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#include "stdafx.h"

     2

#include "openttd.h"

     3

#include "debug.h"

     4

#include "map.h"

     5

#include "tile.h"

     6

#include "command.h"

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#include "ai_new.h"

     8

#include "depot.h"

    10

    11

#define TEST_STATION_NO_DIR 0xFF

    12

    13

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

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// TODO: make it train compatible

    15

static bool TestCanBuildStationHere(TileIndex tile, byte dir)

    16

{

    17

	Player *p = GetPlayer(_current_player);

    18

    19

	if (dir == TEST_STATION_NO_DIR) {

    20

		int32 ret;

    21

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

    22

		//  should be fixed!!!

    23

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

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

    25

			if (!CmdFailed(ret)) return true;

    26

		}

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		return false;

    28

	}

    29

    30

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

    31

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

    32

}

    33

    34

    35

static bool IsRoad(TileIndex tile)

    36

{

    37

	return

    38

		// MP_STREET, but not a road depot?

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

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		(IsTileType(tile, MP_TUNNELBRIDGE) && (

    41

			// road tunnel?

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

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			// road bridge?

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

    45

		));

    46

}

    47

    48

    49

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

    50

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

    51

    52

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

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

    54

{

    55

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

    56

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

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

    58

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

    59

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

    60

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

    61

				return AYSTAR_FOUND_END_NODE;

    62

    63

	return AYSTAR_DONE;

    64

}

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    66

// Calculates the hash

    67

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

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static uint AiPathFinder_Hash(uint key1, uint key2)

    69

{

    70

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

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}

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    73

// Clear the memory of all the things

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static void AyStar_AiPathFinder_Free(AyStar *aystar)

    75

{

    76

	AyStarMain_Free(aystar);

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	free(aystar);

    78

}

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    80

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);

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

    83

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

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    85

// This creates the AiPathFinder

    86

AyStar *new_AyStar_AiPathFinder(int max_tiles_around, Ai_PathFinderInfo *PathFinderInfo)

    87

{

    88

	PathNode start_node;

    89

	uint x;

    90

	uint y;

    91

	// Create AyStar

    92

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

    93

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

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	// Set the function pointers

    95

	result->CalculateG = AyStar_AiPathFinder_CalculateG;

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	result->CalculateH = AyStar_AiPathFinder_CalculateH;

    97

	result->EndNodeCheck = AyStar_AiPathFinder_EndNodeCheck;

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	result->FoundEndNode = AyStar_AiPathFinder_FoundEndNode;

    99

	result->GetNeighbours = AyStar_AiPathFinder_GetNeighbours;

   100

   101

	result->BeforeExit = NULL;

   102

   103

	result->free = AyStar_AiPathFinder_Free;

   104

   105

	// Set some information

   106

	result->loops_per_tick = AI_PATHFINDER_LOOPS_PER_TICK;

   107

	result->max_path_cost = 0;

   108

	result->max_search_nodes = AI_PATHFINDER_MAX_SEARCH_NODES;

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   110

	// Set the user_data to the PathFinderInfo

   111

	result->user_target = PathFinderInfo;

   112

   113

	// Set the start node

   114

	start_node.parent = NULL;

   115

	start_node.node.direction = 0;

   116

	start_node.node.user_data[0] = 0;

   117

   118

	// Now we add all the starting tiles

   119

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

   120

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

   121

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

   122

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

   123

		}

   124

	}

   125

   126

	return result;

   127

}

   128

   129

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

   130

void clean_AyStar_AiPathFinder(AyStar *aystar, Ai_PathFinderInfo *PathFinderInfo)

   131

{

   132

	PathNode start_node;

   133

	uint x;

   134

	uint y;

   135

   136

	aystar->clear(aystar);

   137

   138

	// Set the user_data to the PathFinderInfo

   139

	aystar->user_target = PathFinderInfo;

   140

   141

	// Set the start node

   142

	start_node.parent = NULL;

   143

	start_node.node.direction = 0;

   144

	start_node.node.user_data[0] = 0;

   145

	start_node.node.tile = PathFinderInfo->start_tile_tl;

   146

   147

	// Now we add all the starting tiles

   148

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

   149

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

   150

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

   151

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

   152

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

   153

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

   154

		}

   155

	}

   156

}

   157

   158

// The h-value, simple calculation

   159

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

   160

{

   161

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

   162

	int r, r2;

   163

	if (PathFinderInfo->end_direction != AI_PATHFINDER_NO_DIRECTION) {

   164

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

   165

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

   166

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

   167

	} else {

   168

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

   169

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

   170

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

   171

	}

   172

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

   173

	if (r2 < r) r = r2;

   174

	return r * AI_PATHFINDER_H_MULTIPLER;

   175

}

   176

   177

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

   178

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

   179

{

   180

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

   181

	uint i = 0;

   182

	PathNode *parent = &current->path;

   183

   184

	do {

   185

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

   186

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

   187

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

   188

			// We ran out of space for the PathFinder

   189

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

   190

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

   191

			return;

   192

		}

   193

		parent = parent->parent;

   194

	} while (parent != NULL);

   195

	PathFinderInfo->route_length = i;

   196

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

   197

}

   198

   199

// What tiles are around us.

   200

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

   201

{

   202

	uint i;

   203

	int ret;

   204

	int dir;

   205

   206

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

   207

   208

	aystar->num_neighbours = 0;

   209

   210

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

   211

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

   212

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

   213

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

   214

   215

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

   216

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

   217

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

   218

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

   219

   220

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

   221

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

   222

				if (IsTileType(atile, MP_TUNNELBRIDGE)) {

   223

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

   224

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

   225

					// This problem only is valid for tunnels:

   226

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

   227

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

   228

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

   229

					}

   230

				}

   231

			}

   232

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

   233

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

   234

				if (IsTileType(ctile, MP_TUNNELBRIDGE)) {

   235

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

   236

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

   237

				}

   238

			}

   239

   240

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

   241

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

   242

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

   243

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

   244

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

   245

			}

   246

			dir = 0;

   247

   248

			// First, check if we have a parent

   249

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

   250

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

   251

				if (PathFinderInfo->start_direction != AI_PATHFINDER_NO_DIRECTION) {

   252

					// We do need a direction?

   253

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

   254

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

   255

						continue;

   256

					}

   257

				}

   258

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

   259

				if (PathFinderInfo->rail_or_road) {

   260

					// Rail check

   261

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

   262

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

   263

					if (CmdFailed(ret)) continue;

   264

#ifdef AI_PATHFINDER_NO_90DEGREES_TURN

   265

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

   266

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

   267

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

   268

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

   269

							continue;

   270

						}

   271

					}

   272

#endif

   273

				} else {

   274

					// Road check

   275

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

   276

					if (IsRoad(ctile)) {

   277

						if (IsTileType(ctile, MP_TUNNELBRIDGE)) {

   278

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

   279

							dir = 0;

   280

						} else {

   281

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

   282

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

   283

								// We do miss some pieces :(

   284

								dir &= ~_m[ctile].m5;

   285

							} else {

   286

								dir = 0;

   287

							}

   288

						}

   289

					}

   290

					// Only destruct things if it is MP_CLEAR of MP_TREES

   291

					if (dir != 0) {

   292

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

   293

						if (CmdFailed(ret)) continue;

   294

					}

   295

				}

   296

			}

   297

   298

			// The tile can be connected

   299

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

   300

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

   301

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

   302

		}

   303

	}

   304

   305

	// Next step, check for bridges and tunnels

   306

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

   307

		TileInfo ti;

   308

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

   309

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

   310

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

   311

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

   312

		TileIndex new_tile = tile;

   313

   314

		FindLandscapeHeightByTile(&ti, tile);

   315

   316

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

   317

		//  And if there is a road or rail blocking

   318

		if (ti.tileh != 0 ||

   319

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

   320

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

   321

   322

			for (;;) {

   323

				new_tile += TileOffsByDir(dir);

   324

   325

				// Precheck, is the length allowed?

   326

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

   327

   328

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

   329

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

   330

   331

				// Try building the bridge..

   332

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

   333

				if (CmdFailed(ret)) continue;

   334

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

   335

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

   336

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

   337

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

   338

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

   339

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

   340

			}

   341

		}

   342

   343

		// Next, check for tunnels!

   344

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

   345

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

   346

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

   347

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

   348

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

   349

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

   350

			// Now simply check if a tunnel can be build

   351

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

   352

			FindLandscapeHeightByTile(&ti, _build_tunnel_endtile);

   353

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

   354

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

   355

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

   356

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

   357

			}

   358

		}

   359

	}

   360

}

   361

   362

extern uint GetRailFoundation(uint tileh, uint bits);

   363

extern uint GetRoadFoundation(uint tileh, uint bits);

   364

extern uint GetBridgeFoundation(uint tileh, byte direction);

   365

enum {

   366

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

   367

};

   368

   369

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

   370

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

   371

{

   372

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

   373

	int r, res = 0;

   374

	TileInfo ti, parent_ti;

   375

   376

	// Gather some information about the tile..

   377

	FindLandscapeHeightByTile(&ti, current->tile);

   378

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

   379

   380

	// Check if we hit the end-tile

   381

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

   382

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

   383

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

   384

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

   385

			return AYSTAR_INVALID_NODE;

   386

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

   387

		return 0;

   388

	}

   389

   390

	// Give everything a small penalty

   391

	res += AI_PATHFINDER_PENALTY;

   392

   393

	if (!PathFinderInfo->rail_or_road) {

   394

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

   395

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

   396

		if (IsRoad(current->tile)) {

   397

			res -= AI_PATHFINDER_ROAD_ALREADY_EXISTS_BONUS;

   398

		}

   399

	}

   400

   401

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

   402

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

   403

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

   404

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

   405

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

   406

	//  from one side.

   407

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

   408

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

   409

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

   410

			if (PathFinderInfo->rail_or_road) {

   411

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

   412

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

   413

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

   414

					res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   415

				} else {

   416

					res += AI_PATHFINDER_FOUNDATION_PENALTY;

   417

				}

   418

			} else {

   419

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

   420

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

   421

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

   422

						res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   423

					else

   424

						res += AI_PATHFINDER_FOUNDATION_PENALTY;

   425

				}

   426

			}

   427

		}

   428

	}

   429

   430

	// Are we part of a tunnel?

   431

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

   432

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

   433

		// Ironicly, we are using BridgeCode here ;)

   434

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

   435

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

   436

	}

   437

   438

	// Are we part of a bridge?

   439

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

   440

		// That means for every length a penalty

   441

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

   442

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

   443

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

   444

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

   445

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

   446

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   447

		}

   448

		// Second for the end point

   449

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

   450

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

   451

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   452

		}

   453

		if (parent_ti.tileh == 0)

   454

			res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   455

		if (ti.tileh == 0)

   456

			res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   457

	}

   458

   459

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

   460

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

   461

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

   462

	if (!PathFinderInfo->rail_or_road) {

   463

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

   464

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

   465

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

   466

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

   467

				res += AI_PATHFINDER_DIRECTION_CHANGE_ON_EXISTING_ROAD_PENALTY;

   468

			else

   469

				res += AI_PATHFINDER_DIRECTION_CHANGE_PENALTY;

   470

		}

   471

	} else {

   472

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

   473

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

   474

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

   475

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

   476

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

   477

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

   478

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

   479

   480

			// First see if they are different

   481

			if (dir1 != dir2) {

   482

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

   483

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

   484

					// It is not, so we changed of direction

   485

					res += AI_PATHFINDER_DIRECTION_CHANGE_PENALTY;

   486

				}