1

/* $Id$ */

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#include "stdafx.h"

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#include "openttd.h"

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#include "debug.h"

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#include "functions.h"

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#include "map.h"

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#include "tile.h"

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#include "command.h"

    10

#include "ai_new.h"

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#include "depot.h"

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#include "variables.h"

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    14

#define TEST_STATION_NO_DIR 0xFF

    15

    16

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

    17

// TODO: make it train compatible

    18

static bool TestCanBuildStationHere(TileIndex tile, byte dir)

    19

{

    20

	Player *p = GetPlayer(_current_player);

    21

    22

	if (dir == TEST_STATION_NO_DIR) {

    23

		int32 ret;

    24

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

    25

		//  should be fixed!!!

    26

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

    27

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

    28

			if (!CmdFailed(ret)) return true;

    29

		}

    30

		return false;

    31

	}

    32

    33

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

    34

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

    35

}

    36

    37

    38

static bool IsRoad(TileIndex tile)

    39

{

    40

	return

    41

		// MP_STREET, but not a road depot?

    42

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

    43

		(IsTileType(tile, MP_TUNNELBRIDGE) && (

    44

			// road tunnel?

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

    46

			// road bridge?

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

    48

		));

    49

}

    50

    51

    52

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

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

    54

    55

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

    56

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

    57

{

    58

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

    59

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

    60

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

    61

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

    62

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

    63

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

    64

				return AYSTAR_FOUND_END_NODE;

    65

    66

	return AYSTAR_DONE;

    67

}

    68

    69

// Calculates the hash

    70

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

    71

static uint AiPathFinder_Hash(uint key1, uint key2)

    72

{

    73

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

    74

}

    75

    76

// Clear the memory of all the things

    77

static void AyStar_AiPathFinder_Free(AyStar *aystar)

    78

{

    79

	AyStarMain_Free(aystar);

    80

	free(aystar);

    81

}

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    83

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

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

    85

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

    86

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

    87

    88

// This creates the AiPathFinder

    89

AyStar *new_AyStar_AiPathFinder(int max_tiles_around, Ai_PathFinderInfo *PathFinderInfo)

    90

{

    91

	PathNode start_node;

    92

	uint x;

    93

	uint y;

    94

	// Create AyStar

    95

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

    96

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

    97

	// Set the function pointers

    98

	result->CalculateG = AyStar_AiPathFinder_CalculateG;

    99

	result->CalculateH = AyStar_AiPathFinder_CalculateH;

   100

	result->EndNodeCheck = AyStar_AiPathFinder_EndNodeCheck;

   101

	result->FoundEndNode = AyStar_AiPathFinder_FoundEndNode;

   102

	result->GetNeighbours = AyStar_AiPathFinder_GetNeighbours;

   103

   104

	result->BeforeExit = NULL;

   105

   106

	result->free = AyStar_AiPathFinder_Free;

   107

   108

	// Set some information

   109

	result->loops_per_tick = AI_PATHFINDER_LOOPS_PER_TICK;

   110

	result->max_path_cost = 0;

   111

	result->max_search_nodes = AI_PATHFINDER_MAX_SEARCH_NODES;

   112

   113

	// Set the user_data to the PathFinderInfo

   114

	result->user_target = PathFinderInfo;

   115

   116

	// Set the start node

   117

	start_node.parent = NULL;

   118

	start_node.node.direction = 0;

   119

	start_node.node.user_data[0] = 0;

   120

   121

	// Now we add all the starting tiles

   122

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

   123

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

   124

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

   125

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

   126

		}

   127

	}

   128

   129

	return result;

   130

}

   131

   132

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

   133

void clean_AyStar_AiPathFinder(AyStar *aystar, Ai_PathFinderInfo *PathFinderInfo)

   134

{

   135

	PathNode start_node;

   136

	uint x;

   137

	uint y;

   138

   139

	aystar->clear(aystar);

   140

   141

	// Set the user_data to the PathFinderInfo

   142

	aystar->user_target = PathFinderInfo;

   143

   144

	// Set the start node

   145

	start_node.parent = NULL;

   146

	start_node.node.direction = 0;

   147

	start_node.node.user_data[0] = 0;

   148

	start_node.node.tile = PathFinderInfo->start_tile_tl;

   149

   150

	// Now we add all the starting tiles

   151

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

   152

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

   153

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

   154

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

   155

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

   156

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

   157

		}

   158

	}

   159

}

   160

   161

// The h-value, simple calculation

   162

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

   163

{

   164

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

   165

	int r, r2;

   166

	if (PathFinderInfo->end_direction != AI_PATHFINDER_NO_DIRECTION) {

   167

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

   168

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

   169

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

   170

	} else {

   171

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

   172

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

   173

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

   174

	}

   175

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

   176

	if (r2 < r) r = r2;

   177

	return r * AI_PATHFINDER_H_MULTIPLER;

   178

}

   179

   180

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

   181

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

   182

{

   183

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

   184

	uint i = 0;

   185

	PathNode *parent = &current->path;

   186

   187

	do {

   188

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

   189

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

   190

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

   191

			// We ran out of space for the PathFinder

   192

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

   193

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

   194

			return;

   195

		}

   196

		parent = parent->parent;

   197

	} while (parent != NULL);

   198

	PathFinderInfo->route_length = i;

   199

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

   200

}

   201

   202

// What tiles are around us.

   203

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

   204

{

   205

	uint i;

   206

	int ret;

   207

	int dir;

   208

   209

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

   210

   211

	aystar->num_neighbours = 0;

   212

   213

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

   214

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

   215

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

   216

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

   217

   218

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

   219

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

   220

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

   221

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

   222

   223

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

   224

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

   225

				if (IsTileType(atile, MP_TUNNELBRIDGE)) {

   226

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

   227

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

   228

					// This problem only is valid for tunnels:

   229

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

   230

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

   231

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

   232

					}

   233

				}

   234

			}

   235

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

   236

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

   237

				if (IsTileType(ctile, MP_TUNNELBRIDGE)) {

   238

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

   239

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

   240

				}

   241

			}

   242

   243

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

   244

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

   245

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

   246

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

   247

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

   248

			}

   249

			dir = 0;

   250

   251

			// First, check if we have a parent

   252

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

   253

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

   254

				if (PathFinderInfo->start_direction != AI_PATHFINDER_NO_DIRECTION) {

   255

					// We do need a direction?

   256

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

   257

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

   258

						continue;

   259

					}

   260

				}

   261

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

   262

				if (PathFinderInfo->rail_or_road) {

   263

					// Rail check

   264

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

   265

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

   266

					if (CmdFailed(ret)) continue;

   267

#ifdef AI_PATHFINDER_NO_90DEGREES_TURN

   268

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

   269

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

   270

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

   271

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

   272

							continue;

   273

						}

   274

					}

   275

#endif

   276

				} else {

   277

					// Road check

   278

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

   279

					if (IsRoad(ctile)) {

   280

						if (IsTileType(ctile, MP_TUNNELBRIDGE)) {

   281

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

   282

							dir = 0;

   283

						} else {

   284

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

   285

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

   286

								// We do miss some pieces :(

   287

								dir &= ~_m[ctile].m5;

   288

							} else {

   289

								dir = 0;

   290

							}

   291

						}

   292

					}

   293

					// Only destruct things if it is MP_CLEAR of MP_TREES

   294

					if (dir != 0) {

   295

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

   296

						if (CmdFailed(ret)) continue;

   297

					}

   298

				}

   299

			}

   300

   301

			// The tile can be connected

   302

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

   303

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

   304

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

   305

		}

   306

	}

   307

   308

	// Next step, check for bridges and tunnels

   309

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

   310

		TileInfo ti;

   311

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

   312

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

   313

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

   314

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

   315

		TileIndex new_tile = tile;

   316

   317

		FindLandscapeHeightByTile(&ti, tile);

   318

   319

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

   320

		//  And if there is a road or rail blocking

   321

		if (ti.tileh != 0 ||

   322

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

   323

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

   324

   325

			for (;;) {

   326

				new_tile += TileOffsByDir(dir);

   327

   328

				// Precheck, is the length allowed?

   329

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

   330

   331

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

   332

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

   333

   334

				// Try building the bridge..

   335

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

   336

				if (CmdFailed(ret)) continue;

   337

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

   338

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

   339

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

   340

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

   341

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

   342

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

   343

			}

   344

		}

   345

   346

		// Next, check for tunnels!

   347

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

   348

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

   349

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

   350

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

   351

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

   352

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

   353

			// Now simply check if a tunnel can be build

   354

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

   355

			FindLandscapeHeightByTile(&ti, _build_tunnel_endtile);

   356

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

   357

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

   358

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

   359

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

   360

			}

   361

		}

   362

	}

   363

}

   364

   365

extern uint GetRailFoundation(uint tileh, uint bits);

   366

extern uint GetRoadFoundation(uint tileh, uint bits);

   367

extern uint GetBridgeFoundation(uint tileh, byte direction);

   368

enum {

   369

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

   370

};

   371

   372

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

   373

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

   374

{

   375

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

   376

	int r, res = 0;

   377

	TileInfo ti, parent_ti;

   378

   379

	// Gather some information about the tile..

   380

	FindLandscapeHeightByTile(&ti, current->tile);

   381

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

   382

   383

	// Check if we hit the end-tile

   384

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

   385

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

   386

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

   387

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

   388

			return AYSTAR_INVALID_NODE;

   389

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

   390

		return 0;

   391

	}

   392

   393

	// Give everything a small penalty

   394

	res += AI_PATHFINDER_PENALTY;

   395

   396

	if (!PathFinderInfo->rail_or_road) {

   397

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

   398

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

   399

		if (IsRoad(current->tile)) {

   400

			res -= AI_PATHFINDER_ROAD_ALREADY_EXISTS_BONUS;

   401

		}

   402

	}

   403

   404

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

   405

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

   406

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

   407

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

   408

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

   409

	//  from one side.

   410

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

   411

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

   412

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

   413

			if (PathFinderInfo->rail_or_road) {

   414

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

   415

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

   416

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

   417

					res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   418

				} else {

   419

					res += AI_PATHFINDER_FOUNDATION_PENALTY;

   420

				}

   421

			} else {

   422

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

   423

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

   424

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

   425

						res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   426

					else

   427

						res += AI_PATHFINDER_FOUNDATION_PENALTY;

   428

				}

   429

			}

   430

		}

   431

	}

   432

   433

	// Are we part of a tunnel?

   434

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

   435

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

   436

		// Ironicly, we are using BridgeCode here ;)

   437

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

   438

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

   439

	}

   440

   441

	// Are we part of a bridge?

   442

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

   443

		// That means for every length a penalty

   444

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

   445

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

   446

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

   447

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

   448

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

   449

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   450

		}

   451

		// Second for the end point

   452

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

   453

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

   454

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   455

		}

   456

		if (parent_ti.tileh == 0)

   457

			res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   458

		if (ti.tileh == 0)

   459

			res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   460

	}

   461

   462

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

   463

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

   464

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

   465

	if (!PathFinderInfo->rail_or_road) {

   466

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

   467

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

   468

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

   469

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

   470

				res += AI_PATHFINDER_DIRECTION_CHANGE_ON_EXISTING_ROAD_PENALTY;

   471

			else

   472

				res += AI_PATHFINDER_DIRECTION_CHANGE_PENALTY;

   473

		}

   474

	} else {

   475

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

   476

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

   477

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

   478

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

   479

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

   480

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

   481

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

   482

   483

			// First see if they are different

   484

			if (dir1 != dir2) {

   485

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

   486

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