1

#include "stdafx.h"

     2

#include "openttd.h"

     3

#include "debug.h"

     5

#include "map.h"

     6

#include "tile.h"

     7

#include "command.h"

     8

#include "ai_new.h"

     9

#include "depot.h"

    10

#include "variables.h"

    11

    12

#define TEST_STATION_NO_DIR 0xFF

    13

    14

// Tests if a station can be build on the given spot

    15

// TODO: make it train compatible

    16

static bool TestCanBuildStationHere(TileIndex tile, byte dir)

    17

{

    18

	Player *p = GetPlayer(_current_player);

    19

    20

	if (dir == TEST_STATION_NO_DIR) {

    21

		int32 ret;

    22

		// TODO: currently we only allow spots that can be access from al 4 directions...

    23

		//  should be fixed!!!

    24

		for (dir = 0; dir < 4; dir++) {

    25

			ret = AiNew_Build_Station(p, p->ainew.tbt, tile, 1, 1, dir, DC_QUERY_COST);

    26

			if (!CmdFailed(ret)) return true;

    27

		}

    28

		return false;

    29

	}

    30

    31

	// return true if command succeeded, so the inverse of CmdFailed()

    32

	return !CmdFailed(AiNew_Build_Station(p, p->ainew.tbt, tile, 1, 1, dir, DC_QUERY_COST));

    33

}

    34

    35

    36

static bool IsRoad(TileIndex tile)

    37

{

    38

	return

    39

		// MP_STREET, but not a road depot?

    40

		(IsTileType(tile, MP_STREET) && !IsTileDepotType(tile, TRANSPORT_ROAD)) ||

    41

		(IsTileType(tile, MP_TUNNELBRIDGE) && (

    42

			// road tunnel?

    43

			((_m[tile].m5 & 0x80) == 0 && (_m[tile].m5 & 0x4) == 0x4) ||

    44

			// road bridge?

    45

			((_m[tile].m5 & 0x80) != 0 && (_m[tile].m5 & 0x2) == 0x2)

    46

		));

    47

}

    48

    49

    50

// Checks if a tile 'a' is between the tiles 'b' and 'c'

    51

#define TILES_BETWEEN(a, b, c) (TileX(a) >= TileX(b) && TileX(a) <= TileX(c) && TileY(a) >= TileY(b) && TileY(a) <= TileY(c))

    52

    53

// Check if the current tile is in our end-area

    54

static int32 AyStar_AiPathFinder_EndNodeCheck(AyStar *aystar, OpenListNode *current)

    55

{

    56

	Ai_PathFinderInfo *PathFinderInfo = (Ai_PathFinderInfo*)aystar->user_target;

    57

	// It is not allowed to have a station on the end of a bridge or tunnel ;)

    58

	if (current->path.node.user_data[0] != 0) return AYSTAR_DONE;

    59

	if (TILES_BETWEEN(current->path.node.tile, PathFinderInfo->end_tile_tl, PathFinderInfo->end_tile_br))

    60

		if (IsTileType(current->path.node.tile, MP_CLEAR) || IsTileType(current->path.node.tile, MP_TREES))

    61

			if (current->path.parent == NULL || TestCanBuildStationHere(current->path.node.tile, AiNew_GetDirection(current->path.parent->node.tile, current->path.node.tile)))

    62

				return AYSTAR_FOUND_END_NODE;

    63

    64

	return AYSTAR_DONE;

    65

}

    66

    67

// Calculates the hash

    68

//   Currently it is a 10 bit hash, so the hash array has a max depth of 6 bits (so 64)

    69

static uint AiPathFinder_Hash(uint key1, uint key2)

    70

{

    71

	return (TileX(key1) & 0x1F) + ((TileY(key1) & 0x1F) << 5);

    72

}

    73

    74

// Clear the memory of all the things

    75

static void AyStar_AiPathFinder_Free(AyStar *aystar)

    76

{

    77

	AyStarMain_Free(aystar);

    78

	free(aystar);

    79

}

    80

    81

static int32 AyStar_AiPathFinder_CalculateG(AyStar *aystar, AyStarNode *current, OpenListNode *parent);

    82

static int32 AyStar_AiPathFinder_CalculateH(AyStar *aystar, AyStarNode *current, OpenListNode *parent);

    83

static void AyStar_AiPathFinder_FoundEndNode(AyStar *aystar, OpenListNode *current);

    84

static void AyStar_AiPathFinder_GetNeighbours(AyStar *aystar, OpenListNode *current);

    85

    86

// This creates the AiPathFinder

    87

AyStar *new_AyStar_AiPathFinder(int max_tiles_around, Ai_PathFinderInfo *PathFinderInfo)

    88

{

    89

	PathNode start_node;

    90

	uint x;

    91

	uint y;

    92

	// Create AyStar

    93

	AyStar *result = malloc(sizeof(AyStar));

    94

	init_AyStar(result, AiPathFinder_Hash, 1 << 10);

    95

	// Set the function pointers

    96

	result->CalculateG = AyStar_AiPathFinder_CalculateG;

    97

	result->CalculateH = AyStar_AiPathFinder_CalculateH;

    98

	result->EndNodeCheck = AyStar_AiPathFinder_EndNodeCheck;

    99

	result->FoundEndNode = AyStar_AiPathFinder_FoundEndNode;

   100

	result->GetNeighbours = AyStar_AiPathFinder_GetNeighbours;

   101

   102

	result->BeforeExit = NULL;

   103

   104

	result->free = AyStar_AiPathFinder_Free;

   105

   106

	// Set some information

   107

	result->loops_per_tick = AI_PATHFINDER_LOOPS_PER_TICK;

   108

	result->max_path_cost = 0;

   109

	result->max_search_nodes = AI_PATHFINDER_MAX_SEARCH_NODES;

   110

   111

	// Set the user_data to the PathFinderInfo

   112

	result->user_target = PathFinderInfo;

   113

   114

	// Set the start node

   115

	start_node.parent = NULL;

   116

	start_node.node.direction = 0;

   117

	start_node.node.user_data[0] = 0;

   118

   119

	// Now we add all the starting tiles

   120

	for (x = TileX(PathFinderInfo->start_tile_tl); x <= TileX(PathFinderInfo->start_tile_br); x++) {

   121

		for (y = TileY(PathFinderInfo->start_tile_tl); y <= TileY(PathFinderInfo->start_tile_br); y++) {

   122

			start_node.node.tile = TileXY(x, y);

   123

			result->addstart(result, &start_node.node, 0);

   124

		}

   125

	}

   126

   127

	return result;

   128

}

   129

   130

// To reuse AyStar we sometimes have to clean all the memory

   131

void clean_AyStar_AiPathFinder(AyStar *aystar, Ai_PathFinderInfo *PathFinderInfo)

   132

{

   133

	PathNode start_node;

   134

	uint x;

   135

	uint y;

   136

   137

	aystar->clear(aystar);

   138

   139

	// Set the user_data to the PathFinderInfo

   140

	aystar->user_target = PathFinderInfo;

   141

   142

	// Set the start node

   143

	start_node.parent = NULL;

   144

	start_node.node.direction = 0;

   145

	start_node.node.user_data[0] = 0;

   146

	start_node.node.tile = PathFinderInfo->start_tile_tl;

   147

   148

	// Now we add all the starting tiles

   149

	for (x = TileX(PathFinderInfo->start_tile_tl); x <= TileX(PathFinderInfo->start_tile_br); x++) {

   150

		for (y = TileY(PathFinderInfo->start_tile_tl); y <= TileY(PathFinderInfo->start_tile_br); y++) {

   151

			if (!(IsTileType(TileXY(x, y), MP_CLEAR) || IsTileType(TileXY(x, y), MP_TREES))) continue;

   152

			if (!TestCanBuildStationHere(TileXY(x, y), TEST_STATION_NO_DIR)) continue;

   153

			start_node.node.tile = TileXY(x, y);

   154

			aystar->addstart(aystar, &start_node.node, 0);

   155

		}

   156

	}

   157

}

   158

   159

// The h-value, simple calculation

   160

static int32 AyStar_AiPathFinder_CalculateH(AyStar *aystar, AyStarNode *current, OpenListNode *parent)

   161

{

   162

	Ai_PathFinderInfo *PathFinderInfo = (Ai_PathFinderInfo*)aystar->user_target;

   163

	int r, r2;

   164

	if (PathFinderInfo->end_direction != AI_PATHFINDER_NO_DIRECTION) {

   165

		// The station is pointing to a direction, add a tile towards that direction, so the H-value is more accurate

   166

		r = DistanceManhattan(current->tile, PathFinderInfo->end_tile_tl + TileOffsByDir(PathFinderInfo->end_direction));

   167

		r2 = DistanceManhattan(current->tile, PathFinderInfo->end_tile_br + TileOffsByDir(PathFinderInfo->end_direction));

   168

	} else {

   169

		// No direction, so just get the fastest route to the station

   170

		r = DistanceManhattan(current->tile, PathFinderInfo->end_tile_tl);

   171

		r2 = DistanceManhattan(current->tile, PathFinderInfo->end_tile_br);

   172

	}

   173

	// See if the bottomright is faster than the topleft..

   174

	if (r2 < r) r = r2;

   175

	return r * AI_PATHFINDER_H_MULTIPLER;

   176

}

   177

   178

// We found the end.. let's get the route back and put it in an array

   179

static void AyStar_AiPathFinder_FoundEndNode(AyStar *aystar, OpenListNode *current)

   180

{

   181

	Ai_PathFinderInfo *PathFinderInfo = (Ai_PathFinderInfo*)aystar->user_target;

   182

	uint i = 0;

   183

	PathNode *parent = &current->path;

   184

   185

	do {

   186

		PathFinderInfo->route_extra[i] = parent->node.user_data[0];

   187

		PathFinderInfo->route[i++] = parent->node.tile;

   188

		if (i > lengthof(PathFinderInfo->route)) {

   189

			// We ran out of space for the PathFinder

   190

			DEBUG(ai, 0)("[AiPathFinder] Ran out of space in the route[] array!!!");

   191

			PathFinderInfo->route_length = -1; // -1 indicates out of space

   192

			return;

   193

		}

   194

		parent = parent->parent;

   195

	} while (parent != NULL);

   196

	PathFinderInfo->route_length = i;

   197

	DEBUG(ai, 1)("[Ai-PathFinding] Found route of %d nodes long in %d nodes of searching", i, Hash_Size(&aystar->ClosedListHash));

   198

}

   199

   200

// What tiles are around us.

   201

static void AyStar_AiPathFinder_GetNeighbours(AyStar *aystar, OpenListNode *current)

   202

{

   203

	uint i;

   204

	int ret;

   205

	int dir;

   206

   207

	Ai_PathFinderInfo *PathFinderInfo = (Ai_PathFinderInfo*)aystar->user_target;

   208

   209

	aystar->num_neighbours = 0;

   210

   211

	// Go through all surrounding tiles and check if they are within the limits

   212

	for (i = 0; i < 4; i++) {

   213

		TileIndex ctile = current->path.node.tile; // Current tile

   214

		TileIndex atile = ctile + TileOffsByDir(i); // Adjacent tile

   215

   216

		if (TileX(atile) > 1 && TileX(atile) < MapMaxX() - 1 &&

   217

				TileY(atile) > 1 && TileY(atile) < MapMaxY() - 1) {

   218

			// We also directly test if the current tile can connect to this tile..

   219

			//  We do this simply by just building the tile!

   220

   221

			// If the next step is a bridge, we have to enter it the right way

   222

			if (!PathFinderInfo->rail_or_road && IsRoad(atile)) {

   223

				if (IsTileType(atile, MP_TUNNELBRIDGE)) {

   224

					// An existing bridge... let's test the direction ;)

   225

					if ((_m[atile].m5 & 1U) != (i & 1)) continue;

   226

					// This problem only is valid for tunnels:

   227

					// When the last tile was not yet a tunnel, check if we enter from the right side..

   228

					if ((_m[atile].m5 & 0x80) == 0) {

   229

						if (i != (_m[atile].m5 & 3U)) continue;

   230

					}

   231

				}

   232

			}

   233

			// But also if we are on a bridge, we can only move a certain direction

   234

			if (!PathFinderInfo->rail_or_road && IsRoad(ctile)) {

   235

				if (IsTileType(ctile, MP_TUNNELBRIDGE)) {

   236

					// An existing bridge/tunnel... let's test the direction ;)

   237

					if ((_m[ctile].m5 & 1U) != (i & 1)) continue;

   238

				}

   239

			}

   240

   241

			if ((AI_PATHFINDER_FLAG_BRIDGE & current->path.node.user_data[0]) != 0 ||

   242

					(AI_PATHFINDER_FLAG_TUNNEL & current->path.node.user_data[0]) != 0) {

   243

				// We are a bridge/tunnel, how cool!!

   244

				//  This means we can only point forward.. get the direction from the user_data

   245

				if (i != (current->path.node.user_data[0] >> 8)) continue;

   246

			}

   247

			dir = 0;

   248

   249

			// First, check if we have a parent

   250

			if (current->path.parent == NULL && current->path.node.user_data[0] == 0) {

   251

				// If not, this means we are at the starting station

   252

				if (PathFinderInfo->start_direction != AI_PATHFINDER_NO_DIRECTION) {

   253

					// We do need a direction?

   254

					if (AiNew_GetDirection(ctile, atile) != PathFinderInfo->start_direction) {

   255

						// We are not pointing the right way, invalid tile

   256

						continue;

   257

					}

   258

				}

   259

			} else if (current->path.node.user_data[0] == 0) {

   260

				if (PathFinderInfo->rail_or_road) {

   261

					// Rail check

   262

					dir = AiNew_GetRailDirection(current->path.parent->node.tile, ctile, atile);

   263

					ret = DoCommandByTile(ctile, 0, dir, DC_AUTO | DC_NO_WATER, CMD_BUILD_SINGLE_RAIL);

   264

					if (CmdFailed(ret)) continue;

   265

#ifdef AI_PATHFINDER_NO_90DEGREES_TURN

   266

					if (current->path.parent->parent != NULL) {

   267

						// Check if we don't make a 90degree curve

   268

						int dir1 = AiNew_GetRailDirection(current->path.parent->parent->node.tile, current->path.parent->node.tile, ctile);

   269

						if (_illegal_curves[dir1] == dir || _illegal_curves[dir] == dir1) {

   270

							continue;

   271

						}

   272

					}

   273

#endif

   274

				} else {

   275

					// Road check

   276

					dir = AiNew_GetRoadDirection(current->path.parent->node.tile, ctile, atile);

   277

					if (IsRoad(ctile)) {

   278

						if (IsTileType(ctile, MP_TUNNELBRIDGE)) {

   279

							// We have a bridge, how nicely! We should mark it...

   280

							dir = 0;

   281

						} else {

   282

							// It already has road.. check if we miss any bits!

   283

							if ((_m[ctile].m5 & dir) != dir) {

   284

								// We do miss some pieces :(

   285

								dir &= ~_m[ctile].m5;

   286

							} else {

   287

								dir = 0;

   288

							}

   289

						}

   290

					}

   291

					// Only destruct things if it is MP_CLEAR of MP_TREES

   292

					if (dir != 0) {

   293

						ret = DoCommandByTile(ctile, dir, 0, DC_AUTO | DC_NO_WATER, CMD_BUILD_ROAD);

   294

						if (CmdFailed(ret)) continue;

   295

					}

   296

				}

   297

			}

   298

   299

			// The tile can be connected

   300

			aystar->neighbours[aystar->num_neighbours].tile = atile;

   301

			aystar->neighbours[aystar->num_neighbours].user_data[0] = 0;

   302

			aystar->neighbours[aystar->num_neighbours++].direction = 0;

   303

		}

   304

	}

   305

   306

	// Next step, check for bridges and tunnels

   307

	if (current->path.parent != NULL && current->path.node.user_data[0] == 0) {

   308

		TileInfo ti;

   309

		// First we get the dir from this tile and his parent

   310

		int dir = AiNew_GetDirection(current->path.parent->node.tile, current->path.node.tile);

   311

		// It means we can only walk with the track, so the bridge has to be in the same direction

   312

		TileIndex tile = current->path.node.tile;

   313

		TileIndex new_tile = tile;

   314

   315

		FindLandscapeHeightByTile(&ti, tile);

   316

   317

		// Bridges can only be build on land that is not flat

   318

		//  And if there is a road or rail blocking

   319

		if (ti.tileh != 0 ||

   320

				(PathFinderInfo->rail_or_road && IsTileType(tile + TileOffsByDir(dir), MP_STREET)) ||

   321

				(!PathFinderInfo->rail_or_road && IsTileType(tile + TileOffsByDir(dir), MP_RAILWAY))) {

   322

   323

			for (;;) {

   324

				new_tile += TileOffsByDir(dir);

   325

   326

				// Precheck, is the length allowed?

   327

				if (!CheckBridge_Stuff(0, GetBridgeLength(tile, new_tile))) break;

   328

   329

				// Check if we hit the station-tile.. we don't like that!

   330

				if (TILES_BETWEEN(new_tile, PathFinderInfo->end_tile_tl, PathFinderInfo->end_tile_br)) break;

   331

   332

				// Try building the bridge..

   333

				ret = DoCommandByTile(tile, new_tile, (0 << 8) + (MAX_BRIDGES / 2), DC_AUTO, CMD_BUILD_BRIDGE);

   334

				if (CmdFailed(ret)) continue;

   335

				// We can build a bridge here.. add him to the neighbours

   336

				aystar->neighbours[aystar->num_neighbours].tile = new_tile;

   337

				aystar->neighbours[aystar->num_neighbours].user_data[0] = AI_PATHFINDER_FLAG_BRIDGE + (dir << 8);

   338

				aystar->neighbours[aystar->num_neighbours++].direction = 0;

   339

				// We can only have 12 neighbours, and we need 1 left for tunnels

   340

				if (aystar->num_neighbours == 11) break;

   341

			}

   342

		}

   343

   344

		// Next, check for tunnels!

   345

		// Tunnels can only be build with tileh of 3, 6, 9 or 12, depending on the direction

   346

		//  For now, we check both sides for this tile.. terraforming gives fuzzy result

   347

		if ((dir == 0 && ti.tileh == 12) ||

   348

				(dir == 1 && ti.tileh == 6) ||

   349

				(dir == 2 && ti.tileh == 3) ||

   350

				(dir == 3 && ti.tileh == 9)) {

   351

			// Now simply check if a tunnel can be build

   352

			ret = DoCommandByTile(tile, (PathFinderInfo->rail_or_road?0:0x200), 0, DC_AUTO, CMD_BUILD_TUNNEL);

   353

			FindLandscapeHeightByTile(&ti, _build_tunnel_endtile);

   354

			if (!CmdFailed(ret) && (ti.tileh == 3 || ti.tileh == 6 || ti.tileh == 9 || ti.tileh == 12)) {

   355

				aystar->neighbours[aystar->num_neighbours].tile = _build_tunnel_endtile;

   356

				aystar->neighbours[aystar->num_neighbours].user_data[0] = AI_PATHFINDER_FLAG_TUNNEL + (dir << 8);

   357

				aystar->neighbours[aystar->num_neighbours++].direction = 0;

   358

			}

   359

		}

   360

	}

   361

}

   362

   363

extern uint GetRailFoundation(uint tileh, uint bits);

   364

extern uint GetRoadFoundation(uint tileh, uint bits);

   365

extern uint GetBridgeFoundation(uint tileh, byte direction);

   366

enum {

   367

	BRIDGE_NO_FOUNDATION = 1 << 0 | 1 << 3 | 1 << 6 | 1 << 9 | 1 << 12,

   368

};

   369

   370

// The most important function: it calculates the g-value

   371

static int32 AyStar_AiPathFinder_CalculateG(AyStar *aystar, AyStarNode *current, OpenListNode *parent)

   372

{

   373

	Ai_PathFinderInfo *PathFinderInfo = (Ai_PathFinderInfo*)aystar->user_target;

   374

	int r, res = 0;

   375

	TileInfo ti, parent_ti;

   376

   377

	// Gather some information about the tile..

   378

	FindLandscapeHeightByTile(&ti, current->tile);

   379

	FindLandscapeHeightByTile(&parent_ti, parent->path.node.tile);

   380

   381

	// Check if we hit the end-tile

   382

	if (TILES_BETWEEN(current->tile, PathFinderInfo->end_tile_tl, PathFinderInfo->end_tile_br)) {

   383

		// We are at the end-tile, check if we had a direction or something...

   384

		if (PathFinderInfo->end_direction != AI_PATHFINDER_NO_DIRECTION && AiNew_GetDirection(current->tile, parent->path.node.tile) != PathFinderInfo->end_direction)

   385

			// We are not pointing the right way, invalid tile

   386

			return AYSTAR_INVALID_NODE;

   387

		// If it was valid, drop out.. we don't build on the endtile

   388

		return 0;

   389

	}

   390

   391

	// Give everything a small penalty

   392

	res += AI_PATHFINDER_PENALTY;

   393

   394

	if (!PathFinderInfo->rail_or_road) {

   395

		// Road has the lovely advantage it can use other road... check if

   396

		//  the current tile is road, and if so, give a good bonus

   397

		if (IsRoad(current->tile)) {

   398

			res -= AI_PATHFINDER_ROAD_ALREADY_EXISTS_BONUS;

   399

		}

   400

	}

   401

   402

	// We should give a penalty when the tile is going up or down.. this is one way to do so!

   403

	//  Too bad we have to count it from the parent.. but that is not so bad.

   404

	// We also dislike long routes on slopes, since they do not look too realistic

   405

	//  when there is a flat land all around, they are more expensive to build, and

   406

	//  especially they essentially block the ability to connect or cross the road

   407

	//  from one side.

   408

	if (parent_ti.tileh != 0 && parent->path.parent != NULL) {

   409

		// Skip if the tile was from a bridge or tunnel

   410

		if (parent->path.node.user_data[0] == 0 && current->user_data[0] == 0) {

   411

			if (PathFinderInfo->rail_or_road) {

   412

				r = GetRailFoundation(parent_ti.tileh, 1 << AiNew_GetRailDirection(parent->path.parent->node.tile, parent->path.node.tile, current->tile));

   413

				// Maybe is BRIDGE_NO_FOUNDATION a bit strange here, but it contains just the right information..

   414

				if (r >= 15 || (r == 0 && (BRIDGE_NO_FOUNDATION & (1 << ti.tileh)))) {

   415

					res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   416

				} else {

   417

					res += AI_PATHFINDER_FOUNDATION_PENALTY;

   418

				}

   419

			} else {

   420

				if (!(IsRoad(parent->path.node.tile) && IsTileType(parent->path.node.tile, MP_TUNNELBRIDGE))) {

   421

					r = GetRoadFoundation(parent_ti.tileh, AiNew_GetRoadDirection(parent->path.parent->node.tile, parent->path.node.tile, current->tile));

   422

					if (r >= 15 || r == 0)

   423

						res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   424

					else

   425

						res += AI_PATHFINDER_FOUNDATION_PENALTY;

   426

				}

   427

			}

   428

		}

   429

	}

   430

   431

	// Are we part of a tunnel?

   432

	if ((AI_PATHFINDER_FLAG_TUNNEL & current->user_data[0]) != 0) {

   433

		// Tunnels are very expensive when build on long routes..

   434

		// Ironicly, we are using BridgeCode here ;)

   435

		r = AI_PATHFINDER_TUNNEL_PENALTY * GetBridgeLength(current->tile, parent->path.node.tile);

   436

		res += r + (r >> 8);

   437

	}

   438

   439

	// Are we part of a bridge?

   440

	if ((AI_PATHFINDER_FLAG_BRIDGE & current->user_data[0]) != 0) {

   441

		// That means for every length a penalty

   442

		res += AI_PATHFINDER_BRIDGE_PENALTY * GetBridgeLength(current->tile, parent->path.node.tile);

   443

		// Check if we are going up or down, first for the starting point

   444

		// In user_data[0] is at the 8th bit the direction

   445

		if (!(BRIDGE_NO_FOUNDATION & (1 << parent_ti.tileh))) {

   446

			if (GetBridgeFoundation(parent_ti.tileh, (current->user_data[0] >> 8) & 1) < 15)

   447

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   448

		}

   449

		// Second for the end point

   450

		if (!(BRIDGE_NO_FOUNDATION & (1 << ti.tileh))) {

   451

			if (GetBridgeFoundation(ti.tileh, (current->user_data[0] >> 8) & 1) < 15)

   452

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   453

		}

   454

		if (parent_ti.tileh == 0)

   455

			res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   456

		if (ti.tileh == 0)

   457

			res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   458

	}

   459

   460

	//  To prevent the AI from taking the fastest way in tiles, but not the fastest way

   461

	//    in speed, we have to give a good penalty to direction changing

   462

	//  This way, we get almost the fastest way in tiles, and a very good speed on the track

   463

	if (!PathFinderInfo->rail_or_road) {

   464

		if (parent->path.parent != NULL &&

   465

			AiNew_GetDirection(current->tile, parent->path.node.tile) != AiNew_GetDirection(parent->path.node.tile, parent->path.parent->node.tile)) {

   466

			// When road exists, we don't like turning, but its free, so don't be to piggy about it

   467

			if (IsRoad(parent->path.node.tile))

   468

				res += AI_PATHFINDER_DIRECTION_CHANGE_ON_EXISTING_ROAD_PENALTY;

   469

			else

   470

				res += AI_PATHFINDER_DIRECTION_CHANGE_PENALTY;

   471

		}

   472

	} else {

   473

		// For rail we have 1 exeption: diagonal rail..

   474

		// So we fetch 2 raildirection. That of the current one, and of the one before that

   475

		if (parent->path.parent != NULL && parent->path.parent->parent != NULL) {

   476

			int dir1 = AiNew_GetRailDirection(parent->path.parent->node.tile, parent->path.node.tile, current->tile);

   477

			int dir2 = AiNew_GetRailDirection(parent->path.parent->parent->node.tile, parent->path.parent->node.tile, parent->path.node.tile);

   478

			// First, see if we are on diagonal path, that is better than straight path

   479

			if (dir1 > 1) { res -= AI_PATHFINDER_DIAGONAL_BONUS; }

   480

   481

			// First see if they are different

   482

			if (dir1 != dir2) {

   483

				// dir 2 and 3 are 1 diagonal track, and 4 and 5.

   484

				if (!(((dir1 == 2 || dir1 == 3) && (dir2 == 2 || dir2 == 3)) || ((dir1 == 4 || dir1 == 5) && (dir2 == 4 || dir2 == 5)))) {

   485

					// It is not, so we changed of direction

   486

					res += AI_PATHFINDER_DIRECTION_CHANGE_PENALTY;