1

/* $Id$ */

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

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

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#include "../../bridge_map.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"

    10

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

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#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"

    16

    17

#define TEST_STATION_NO_DIR 0xFF

    18

    19

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

    20

// TODO: make it train compatible

    21

static bool TestCanBuildStationHere(TileIndex tile, byte dir)

    22

{

    23

	Player *p = GetPlayer(_current_player);

    24

    25

	if (dir == TEST_STATION_NO_DIR) {

    26

		int32 ret;

    27

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

    28

		//  should be fixed!!!

    29

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

    30

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

    31

			if (!CmdFailed(ret)) return true;

    32

		}

    33

		return false;

    34

	}

    35

    36

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

    37

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

    38

}

    39

    40

    41

static bool IsRoad(TileIndex tile)

    42

{

    43

	return

    44

		// MP_STREET, but not a road depot?

    45

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

    46

		(IsTileType(tile, MP_TUNNELBRIDGE) && (

    47

			(IsTunnel(tile) && GetTunnelTransportType(tile) == TRANSPORT_ROAD) ||

    48

			(IsBridge(tile) && GetBridgeTransportType(tile) == TRANSPORT_ROAD)

    49

		));

    50

}

    51

    52

    53

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

    54

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

    55

    56

    57

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

    58

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

    59

{

    60

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

    61

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

    62

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

    63

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

    64

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

    65

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

    66

				return AYSTAR_FOUND_END_NODE;

    67

    68

	return AYSTAR_DONE;

    69

}

    70

    71

    72

// Calculates the hash

    73

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

    74

static uint AiPathFinder_Hash(uint key1, uint key2)

    75

{

    76

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

    77

}

    78

    79

    80

// Clear the memory of all the things

    81

static void AyStar_AiPathFinder_Free(AyStar *aystar)

    82

{

    83

	AyStarMain_Free(aystar);

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	free(aystar);

    85

}

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    87

    88

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

    89

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

    90

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

    91

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

    92

    93

    94

// This creates the AiPathFinder

    95

AyStar *new_AyStar_AiPathFinder(int max_tiles_around, Ai_PathFinderInfo *PathFinderInfo)

    96

{

    97

	PathNode start_node;

    98

	uint x;

    99

	uint y;

   100

	// Create AyStar

   101

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

   102

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

   103

	// Set the function pointers

   104

	result->CalculateG = AyStar_AiPathFinder_CalculateG;

   105

	result->CalculateH = AyStar_AiPathFinder_CalculateH;

   106

	result->EndNodeCheck = AyStar_AiPathFinder_EndNodeCheck;

   107

	result->FoundEndNode = AyStar_AiPathFinder_FoundEndNode;

   108

	result->GetNeighbours = AyStar_AiPathFinder_GetNeighbours;

   109

   110

	result->free = AyStar_AiPathFinder_Free;

   111

   112

	// Set some information

   113

	result->loops_per_tick = AI_PATHFINDER_LOOPS_PER_TICK;

   114

	result->max_path_cost = 0;

   115

	result->max_search_nodes = AI_PATHFINDER_MAX_SEARCH_NODES;

   116

   117

	// Set the user_data to the PathFinderInfo

   118

	result->user_target = PathFinderInfo;

   119

   120

	// Set the start node

   121

	start_node.parent = NULL;

   122

	start_node.node.direction = 0;

   123

	start_node.node.user_data[0] = 0;

   124

   125

	// Now we add all the starting tiles

   126

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

   127

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

   128

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

   129

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

   130

		}

   131

	}

   132

   133

	return result;

   134

}

   135

   136

   137

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

   138

void clean_AyStar_AiPathFinder(AyStar *aystar, Ai_PathFinderInfo *PathFinderInfo)

   139

{

   140

	PathNode start_node;

   141

	uint x;

   142

	uint y;

   143

   144

	aystar->clear(aystar);

   145

   146

	// Set the user_data to the PathFinderInfo

   147

	aystar->user_target = PathFinderInfo;

   148

   149

	// Set the start node

   150

	start_node.parent = NULL;

   151

	start_node.node.direction = 0;

   152

	start_node.node.user_data[0] = 0;

   153

	start_node.node.tile = PathFinderInfo->start_tile_tl;

   154

   155

	// Now we add all the starting tiles

   156

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

   157

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

   158

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

   159

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

   160

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

   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

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

   171

	int r, r2;

   172

	if (PathFinderInfo->end_direction != AI_PATHFINDER_NO_DIRECTION) {

   173

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

   174

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

   175

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

   176

	} else {

   177

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

   178

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

   179

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

   180

	}

   181

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

   182

	if (r2 < r) r = r2;

   183

	return r * AI_PATHFINDER_H_MULTIPLER;

   184

}

   185

   186

   187

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

   188

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

   189

{

   190

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

   191

	uint i = 0;

   192

	PathNode *parent = &current->path;

   193

   194

	do {

   195

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

   196

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

   197

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

   198

			// We ran out of space for the PathFinder

   199

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

   200

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

   201

			return;

   202

		}

   203

		parent = parent->parent;

   204

	} while (parent != NULL);

   205

	PathFinderInfo->route_length = i;

   206

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

   207

}

   208

   209

   210

// What tiles are around us.

   211

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

   212

{

   213

	uint i;

   214

	int ret;

   215

	int dir;

   216

   217

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

   218

   219

	aystar->num_neighbours = 0;

   220

   221

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

   222

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

   223

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

   224

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

   225

   226

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

   227

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

   228

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

   229

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

   230

   231

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

   232

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

   233

				if (IsTileType(atile, MP_TUNNELBRIDGE)) {

   234

					if (IsTunnel(atile)) {

   235

						if (GetTunnelDirection(atile) != i) continue;

   236

					} else {

   237

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

   238

					}

   239

				}

   240

			}

   241

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

   242

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

   243

				if (IsTileType(ctile, MP_TUNNELBRIDGE)) {

   244

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

   245

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

   246

				}

   247

			}

   248

   249

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

   250

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

   251

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

   252

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

   253

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

   254

			}

   255

			dir = 0;

   256

   257

			// First, check if we have a parent

   258

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

   259

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

   260

				if (PathFinderInfo->start_direction != AI_PATHFINDER_NO_DIRECTION) {

   261

					// We do need a direction?

   262

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

   263

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

   264

						continue;

   265

					}

   266

				}

   267

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

   268

				if (PathFinderInfo->rail_or_road) {

   269

					// Rail check

   270

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

   271

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

   272

					if (CmdFailed(ret)) continue;

   273

#ifdef AI_PATHFINDER_NO_90DEGREES_TURN

   274

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

   275

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

   276

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

   277

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

   278

							continue;

   279

						}

   280

					}

   281

#endif

   282

				} else {

   283

					// Road check

   284

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

   285

					if (IsRoad(ctile)) {

   286

						if (IsTileType(ctile, MP_TUNNELBRIDGE)) {

   287

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

   288

							dir = 0;

   289

						} else {

   290

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

   291

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

   292

								// We do miss some pieces :(

   293

								dir &= ~_m[ctile].m5;

   294

							} else {

   295

								dir = 0;

   296

							}

   297

						}

   298

					}

   299

					// Only destruct things if it is MP_CLEAR of MP_TREES

   300

					if (dir != 0) {

   301

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

   302

						if (CmdFailed(ret)) continue;

   303

					}

   304

				}

   305

			}

   306

   307

			// The tile can be connected

   308

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

   309

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

   310

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

   311

		}

   312

	}

   313

   314

	// Next step, check for bridges and tunnels

   315

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

   316

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

   317

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

   318

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

   319

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

   320

		TileIndex new_tile = tile;

   321

		Slope tileh = GetTileSlope(tile, NULL);

   322

   323

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

   324

		//  And if there is a road or rail blocking

   325

		if (tileh != SLOPE_FLAT ||

   326

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

   327

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

   328

			for (;;) {

   329

				new_tile += TileOffsByDir(dir);

   330

   331

				// Precheck, is the length allowed?

   332

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

   333

   334

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

   335

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

   336

   337

				// Try building the bridge..

   338

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

   339

				if (CmdFailed(ret)) continue;

   340

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

   341

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

   342

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

   343

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

   344

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

   345

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

   346

			}

   347

		}

   348

   349

		// Next, check for tunnels!

   350

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

   351

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

   352

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

   353

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

   354

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

   355

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

   356

			// Now simply check if a tunnel can be build

   357

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

   358

			tileh = GetTileSlope(_build_tunnel_endtile, NULL);

   359

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

   360

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

   361

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

   362

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

   363

			}

   364

		}

   365

	}

   366

}

   367

   368

   369

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

   370

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

   371

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

   372

enum {

   373

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

   374

};

   375

   376

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

   377

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

   378

{

   379

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

   380

	int r, res = 0;

   381

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

   382

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

   383

   384

	// Check if we hit the end-tile

   385

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

   386

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

   387

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

   388

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

   389

			return AYSTAR_INVALID_NODE;

   390

		}

   391

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

   392

		return 0;

   393

	}

   394

   395

	// Give everything a small penalty

   396

	res += AI_PATHFINDER_PENALTY;

   397

   398

	if (!PathFinderInfo->rail_or_road) {

   399

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

   400

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

   401

		if (IsRoad(current->tile)) {

   402

			res -= AI_PATHFINDER_ROAD_ALREADY_EXISTS_BONUS;

   403

		}

   404

	}

   405

   406

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

   407

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

   408

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

   409

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

   410

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

   411

	//  from one side.

   412

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

   413

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

   414

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

   415

			if (PathFinderInfo->rail_or_road) {

   416

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

   417

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

   418

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

   419

					res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   420

				} else {

   421

					res += AI_PATHFINDER_FOUNDATION_PENALTY;

   422

				}

   423

			} else {

   424

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

   425

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

   426

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

   427

						res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   428

					else

   429

						res += AI_PATHFINDER_FOUNDATION_PENALTY;

   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

		// Second for the end point

   454

		if (!HASBIT(BRIDGE_NO_FOUNDATION, tileh)) {

   455

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

   456

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   457

		}

   458

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

   459

		if (tileh == SLOPE_FLAT) 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)))) {

   487

					// It is not, so we changed of direction

   488

					res += AI_PATHFINDER_DIRECTION_CHANGE_PENALTY;

   489

				}

   490

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

   491

					int dir3 = AiNew_GetRailDirection(parent->path.parent->parent->parent->node.tile, parent->path.parent->parent->node.tile, parent->path.parent->node.tile);

   492

					// Check if we changed 3 tiles of direction in 3 tiles.. bad!!!

   493

					if ((dir1 == 0 || dir1 == 1) && dir2 > 1 && (dir3 == 0 || dir3 == 1)) {

   494

						res += AI_PATHFINDER_CURVE_PENALTY;

   495

					}

   496

				}

   497

			}

   498

		}

   499

	}

   500

   501

	return (res < 0) ? 0 : res;

   502

}