
@@ -708,11 +708,12 @@ static bool IsNeighborRoadTile(TileIndex tile, const DiagDirection dir, uint dis
 /**
  * Check if a Road is allowed on a given tile
  *
+ * @param t The current town
  * @param tile The target tile
  * @param dir The direction in which we want to extend the town
  * @return true if it is allowed else false
  */
-static bool IsRoadAllowedHere(TileIndex tile, DiagDirection dir)
+static bool IsRoadAllowedHere(Town *t, TileIndex tile, DiagDirection dir)
 {
 	if (TileX(tile) < 2 || TileX(tile) >= MapMaxX() || TileY(tile) < 2 || TileY(tile) >= MapMaxY()) return false;
 
@@ -733,7 +734,7 @@ static bool IsRoadAllowedHere(TileIndex tile, DiagDirection dir)
 		if (cur_slope == SLOPE_FLAT) {
 no_slope:
 			/* Tile has no slope */
-			switch (_patches.town_layout) {
+			switch (t->GetActiveLayout()) {
 				default: NOT_REACHED();
 
 				case TL_ORIGINAL: // Disallow the road if any neighboring tile has a road (distance: 1)
@@ -804,13 +805,13 @@ static void LevelTownLand(TileIndex tile)
  * @return the RoadBit of the current tile regarding
  *  the selected town layout
  */
-static RoadBits GetTownRoadGridElement(Town* t, TileIndex tile, DiagDirection dir)
+static RoadBits GetTownRoadGridElement(Town *t, TileIndex tile, DiagDirection dir)
 {
 	/* align the grid to the downtown */
 	TileIndexDiffC grid_pos = TileIndexToTileIndexDiffC(t->xy, tile); // Vector from downtown to the tile
 	RoadBits rcmd = ROAD_NONE;
 
-	switch (_patches.town_layout) {
+	switch (t->GetActiveLayout()) {
 		default: NOT_REACHED();
 
 		case TL_2X2_GRID:
@@ -993,7 +994,7 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t
 		LevelTownLand(tile);
 
 		/* Is a road allowed here? */
-		switch (_patches.town_layout) {
+		switch (t1->GetActiveLayout()) {
 			default: NOT_REACHED();
 
 			case TL_NO_ROADS: /* Disallow Roads */
@@ -1007,7 +1008,7 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t
 
 			case TL_BETTER_ROADS:
 			case TL_ORIGINAL:
-				if (!IsRoadAllowedHere(tile, target_dir)) return;
+				if (!IsRoadAllowedHere(t1, tile, target_dir)) return;
 
 				DiagDirection source_dir = ReverseDiagDir(target_dir);
 
@@ -1016,7 +1017,7 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t
 					do target_dir = RandomDiagDir(); while (target_dir == source_dir);
 				}
 
-				if (!IsRoadAllowedHere(TileAddByDiagDir(tile, target_dir), target_dir)) {
+				if (!IsRoadAllowedHere(t1, TileAddByDiagDir(tile, target_dir), target_dir)) {
 					/* A road is not allowed to continue the randomized road,
 					 *  return if the road we're trying to build is curved. */
 					if (target_dir != ReverseDiagDir(source_dir)) return;
@@ -1041,7 +1042,7 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t
 		 * the fitting RoadBits */
 		_grow_town_result = GROWTH_SEARCH_STOPPED;
 
-		switch (_patches.town_layout) {
+		switch (t1->GetActiveLayout()) {
 			default: NOT_REACHED();
 
 			case TL_NO_ROADS: /* Disallow Roads */
@@ -1079,7 +1080,7 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t
 		/* Don't walk into water. */
 		if (IsWaterTile(house_tile)) return;
 
-		switch (_patches.town_layout) {
+		switch (t1->GetActiveLayout()) {
 			default: NOT_REACHED();
 
 			case TL_NO_ROADS:
@@ -1103,7 +1104,7 @@ static void GrowTownInTile(TileIndex *tile_ptr, RoadBits cur_rb, DiagDirection t
 				 /* Allow a house at the edge. 60% chance or
 				  * always ok if no road allowed. */
 				rcmd = DiagDirToRoadBits(target_dir);
-				allow_house = (!IsRoadAllowedHere(house_tile, target_dir) || Chance16(6, 10));
+				allow_house = (!IsRoadAllowedHere(t1, house_tile, target_dir) || Chance16(6, 10));
 				break;
 		}
 
@@ -1157,7 +1158,7 @@ static int GrowTownAtRoad(Town *t, TileIndex tile)
 	/* Number of times to search.
 	 * Better roads, 2X2 and 3X3 grid grow quite fast so we give
 	 * them a little handicap. */
-	switch (_patches.town_layout) {
+	switch (t->GetActiveLayout()) {
 		case TL_BETTER_ROADS:
 			_grow_town_result = 10 + t->num_houses * 2 / 9;
 			break;
@@ -1447,6 +1448,8 @@ static void DoCreateTown(Town *t, TileIndex tile, uint32 townnameparts, TownSize
 	UpdateTownVirtCoord(t);
 	_town_sort_dirty = true;
 
+	t->InitializeLayout();
+
 	/* Random town size. */
 	x = (Random() & 0xF) + 8;
 
@@ -1736,7 +1739,7 @@ static inline bool TownLayoutAllowsHouseHere(Town *t, TileIndex tile)
 {
 	TileIndexDiffC grid_pos = TileIndexToTileIndexDiffC(t->xy, tile);
 
-	switch (_patches.town_layout) {
+	switch (t->GetActiveLayout()) {
 		case TL_2X2_GRID:
 			if ((grid_pos.x % 3) == 0 || (grid_pos.y % 3) == 0) return false;
 			break;
@@ -1767,7 +1770,7 @@ static inline bool TownLayoutAllows2x2HouseHere(Town *t, TileIndex tile)
 	uint dx = MapSize() + TileX(t->xy) - TileX(tile);
 	uint dy = MapSize() + TileY(t->xy) - TileY(tile);
 
-	switch (_patches.town_layout) {
+	switch (t->GetActiveLayout()) {
 		case TL_2X2_GRID:
 			if ((dx % 3) != 0 || (dy % 3) != 0) return false;
 			break;
@@ -2700,6 +2703,9 @@ static void Load_TOWN()
 void AfterLoadTown()
 {
 	_town_sort_dirty = true;
+
+	Town *t;
+	FOR_ALL_TOWNS(t) t->InitializeLayout();
 }
 
 extern const ChunkHandler _town_chunk_handlers[] = {
diff --git a/src/town_type.h b/src/town_type.h
index 3491b68d7..c800a5154 100644
--- a/src/town_type.h
+++ b/src/town_type.h
@@ -66,6 +66,8 @@ enum TownLayout {
 	TL_2X2_GRID,         ///< Geometric 2x2 grid algorithm
 	TL_3X3_GRID,         ///< Geometric 3x3 grid algorithm
 
+	TL_RANDOM,           ///< Random town layout
+
 	NUM_TLS,             ///< Number of town layouts
 };