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#include "stdafx.h"

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#include "ttd.h"

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#include "debug.h"

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#include "map.h"

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#include "tile.h"

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#include "command.h"

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#include "ai.h"

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#include "depot.h"

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    10

#define TEST_STATION_NO_DIR 0xFF

    11

    12

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

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// TODO: make it train compatible

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static bool TestCanBuildStationHere(uint tile, byte dir)

    15

{

    16

    Player *p = DEREF_PLAYER(_current_player);

    17

    if (dir == TEST_STATION_NO_DIR) {

    18

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

    19

        //  should be fixed!!!

    20

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

    21

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

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            if (res != CMD_ERROR)

    23

            	return true;

    24

        }

    25

        return false;

    26

    } else {

    27

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

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        if (res == CMD_ERROR)

    29

        	return false;

    30

    }

    31

    return true;

    32

}

    33

    34

    35

static bool IsRoad(TileIndex tile)

    36

{

    37

	return

    38

		// MP_STREET, but not a road depot?

    39

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

    40

		(IsTileType(tile, MP_TUNNELBRIDGE) && (

    41

			// road tunnel?

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

    43

			// road bridge?

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

    45

		));

    46

}

    47

    48

    49

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

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

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    52

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

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static int32 AyStar_AiPathFinder_EndNodeCheck(AyStar *aystar, AyStarNode *node)

    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 ;)

    57

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

    58

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

    59

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

    60

			/* XXX: The next line used to be here, but the argument to this function

    61

			 * changed to an AyStarNode* instead of an OpenListNode*, so we don't

    62

			 * have the parent available here anymore. Still, if we can build a

    63

			 * station in anyone direction, we can build it in any direction, right?*/

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

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			if ( TestCanBuildStationHere(node->tile,0))

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    			return AYSTAR_FOUND_END_NODE;

    67

    68

	return AYSTAR_DONE;

    69

}

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    71

// Calculates the hash

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//   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)

    74

{

    75

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

    76

}

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    78

// Clear the memory of all the things

    79

static void AyStar_AiPathFinder_Free(AyStar *aystar)

    80

{

    81

	AyStarMain_Free(aystar);

    82

	free(aystar);

    83

}

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    85

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

    86

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

    87

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

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

    89

    90

// This creates the AiPathFinder

    91

AyStar *new_AyStar_AiPathFinder(int max_tiles_around, Ai_PathFinderInfo *PathFinderInfo) {

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	PathNode start_node;

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	uint x,y;

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	// Create AyStar

    95

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

    96

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

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	// Set the function pointers

    98

	result->CalculateG = AyStar_AiPathFinder_CalculateG;

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	result->CalculateH = AyStar_AiPathFinder_CalculateH;

   100

	result->EndNodeCheck = AyStar_AiPathFinder_EndNodeCheck;

   101

	result->FoundEndNode = AyStar_AiPathFinder_FoundEndNode;

   102

	result->GetNeighbours = AyStar_AiPathFinder_GetNeighbours;

   103

   104

	result->free = AyStar_AiPathFinder_Free;

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   106

	// Set some information

   107

	result->loops_per_tick = AI_PATHFINDER_LOOPS_PER_TICK;

   108

	result->max_path_cost = 0;

   109

	result->max_search_nodes = AI_PATHFINDER_MAX_SEARCH_NODES;

   110

   111

	// Set the user_data to the PathFinderInfo

   112

	result->user_target = PathFinderInfo;

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   114

	// Set the start node

   115

	start_node.parent = NULL;

   116

	start_node.node.direction = 0;

   117

	start_node.node.user_data[0] = 0;

   118

   119

	// Now we add all the starting tiles

   120

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

   121

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

   122

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

   123

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

   124

		}

   125

	}

   126

   127

	return result;

   128

}

   129

   130

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

   131

void clean_AyStar_AiPathFinder(AyStar *aystar, Ai_PathFinderInfo *PathFinderInfo) {

   132

	PathNode start_node;

   133

	uint x,y;

   134

   135

	aystar->clear(aystar);

   136

   137

	// Set the user_data to the PathFinderInfo

   138

	aystar->user_target = PathFinderInfo;

   139

   140

	// Set the start node

   141

	start_node.parent = NULL;

   142

	start_node.node.direction = 0;

   143

	start_node.node.user_data[0] = 0;

   144

	start_node.node.tile = PathFinderInfo->start_tile_tl;

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   146

	// Now we add all the starting tiles

   147

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

   148

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

   149

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

   150

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

   151

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

   152

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

   153

		}

   154

	}

   155

}

   156

   157

// The h-value, simple calculation

   158

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

   159

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

   160

	int r, r2;

   161

	if (PathFinderInfo->end_direction != AI_PATHFINDER_NO_DIRECTION) {

   162

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

   163

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

   164

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

   165

	} else {

   166

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

   167

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

   168

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

   169

	}

   170

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

   171

	if (r2 < r) r = r2;

   172

	return r * AI_PATHFINDER_H_MULTIPLER;

   173

}

   174

   175

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

   176

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

   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 spacein 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

}

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   196

// What tiles are around us.

   197

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

   198

		uint i;

   199

		int r;

   200

		int dir;

   201

   202

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

   203

   204

    aystar->num_neighbours = 0;

   205

   206

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

   207

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

   208

   		if (TileX(TileOffsByDir(i) + current->path.node.tile) > 1 &&

   209

					TileX(TileOffsByDir(i) + current->path.node.tile) < MapMaxX() - 1 &&

   210

       		TileY(TileOffsByDir(i) + current->path.node.tile) > 1 &&

   211

					TileY(TileOffsByDir(i) + current->path.node.tile) < MapMaxY() - 1) {

   212

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

   213

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

   214

   215

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

   216

       		if (!PathFinderInfo->rail_or_road && IsRoad(current->path.node.tile + TileOffsByDir(i))) {

   217

       			if (IsTileType(current->path.node.tile + TileOffsByDir(i), MP_TUNNELBRIDGE)) {

   218

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

   219

       				if ((_map5[current->path.node.tile + TileOffsByDir(i)] & 1U) != (i & 1)) continue;

   220

   					// This problem only is valid for tunnels:

   221

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

   222

       				if ((_map5[current->path.node.tile + TileOffsByDir(i)] & 0x80) == 0) {

   223

       					if (i != (_map5[current->path.node.tile + TileOffsByDir(i)] & 3U)) continue;

   224

       				}

   225

       			}

   226

       		}

   227

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

   228

       		if (!PathFinderInfo->rail_or_road && IsRoad(current->path.node.tile)) {

   229

       			if (IsTileType(current->path.node.tile, MP_TUNNELBRIDGE)) {

   230

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

   231

       				if ((_map5[current->path.node.tile] & 1U) != (i & 1)) continue;

   232

       			}

   233

       		}

   234

   235

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

   236

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

   237

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

   238

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

   239

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

   240

       		}

   241

       		dir = 0;

   242

   243

       		// First, check if we have a parent

   244

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

   245

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

   246

       			if (PathFinderInfo->start_direction != AI_PATHFINDER_NO_DIRECTION) {

   247

		       		// We do need a direction?

   248

		       		if (AiNew_GetDirection(current->path.node.tile, current->path.node.tile + TileOffsByDir(i)) != PathFinderInfo->start_direction)

   249

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

   250

		       			continue;

   251

		       	}

   252

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

   253

       			if (PathFinderInfo->rail_or_road) {

   254

       				// Rail check

   255

       				dir = AiNew_GetRailDirection(current->path.parent->node.tile, current->path.node.tile, current->path.node.tile + TileOffsByDir(i));

   256

       				r = DoCommandByTile(current->path.node.tile, 0, dir, DC_AUTO | DC_NO_WATER, CMD_BUILD_SINGLE_RAIL);

   257

       				if (r == CMD_ERROR) continue;

   258

#ifdef AI_PATHFINDER_NO_90DEGREES_TURN

   259

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

   260

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

   261

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

   262

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

   263

       						continue;

   264

       					}

   265

       				}

   266

#endif

   267

       			} else {

   268

       				// Road check

   269

       				dir = AiNew_GetRoadDirection(current->path.parent->node.tile, current->path.node.tile, current->path.node.tile + TileOffsByDir(i));

   270

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

   271

       					if (IsTileType(current->path.node.tile, MP_TUNNELBRIDGE)) {

   272

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

   273

       						dir = 0;

   274

       					} else {

   275

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

   276

	       					if ((_map5[current->path.node.tile] & dir) != dir) {

   277

	       						// We do miss some pieces :(

   278

	       						dir &= ~_map5[current->path.node.tile];

   279

	       					} else {

   280

	       						dir = 0;

   281

    	   					}

   282

    	   				}

   283

       				}

   284

       				// Only destruct things if it is MP_CLEAR of MP_TREES

   285

       				if (dir != 0) {

   286

       					r = DoCommandByTile(current->path.node.tile, dir, 0, DC_AUTO | DC_NO_WATER, CMD_BUILD_ROAD);

   287

       					if (r == CMD_ERROR) continue;

   288

       				}

   289

       			}

   290

   291

       		}

   292

   293

			// The tile can be connected

   294

   			aystar->neighbours[aystar->num_neighbours].tile = TileOffsByDir(i) + current->path.node.tile;

   295

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

   296

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

   297

       	}

   298

    }

   299

   300

    // Next step, check for bridges and tunnels

   301

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

   302

   303

        TileInfo ti;

   304

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

   305

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

   306

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

   307

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

   308

    	TileIndex new_tile = tile;

   309

   310

    	FindLandscapeHeightByTile(&ti, tile);

   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 (ti.tileh != 0 ||

   315

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

   316

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

   317

   318

    		for (;;) {

   319

    			new_tile += TileOffsByDir(dir);

   320

   321

    	    	// Precheck, is the length allowed?

   322

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

   323

   324

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

   325

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

   326

   327

    	    	// Try building the bridge..

   328

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

   329

	    	   	if (r == CMD_ERROR) continue;

   330

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

   331

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

   332

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

   333

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

   334

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

   335

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

   336

			}

   337

    	}

   338

   339

    	// Next, check for tunnels!

   340

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

   341

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

   342

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

   343

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

   344

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

   345

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

   346

    		// Now simply check if a tunnel can be build

   347

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

   348

    		FindLandscapeHeightByTile(&ti, _build_tunnel_endtile);

   349

    		if (r != CMD_ERROR && (ti.tileh == 3 || ti.tileh == 6 || ti.tileh == 9 || ti.tileh == 12)) {

   350

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

   351

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

   352

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

   353

    		}

   354

    	}

   355

  	}

   356

}

   357

   358

extern uint GetRailFoundation(uint tileh, uint bits);

   359

extern uint GetRoadFoundation(uint tileh, uint bits);

   360

extern uint GetBridgeFoundation(uint tileh, byte direction);

   361

enum {

   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

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

   368

	int r, res = 0;

   369

	TileInfo ti, parent_ti;

   370

   371

	// Gather some information about the tile..

   372

	FindLandscapeHeightByTile(&ti, current->tile);

   373

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

   374

   375

	// Check if we hit the end-tile

   376

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

   377

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

   378

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

   379

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

   380

			return AYSTAR_INVALID_NODE;

   381

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

   382

		return 0;

   383

	}

   384

   385

	// Give everything a small penalty

   386

	res += AI_PATHFINDER_PENALTY;

   387

   388

	if (!PathFinderInfo->rail_or_road) {

   389

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

   390

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

   391

		if (IsRoad(current->tile)) {

   392

			res -= AI_PATHFINDER_ROAD_ALREADY_EXISTS_BONUS;

   393

		}

   394

	}

   395

   396

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

   397

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

   398

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

   399

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

   400

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

   401

			if (PathFinderInfo->rail_or_road) {

   402

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

   403

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

   404

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

   405

					res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   406

				}

   407

			} else {

   408

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

   409

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

   410

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

   411

						res += AI_PATHFINDER_TILE_GOES_UP_PENALTY;

   412

				}

   413

			}

   414

		}

   415

	}

   416

   417

	// Are we part of a tunnel?

   418

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

   419

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

   420

		// Ironicly, we are using BridgeCode here ;)

   421

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

   422

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

   423

	}

   424

   425

	// Are we part of a bridge?

   426

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

   427

		// That means for every length a penalty

   428

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

   429

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

   430

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

   431

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

   432

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

   433

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   434

		}

   435

		// Second for the end point

   436

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

   437

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

   438

				res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   439

		}

   440

		if (parent_ti.tileh == 0)

   441

			res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   442

		if (ti.tileh == 0)

   443

			res += AI_PATHFINDER_BRIDGE_GOES_UP_PENALTY;

   444

	}

   445

   446

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

   447

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

   448

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

   449

	if (!PathFinderInfo->rail_or_road) {

   450

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

   451

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

   452

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

   453

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

   454

				res += AI_PATHFINDER_DIRECTION_CHANGE_ON_EXISTING_ROAD_PENALTY;

   455

			else

   456

				res += AI_PATHFINDER_DIRECTION_CHANGE_PENALTY;

   457

		}

   458

	} else {

   459

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

   460

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

   461

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

   462

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

   463

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

   464

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

   465

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

   466

   467

			// First see if they are different

   468

			if (dir1 != dir2) {

   469

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

   470

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

   471

					// It is not, so we changed of direction

   472

					res += AI_PATHFINDER_DIRECTION_CHANGE_PENALTY;

   473

				}

   474

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

   475

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

   476

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

   477

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

   478

						res += AI_PATHFINDER_CURVE_PENALTY;

   479

					}

   480

				}

   481

			}

   482

		}

   483

	}

   484

   485

	// Res should never be below zero.. if so, make it zero!

   486

	if (res < 0) { res = 0; }

   487

   488

	// Return our value

   489

	return res;