/* $Id: landscape.c 5499 2006-07-15 09:21:29Z tron $ */

#include "stdafx.h"
#include "openttd.h"
#include "functions.h"
#include "map.h"
#include "player.h"
#include "spritecache.h"
#include "table/sprites.h"
#include "tile.h"
#include <stdarg.h>
#include "viewport.h"
#include "command.h"
#include "vehicle.h"
#include "variables.h"

extern const TileTypeProcs
	_tile_type_clear_procs,
	_tile_type_rail_procs,
	_tile_type_road_procs,
	_tile_type_town_procs,
	_tile_type_trees_procs,
	_tile_type_station_procs,
	_tile_type_water_procs,
	_tile_type_dummy_procs,
	_tile_type_industry_procs,
	_tile_type_tunnelbridge_procs,
	_tile_type_unmovable_procs;

const TileTypeProcs * const _tile_type_procs[16] = {
	&_tile_type_clear_procs,
	&_tile_type_rail_procs,
	&_tile_type_road_procs,
	&_tile_type_town_procs,
	&_tile_type_trees_procs,
	&_tile_type_station_procs,
	&_tile_type_water_procs,
	&_tile_type_dummy_procs,
	&_tile_type_industry_procs,
	&_tile_type_tunnelbridge_procs,
	&_tile_type_unmovable_procs,
};

/* landscape slope => sprite */
const byte _tileh_to_sprite[32] = {
	0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,0,
	0,0,0,0,0,0,0,16,0,0,0,17,0,15,18,0,
};

const byte _inclined_tileh[] = {
	3, 9, 3, 6, 12, 6, 12, 9
};


void FindLandscapeHeightByTile(TileInfo *ti, TileIndex tile)
{
	assert(tile < MapSize());

	ti->tile = tile;
	ti->map5 = _m[tile].m5;
	ti->type = GetTileType(tile);
	ti->tileh = GetTileSlope(tile, &ti->z);
}

/* find the landscape height for the coordinates x y */
void FindLandscapeHeight(TileInfo *ti, uint x, uint y)
{
	ti->x = x;
	ti->y = y;

	if (x >= MapMaxX() * 16 - 1 || y >= MapMaxY() * 16 - 1) {
		ti->tileh = 0;
		ti->type = MP_VOID;
		ti->tile = 0;
		ti->map5 = 0;
		ti->z = 0;
		return;
	}

	FindLandscapeHeightByTile(ti, TileVirtXY(x, y));
}

uint GetPartialZ(int x, int y, int corners)
{
	int z = 0;

	switch(corners) {
	case 1:
		if (x - y >= 0)
			z = (x - y) >> 1;
		break;

	case 2:
		y^=0xF;
		if ( (x - y) >= 0)
			z = (x - y) >> 1;
		break;

	case 3:
		z = (x>>1) + 1;
		break;

	case 4:
		if (y - x >= 0)
			z = (y - x) >> 1;
		break;

	case 5:
	case 10:
	case 15:
		z = 4;
		break;

	case 6:
		z = (y>>1) + 1;
		break;

	case 7:
		z = 8;
		y^=0xF;
		if (x - y < 0)
			z += (x - y) >> 1;
		break;

	case 8:
		y ^= 0xF;
		if (y - x >= 0)
			z = (y - x) >> 1;
		break;

	case 9:
		z = (y^0xF)>>1;
		break;

	case 11:
		z = 8;
		if (x - y < 0)
			z += (x - y) >> 1;
		break;

	case 12:
		z = (x^0xF)>>1;
		break;

	case 13:
		z = 8;
		y ^= 0xF;
		if (y - x < 0)
			z += (y - x) >> 1;
		break;

	case 14:
		z = 8;
		if (y - x < 0)
			z += (y - x) >> 1;
		break;

	case 23:
		z = 1 + ((x+y)>>1);
		break;

	case 27:
		z = 1 + ((x+(y^0xF))>>1);
		break;

	case 29:
		z = 1 + (((x^0xF)+(y^0xF))>>1);
		break;

	case 30:
		z = 1 + (((x^0xF)+(y^0xF))>>1);
		break;
	}

	return z;
}

uint GetSlopeZ(int x,  int y)
{
	TileInfo ti;

	FindLandscapeHeight(&ti, x, y);

	return _tile_type_procs[ti.type]->get_slope_z_proc(&ti);
}


static Slope GetFoundationSlope(TileIndex tile, uint* z)
{
	TileInfo ti;
	Slope tileh;
	Slope slope;

	FindLandscapeHeightByTile(&ti, tile);
	tileh = ti.tileh;
	*z    = ti.z;
	slope = _tile_type_procs[GetTileType(tile)]->get_slope_tileh_proc(&ti);

	// Flatter slope -> higher base height
	if (slope < tileh) *z += TILE_HEIGHT;
	return slope;
}


static bool HasFoundationNW(TileIndex tile, Slope slope_here, uint z_here)
{
	uint z;
	Slope slope = GetFoundationSlope(TILE_ADDXY(tile, 0, -1), &z);

	return
		(z_here + (slope_here & SLOPE_N ? TILE_HEIGHT : 0) > z + (slope & SLOPE_E ? TILE_HEIGHT : 0)) ||
		(z_here + (slope_here & SLOPE_W ? TILE_HEIGHT : 0) > z + (slope & SLOPE_S ? TILE_HEIGHT : 0));
}


static bool HasFoundationNE(TileIndex tile, Slope slope_here, uint z_here)
{
	uint z;
	Slope slope = GetFoundationSlope(TILE_ADDXY(tile, -1, 0), &z);

	return
		(z_here + (slope_here & SLOPE_N ? TILE_HEIGHT : 0) > z + (slope & SLOPE_W ? TILE_HEIGHT : 0)) ||
		(z_here + (slope_here & SLOPE_E ? TILE_HEIGHT : 0) > z + (slope & SLOPE_S ? TILE_HEIGHT : 0));
}


void DrawFoundation(TileInfo *ti, uint f)
{
	uint32 sprite_base = SPR_SLOPES_BASE-14;
	Slope slope;
	uint z;

	slope = GetFoundationSlope(ti->tile, &z);
	if (!HasFoundationNW(ti->tile, slope, z)) sprite_base += 22;
	if (!HasFoundationNE(ti->tile, slope, z)) sprite_base += 44;

	if (f < 15) {
		// leveled foundation
		if (sprite_base < SPR_SLOPES_BASE) sprite_base = SPR_FOUNDATION_BASE + 1; // use original slope sprites

		AddSortableSpriteToDraw(f - 1 + sprite_base, ti->x, ti->y, 16, 16, 7, ti->z);
		ti->z += 8;
		ti->tileh = 0;
		OffsetGroundSprite(31, 1);
	} else {
		// inclined foundation
		sprite_base += 14;

		AddSortableSpriteToDraw(
			HASBIT((1<<1) | (1<<2) | (1<<4) | (1<<8), ti->tileh) ? sprite_base + (f - 15) : SPR_FOUNDATION_BASE + ti->tileh,
			ti->x, ti->y, 1, 1, 1, ti->z
		);

		ti->tileh = _inclined_tileh[f - 15];
		OffsetGroundSprite(31, 9);
	}
}

void DoClearSquare(TileIndex tile)
{
	ModifyTile(tile,
		MP_SETTYPE(MP_CLEAR) |
		MP_MAP2_CLEAR | MP_MAP3LO_CLEAR | MP_MAP3HI_CLEAR | MP_MAPOWNER | MP_MAP5,
		OWNER_NONE, /* map_owner */
		_generating_world ? 3 : 0 /* map5 */
	);
}

uint32 GetTileTrackStatus(TileIndex tile, TransportType mode)
{
	return _tile_type_procs[GetTileType(tile)]->get_tile_track_status_proc(tile, mode);
}

void ChangeTileOwner(TileIndex tile, byte old_player, byte new_player)
{
	_tile_type_procs[GetTileType(tile)]->change_tile_owner_proc(tile, old_player, new_player);
}

void GetAcceptedCargo(TileIndex tile, AcceptedCargo ac)
{
	memset(ac, 0, sizeof(AcceptedCargo));
	_tile_type_procs[GetTileType(tile)]->get_accepted_cargo_proc(tile, ac);
}

void AnimateTile(TileIndex tile)
{
	_tile_type_procs[GetTileType(tile)]->animate_tile_proc(tile);
}

void ClickTile(TileIndex tile)
{
	_tile_type_procs[GetTileType(tile)]->click_tile_proc(tile);
}

void DrawTile(TileInfo *ti)
{
	_tile_type_procs[ti->type]->draw_tile_proc(ti);
}

void GetTileDesc(TileIndex tile, TileDesc *td)
{
	_tile_type_procs[GetTileType(tile)]->get_tile_desc_proc(tile, td);
}

/** Clear a piece of landscape
 * @param x,y coordinates of clearance
 * @param p1 unused
 * @param p2 unused
 */
int32 CmdLandscapeClear(int x, int y, uint32 flags, uint32 p1, uint32 p2)
{
	TileIndex tile = TileVirtXY(x, y);

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	return _tile_type_procs[GetTileType(tile)]->clear_tile_proc(tile, flags);
}

/** Clear a big piece of landscape
 * @param x,y end coordinates of area dragging
 * @param p1 start tile of area dragging
 * @param p2 unused
 */
int32 CmdClearArea(int ex, int ey, uint32 flags, uint32 p1, uint32 p2)
{
	int32 cost, ret, money;
	int sx,sy;
	int x,y;
	bool success = false;

	if (p1 >= MapSize()) return CMD_ERROR;

	SET_EXPENSES_TYPE(EXPENSES_CONSTRUCTION);

	// make sure sx,sy are smaller than ex,ey
	sx = TileX(p1) * 16;
	sy = TileY(p1) * 16;
	if (ex < sx) intswap(ex, sx);
	if (ey < sy) intswap(ey, sy);

	money = GetAvailableMoneyForCommand();
	cost = 0;

	for (x = sx; x <= ex; x += 16) {
		for (y = sy; y <= ey; y += 16) {
			ret = DoCommandByTile(TileVirtXY(x, y), 0, 0, flags & ~DC_EXEC, CMD_LANDSCAPE_CLEAR);
			if (CmdFailed(ret)) continue;
			cost += ret;
			success = true;

			if (flags & DC_EXEC) {
				if (ret > 0 && (money -= ret) < 0) {
					_additional_cash_required = ret;
					return cost - ret;
				}
				DoCommandByTile(TileVirtXY(x, y), 0, 0, flags, CMD_LANDSCAPE_CLEAR);

				// draw explosion animation...
				if ((x == sx || x == ex) && (y == sy || y == ey)) {
					// big explosion in each corner, or small explosion for single tiles
					CreateEffectVehicleAbove(x + 8, y + 8, 2,
						sy == ey && sx == ex ? EV_EXPLOSION_SMALL : EV_EXPLOSION_LARGE
					);
				}
			}
		}
	}

	return (success) ? cost : CMD_ERROR;
}


/* utility function used to modify a tile */
void CDECL ModifyTile(TileIndex tile, uint flags, ...)
{
	va_list va;
	int i;

	va_start(va, flags);

	if ((i = GB(flags, 8, 4)) != 0) {
		SetTileType(tile, i - 1);
	}

	if (flags & (MP_MAP2_CLEAR | MP_MAP2)) {
		int x = 0;
		if (flags & MP_MAP2) x = va_arg(va, int);
		_m[tile].m2 = x;
	}

	if (flags & (MP_MAP3LO_CLEAR | MP_MAP3LO)) {
		int x = 0;
		if (flags & MP_MAP3LO) x = va_arg(va, int);
		_m[tile].m3 = x;
	}

	if (flags & (MP_MAP3HI_CLEAR | MP_MAP3HI)) {
		int x = 0;
		if (flags & MP_MAP3HI) x = va_arg(va, int);
		_m[tile].m4 = x;
	}

	if (flags & (MP_MAPOWNER|MP_MAPOWNER_CURRENT)) {
		PlayerID x = _current_player;
		if (flags & MP_MAPOWNER) x = va_arg(va, int);
		_m[tile].m1 = x;
	}

	if (flags & MP_MAP5) {
		_m[tile].m5 = va_arg(va, int);
	}

	va_end(va);

	if (!(flags & MP_NODIRTY))
		MarkTileDirtyByTile(tile);
}


#define TILELOOP_BITS 4
#define TILELOOP_SIZE (1 << TILELOOP_BITS)
#define TILELOOP_ASSERTMASK ((TILELOOP_SIZE-1) + ((TILELOOP_SIZE-1) << MapLogX()))
#define TILELOOP_CHKMASK (((1 << (MapLogX() - TILELOOP_BITS))-1) << TILELOOP_BITS)

void RunTileLoop(void)
{
	TileIndex tile;
	uint count;

	tile = _cur_tileloop_tile;

	assert( (tile & ~TILELOOP_ASSERTMASK) == 0);
	count = (MapSizeX() / TILELOOP_SIZE) * (MapSizeY() / TILELOOP_SIZE);
	do {
		_tile_type_procs[GetTileType(tile)]->tile_loop_proc(tile);

		if (TileX(tile) < MapSizeX() - TILELOOP_SIZE) {
			tile += TILELOOP_SIZE; /* no overflow */
		} else {
			tile = TILE_MASK(tile - TILELOOP_SIZE * (MapSizeX() / TILELOOP_SIZE - 1) + TileDiffXY(0, TILELOOP_SIZE)); /* x would overflow, also increase y */
		}
	} while (--count);
	assert( (tile & ~TILELOOP_ASSERTMASK) == 0);

	tile += 9;
	if (tile & TILELOOP_CHKMASK)
		tile = (tile + MapSizeX()) & TILELOOP_ASSERTMASK;
	_cur_tileloop_tile = tile;
}

void InitializeLandscape(void)
{
	uint map_size;
	uint i;


	map_size = MapSize();
	for (i = 0; i < map_size; i++) {
		_m[i].type_height = MP_CLEAR << 4;
		_m[i].m1          = OWNER_NONE;
		_m[i].m2          = 0;
		_m[i].m3          = 0;
		_m[i].m4          = 0;
		_m[i].m5          = 3;
		_m[i].extra       = 0;
	}

	// create void tiles at the border
	for (i = 0; i < MapMaxY(); ++i)
		SetTileType(i * MapSizeX() + MapMaxX(), MP_VOID);
	for (i = 0; i < MapSizeX(); ++i)
		SetTileType(MapSizeX() * MapMaxY() + i, MP_VOID);
}

void ConvertGroundTilesIntoWaterTiles(void)
{
	TileIndex tile = 0;
	uint h;

	for (tile = 0; tile < MapSize(); ++tile) {
		if (IsTileType(tile, MP_CLEAR) && GetTileSlope(tile, &h) == 0 && h == 0) {
			SetTileType(tile, MP_WATER);
			_m[tile].m5 = 0;
			SetTileOwner(tile, OWNER_WATER);
		}
	}
}

static const byte _genterrain_tbl_1[5] = { 10, 22, 33, 37, 4 };
static const byte _genterrain_tbl_2[5] = { 0, 0, 0, 0, 33 };

static void GenerateTerrain(int type, int flag)
{
	uint32 r;
	uint x;
	uint y;
	uint w;
	uint h;
	const Sprite* template;
	const byte *p;
	Tile* tile;
	byte direction;

	r = Random();
	template = GetSprite((((r >> 24) * _genterrain_tbl_1[type]) >> 8) + _genterrain_tbl_2[type] + 4845);

	x = r & MapMaxX();
	y = (r >> MapLogX()) & MapMaxY();


	if (x < 2 || y < 2)
		return;

	direction = GB(r, 22, 2);
	if (direction & 1) {
		w = template->height;
		h = template->width;
	} else {
		w = template->width;
		h = template->height;
	}
	p = template->data;

	if (flag & 4) {
		uint xw = x * MapSizeY();
		uint yw = y * MapSizeX();
		uint bias = (MapSizeX() + MapSizeY()) * 16;

		switch (flag & 3) {
			case 0:
				if (xw + yw > MapSize() - bias) return;
				break;

			case 1:
				if (yw < xw + bias) return;
				break;

			case 2:
				if (xw + yw < MapSize() + bias) return;
				break;

			case 3:
				if (xw < yw + bias) return;
				break;
		}
	}

	if (x + w >= MapMaxX() - 1)
		return;

	if (y + h >= MapMaxY() - 1)
		return;

	tile = &_m[TileXY(x, y)];

	switch (direction) {
		case 0:
			do {
				Tile* tile_cur = tile;
				uint w_cur;

				for (w_cur = w; w_cur != 0; --w_cur) {
					if (*p >= tile_cur->type_height) tile_cur->type_height = *p;
					p++;
					tile_cur++;
				}
				tile += TileDiffXY(0, 1);
			} while (--h != 0);
			break;

		case 1:
			do {
				Tile* tile_cur = tile;
				uint h_cur;

				for (h_cur = h; h_cur != 0; --h_cur) {
					if (*p >= tile_cur->type_height) tile_cur->type_height = *p;
					p++;
					tile_cur += TileDiffXY(0, 1);
				}
				tile++;
			} while (--w != 0);
			break;

		case 2:
			tile += TileDiffXY(w - 1, 0);
			do {
				Tile* tile_cur = tile;
				uint w_cur;

				for (w_cur = w; w_cur != 0; --w_cur) {
					if (*p >= tile_cur->type_height) tile_cur->type_height = *p;
					p++;
					tile_cur--;
				}
				tile += TileDiffXY(0, 1);
			} while (--h != 0);
			break;

		case 3:
			tile += TileDiffXY(0, h - 1);
			do {
				Tile* tile_cur = tile;
				uint h_cur;

				for (h_cur = h; h_cur != 0; --h_cur) {
					if (*p >= tile_cur->type_height) tile_cur->type_height = *p;
					p++;
					tile_cur -= TileDiffXY(0, 1);
				}
				tile++;
			} while (--w != 0);
			break;
	}
}


#include "table/genland.h"

static void CreateDesertOrRainForest(void)
{
	TileIndex tile;
	const TileIndexDiffC *data;
	uint i;

	for (tile = 0; tile != MapSize(); ++tile) {
		for (data = _make_desert_or_rainforest_data;
				data != endof(_make_desert_or_rainforest_data); ++data) {
			TileIndex t = TILE_MASK(tile + ToTileIndexDiff(*data));
			if (TileHeight(t) >= 4 || IsTileType(t, MP_WATER)) break;
		}
		if (data == endof(_make_desert_or_rainforest_data))
			SetMapExtraBits(tile, 1);
	}

	for (i = 0; i != 256; i++)
		RunTileLoop();

	for (tile = 0; tile != MapSize(); ++tile) {
		for (data = _make_desert_or_rainforest_data;
				data != endof(_make_desert_or_rainforest_data); ++data) {
			TileIndex t = TILE_MASK(tile + ToTileIndexDiff(*data));
			if (IsTileType(t, MP_CLEAR) && (_m[t].m5 & 0x1c) == 0x14) break;
		}
		if (data == endof(_make_desert_or_rainforest_data))
			SetMapExtraBits(tile, 2);
	}
}

void GenerateLandscape(void)
{
	uint i;
	uint flag;
	uint32 r;

	if (_opt.landscape == LT_HILLY) {
		for (i = ScaleByMapSize((Random() & 0x7F) + 950); i != 0; --i)
			GenerateTerrain(2, 0);

		r = Random();
		flag = GB(r, 0, 2) | 4;
		for (i = ScaleByMapSize(GB(r, 16, 7) + 450); i != 0; --i)
			GenerateTerrain(4, flag);
	} else if (_opt.landscape == LT_DESERT) {
		for (i = ScaleByMapSize((Random()&0x7F) + 170); i != 0; --i)
			GenerateTerrain(0, 0);

		r = Random();
		flag = GB(r, 0, 2) | 4;
		for (i = ScaleByMapSize(GB(r, 16, 8) + 1700); i != 0; --i)
			GenerateTerrain(0, flag);

		flag ^= 2;

		for (i = ScaleByMapSize((Random() & 0x7F) + 410); i != 0; --i)
			GenerateTerrain(3, flag);
	} else {
		i = ScaleByMapSize((Random() & 0x7F) + (3 - _opt.diff.quantity_sea_lakes) * 256 + 100);
		for (; i != 0; --i)
			GenerateTerrain(_opt.diff.terrain_type, 0);
	}

	ConvertGroundTilesIntoWaterTiles();

	if (_opt.landscape == LT_DESERT)
		CreateDesertOrRainForest();
}

void OnTick_Town(void);
void OnTick_Trees(void);
void OnTick_Station(void);
void OnTick_Industry(void);

void OnTick_Players(void);
void OnTick_Train(void);

void CallLandscapeTick(void)
{
	OnTick_Town();
	OnTick_Trees();
	OnTick_Station();
	OnTick_Industry();

	OnTick_Players();
	OnTick_Train();
}

TileIndex AdjustTileCoordRandomly(TileIndex a, byte rng)
{
	int rn = rng;
	uint32 r = Random();

	return TILE_MASK(TileXY(
		TileX(a) + (GB(r, 0, 8) * rn * 2 >> 8) - rn,
		TileY(a) + (GB(r, 8, 8) * rn * 2 >> 8) - rn
	));
}

bool IsValidTile(TileIndex tile)
{
	return (tile < MapSizeX() * MapMaxY() && TileX(tile) != MapMaxX());
}
