#include "stdafx.h"

#include "openttd.h"

#include "functions.h"

#include "rail_map.h"

#include "road.h"

#include "road_map.h"

#include "water_map.h"

#include "macros.h"

bool IsPossibleCrossing(const TileIndex tile, Axis ax)

{

	return (IsTileType(tile, MP_RAILWAY) &&

		!HasSignals(tile) &&

		GetTrackBits(tile) == (ax == AXIS_X ?  TRACK_BIT_Y : TRACK_BIT_X) &&

		GetTileSlope(tile, NULL) == SLOPE_FLAT);

}

RoadBits CleanUpRoadBits(const TileIndex tile, RoadBits org_rb)

{

	for (DiagDirection dir = DIAGDIR_BEGIN; dir < DIAGDIR_END; dir++) {

		const TileIndex neighbor_tile = TileAddByDiagDir(tile, dir);

		/* Get the Roadbit pointing to the neighbor_tile */

		const RoadBits target_rb = DiagDirToRoadBits(dir);

		/* If the roadbit is in the current plan */

		if (org_rb & target_rb) {

			bool connective = false;

			const RoadBits mirrored_rb = MirrorRoadBits(target_rb);

			switch (GetTileType(neighbor_tile)) {

				/* Allways connective ones */

				case MP_CLEAR: case MP_TREES:

					connective = true;

					break;

				/* The conditionaly connective ones */

				case MP_TUNNELBRIDGE:

				case MP_STATION:

				case MP_ROAD: {

					const RoadBits neighbor_rb = GetAnyRoadBits(neighbor_tile, ROADTYPE_ROAD) | GetAnyRoadBits(neighbor_tile, ROADTYPE_TRAM);

					/* Accept only connective tiles */

					connective = (neighbor_rb & mirrored_rb) || // Neighbor has got the fitting RoadBit

							COUNTBITS(neighbor_rb) == 1; // Neighbor has got only one Roadbit

				} break;

				case MP_RAILWAY:

					connective = IsPossibleCrossing(neighbor_tile, DiagDirToAxis(dir));

					break;

				case MP_WATER:

					/* Check for real water tile */

					connective = !IsWater(neighbor_tile);

					break;

				/* The defentetly not connective ones */

				default: break;

			}

			/* If the neighbor tile is inconnective remove the planed road connection to it */

			if (!connective) org_rb ^= target_rb;

		}

	}

	return org_rb;

}