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/* $Id$ */

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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 "../../map.h"

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#include "../../command_func.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 "../../tunnelbridge_map.h"

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#include "../ai.h"

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    16

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#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

		CommandCost 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 (CmdSucceeded(ret)) return true;

    32

		}

    33

		return false;

    34

	}

    35

    36

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

    37

	return CmdSucceeded(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_ROAD, but not a road depot?

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

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		(IsTileType(tile, MP_TUNNELBRIDGE) && GetTunnelBridgeTransportType(tile) == TRANSPORT_ROAD);

    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 = (Ai_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

}

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    77

    78

// Clear the memory of all the things

    79

static void AyStar_AiPathFinder_Free(AyStar *aystar)

    80

{

    81

	AyStarMain_Free(aystar);

    82

	delete aystar;

    83

}

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    85

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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);

    88

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

    89

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

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    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 = new 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 = (Ai_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

	CommandCost 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 (DiagDirection i = DIAGDIR_BEGIN; i < DIAGDIR_END; i++) {

   223

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

   224

		TileIndex atile = ctile + TileOffsByDiagDir(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 (GetTunnelBridgeDirection(atile) != i) continue;

   235

				}

   236

			}

   237

   238

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

   239

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

   240

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

   241

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

   242

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

   243

			}

   244

			dir = 0;

   245

   246

			// First, check if we have a parent

   247

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

   248

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

   249

				if (PathFinderInfo->start_direction != AI_PATHFINDER_NO_DIRECTION) {

   250

					// We do need a direction?

   251

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

   252

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

   253

						continue;

   254

					}

   255

				}

   256

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

   257

				if (PathFinderInfo->rail_or_road) {

   258

					// Rail check

   259

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

   260

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

   261

					if (CmdFailed(ret)) continue;

   262

#ifdef AI_PATHFINDER_NO_90DEGREES_TURN

   263

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

   264

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

   265

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

   266

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

   267

							continue;

   268

						}

   269

					}

   270

#endif

   271

				} else {

   272

					// Road check

   273

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

   274

					if (IsRoad(ctile)) {

   275

						if (IsTileType(ctile, MP_TUNNELBRIDGE)) {

   276

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

   277

							dir = 0;

   278

						} else {

   279

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

   280

							if ((GetAnyRoadBits(ctile, ROADTYPE_ROAD) & dir) != dir) {

   281

								// We do miss some pieces :(

   282

								dir &= ~GetAnyRoadBits(ctile, ROADTYPE_ROAD);

   283

							} else {

   284

								dir = 0;

   285

							}

   286

						}

   287

					}

   288

					// Only destruct things if it is MP_CLEAR of MP_TREES

   289

					if (dir != 0) {

   290

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

   291

						if (CmdFailed(ret)) continue;

   292

					}

   293

				}

   294

			}

   295

   296

			// The tile can be connected

   297

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

   298

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

   299

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

   300

		}

   301

	}

   302

   303

	// Next step, check for bridges and tunnels

   304

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

   305

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

   306

		DiagDirection 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

		Slope tileh = GetTileSlope(tile, NULL);

   311

   312

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

   313

		//  And if there is a road or rail blocking

   314

		if (tileh != SLOPE_FLAT ||

   315

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

   316

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

   317

			for (;;) {

   318

				new_tile += TileOffsByDiagDir(dir);

   319

   320

				// Precheck, is the length allowed?

   321

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

   322

   323

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

   324

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

   325

   326

				// Try building the bridge..

   327

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

   328

				if (CmdFailed(ret)) continue;

   329

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

   330

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

   331

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

   332

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

   333

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

   334

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

   335

			}

   336

		}

   337

   338

		// Next, check for tunnels!

   339

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

   340

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

   341

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

   342

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

   343

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

   344

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

   345

			// Now simply check if a tunnel can be build

   346

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

   347

			tileh = GetTileSlope(_build_tunnel_endtile, NULL);

   348

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

   349

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

   350

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

   351

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

   352

			}

   353

		}

   354

	}

   355

}

   356

   357

   358

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

   359

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

   360

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

   361

enum BridgeFoundation {

   362

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

   363

};

   364

   365

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

   366

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

   367

{

   368

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

   369

	int res = 0;

   370

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

   371

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

   372

   373

	// Check if we hit the end-tile

   374

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

   375

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

   376

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

   377

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

   378

			return AYSTAR_INVALID_NODE;

   379

		}

   380

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

   381

		return 0;

   382

	}

   383

   384

	// Give everything a small penalty

   385

	res += AI_PATHFINDER_PENALTY;

   386

   387

	if (!PathFinderInfo->rail_or_road) {

   388

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

   389

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

   390

		if (IsRoad(current->tile)) {

   391

			res -= AI_PATHFINDER_ROAD_ALREADY_EXISTS_BONUS;

   392

		}

   393

	}

   394

   395

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

   396

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

   397

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

   398

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

   399

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

   400

	//  from one side.

   401

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

   402

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

   403

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

   404

			if (PathFinderInfo->rail_or_road) {

   405

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

   406

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

   407

				if (IsInclinedFoundation(f) || (!IsFoundation(f) && HasBit(BRIDGE_NO_FOUNDATION, parent_tileh))) {

   408

					res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   409

				} else {

   410

					res += AI_PATHFINDER_FOUNDATION_PENALTY;

   411

				}

   412

			} else {

   413

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

   414

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

   415

					if (IsInclinedFoundation(f) || (!IsFoundation(f) && HasBit(BRIDGE_NO_FOUNDATION, parent_tileh))) {

   416

						res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   417

					} else {

   418

						res += AI_PATHFINDER_FOUNDATION_PENALTY;

   419

					}

   420

				}

   421

			}

   422

		}

   423

	}

   424

   425

	// Are we part of a tunnel?

   426

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

   427

		int r;

   428

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

   429

		// Ironicly, we are using BridgeCode here ;)

   430

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

   431

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

   432

	}

   433

   434

	// Are we part of a bridge?

   435

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

   436

		// That means for every length a penalty

   437

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

   438

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

   439

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

   440

		if (!HasBit(BRIDGE_NO_FOUNDATION, parent_tileh)) {

   441

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

   442

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   443

			}

   444

		}

   445

		// Second for the end point

   446

		if (!HasBit(BRIDGE_NO_FOUNDATION, tileh)) {

   447

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

   448

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   449

			}

   450

		}

   451

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

   452

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

   453

	}

   454

   455

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

   456

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

   457

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

   458

	if (!PathFinderInfo->rail_or_road) {

   459

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

   460

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

   461

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

   462

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

   463

				res += AI_PATHFINDER_DIRECTION_CHANGE_ON_EXISTING_ROAD_PENALTY;

   464

			} else {

   465

				res += AI_PATHFINDER_DIRECTION_CHANGE_PENALTY;

   466

			}

   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)) {

   488

						res += AI_PATHFINDER_CURVE_PENALTY;

   489

					}

   490

				}

   491

			}

   492

		}

   493

	}

   494

   495

	return (res < 0) ? 0 : res;

   496

}