1

#include "stdafx.h"

     2

#include "openttd.h"

     3

#include "debug.h"

     4

#include "map.h"

     5

#include "tile.h"

     6

#include "command.h"

     7

#include "ai.h"

     8

#include "depot.h"

     9

    10

#define TEST_STATION_NO_DIR 0xFF

    11

    12

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

    13

// TODO: make it train compatible

    15

{

    16

	Player *p = GetPlayer(_current_player);

    17

    18

	if (dir == TEST_STATION_NO_DIR) {

    19

		int32 ret;

    20

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

    21

		//  should be fixed!!!

    22

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

    23

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

    24

			if (!CmdFailed(ret)) return true;

    25

		}

    26

		return false;

    27

	}

    28

    29

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

    30

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

    31

}

    32

    33

    34

static bool IsRoad(TileIndex tile)

    35

{

    36

	return

    37

		// MP_STREET, but not a road depot?

    38

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

    39

		(IsTileType(tile, MP_TUNNELBRIDGE) && (

    40

			// road tunnel?

    41

			((_map5[tile] & 0x80) == 0 && (_map5[tile] & 0x4) == 0x4) ||

    42

			// road bridge?

    43

			((_map5[tile] & 0x80) != 0 && (_map5[tile] & 0x2) == 0x2)

    44

		));

    45

}

    46

    47

    48

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

    49

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

    50

    51

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

    52

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

    53

{

    54

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

    55

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

    56

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

    57

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

    58

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

    59

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

    60

				return AYSTAR_FOUND_END_NODE;

    61

    62

	return AYSTAR_DONE;

    63

}

    64

    65

// Calculates the hash

    66

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

    67

static uint AiPathFinder_Hash(uint key1, uint key2)

    68

{

    69

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

    70

}

    71

    72

// Clear the memory of all the things

    73

static void AyStar_AiPathFinder_Free(AyStar *aystar)

    74

{

    75

	AyStarMain_Free(aystar);

    76

	free(aystar);

    77

}

    78

    79

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

    80

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

    81

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

    82

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

    83

    84

// This creates the AiPathFinder

    85

AyStar *new_AyStar_AiPathFinder(int max_tiles_around, Ai_PathFinderInfo *PathFinderInfo)

    86

{

    87

	PathNode start_node;

    88

	uint x;

    89

	uint y;

    90

	// Create AyStar

    91

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

    92

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

    93

	// Set the function pointers

    94

	result->CalculateG = AyStar_AiPathFinder_CalculateG;

    95

	result->CalculateH = AyStar_AiPathFinder_CalculateH;

    96

	result->EndNodeCheck = AyStar_AiPathFinder_EndNodeCheck;

    97

	result->FoundEndNode = AyStar_AiPathFinder_FoundEndNode;

    98

	result->GetNeighbours = AyStar_AiPathFinder_GetNeighbours;

    99

   100

	result->free = AyStar_AiPathFinder_Free;

   101

   102

	// Set some information

   103

	result->loops_per_tick = AI_PATHFINDER_LOOPS_PER_TICK;

   104

	result->max_path_cost = 0;

   105

	result->max_search_nodes = AI_PATHFINDER_MAX_SEARCH_NODES;

   106

   107

	// Set the user_data to the PathFinderInfo

   108

	result->user_target = PathFinderInfo;

   109

   110

	// Set the start node

   111

	start_node.parent = NULL;

   112

	start_node.node.direction = 0;

   113

	start_node.node.user_data[0] = 0;

   114

   115

	// Now we add all the starting tiles

   116

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

   117

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

   118

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

   119

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

   120

		}

   121

	}

   122

   123

	return result;

   124

}

   125

   126

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

   127

void clean_AyStar_AiPathFinder(AyStar *aystar, Ai_PathFinderInfo *PathFinderInfo)

   128

{

   129

	PathNode start_node;

   130

	uint x;

   131

	uint y;

   132

   133

	aystar->clear(aystar);

   134

   135

	// Set the user_data to the PathFinderInfo

   136

	aystar->user_target = PathFinderInfo;

   137

   138

	// Set the start node

   139

	start_node.parent = NULL;

   140

	start_node.node.direction = 0;

   141

	start_node.node.user_data[0] = 0;

   142

	start_node.node.tile = PathFinderInfo->start_tile_tl;

   143

   144

	// Now we add all the starting tiles

   145

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

   146

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

   147

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

   148

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

   149

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

   150

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

   151

		}

   152

	}

   153

}

   154

   155

// The h-value, simple calculation

   156

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

   157

{

   158

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

   159

	int r, r2;

   160

	if (PathFinderInfo->end_direction != AI_PATHFINDER_NO_DIRECTION) {

   161

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

   162

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

   163

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

   164

	} else {

   165

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

   166

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

   167

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

   168

	}

   169

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

   170

	if (r2 < r) r = r2;

   171

	return r * AI_PATHFINDER_H_MULTIPLER;

   172

}

   173

   174

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

   175

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

   176

{

   177

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

   178

	uint i = 0;

   179

	PathNode *parent = &current->path;

   180

   181

	do {

   182

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

   183

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

   184

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

   185

			// We ran out of space for the PathFinder

   186

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

   187

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

   188

			return;

   189

		}

   190

		parent = parent->parent;

   191

	} while (parent != NULL);

   192

	PathFinderInfo->route_length = i;

   193

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

   194

}

   195

   196

// What tiles are around us.

   197

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

   198

{

   199

	uint i;

   200

	int ret;

   201

	int dir;

   202

   203

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

   204

   205

	aystar->num_neighbours = 0;

   206

   207

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

   208

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

   209

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

   210

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

   211

   212

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

   213

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

   214

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

   215

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

   216

   217

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

   218

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

   219

				if (IsTileType(atile, MP_TUNNELBRIDGE)) {

   220

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

   221

					if ((_map5[atile] & 1U) != (i & 1)) continue;

   222

					// This problem only is valid for tunnels:

   223

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

   224

					if ((_map5[atile] & 0x80) == 0) {

   225

						if (i != (_map5[atile] & 3U)) continue;

   226

					}

   227

				}

   228

			}

   229

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

   230

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

   231

				if (IsTileType(ctile, MP_TUNNELBRIDGE)) {

   232

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

   233

					if ((_map5[ctile] & 1U) != (i & 1)) continue;

   234

				}

   235

			}

   236

   237

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

   238

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

   239

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

   240

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

   241

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

   242

			}

   243

			dir = 0;

   244

   245

			// First, check if we have a parent

   246

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

   247

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

   248

				if (PathFinderInfo->start_direction != AI_PATHFINDER_NO_DIRECTION) {

   249

					// We do need a direction?

   250

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

   251

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

   252

						continue;

   253

					}

   254

				}

   255

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

   256

				if (PathFinderInfo->rail_or_road) {

   257

					// Rail check

   258

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

   259

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

   260

					if (CmdFailed(ret)) continue;

   261

#ifdef AI_PATHFINDER_NO_90DEGREES_TURN

   262

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

   263

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

   264

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

   265

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

   266

							continue;

   267

						}

   268

					}

   269

#endif

   270

				} else {

   271

					// Road check

   272

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

   273

					if (IsRoad(ctile)) {

   274

						if (IsTileType(ctile, MP_TUNNELBRIDGE)) {

   275

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

   276

							dir = 0;

   277

						} else {

   278

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

   279

							if ((_map5[ctile] & dir) != dir) {

   280

								// We do miss some pieces :(

   281

								dir &= ~_map5[ctile];

   282

							} else {

   283

								dir = 0;

   284

							}

   285

						}

   286

					}

   287

					// Only destruct things if it is MP_CLEAR of MP_TREES

   288

					if (dir != 0) {

   289

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

   290

						if (CmdFailed(ret)) continue;

   291

					}

   292

				}

   293

			}

   294

   295

			// The tile can be connected

   296

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

   297

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

   298

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

   299

		}

   300

	}

   301

   302

	// Next step, check for bridges and tunnels

   303

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

   304

		TileInfo ti;

   305

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

   306

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

   307

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

   308

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

   309

		TileIndex new_tile = tile;

   310

   311

		FindLandscapeHeightByTile(&ti, tile);

   312

   313

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

   314

		//  And if there is a road or rail blocking

   315

		if (ti.tileh != 0 ||

   316

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

   317

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

   318

   319

			for (;;) {

   320

				new_tile += TileOffsByDir(dir);

   321

   322

				// Precheck, is the length allowed?

   323

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

   324

   325

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

   326

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

   327

   328

				// Try building the bridge..

   329

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

   330

				if (CmdFailed(ret)) continue;

   331

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

   332

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

   333

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

   334

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

   335

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

   336

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

   337

			}

   338

		}

   339

   340

		// Next, check for tunnels!

   341

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

   342

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

   343

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

   344

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

   345

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

   346

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

   347

			// Now simply check if a tunnel can be build

   348

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

   349

			FindLandscapeHeightByTile(&ti, _build_tunnel_endtile);

   350

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

   351

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

   352

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

   353

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

   354

			}

   355

		}

   356

	}

   357

}

   358

   359

extern uint GetRailFoundation(uint tileh, uint bits);

   360

extern uint GetRoadFoundation(uint tileh, uint bits);

   361

extern uint GetBridgeFoundation(uint tileh, byte direction);

   362

enum {

   363

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

   364

};

   365

   366

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

   367

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

   368

{

   369

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

   370

	int r, res = 0;

   371

	TileInfo ti, parent_ti;

   372

   373

	// Gather some information about the tile..

   374

	FindLandscapeHeightByTile(&ti, current->tile);

   375

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

   376

   377

	// Check if we hit the end-tile

   378

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

   379

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

   380

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

   381

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

   382

			return AYSTAR_INVALID_NODE;

   383

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

   384

		return 0;

   385

	}

   386

   387

	// Give everything a small penalty

   388

	res += AI_PATHFINDER_PENALTY;

   389

   390

	if (!PathFinderInfo->rail_or_road) {

   391

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

   392

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

   393

		if (IsRoad(current->tile)) {

   394

			res -= AI_PATHFINDER_ROAD_ALREADY_EXISTS_BONUS;

   395

		}

   396

	}

   397

   398

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

   399

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

   400

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

   401

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

   402

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

   403

	//  from one side.

   404

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

   405

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

   406

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

   407

			if (PathFinderInfo->rail_or_road) {

   408

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

   409

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

   410

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

   411

					res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   412

				} else {

   413

					res += AI_PATHFINDER_FOUNDATION_PENALTY;

   414

				}

   415

			} else {

   416

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

   417

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

   418

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

   419

						res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   420

					else

   421

						res += AI_PATHFINDER_FOUNDATION_PENALTY;

   422

				}

   423

			}

   424

		}

   425

	}

   426

   427

	// Are we part of a tunnel?

   428

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

   429

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

   430

		// Ironicly, we are using BridgeCode here ;)

   431

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

   432

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

   433

	}

   434

   435

	// Are we part of a bridge?

   436

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

   437

		// That means for every length a penalty

   438

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

   439

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

   440

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

   441

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

   442

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

   443

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   444

		}

   445

		// Second for the end point

   446

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

   447

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

   448

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   449

		}

   450

		if (parent_ti.tileh == 0)

   451

			res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   452

		if (ti.tileh == 0)

   453

			res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   454

	}

   455

   456

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

   457

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

   458

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

   459

	if (!PathFinderInfo->rail_or_road) {

   460

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

   461

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

   462

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

   463

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

   464

				res += AI_PATHFINDER_DIRECTION_CHANGE_ON_EXISTING_ROAD_PENALTY;

   465

			else

   466

				res += AI_PATHFINDER_DIRECTION_CHANGE_PENALTY;

   467

		}

   468

	} else {

   469

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

   470

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

   471

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

   472

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

   473

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

   474

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

   475

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

   476

   477

			// First see if they are different

   478

			if (dir1 != dir2) {

   479

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

   480

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

   481

					// It is not, so we changed of direction

   482

					res += AI_PATHFINDER_DIRECTION_CHANGE_PENALTY;

   483

				}

   484

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

   485

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

   486

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

   487

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