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/* $Id$ */

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#include "../../stdafx.h"

     4

#include "../../openttd.h"

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#include "../../debug.h"

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#include "../../functions.h"

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#include "../../map.h"

     8

#include "../../tile.h"

     9

#include "../../command.h"

    10

#include "trolly.h"

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#include "../../depot.h"

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#include "../../tunnel_map.h"

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#include "../../bridge.h"

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#include "../ai.h"

    15

    16

#define TEST_STATION_NO_DIR 0xFF

    17

    18

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

    19

// TODO: make it train compatible

    20

static bool TestCanBuildStationHere(TileIndex tile, byte dir)

    21

{

    22

	Player *p = GetPlayer(_current_player);

    23

    24

	if (dir == TEST_STATION_NO_DIR) {

    25

		int32 ret;

    26

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

    27

		//  should be fixed!!!

    28

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

    29

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

    30

			if (!CmdFailed(ret)) return true;

    31

		}

    32

		return false;

    33

	}

    34

    35

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

    36

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

    37

}

    38

    39

    40

static bool IsRoad(TileIndex tile)

    41

{

    42

	return

    43

		// MP_STREET, but not a road depot?

    44

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

    45

		(IsTileType(tile, MP_TUNNEL) && GetTunnelTransportType(tile) == TRANSPORT_ROAD) ||

    46

		IsTileType(tile, MP_STREET_BRIDGE);

    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

    54

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

    55

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

    56

{

    57

	const Ai_PathFinderInfo* PathFinderInfo = aystar->user_target;

    58

    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

    70

// Calculates the hash

    71

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

    72

static uint AiPathFinder_Hash(uint key1, uint key2)

    73

{

    74

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

    75

}

    76

    77

    78

// Clear the memory of all the things

    79

static void AyStar_AiPathFinder_Free(AyStar *aystar)

    80

{

    81

	AyStarMain_Free(aystar);

    82

	free(aystar);

    83

}

    84

    85

    86

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

    87

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

    88

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

    89

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

    90

    91

    92

// This creates the AiPathFinder

    93

AyStar *new_AyStar_AiPathFinder(int max_tiles_around, Ai_PathFinderInfo *PathFinderInfo)

    94

{

    95

	PathNode start_node;

    96

	uint x;

    97

	uint y;

    98

	// Create AyStar

    99

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

   100

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

   101

	// Set the function pointers

   102

	result->CalculateG = AyStar_AiPathFinder_CalculateG;

   103

	result->CalculateH = AyStar_AiPathFinder_CalculateH;

   104

	result->EndNodeCheck = AyStar_AiPathFinder_EndNodeCheck;

   105

	result->FoundEndNode = AyStar_AiPathFinder_FoundEndNode;

   106

	result->GetNeighbours = AyStar_AiPathFinder_GetNeighbours;

   107

   108

	result->free = AyStar_AiPathFinder_Free;

   109

   110

	// Set some information

   111

	result->loops_per_tick = AI_PATHFINDER_LOOPS_PER_TICK;

   112

	result->max_path_cost = 0;

   113

	result->max_search_nodes = AI_PATHFINDER_MAX_SEARCH_NODES;

   114

   115

	// Set the user_data to the PathFinderInfo

   116

	result->user_target = PathFinderInfo;

   117

   118

	// Set the start node

   119

	start_node.parent = NULL;

   120

	start_node.node.direction = 0;

   121

	start_node.node.user_data[0] = 0;

   122

   123

	// Now we add all the starting tiles

   124

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

   125

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

   126

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

   127

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

   128

		}

   129

	}

   130

   131

	return result;

   132

}

   133

   134

   135

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

   136

void clean_AyStar_AiPathFinder(AyStar *aystar, Ai_PathFinderInfo *PathFinderInfo)

   137

{

   138

	PathNode start_node;

   139

	uint x;

   140

	uint y;

   141

   142

	aystar->clear(aystar);

   143

   144

	// Set the user_data to the PathFinderInfo

   145

	aystar->user_target = PathFinderInfo;

   146

   147

	// Set the start node

   148

	start_node.parent = NULL;

   149

	start_node.node.direction = 0;

   150

	start_node.node.user_data[0] = 0;

   151

	start_node.node.tile = PathFinderInfo->start_tile_tl;

   152

   153

	// Now we add all the starting tiles

   154

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

   155

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

   156

			TileIndex tile = TileXY(x, y);

   157

   158

			if (!IsTileType(tile, MP_CLEAR) && !IsTileType(tile, MP_TREES)) continue;

   159

			if (!TestCanBuildStationHere(tile, TEST_STATION_NO_DIR)) continue;

   160

			start_node.node.tile = tile;

   161

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

   162

		}

   163

	}

   164

}

   165

   166

   167

// The h-value, simple calculation

   168

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

   169

{

   170

	const Ai_PathFinderInfo* PathFinderInfo = aystar->user_target;

   171

	int r, r2;

   172

   173

	if (PathFinderInfo->end_direction != AI_PATHFINDER_NO_DIRECTION) {

   174

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

   175

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

   176

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

   177

	} else {

   178

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

   179

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

   180

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

   181

	}

   182

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

   183

	if (r2 < r) r = r2;

   184

	return r * AI_PATHFINDER_H_MULTIPLER;

   185

}

   186

   187

   188

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

   189

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

   190

{

   191

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

   192

	uint i = 0;

   193

	PathNode *parent = &current->path;

   194

   195

	do {

   196

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

   197

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

   198

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

   199

			// We ran out of space for the PathFinder

   200

			DEBUG(ai, 0, "No more space in pathfinder route[] array");

   201

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

   202

			return;

   203

		}

   204

		parent = parent->parent;

   205

	} while (parent != NULL);

   206

	PathFinderInfo->route_length = i;

   207

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

   208

}

   209

   210

   211

// What tiles are around us.

   212

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

   213

{

   214

	uint i;

   215

	int ret;

   216

	int dir;

   217

   218

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

   219

   220

	aystar->num_neighbours = 0;

   221

   222

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

   223

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

   224

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

   225

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

   226

   227

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

   228

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

   229

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

   230

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

   231

   232

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

   233

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

   234

				if (IsTileType(atile, MP_TUNNEL) && GetTunnelDirection(atile) != i) continue;

   235

   236

				if (IsTileType(atile, MP_STREET_BRIDGE) || IsTileType(atile, MP_RAILWAY_BRIDGE)) {

   237

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

   238

				}

   239

			}

   240

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

   241

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

   242

				if (IsTileType(ctile, MP_TUNNEL) || IsTileType(ctile, MP_RAILWAY_BRIDGE) || IsTileType(ctile, MP_STREET_BRIDGE)) {

   243

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

   244

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

   245

				}

   246

			}

   247

   248

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

   249

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

   250

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

   251

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

   252

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

   253

			}

   254

			dir = 0;

   255

   256

			// First, check if we have a parent

   257

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

   258

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

   259

				if (PathFinderInfo->start_direction != AI_PATHFINDER_NO_DIRECTION) {

   260

					// We do need a direction?

   261

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

   262

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

   263

						continue;

   264

					}

   265

				}

   266

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

   267

				if (PathFinderInfo->rail_or_road) {

   268

					// Rail check

   269

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

   270

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

   271

					if (CmdFailed(ret)) continue;

   272

#ifdef AI_PATHFINDER_NO_90DEGREES_TURN

   273

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

   274

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

   275

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

   276

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

   277

							continue;

   278

						}

   279

					}

   280

#endif

   281

				} else {

   282

					// Road check

   283

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

   284

					if (IsRoad(ctile)) {

   285

						if (IsTileType(ctile, MP_TUNNEL) || IsTileType(ctile, MP_STREET_BRIDGE) || IsTileType(ctile, MP_RAILWAY_BRIDGE)) {

   286

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

   287

							dir = 0;

   288

						} else {

   289

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

   290

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

   291

								// We do miss some pieces :(

   292

								dir &= ~_m[ctile].m5;

   293

							} else {

   294

								dir = 0;

   295

							}

   296

						}

   297

					}

   298

					// Only destruct things if it is MP_CLEAR of MP_TREES

   299

					if (dir != 0) {

   300

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

   301

						if (CmdFailed(ret)) continue;

   302

					}

   303

				}

   304

			}

   305

   306

			// The tile can be connected

   307

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

   308

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

   309

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

   310

		}

   311

	}

   312

   313

	// Next step, check for bridges and tunnels

   314

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

   315

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

   316

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

   317

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

   318

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

   319

		TileIndex new_tile = tile;

   320

		Slope tileh = GetTileSlope(tile, NULL);

   321

   322

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

   323

		//  And if there is a road or rail blocking

   324

		if (tileh != SLOPE_FLAT ||

   325

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

   326

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

   327

			for (;;) {

   328

				new_tile += TileOffsByDiagDir(dir);

   329

   330

				// Precheck, is the length allowed?

   331

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

   332

   333

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

   334

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

   335

   336

				// Try building the bridge..

   337

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

   338

				if (CmdFailed(ret)) continue;

   339

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

   340

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

   341

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

   342

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

   343

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

   344

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

   345

			}

   346

		}

   347

   348

		// Next, check for tunnels!

   349

		// Tunnels can only be built on slopes corresponding to the direction

   350

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

   351

		if ((dir == DIAGDIR_NE && tileh == SLOPE_NE) ||

   352

				(dir == DIAGDIR_SE && tileh == SLOPE_SE) ||

   353

				(dir == DIAGDIR_SW && tileh == SLOPE_SW) ||

   354

				(dir == DIAGDIR_NW && tileh == SLOPE_NW)) {

   355

			// Now simply check if a tunnel can be build

   356

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

   357

			tileh = GetTileSlope(_build_tunnel_endtile, NULL);

   358

			if (!CmdFailed(ret) && (tileh == SLOPE_SW || tileh == SLOPE_SE || tileh == SLOPE_NW || tileh == SLOPE_NE)) {

   359

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

   360

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

   361

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

   362

			}

   363

		}

   364

	}

   365

}

   366

   367

   368

extern uint GetRailFoundation(Slope tileh, TrackBits bits); // XXX function declaration in .c

   369

extern uint GetRoadFoundation(Slope tileh, uint bits); // XXX function declaration in .c

   370

extern uint GetBridgeFoundation(Slope tileh, Axis); // XXX function declaration in .c

   371

enum {

   372

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

   373

};

   374

   375

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

   376

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

   377

{

   378

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

   379

	int r, res = 0;

   380

	Slope tileh = GetTileSlope(current->tile, NULL);

   381

	Slope parent_tileh = GetTileSlope(parent->path.node.tile, NULL);

   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

		}

   390

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

   391

		return 0;

   392

	}

   393

   394

	// Give everything a small penalty

   395

	res += AI_PATHFINDER_PENALTY;

   396

   397

	if (!PathFinderInfo->rail_or_road) {

   398

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

   399

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

   400

		if (IsRoad(current->tile)) {

   401

			res -= AI_PATHFINDER_ROAD_ALREADY_EXISTS_BONUS;

   402

		}

   403

	}

   404

   405

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

   406

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

   407

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

   408

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

   409

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

   410

	//  from one side.

   411

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

   412

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

   413

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

   414

			if (PathFinderInfo->rail_or_road) {

   415

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

   416

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

   417

				if (r >= 15 || (r == 0 && HASBIT(BRIDGE_NO_FOUNDATION, tileh))) {

   418

					res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   419

				} else {

   420

					res += AI_PATHFINDER_FOUNDATION_PENALTY;

   421

				}

   422

			} else {

   423

				if (!IsRoad(parent->path.node.tile) || !(IsTileType(parent->path.node.tile, MP_TUNNEL) || IsTileType(parent->path.node.tile, MP_STREET_BRIDGE) || IsTileType(parent->path.node.tile, MP_RAILWAY_BRIDGE))) {

   424

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

   425

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

   426

						res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   427

					} else {

   428

						res += AI_PATHFINDER_FOUNDATION_PENALTY;

   429

					}

   430

				}

   431

			}

   432

		}

   433

	}

   434

   435

	// Are we part of a tunnel?

   436

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

   437

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

   438

		// Ironicly, we are using BridgeCode here ;)

   439

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

   440

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

   441

	}

   442

   443

	// Are we part of a bridge?

   444

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

   445

		// That means for every length a penalty

   446

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

   447

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

   448

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

   449

		if (!HASBIT(BRIDGE_NO_FOUNDATION, parent_tileh)) {

   450

			if (GetBridgeFoundation(parent_tileh, (current->user_data[0] >> 8) & 1) < 15) {

   451

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   452

			}

   453

		}

   454

		// Second for the end point

   455

		if (!HASBIT(BRIDGE_NO_FOUNDATION, tileh)) {

   456

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

   457

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   458

			}

   459

		}

   460

		if (parent_tileh == SLOPE_FLAT) res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   461

		if (tileh == SLOPE_FLAT) res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   462

	}

   463

   464

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

   465

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

   466

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

   467

	if (!PathFinderInfo->rail_or_road) {

   468

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

   469

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

   470

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

   471

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

   472

				res += AI_PATHFINDER_DIRECTION_CHANGE_ON_EXISTING_ROAD_PENALTY;

   473

			} else {

   474

				res += AI_PATHFINDER_DIRECTION_CHANGE_PENALTY;

   475

			}

   476

		}

   477

	} else {

   478

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

   479

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

   480

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

   481

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

   482

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