[Refactor] #37353 dungeon.c/h を追加。

[hengband/hengband.git] / src / grid.c


 /*!
  * @file grid.c
  * @brief グリッドの実装 / low level dungeon routines -BEN-
  * @date 2013/12/30
  * @author
  * Copyright (c) 1997 Ben Harrison, James E. Wilson, Robert A. Koeneke\n
  *\n
  * This software may be copied and distributed for educational, research,\n
  * and not for profit purposes provided that this copyright and statement\n
  * are included in all such copies.  Other copyrights may also apply.\n
  * \n
  * Support for Adam Bolt's tileset, lighting and transparency effects\n
  * by Robert Ruehlmann (rr9@angband.org)\n
  * \n
  * 2013 Deskull Doxygen向けのコメント整理\n
  */


#include "angband.h"
#include "util.h"

#include "floor.h"
#include "world.h"
#include "object-flavor.h"
#include "object-hook.h"
#include "dungeon.h"
#include "floor-generate.h"
#include "grid.h"
#include "trap.h"
#include "rooms.h"
#include "monster.h"
#include "quest.h"
#include "feature.h"
#include "monster-status.h"
#include "player-status.h"
#include "player-effects.h"
#include "spells.h"
#include "view-mainwindow.h"

/*!
 * @brief 新規フロアに入りたてのプレイヤーをランダムな場所に配置する / Returns random co-ordinates for player/monster/object
 * @return 配置に成功したらTRUEを返す
 */
bool new_player_spot(void)
{
        POSITION y = 0, x = 0;
        int max_attempts = 10000;

        grid_type *g_ptr;
        feature_type *f_ptr;

        /* Place the player */
        while (max_attempts--)
        {
                /* Pick a legal spot */
                y = (POSITION)rand_range(1, current_floor_ptr->height - 2);
                x = (POSITION)rand_range(1, current_floor_ptr->width - 2);

                g_ptr = &current_floor_ptr->grid_array[y][x];

                /* Must be a "naked" floor grid */
                if (g_ptr->m_idx) continue;
                if (current_floor_ptr->dun_level)
                {
                        f_ptr = &f_info[g_ptr->feat];

                        if (max_attempts > 5000) /* Rule 1 */
                        {
                                if (!have_flag(f_ptr->flags, FF_FLOOR)) continue;
                        }
                        else /* Rule 2 */
                        {
                                if (!have_flag(f_ptr->flags, FF_MOVE)) continue;
                                if (have_flag(f_ptr->flags, FF_HIT_TRAP)) continue;
                        }

                        /* Refuse to start on anti-teleport grids in dungeon */
                        if (!have_flag(f_ptr->flags, FF_TELEPORTABLE)) continue;
                }
                if (!player_can_enter(g_ptr->feat, 0)) continue;
                if (!in_bounds(y, x)) continue;

                /* Refuse to start on anti-teleport grids */
                if (g_ptr->info & (CAVE_ICKY)) continue;

                break;
        }

        if (max_attempts < 1) /* Should be -1, actually if we failed... */
                return FALSE;

        /* Save the new player grid */
        p_ptr->y = y;
        p_ptr->x = x;

        return TRUE;
}



/*!
 * @brief 所定の位置に上り階段か下り階段を配置する / Place an up/down staircase at given location
 * @param y 配置を試みたいマスのY座標
 * @param x 配置を試みたいマスのX座標
 * @return なし
 */
void place_random_stairs(POSITION y, POSITION x)
{
        bool up_stairs = TRUE;
        bool down_stairs = TRUE;
        grid_type *g_ptr;
        g_ptr = &current_floor_ptr->grid_array[y][x];
        if (!is_floor_grid(g_ptr) || g_ptr->o_idx) return;

        /* Town */
        if (!current_floor_ptr->dun_level) up_stairs = FALSE;

        /* Ironman */
        if (ironman_downward) up_stairs = FALSE;

        /* Bottom */
        if (current_floor_ptr->dun_level >= d_info[p_ptr->dungeon_idx].maxdepth) down_stairs = FALSE;

        /* Quest-level */
        if (quest_number(current_floor_ptr->dun_level) && (current_floor_ptr->dun_level > 1)) down_stairs = FALSE;

        /* We can't place both */
        if (down_stairs && up_stairs)
        {
                /* Choose a staircase randomly */
                if (randint0(100) < 50) up_stairs = FALSE;
                else down_stairs = FALSE;
        }

        /* Place the stairs */
        if (up_stairs) place_up_stairs(y, x);
        else if (down_stairs) place_down_stairs(y, x);
}

/*!
 * @brief 所定の位置にさまざまな状態や種類のドアを配置する / Place a random type of door at the given location
 * @param y ドアの配置を試みたいマスのY座標
 * @param x ドアの配置を試みたいマスのX座標
 * @param room 部屋に接している場合向けのドア生成か否か
 * @return なし
 */
void place_random_door(POSITION y, POSITION x, bool room)
{
        int tmp, type;
        FEAT_IDX feat = feat_none;
        grid_type *g_ptr = &current_floor_ptr->grid_array[y][x];

        /* Initialize mimic info */
        g_ptr->mimic = 0;

        if (d_info[p_ptr->dungeon_idx].flags1 & DF1_NO_DOORS)
        {
                place_floor_bold(y, x);
                return;
        }

        type = ((d_info[p_ptr->dungeon_idx].flags1 & DF1_CURTAIN) &&
                one_in_((d_info[p_ptr->dungeon_idx].flags1 & DF1_NO_CAVE) ? 16 : 256)) ? DOOR_CURTAIN :
                ((d_info[p_ptr->dungeon_idx].flags1 & DF1_GLASS_DOOR) ? DOOR_GLASS_DOOR : DOOR_DOOR);

        /* Choose an object */
        tmp = randint0(1000);

        /* Open doors (300/1000) */
        if (tmp < 300)
        {
                /* Create open door */
                feat = feat_door[type].open;
        }

        /* Broken doors (100/1000) */
        else if (tmp < 400)
        {
                /* Create broken door */
                feat = feat_door[type].broken;
        }

        /* Secret doors (200/1000) */
        else if (tmp < 600)
        {
                /* Create secret door */
                place_closed_door(y, x, type);

                if (type != DOOR_CURTAIN)
                {
                        /* Hide. If on the edge of room, use outer wall. */
                        g_ptr->mimic = room ? feat_wall_outer : feat_wall_type[randint0(100)];

                        /* Floor type terrain cannot hide a door */
                        if (feat_supports_los(g_ptr->mimic) && !feat_supports_los(g_ptr->feat))
                        {
                                if (have_flag(f_info[g_ptr->mimic].flags, FF_MOVE) || have_flag(f_info[g_ptr->mimic].flags, FF_CAN_FLY))
                                {
                                        g_ptr->feat = one_in_(2) ? g_ptr->mimic : feat_ground_type[randint0(100)];
                                }
                                g_ptr->mimic = 0;
                        }
                }
        }

        /* Closed, locked, or stuck doors (400/1000) */
        else place_closed_door(y, x, type);

        if (tmp < 400)
        {
                if (feat != feat_none)
                {
                        set_cave_feat(y, x, feat);
                }
                else
                {
                        place_floor_bold(y, x);
                }
        }

        delete_monster(y, x);
}

/*!
 * @brief 所定の位置に各種の閉じたドアを配置する / Place a random type of normal door at the given location.
 * @param y ドアの配置を試みたいマスのY座標
 * @param x ドアの配置を試みたいマスのX座標
 * @param type ドアの地形ID
 * @return なし
 */
void place_closed_door(POSITION y, POSITION x, int type)
{
        int tmp;
        FEAT_IDX feat = feat_none;

        if (d_info[p_ptr->dungeon_idx].flags1 & DF1_NO_DOORS)
        {
                place_floor_bold(y, x);
                return;
        }

        /* Choose an object */
        tmp = randint0(400);

        /* Closed doors (300/400) */
        if (tmp < 300)
        {
                /* Create closed door */
                feat = feat_door[type].closed;
        }

        /* Locked doors (99/400) */
        else if (tmp < 399)
        {
                /* Create locked door */
                feat = feat_locked_door_random(type);
        }

        /* Stuck doors (1/400) */
        else
        {
                /* Create jammed door */
                feat = feat_jammed_door_random(type);
        }

        if (feat != feat_none)
        {
                cave_set_feat(y, x, feat);

                /* Now it is not floor */
                current_floor_ptr->grid_array[y][x].info &= ~(CAVE_MASK);
        }
        else
        {
                place_floor_bold(y, x);
        }
}

/*!
* @brief 鍵のかかったドアを配置する
* @param y 配置したいフロアのY座標
* @param x 配置したいフロアのX座標
* @return なし
*/
void place_locked_door(POSITION y, POSITION x)
{
        if (d_info[p_ptr->dungeon_idx].flags1 & DF1_NO_DOORS)
        {
                place_floor_bold(y, x);
        }
        else
        {
                set_cave_feat(y, x, feat_locked_door_random((d_info[p_ptr->dungeon_idx].flags1 & DF1_GLASS_DOOR) ? DOOR_GLASS_DOOR : DOOR_DOOR));
                current_floor_ptr->grid_array[y][x].info &= ~(CAVE_FLOOR);
                delete_monster(y, x);
        }
}


/*!
* @brief 隠しドアを配置する
* @param y 配置したいフロアのY座標
* @param x 配置したいフロアのX座標
* @param type DOOR_DEFAULT / DOOR_DOOR / DOOR_GLASS_DOOR / DOOR_CURTAIN のいずれか
* @return なし
*/
void place_secret_door(POSITION y, POSITION x, int type)
{
        if (d_info[p_ptr->dungeon_idx].flags1 & DF1_NO_DOORS)
        {
                place_floor_bold(y, x);
        }
        else
        {
                grid_type *g_ptr = &current_floor_ptr->grid_array[y][x];

                if (type == DOOR_DEFAULT)
                {
                        type = ((d_info[p_ptr->dungeon_idx].flags1 & DF1_CURTAIN) &&
                                one_in_((d_info[p_ptr->dungeon_idx].flags1 & DF1_NO_CAVE) ? 16 : 256)) ? DOOR_CURTAIN :
                                ((d_info[p_ptr->dungeon_idx].flags1 & DF1_GLASS_DOOR) ? DOOR_GLASS_DOOR : DOOR_DOOR);
                }

                /* Create secret door */
                place_closed_door(y, x, type);

                if (type != DOOR_CURTAIN)
                {
                        /* Hide by inner wall because this is used in rooms only */
                        g_ptr->mimic = feat_wall_inner;

                        /* Floor type terrain cannot hide a door */
                        if (feat_supports_los(g_ptr->mimic) && !feat_supports_los(g_ptr->feat))
                        {
                                if (have_flag(f_info[g_ptr->mimic].flags, FF_MOVE) || have_flag(f_info[g_ptr->mimic].flags, FF_CAN_FLY))
                                {
                                        g_ptr->feat = one_in_(2) ? g_ptr->mimic : feat_ground_type[randint0(100)];
                                }
                                g_ptr->mimic = 0;
                        }
                }

                g_ptr->info &= ~(CAVE_FLOOR);
                delete_monster(y, x);
        }
}

/*
 * Routine used by the random vault creators to add a door to a location
 * Note that range checking has to be done in the calling routine.
 *
 * The doors must be INSIDE the allocated region.
 */
void add_door(POSITION x, POSITION y)
{
        /* Need to have a wall in the center square */
        if (!is_outer_bold(y, x)) return;

        /* look at:
        *  x#x
        *  .#.
        *  x#x
        *
        *  where x=don't care
        *  .=floor, #=wall
        */

        if (is_floor_bold(y - 1, x) && is_floor_bold(y + 1, x) &&
                (is_outer_bold(y, x - 1) && is_outer_bold(y, x + 1)))
        {
                /* secret door */
                place_secret_door(y, x, DOOR_DEFAULT);

                /* set boundarys so don't get wide doors */
                place_solid_bold(y, x - 1);
                place_solid_bold(y, x + 1);
        }


        /* look at:
        *  x#x
        *  .#.
        *  x#x
        *
        *  where x = don't care
        *  .=floor, #=wall
        */
        if (is_outer_bold(y - 1, x) && is_outer_bold(y + 1, x) &&
                is_floor_bold(y, x - 1) && is_floor_bold(y, x + 1))
        {
                /* secret door */
                place_secret_door(y, x, DOOR_DEFAULT);

                /* set boundarys so don't get wide doors */
                place_solid_bold(y - 1, x);
                place_solid_bold(y + 1, x);
        }
}

/*!
* @brief 隣接4マスに存在する通路の数を返す / Count the number of "corridor" grids adjacent to the given grid.
* @param y1 基準となるマスのY座標
* @param x1 基準となるマスのX座標
* @return 通路の数
* @note Assumes "in_bounds(y1, x1)"
* @details
* XXX XXX This routine currently only counts actual "empty floor"\n
* grids which are not in rooms.  We might want to also count stairs,\n
* open doors, closed doors, etc.
*/
static int next_to_corr(POSITION y1, POSITION x1)
{
        int i, k = 0;
        POSITION y, x;

        grid_type *g_ptr;

        /* Scan adjacent grids */
        for (i = 0; i < 4; i++)
        {
                /* Extract the location */
                y = y1 + ddy_ddd[i];
                x = x1 + ddx_ddd[i];
                g_ptr = &current_floor_ptr->grid_array[y][x];

                /* Skip non floors */
                if (cave_have_flag_grid(g_ptr, FF_WALL)) continue;

                /* Skip non "empty floor" grids */
                if (!is_floor_grid(g_ptr))
                        continue;

                /* Skip grids inside rooms */
                if (g_ptr->info & (CAVE_ROOM)) continue;

                /* Count these grids */
                k++;
        }

        /* Return the number of corridors */
        return (k);
}

/*!
* @brief ドアを設置可能な地形かを返す / Determine if the given location is "between" two walls, and "next to" two corridor spaces.
* @param y 判定を行いたいマスのY座標
* @param x 判定を行いたいマスのX座標
* @return ドアを設置可能ならばTRUEを返す
* @note Assumes "in_bounds(y1, x1)"
* @details
* \n
* Assumes "in_bounds(y, x)"\n
*/
static bool possible_doorway(POSITION y, POSITION x)
{
        /* Count the adjacent corridors */
        if (next_to_corr(y, x) >= 2)
        {
                /* Check Vertical */
                if (cave_have_flag_bold(y - 1, x, FF_WALL) &&
                        cave_have_flag_bold(y + 1, x, FF_WALL))
                {
                        return (TRUE);
                }

                /* Check Horizontal */
                if (cave_have_flag_bold(y, x - 1, FF_WALL) &&
                        cave_have_flag_bold(y, x + 1, FF_WALL))
                {
                        return (TRUE);
                }
        }

        /* No doorway */
        return (FALSE);
}

/*!
* @brief ドアの設置を試みる / Places door at y, x position if at least 2 walls found
* @param y 設置を行いたいマスのY座標
* @param x 設置を行いたいマスのX座標
* @return なし
*/
void try_door(POSITION y, POSITION x)
{       if (!in_bounds(y, x)) return;

        /* Ignore walls */
        if (cave_have_flag_bold(y, x, FF_WALL)) return;

        /* Ignore room grids */
        if (current_floor_ptr->grid_array[y][x].info & (CAVE_ROOM)) return;

        /* Occasional door (if allowed) */
        if ((randint0(100) < dun_tun_jct) && possible_doorway(y, x) && !(d_info[p_ptr->dungeon_idx].flags1 & DF1_NO_DOORS))
        {
                /* Place a door */
                place_random_door(y, x, FALSE);
        }
}


/*!
 * @brief 長方形の空洞を生成する / Make an empty square floor, for the middle of rooms
 * @param x1 長方形の左端X座標(-1)
 * @param x2 長方形の右端X座標(+1)
 * @param y1 長方形の上端Y座標(-1)
 * @param y2 長方形の下端Y座標(+1)
 * @param light 照明の有無
 * @return なし
 */
void place_floor(POSITION x1, POSITION x2, POSITION y1, POSITION y2, bool light)
{
        POSITION x, y;

        /* Place a full floor under the room */
        for (y = y1 - 1; y <= y2 + 1; y++)
        {
                for (x = x1 - 1; x <= x2 + 1; x++)
                {
                        place_floor_bold(y, x);
                        add_cave_info(y, x, CAVE_ROOM);
                        if (light) add_cave_info(y, x, CAVE_GLOW);
                }
        }
}


/*!
 * @brief 長方形の部屋を生成する / Make an empty square room, only floor and wall grids
 * @param x1 長方形の左端X座標(-1)
 * @param x2 長方形の右端X座標(+1)
 * @param y1 長方形の上端Y座標(-1)
 * @param y2 長方形の下端Y座標(+1)
 * @param light 照明の有無
 * @return なし
 */
void place_room(POSITION x1, POSITION x2, POSITION y1, POSITION y2, bool light)
{
        POSITION y, x;

        place_floor(x1, x2, y1, y2, light);

        /* Walls around the room */
        for (y = y1 - 1; y <= y2 + 1; y++)
        {
                place_outer_bold(y, x1 - 1);
                place_outer_bold(y, x2 + 1);
        }
        for (x = x1 - 1; x <= x2 + 1; x++)
        {
                place_outer_bold(y1 - 1, x);
                place_outer_bold(y2 + 1, x);
        }
}


/*!
 * @brief 特殊な部屋向けに各種アイテムを配置する / Create up to "num" objects near the given coordinates
 * @param y 配置したい中心マスのY座標
 * @param x 配置したい中心マスのX座標
 * @param num 配置したい数
 * @return なし
 * @details
 * Only really called by some of the "vault" routines.
 */
void vault_objects(POSITION y, POSITION x, int num)
{
        int dummy = 0;
        int i = 0, j = y, k = x;

        grid_type *g_ptr;


        /* Attempt to place 'num' objects */
        for (; num > 0; --num)
        {
                /* Try up to 11 spots looking for empty space */
                for (i = 0; i < 11; ++i)
                {
                        /* Pick a random location */
                        while (dummy < SAFE_MAX_ATTEMPTS)
                        {
                                j = rand_spread(y, 2);
                                k = rand_spread(x, 3);
                                dummy++;
                                if (!in_bounds(j, k)) continue;
                                break;
                        }

                        if (dummy >= SAFE_MAX_ATTEMPTS && cheat_room)
                        {
                                msg_print(_("警告！地下室のアイテムを配置できません！", "Warning! Could not place vault object!"));
                        }

                        /* Require "clean" floor space */
                        g_ptr = &current_floor_ptr->grid_array[j][k];
                        if (!is_floor_grid(g_ptr) || g_ptr->o_idx) continue;

                        if (randint0(100) < 75)
                        {
                                place_object(j, k, 0L);
                        }
                        else
                        {
                                place_gold(j, k);
                        }

                        /* Placement accomplished */
                        break;
                }
        }
}

/*!
 * @brief 特殊な部屋向けに各種アイテムを配置する(vault_trapのサブセット) / Place a trap with a given displacement of point
 * @param y トラップを配置したいマスの中心Y座標
 * @param x トラップを配置したいマスの中心X座標
 * @param yd Y方向の配置分散マス数
 * @param xd X方向の配置分散マス数
 * @return なし
 * @details
 * Only really called by some of the "vault" routines.
 */
void vault_trap_aux(POSITION y, POSITION x, POSITION yd, POSITION xd)
{
        int count = 0, y1 = y, x1 = x;
        int dummy = 0;

        grid_type *g_ptr;

        /* Place traps */
        for (count = 0; count <= 5; count++)
        {
                /* Get a location */
                while (dummy < SAFE_MAX_ATTEMPTS)
                {
                        y1 = rand_spread(y, yd);
                        x1 = rand_spread(x, xd);
                        dummy++;
                        if (!in_bounds(y1, x1)) continue;
                        break;
                }

                if (dummy >= SAFE_MAX_ATTEMPTS && cheat_room)
                {
                        msg_print(_("警告！地下室のトラップを配置できません！", "Warning! Could not place vault trap!"));
                }

                /* Require "naked" floor grids */
                g_ptr = &current_floor_ptr->grid_array[y1][x1];
                if (!is_floor_grid(g_ptr) || g_ptr->o_idx || g_ptr->m_idx) continue;

                /* Place the trap */
                place_trap(y1, x1);

                break;
        }
}

/*!
 * @brief 特殊な部屋向けに各種アイテムを配置する(メインルーチン) / Place some traps with a given displacement of given location
 * @param y トラップを配置したいマスの中心Y座標
 * @param x トラップを配置したいマスの中心X座標
 * @param yd Y方向の配置分散マス数
 * @param xd X方向の配置分散マス数
 * @param num 配置したいトラップの数
 * @return なし
 * @details
 * Only really called by some of the "vault" routines.
 */
void vault_traps(POSITION y, POSITION x, POSITION yd, POSITION xd, int num)
{
        int i;

        for (i = 0; i < num; i++)
        {
                vault_trap_aux(y, x, yd, xd);
        }
}

/*!
 * @brief 特殊な部屋地形向けにモンスターを配置する / Hack -- Place some sleeping monsters near the given location
 * @param y1 モンスターを配置したいマスの中心Y座標
 * @param x1 モンスターを配置したいマスの中心X座標
 * @param num 配置したいモンスターの数
 * @return なし
 * @details
 * Only really called by some of the "vault" routines.
 */
void vault_monsters(POSITION y1, POSITION x1, int num)
{
        int k, i;
        POSITION y, x;
        grid_type *g_ptr;

        /* Try to summon "num" monsters "near" the given location */
        for (k = 0; k < num; k++)
        {
                /* Try nine locations */
                for (i = 0; i < 9; i++)
                {
                        int d = 1;

                        /* Pick a nearby location */
                        scatter(&y, &x, y1, x1, d, 0);

                        /* Require "empty" floor grids */
                        g_ptr = &current_floor_ptr->grid_array[y][x];
                        if (!cave_empty_grid(g_ptr)) continue;

                        /* Place the monster (allow groups) */
                        current_floor_ptr->monster_level = current_floor_ptr->base_level + 2;
                        (void)place_monster(y, x, (PM_ALLOW_SLEEP | PM_ALLOW_GROUP));
                        current_floor_ptr->monster_level = current_floor_ptr->base_level;
                }
        }
}

/*!
 * @brief 指定のマスが床系地形であるかを返す / Function that sees if a square is a floor.  (Includes range checking.)
 * @param x チェックするマスのX座標
 * @param y チェックするマスのY座標
 * @return 床系地形ならばTRUE
 */
bool get_is_floor(POSITION x, POSITION y)
{
        if (!in_bounds(y, x))
        {
                /* Out of bounds */
                return (FALSE);
        }

        /* Do the real check */
        if (is_floor_bold(y, x)) return (TRUE);

        return (FALSE);
}

/*!
 * @brief 指定のマスを床地形に変える / Set a square to be floor.  (Includes range checking.)
 * @param x 地形を変えたいマスのX座標
 * @param y 地形を変えたいマスのY座標
 * @return なし
 */
void set_floor(POSITION x, POSITION y)
{
        if (!in_bounds(y, x))
        {
                /* Out of bounds */
                return;
        }

        if (current_floor_ptr->grid_array[y][x].info & CAVE_ROOM)
        {
                /* A room border don't touch. */
                return;
        }

        /* Set to be floor if is a wall (don't touch lakes). */
        if (is_extra_bold(y, x))
                place_floor_bold(y, x);
}

/*!
 * @brief マスにフロア端用の永久壁を配置する / Set boundary mimic and add "solid" perma-wall
 * @param g_ptr 永久壁を配置したいマス構造体の参照ポインタ
 * @return なし
 */
void place_bound_perm_wall(grid_type *g_ptr)
{
        if (bound_walls_perm)
        {
                /* Clear boundary mimic */
                g_ptr->mimic = 0;
        }
        else
        {
                feature_type *f_ptr = &f_info[g_ptr->feat];

                /* Hack -- Decline boundary walls with known treasure  */
                if ((have_flag(f_ptr->flags, FF_HAS_GOLD) || have_flag(f_ptr->flags, FF_HAS_ITEM)) &&
                        !have_flag(f_ptr->flags, FF_SECRET))
                        g_ptr->feat = feat_state(g_ptr->feat, FF_ENSECRET);

                /* Set boundary mimic */
                g_ptr->mimic = g_ptr->feat;
        }

        /* Add "solid" perma-wall */
        place_solid_perm_grid(g_ptr);
}

/*!
 * @brief マスに看破済みの罠があるかの判定を行う。 / Return TRUE if the given grid is a known trap
 * @param g_ptr マス構造体の参照ポインタ
 * @return 看破済みの罠があるならTRUEを返す。
 */
bool is_known_trap(grid_type *g_ptr)
{
        if (!g_ptr->mimic && !cave_have_flag_grid(g_ptr, FF_SECRET) &&
                is_trap(g_ptr->feat)) return TRUE;
        else
                return FALSE;
}



/*!
 * @brief マスに隠されたドアがあるかの判定を行う。 / Return TRUE if the given grid is a hidden closed door
 * @param g_ptr マス構造体の参照ポインタ
 * @return 隠されたドアがあるならTRUEを返す。
 */
bool is_hidden_door(grid_type *g_ptr)
{
        if ((g_ptr->mimic || cave_have_flag_grid(g_ptr, FF_SECRET)) &&
                is_closed_door(g_ptr->feat))
                return TRUE;
        else
                return FALSE;
}

#define COMPLEX_WALL_ILLUMINATION /*!< 照明状態を壁により影響を受ける、より複雑な判定に切り替えるマクロ */


/*!
 * @brief 指定された座標のマスが現在照らされているかを返す。 / Check for "local" illumination
 * @param y y座標
 * @param x x座標
 * @return 指定された座標に照明がかかっているならTRUEを返す。。
 */
bool check_local_illumination(POSITION y, POSITION x)
{
        /* Hack -- move towards player */
        POSITION yy = (y < p_ptr->y) ? (y + 1) : (y > p_ptr->y) ? (y - 1) : y;
        POSITION xx = (x < p_ptr->x) ? (x + 1) : (x > p_ptr->x) ? (x - 1) : x;

        /* Check for "local" illumination */

#ifdef COMPLEX_WALL_ILLUMINATION /* COMPLEX_WALL_ILLUMINATION */

        /* Check for "complex" illumination */
        if ((feat_supports_los(get_feat_mimic(&current_floor_ptr->grid_array[yy][xx])) &&
                (current_floor_ptr->grid_array[yy][xx].info & CAVE_GLOW)) ||
                (feat_supports_los(get_feat_mimic(&current_floor_ptr->grid_array[y][xx])) &&
                (current_floor_ptr->grid_array[y][xx].info & CAVE_GLOW)) ||
                        (feat_supports_los(get_feat_mimic(&current_floor_ptr->grid_array[yy][x])) &&
                (current_floor_ptr->grid_array[yy][x].info & CAVE_GLOW)))
        {
                return TRUE;
        }
        else return FALSE;

#else /* COMPLEX_WALL_ILLUMINATION */

        /* Check for "simple" illumination */
        return (current_floor_ptr->grid_array[yy][xx].info & CAVE_GLOW) ? TRUE : FALSE;

#endif /* COMPLEX_WALL_ILLUMINATION */
}


/*! 対象座標のマスの照明状態を更新する際の補助処理マクロ */
#define update_local_illumination_aux(Y, X) \
{ \
        if (player_has_los_bold((Y), (X))) \
        { \
                /* Update the monster */ \
                if (current_floor_ptr->grid_array[(Y)][(X)].m_idx) update_monster(current_floor_ptr->grid_array[(Y)][(X)].m_idx, FALSE); \
\
                /* Notice and redraw */ \
                note_spot((Y), (X)); \
                lite_spot((Y), (X)); \
        } \
}

/*!
 * @brief 指定された座標の照明状態を更新する / Update "local" illumination
 * @param y y座標
 * @param x x座標
 * @return なし
 */
void update_local_illumination(POSITION y, POSITION x)
{
        int i;
        POSITION yy, xx;

        if (!in_bounds(y, x)) return;

#ifdef COMPLEX_WALL_ILLUMINATION /* COMPLEX_WALL_ILLUMINATION */

        if ((y != p_ptr->y) && (x != p_ptr->x))
        {
                yy = (y < p_ptr->y) ? (y - 1) : (y + 1);
                xx = (x < p_ptr->x) ? (x - 1) : (x + 1);
                update_local_illumination_aux(yy, xx);
                update_local_illumination_aux(y, xx);
                update_local_illumination_aux(yy, x);
        }
        else if (x != p_ptr->x) /* y == p_ptr->y */
        {
                xx = (x < p_ptr->x) ? (x - 1) : (x + 1);
                for (i = -1; i <= 1; i++)
                {
                        yy = y + i;
                        update_local_illumination_aux(yy, xx);
                }
                yy = y - 1;
                update_local_illumination_aux(yy, x);
                yy = y + 1;
                update_local_illumination_aux(yy, x);
        }
        else if (y != p_ptr->y) /* x == p_ptr->x */
        {
                yy = (y < p_ptr->y) ? (y - 1) : (y + 1);
                for (i = -1; i <= 1; i++)
                {
                        xx = x + i;
                        update_local_illumination_aux(yy, xx);
                }
                xx = x - 1;
                update_local_illumination_aux(y, xx);
                xx = x + 1;
                update_local_illumination_aux(y, xx);
        }
        else /* Player's grid */
        {
                for (i = 0; i < 8; i++)
                {
                        yy = y + ddy_cdd[i];
                        xx = x + ddx_cdd[i];
                        update_local_illumination_aux(yy, xx);
                }
        }

#else /* COMPLEX_WALL_ILLUMINATION */

        if ((y != p_ptr->y) && (x != p_ptr->x))
        {
                yy = (y < p_ptr->y) ? (y - 1) : (y + 1);
                xx = (x < p_ptr->x) ? (x - 1) : (x + 1);
                update_local_illumination_aux(yy, xx);
        }
        else if (x != p_ptr->x) /* y == p_ptr->y */
        {
                xx = (x < p_ptr->x) ? (x - 1) : (x + 1);
                for (i = -1; i <= 1; i++)
                {
                        yy = y + i;
                        update_local_illumination_aux(yy, xx);
                }
        }
        else if (y != p_ptr->y) /* x == p_ptr->x */
        {
                yy = (y < p_ptr->y) ? (y - 1) : (y + 1);
                for (i = -1; i <= 1; i++)
                {
                        xx = x + i;
                        update_local_illumination_aux(yy, xx);
                }
        }
        else /* Player's grid */
        {
                for (i = 0; i < 8; i++)
                {
                        yy = y + ddy_cdd[i];
                        xx = x + ddx_cdd[i];
                        update_local_illumination_aux(yy, xx);
                }
        }

#endif /* COMPLEX_WALL_ILLUMINATION */
}


/*!
 * @brief 指定された座標をプレイヤーが視覚に収められるかを返す。 / Can the player "see" the given grid in detail?
 * @param y y座標
 * @param x x座標
 * @return 視覚に収められる状態ならTRUEを返す
 * @details
 * He must have vision, illumination, and line of sight.\n
 * \n
 * Note -- "CAVE_LITE" is only set if the "torch" has "los()".\n
 * So, given "CAVE_LITE", we know that the grid is "fully visible".\n
 *\n
 * Note that "CAVE_GLOW" makes little sense for a wall, since it would mean\n
 * that a wall is visible from any direction.  That would be odd.  Except\n
 * under wizard light, which might make sense.  Thus, for walls, we require\n
 * not only that they be "CAVE_GLOW", but also, that they be adjacent to a\n
 * grid which is not only "CAVE_GLOW", but which is a non-wall, and which is\n
 * in line of sight of the player.\n
 *\n
 * This extra check is expensive, but it provides a more "correct" semantics.\n
 *\n
 * Note that we should not run this check on walls which are "outer walls" of\n
 * the dungeon, or we will induce a memory fault, but actually verifying all\n
 * of the locations would be extremely expensive.\n
 *\n
 * Thus, to speed up the function, we assume that all "perma-walls" which are\n
 * "CAVE_GLOW" are "illuminated" from all sides.  This is correct for all cases\n
 * except "vaults" and the "buildings" in town.  But the town is a hack anyway,\n
 * and the player has more important things on his mind when he is attacking a\n
 * monster vault.  It is annoying, but an extremely important optimization.\n
 *\n
 * Note that "glowing walls" are only considered to be "illuminated" if the\n
 * grid which is next to the wall in the direction of the player is also a\n
 * "glowing" grid.  This prevents the player from being able to "see" the\n
 * walls of illuminated rooms from a corridor outside the room.\n
 */
bool player_can_see_bold(POSITION y, POSITION x)
{
        grid_type *g_ptr;

        /* Blind players see nothing */
        if (p_ptr->blind) return FALSE;

        g_ptr = &current_floor_ptr->grid_array[y][x];

        /* Note that "torch-lite" yields "illumination" */
        if (g_ptr->info & (CAVE_LITE | CAVE_MNLT)) return TRUE;

        /* Require line of sight to the grid */
        if (!player_has_los_bold(y, x)) return FALSE;

        /* Noctovision of Ninja */
        if (p_ptr->see_nocto) return TRUE;

        /* Require "perma-lite" of the grid */
        if ((g_ptr->info & (CAVE_GLOW | CAVE_MNDK)) != CAVE_GLOW) return FALSE;

        /* Feature code (applying "mimic" field) */
        /* Floors are simple */
        if (feat_supports_los(get_feat_mimic(g_ptr))) return TRUE;

        /* Check for "local" illumination */
        return check_local_illumination(y, x);
}

/*!
 * @brief 指定された座標をプレイヤー収められていない状態かどうか / Returns true if the player's grid is dark
 * @return 視覚に収められていないならTRUEを返す
 * @details player_can_see_bold()関数の返り値の否定を返している。
 */
bool no_lite(void)
{
        return (!player_can_see_bold(p_ptr->y, p_ptr->x));
}


/*!
 * @brief 指定された座標が地震や階段生成の対象となるマスかを返す。 / Determine if a given location may be "destroyed"
 * @param y y座標
 * @param x x座標
 * @return 各種の変更が可能ならTRUEを返す。
 * @details
 * 条件は永久地形でなく、なおかつ該当のマスにアーティファクトが存在しないか、である。英語の旧コメントに反して＊破壊＊の抑止判定には現在使われていない。
 */
bool cave_valid_bold(POSITION y, POSITION x)
{
        grid_type *g_ptr = &current_floor_ptr->grid_array[y][x];
        OBJECT_IDX this_o_idx, next_o_idx = 0;

        /* Forbid perma-grids */
        if (cave_perma_grid(g_ptr)) return (FALSE);

        /* Check objects */
        for (this_o_idx = g_ptr->o_idx; this_o_idx; this_o_idx = next_o_idx)
        {
                object_type *o_ptr;
                o_ptr = &current_floor_ptr->o_list[this_o_idx];
                next_o_idx = o_ptr->next_o_idx;

                /* Forbid artifact grids */
                if (object_is_artifact(o_ptr)) return (FALSE);
        }

        /* Accept */
        return (TRUE);
}



/*
 * Place an attr/char pair at the given map coordinate, if legal.
 */
void print_rel(SYMBOL_CODE c, TERM_COLOR a, TERM_LEN y, TERM_LEN x)
{
        /* Only do "legal" locations */
        if (panel_contains(y, x))
        {
                /* Hack -- fake monochrome */
                if (!use_graphics)
                {
                        if (current_world_ptr->timewalk_m_idx) a = TERM_DARK;
                        else if (IS_INVULN() || p_ptr->timewalk) a = TERM_WHITE;
                        else if (p_ptr->wraith_form) a = TERM_L_DARK;
                }

                /* Draw the char using the attr */
                Term_queue_bigchar(panel_col_of(x), y - panel_row_prt, a, c, 0, 0);
        }
}





/*
 * Memorize interesting viewable object/features in the given grid
 *
 * This function should only be called on "legal" grids.
 *
 * This function will memorize the object and/or feature in the given
 * grid, if they are (1) viewable and (2) interesting.  Note that all
 * objects are interesting, all terrain features except floors (and
 * invisible traps) are interesting, and floors (and invisible traps)
 * are interesting sometimes (depending on various options involving
 * the illumination of floor grids).
 *
 * The automatic memorization of all objects and non-floor terrain
 * features as soon as they are displayed allows incredible amounts
 * of optimization in various places, especially "map_info()".
 *
 * Note that the memorization of objects is completely separate from
 * the memorization of terrain features, preventing annoying floor
 * memorization when a detected object is picked up from a dark floor,
 * and object memorization when an object is dropped into a floor grid
 * which is memorized but out-of-sight.
 *
 * This function should be called every time the "memorization" of
 * a grid (or the object in a grid) is called into question, such
 * as when an object is created in a grid, when a terrain feature
 * "changes" from "floor" to "non-floor", when any grid becomes
 * "illuminated" or "viewable", and when a "floor" grid becomes
 * "torch-lit".
 *
 * Note the relatively efficient use of this function by the various
 * "update_view()" and "update_lite()" calls, to allow objects and
 * terrain features to be memorized (and drawn) whenever they become
 * viewable or illuminated in any way, but not when they "maintain"
 * or "lose" their previous viewability or illumination.
 *
 * Note the butchered "internal" version of "player_can_see_bold()",
 * optimized primarily for the most common cases, that is, for the
 * non-marked floor grids.
 */
void note_spot(POSITION y, POSITION x)
{
        grid_type *g_ptr = &current_floor_ptr->grid_array[y][x];
        OBJECT_IDX this_o_idx, next_o_idx = 0;

        /* Blind players see nothing */
        if (p_ptr->blind) return;

        /* Analyze non-torch-lit grids */
        if (!(g_ptr->info & (CAVE_LITE | CAVE_MNLT)))
        {
                /* Require line of sight to the grid */
                if (!(g_ptr->info & (CAVE_VIEW))) return;

                /* Require "perma-lite" of the grid */
                if ((g_ptr->info & (CAVE_GLOW | CAVE_MNDK)) != CAVE_GLOW)
                {
                        /* Not Ninja */
                        if (!p_ptr->see_nocto) return;
                }
        }


        /* Hack -- memorize objects */
        for (this_o_idx = g_ptr->o_idx; this_o_idx; this_o_idx = next_o_idx)
        {
                object_type *o_ptr = &current_floor_ptr->o_list[this_o_idx];
                next_o_idx = o_ptr->next_o_idx;

                /* Memorize objects */
                o_ptr->marked |= OM_FOUND;
        }


        /* Hack -- memorize grids */
        if (!(g_ptr->info & (CAVE_MARK)))
        {
                /* Feature code (applying "mimic" field) */
                feature_type *f_ptr = &f_info[get_feat_mimic(g_ptr)];

                /* Memorize some "boring" grids */
                if (!have_flag(f_ptr->flags, FF_REMEMBER))
                {
                        /* Option -- memorize all torch-lit floors */
                        if (view_torch_grids &&
                                ((g_ptr->info & (CAVE_LITE | CAVE_MNLT)) || p_ptr->see_nocto))
                        {
                                g_ptr->info |= (CAVE_MARK);
                        }

                        /* Option -- memorize all perma-lit floors */
                        else if (view_perma_grids && ((g_ptr->info & (CAVE_GLOW | CAVE_MNDK)) == CAVE_GLOW))
                        {
                                g_ptr->info |= (CAVE_MARK);
                        }
                }

                /* Memorize normal grids */
                else if (have_flag(f_ptr->flags, FF_LOS))
                {
                        g_ptr->info |= (CAVE_MARK);
                }

                /* Memorize torch-lit walls */
                else if (g_ptr->info & (CAVE_LITE | CAVE_MNLT))
                {
                        g_ptr->info |= (CAVE_MARK);
                }

                /* Memorize walls seen by noctovision of Ninja */
                else if (p_ptr->see_nocto)
                {
                        g_ptr->info |= (CAVE_MARK);
                }

                /* Memorize certain non-torch-lit wall grids */
                else if (check_local_illumination(y, x))
                {
                        g_ptr->info |= (CAVE_MARK);
                }
        }

        /* Memorize terrain of the grid */
        g_ptr->info |= (CAVE_KNOWN);
}

/*
 * Redraw (on the screen) a given MAP location
 *
 * This function should only be called on "legal" grids
 */
void lite_spot(POSITION y, POSITION x)
{
        /* Redraw if on screen */
        if (panel_contains(y, x) && in_bounds2(y, x))
        {
                TERM_COLOR a;
                SYMBOL_CODE c;
                TERM_COLOR ta;
                SYMBOL_CODE tc;

                map_info(y, x, &a, &c, &ta, &tc);

                /* Hack -- fake monochrome */
                if (!use_graphics)
                {
                        if (current_world_ptr->timewalk_m_idx) a = TERM_DARK;
                        else if (IS_INVULN() || p_ptr->timewalk) a = TERM_WHITE;
                        else if (p_ptr->wraith_form) a = TERM_L_DARK;
                }

                /* Hack -- Queue it */
                Term_queue_bigchar(panel_col_of(x), y - panel_row_prt, a, c, ta, tc);

                /* Update sub-windows */
                p_ptr->window |= (PW_OVERHEAD | PW_DUNGEON);
        }
}

/*
 * Some comments on the grid flags.  -BEN-
 *
 *
 * One of the major bottlenecks in previous versions of Angband was in
 * the calculation of "line of sight" from the player to various grids,
 * such as monsters.  This was such a nasty bottleneck that a lot of
 * silly things were done to reduce the dependancy on "line of sight",
 * for example, you could not "see" any grids in a lit room until you
 * actually entered the room, and there were all kinds of bizarre grid
 * flags to enable this behavior.  This is also why the "call light"
 * spells always lit an entire room.
 *
 * The code below provides functions to calculate the "field of view"
 * for the player, which, once calculated, provides extremely fast
 * calculation of "line of sight from the player", and to calculate
 * the "field of torch lite", which, again, once calculated, provides
 * extremely fast calculation of "which grids are lit by the player's
 * lite source".  In addition to marking grids as "GRID_VIEW" and/or
 * "GRID_LITE", as appropriate, these functions maintain an array for
 * each of these two flags, each array containing the locations of all
 * of the grids marked with the appropriate flag, which can be used to
 * very quickly scan through all of the grids in a given set.
 *
 * To allow more "semantically valid" field of view semantics, whenever
 * the field of view (or the set of torch lit grids) changes, all of the
 * grids in the field of view (or the set of torch lit grids) are "drawn"
 * so that changes in the world will become apparent as soon as possible.
 * This has been optimized so that only grids which actually "change" are
 * redrawn, using the "temp" array and the "GRID_TEMP" flag to keep track
 * of the grids which are entering or leaving the relevent set of grids.
 *
 * These new methods are so efficient that the old nasty code was removed.
 *
 * Note that there is no reason to "update" the "viewable space" unless
 * the player "moves", or walls/doors are created/destroyed, and there
 * is no reason to "update" the "torch lit grids" unless the field of
 * view changes, or the "light radius" changes.  This means that when
 * the player is resting, or digging, or doing anything that does not
 * involve movement or changing the state of the dungeon, there is no
 * need to update the "view" or the "lite" regions, which is nice.
 *
 * Note that the calls to the nasty "los()" function have been reduced
 * to a bare minimum by the use of the new "field of view" calculations.
 *
 * I wouldn't be surprised if slight modifications to the "update_view()"
 * function would allow us to determine "reverse line-of-sight" as well
 * as "normal line-of-sight", which would allow monsters to use a more
 * "correct" calculation to determine if they can "see" the player.  For
 * now, monsters simply "cheat" somewhat and assume that if the player
 * has "line of sight" to the monster, then the monster can "pretend"
 * that it has "line of sight" to the player.
 *
 *
 * The "update_lite()" function maintains the "CAVE_LITE" flag for each
 * grid and maintains an array of all "CAVE_LITE" grids.
 *
 * This set of grids is the complete set of all grids which are lit by
 * the players light source, which allows the "player_can_see_bold()"
 * function to work very quickly.
 *
 * Note that every "CAVE_LITE" grid is also a "CAVE_VIEW" grid, and in
 * fact, the player (unless blind) can always "see" all grids which are
 * marked as "CAVE_LITE", unless they are "off screen".
 *
 *
 * The "update_view()" function maintains the "CAVE_VIEW" flag for each
 * grid and maintains an array of all "CAVE_VIEW" grids.
 *
 * This set of grids is the complete set of all grids within line of sight
 * of the player, allowing the "player_has_los_bold()" macro to work very
 * quickly.
 *
 *
 * The current "update_view()" algorithm uses the "CAVE_XTRA" flag as a
 * temporary internal flag to mark those grids which are not only in view,
 * but which are also "easily" in line of sight of the player.  This flag
 * is always cleared when we are done.
 *
 *
 * The current "update_lite()" and "update_view()" algorithms use the
 * "CAVE_TEMP" flag, and the array of grids which are marked as "CAVE_TEMP",
 * to keep track of which grids were previously marked as "CAVE_LITE" or
 * "CAVE_VIEW", which allows us to optimize the "screen updates".
 *
 * The "CAVE_TEMP" flag, and the array of "CAVE_TEMP" grids, is also used
 * for various other purposes, such as spreading lite or darkness during
 * "lite_room()" / "unlite_room()", and for calculating monster flow.
 *
 *
 * Any grid can be marked as "CAVE_GLOW" which means that the grid itself is
 * in some way permanently lit.  However, for the player to "see" anything
 * in the grid, as determined by "player_can_see()", the player must not be
 * blind, the grid must be marked as "CAVE_VIEW", and, in addition, "wall"
 * grids, even if marked as "perma lit", are only illuminated if they touch
 * a grid which is not a wall and is marked both "CAVE_GLOW" and "CAVE_VIEW".
 *
 *
 * To simplify various things, a grid may be marked as "CAVE_MARK", meaning
 * that even if the player cannot "see" the grid, he "knows" the terrain in
 * that grid.  This is used to "remember" walls/doors/stairs/floors when they
 * are "seen" or "detected", and also to "memorize" floors, after "wiz_lite()",
 * or when one of the "memorize floor grids" options induces memorization.
 *
 * Objects are "memorized" in a different way, using a special "marked" flag
 * on the object itself, which is set when an object is observed or detected.
 *
 *
 * A grid may be marked as "CAVE_ROOM" which means that it is part of a "room",
 * and should be illuminated by "lite room" and "darkness" spells.
 *
 *
 * A grid may be marked as "CAVE_ICKY" which means it is part of a "vault",
 * and should be unavailable for "teleportation" destinations.
 *
 *
 * The "view_perma_grids" allows the player to "memorize" every perma-lit grid
 * which is observed, and the "view_torch_grids" allows the player to memorize
 * every torch-lit grid.  The player will always memorize important walls,
 * doors, stairs, and other terrain features, as well as any "detected" grids.
 *
 * Note that the new "update_view()" method allows, among other things, a room
 * to be "partially" seen as the player approaches it, with a growing cone of
 * floor appearing as the player gets closer to the door.  Also, by not turning
 * on the "memorize perma-lit grids" option, the player will only "see" those
 * floor grids which are actually in line of sight.
 *
 * And my favorite "plus" is that you can now use a special option to draw the
 * "floors" in the "viewable region" brightly (actually, to draw the *other*
 * grids dimly), providing a "pretty" effect as the player runs around, and
 * to efficiently display the "torch lite" in a special color.
 *
 *
 * Some comments on the "update_view()" algorithm...
 *
 * The algorithm is very fast, since it spreads "obvious" grids very quickly,
 * and only has to call "los()" on the borderline cases.  The major axes/diags
 * even terminate early when they hit walls.  I need to find a quick way
 * to "terminate" the other scans.
 *
 * Note that in the worst case (a big empty area with say 5% scattered walls),
 * each of the 1500 or so nearby grids is checked once, most of them getting
 * an "instant" rating, and only a small portion requiring a call to "los()".
 *
 * The only time that the algorithm appears to be "noticeably" too slow is
 * when running, and this is usually only important in town, since the town
 * provides about the worst scenario possible, with large open regions and
 * a few scattered obstructions.  There is a special "efficiency" option to
 * allow the player to reduce his field of view in town, if needed.
 *
 * In the "best" case (say, a normal stretch of corridor), the algorithm
 * makes one check for each viewable grid, and makes no calls to "los()".
 * So running in corridors is very fast, and if a lot of monsters are
 * nearby, it is much faster than the old methods.
 *
 * Note that resting, most normal commands, and several forms of running,
 * plus all commands executed near large groups of monsters, are strictly
 * more efficient with "update_view()" that with the old "compute los() on
 * demand" method, primarily because once the "field of view" has been
 * calculated, it does not have to be recalculated until the player moves
 * (or a wall or door is created or destroyed).
 *
 * Note that we no longer have to do as many "los()" checks, since once the
 * "view" region has been built, very few things cause it to be "changed"
 * (player movement, and the opening/closing of doors, changes in wall status).
 * Note that door/wall changes are only relevant when the door/wall itself is
 * in the "view" region.
 *
 * The algorithm seems to only call "los()" from zero to ten times, usually
 * only when coming down a corridor into a room, or standing in a room, just
 * misaligned with a corridor.  So if, say, there are five "nearby" monsters,
 * we will be reducing the calls to "los()".
 *
 * I am thinking in terms of an algorithm that "walks" from the central point
 * out to the maximal "distance", at each point, determining the "view" code
 * (above).  For each grid not on a major axis or diagonal, the "view" code
 * depends on the "cave_los_bold()" and "view" of exactly two other grids
 * (the one along the nearest diagonal, and the one next to that one, see
 * "update_view_aux()"...).
 *
 * We "memorize" the viewable space array, so that at the cost of under 3000
 * bytes, we reduce the time taken by "forget_view()" to one assignment for
 * each grid actually in the "viewable space".  And for another 3000 bytes,
 * we prevent "erase + redraw" ineffiencies via the "seen" set.  These bytes
 * are also used by other routines, thus reducing the cost to almost nothing.
 *
 * A similar thing is done for "forget_lite()" in which case the savings are
 * much less, but save us from doing bizarre maintenance checking.
 *
 * In the worst "normal" case (in the middle of the town), the reachable space
 * actually reaches to more than half of the largest possible "circle" of view,
 * or about 800 grids, and in the worse case (in the middle of a dungeon level
 * where all the walls have been removed), the reachable space actually reaches
 * the theoretical maximum size of just under 1500 grids.
 *
 * Each grid G examines the "state" of two (?) other (adjacent) grids, G1 & G2.
 * If G1 is lite, G is lite.  Else if G2 is lite, G is half.  Else if G1 and G2
 * are both half, G is half.  Else G is dark.  It only takes 2 (or 4) bits to
 * "name" a grid, so (for MAX_RAD of 20) we could use 1600 bytes, and scan the
 * entire possible space (including initialization) in one step per grid.  If
 * we do the "clearing" as a separate step (and use an array of "view" grids),
 * then the clearing will take as many steps as grids that were viewed, and the
 * algorithm will be able to "stop" scanning at various points.
 * Oh, and outside of the "torch radius", only "lite" grids need to be scanned.
 */

/*
 * Mega-Hack -- Delayed visual update
 * Only used if update_view(), update_lite() or update_mon_lite() was called
 */
void delayed_visual_update(void)
{
        int i;
        POSITION y, x;
        grid_type *g_ptr;

        /* Update needed grids */
        for (i = 0; i < current_floor_ptr->redraw_n; i++)
        {
                y = current_floor_ptr->redraw_y[i];
                x = current_floor_ptr->redraw_x[i];
                g_ptr = &current_floor_ptr->grid_array[y][x];

                /* Update only needed grids (prevent multiple updating) */
                if (!(g_ptr->info & CAVE_REDRAW)) continue;

                /* If required, note */
                if (g_ptr->info & CAVE_NOTE) note_spot(y, x);

                lite_spot(y, x);

                /* Hack -- Visual update of monster on this grid */
                if (g_ptr->m_idx) update_monster(g_ptr->m_idx, FALSE);

                /* No longer in the array */
                g_ptr->info &= ~(CAVE_NOTE | CAVE_REDRAW);
        }

        /* None left */
        current_floor_ptr->redraw_n = 0;
}


/*
 * Hack -- forget the "flow" information
 */
void forget_flow(void)
{
        POSITION x, y;

        /* Check the entire dungeon */
        for (y = 0; y < current_floor_ptr->height; y++)
        {
                for (x = 0; x < current_floor_ptr->width; x++)
                {
                        /* Forget the old data */
                        current_floor_ptr->grid_array[y][x].dist = 0;
                        current_floor_ptr->grid_array[y][x].cost = 0;
                        current_floor_ptr->grid_array[y][x].when = 0;
                }
        }
}


/*
 * Hack - speed up the update_flow algorithm by only doing
 * it everytime the player moves out of LOS of the last
 * "way-point".
 */
static POSITION flow_x = 0;
static POSITION flow_y = 0;



/*
 * Hack -- fill in the "cost" field of every grid that the player
 * can "reach" with the number of steps needed to reach that grid.
 * This also yields the "distance" of the player from every grid.
 *
 * In addition, mark the "when" of the grids that can reach
 * the player with the incremented value of "flow_n".
 *
 * Hack -- use the "seen" array as a "circular queue".
 *
 * We do not need a priority queue because the cost from grid
 * to grid is always "one" and we process them in order.
 */
void update_flow(void)
{
        POSITION x, y;
        DIRECTION d;
        int flow_head = 1;
        int flow_tail = 0;

        /* Paranoia -- make sure the array is empty */
        if (tmp_pos.n) return;

        /* The last way-point is on the map */
        if (running && in_bounds(flow_y, flow_x))
        {
                /* The way point is in sight - do not update.  (Speedup) */
                if (current_floor_ptr->grid_array[flow_y][flow_x].info & CAVE_VIEW) return;
        }

        /* Erase all of the current flow information */
        for (y = 0; y < current_floor_ptr->height; y++)
        {
                for (x = 0; x < current_floor_ptr->width; x++)
                {
                        current_floor_ptr->grid_array[y][x].cost = 0;
                        current_floor_ptr->grid_array[y][x].dist = 0;
                }
        }

        /* Save player position */
        flow_y = p_ptr->y;
        flow_x = p_ptr->x;

        /* Add the player's grid to the queue */
        tmp_pos.y[0] = p_ptr->y;
        tmp_pos.x[0] = p_ptr->x;

        /* Now process the queue */
        while (flow_head != flow_tail)
        {
                int ty, tx;

                /* Extract the next entry */
                ty = tmp_pos.y[flow_tail];
                tx = tmp_pos.x[flow_tail];

                /* Forget that entry */
                if (++flow_tail == TEMP_MAX) flow_tail = 0;

                /* Add the "children" */
                for (d = 0; d < 8; d++)
                {
                        int old_head = flow_head;
                        byte_hack m = current_floor_ptr->grid_array[ty][tx].cost + 1;
                        byte_hack n = current_floor_ptr->grid_array[ty][tx].dist + 1;
                        grid_type *g_ptr;

                        /* Child location */
                        y = ty + ddy_ddd[d];
                        x = tx + ddx_ddd[d];

                        /* Ignore player's grid */
                        if (player_bold(y, x)) continue;

                        g_ptr = &current_floor_ptr->grid_array[y][x];

                        if (is_closed_door(g_ptr->feat)) m += 3;

                        /* Ignore "pre-stamped" entries */
                        if (g_ptr->dist != 0 && g_ptr->dist <= n && g_ptr->cost <= m) continue;

                        /* Ignore "walls" and "rubble" */
                        if (!cave_have_flag_grid(g_ptr, FF_MOVE) && !is_closed_door(g_ptr->feat)) continue;

                        /* Save the flow cost */
                        if (g_ptr->cost == 0 || g_ptr->cost > m) g_ptr->cost = m;
                        if (g_ptr->dist == 0 || g_ptr->dist > n) g_ptr->dist = n;

                        /* Hack -- limit flow depth */
                        if (n == MONSTER_FLOW_DEPTH) continue;

                        /* Enqueue that entry */
                        tmp_pos.y[flow_head] = y;
                        tmp_pos.x[flow_head] = x;

                        /* Advance the queue */
                        if (++flow_head == TEMP_MAX) flow_head = 0;

                        /* Hack -- notice overflow by forgetting new entry */
                        if (flow_head == flow_tail) flow_head = old_head;
                }
        }
}


static int scent_when = 0;

/*
 * Characters leave scent trails for perceptive monsters to track.
 *
 * Smell is rather more limited than sound.  Many creatures cannot use
 * it at all, it doesn't extend very far outwards from the character's
 * current position, and monsters can use it to home in the character,
 * but not to run away from him.
 *
 * Smell is valued according to age.  When a character takes his current_world_ptr->game_turn,
 * scent is aged by one, and new scent of the current age is laid down.
 * Speedy characters leave more scent, true, but it also ages faster,
 * which makes it harder to hunt them down.
 *
 * Whenever the age count loops, most of the scent trail is erased and
 * the age of the remainder is recalculated.
 */
void update_smell(void)
{
        POSITION i, j;
        POSITION y, x;

        /* Create a table that controls the spread of scent */
        const int scent_adjust[5][5] =
        {
                { -1, 0, 0, 0,-1 },
                {  0, 1, 1, 1, 0 },
                {  0, 1, 2, 1, 0 },
                {  0, 1, 1, 1, 0 },
                { -1, 0, 0, 0,-1 },
        };

        /* Loop the age and adjust scent values when necessary */
        if (++scent_when == 254)
        {
                /* Scan the entire dungeon */
                for (y = 0; y < current_floor_ptr->height; y++)
                {
                        for (x = 0; x < current_floor_ptr->width; x++)
                        {
                                int w = current_floor_ptr->grid_array[y][x].when;
                                current_floor_ptr->grid_array[y][x].when = (w > 128) ? (w - 128) : 0;
                        }
                }

                /* Restart */
                scent_when = 126;
        }


        /* Lay down new scent */
        for (i = 0; i < 5; i++)
        {
                for (j = 0; j < 5; j++)
                {
                        grid_type *g_ptr;

                        /* Translate table to map grids */
                        y = i + p_ptr->y - 2;
                        x = j + p_ptr->x - 2;

                        /* Check Bounds */
                        if (!in_bounds(y, x)) continue;

                        g_ptr = &current_floor_ptr->grid_array[y][x];

                        /* Walls, water, and lava cannot hold scent. */
                        if (!cave_have_flag_grid(g_ptr, FF_MOVE) && !is_closed_door(g_ptr->feat)) continue;

                        /* Grid must not be blocked by walls from the character */
                        if (!player_has_los_bold(y, x)) continue;

                        /* Note grids that are too far away */
                        if (scent_adjust[i][j] == -1) continue;

                        /* Mark the grid with new scent */
                        g_ptr->when = scent_when + scent_adjust[i][j];
                }
        }
}



/*
 * Change the "feat" flag for a grid, and notice/redraw the grid
 */
void cave_set_feat(POSITION y, POSITION x, FEAT_IDX feat)
{
        grid_type *g_ptr = &current_floor_ptr->grid_array[y][x];
        feature_type *f_ptr = &f_info[feat];
        bool old_los, old_mirror;

        if (!character_dungeon)
        {
                /* Clear mimic type */
                g_ptr->mimic = 0;

                /* Change the feature */
                g_ptr->feat = feat;

                /* Hack -- glow the GLOW terrain */
                if (have_flag(f_ptr->flags, FF_GLOW) && !(d_info[p_ptr->dungeon_idx].flags1 & DF1_DARKNESS))
                {
                        DIRECTION i;
                        POSITION yy, xx;

                        for (i = 0; i < 9; i++)
                        {
                                yy = y + ddy_ddd[i];
                                xx = x + ddx_ddd[i];
                                if (!in_bounds2(yy, xx)) continue;
                                current_floor_ptr->grid_array[yy][xx].info |= CAVE_GLOW;
                        }
                }

                return;
        }

        old_los = cave_have_flag_bold(y, x, FF_LOS);
        old_mirror = is_mirror_grid(g_ptr);

        /* Clear mimic type */
        g_ptr->mimic = 0;

        /* Change the feature */
        g_ptr->feat = feat;

        /* Remove flag for mirror/glyph */
        g_ptr->info &= ~(CAVE_OBJECT);

        if (old_mirror && (d_info[p_ptr->dungeon_idx].flags1 & DF1_DARKNESS))
        {
                g_ptr->info &= ~(CAVE_GLOW);
                if (!view_torch_grids) g_ptr->info &= ~(CAVE_MARK);

                update_local_illumination(y, x);
        }

        /* Check for change to boring grid */
        if (!have_flag(f_ptr->flags, FF_REMEMBER)) g_ptr->info &= ~(CAVE_MARK);
        if (g_ptr->m_idx) update_monster(g_ptr->m_idx, FALSE);

        note_spot(y, x);
        lite_spot(y, x);

        /* Check if los has changed */
        if (old_los ^ have_flag(f_ptr->flags, FF_LOS))
        {

#ifdef COMPLEX_WALL_ILLUMINATION /* COMPLEX_WALL_ILLUMINATION */

                update_local_illumination(y, x);

#endif /* COMPLEX_WALL_ILLUMINATION */

                /* Update the visuals */
                p_ptr->update |= (PU_VIEW | PU_LITE | PU_MON_LITE | PU_MONSTERS);
        }

        /* Hack -- glow the GLOW terrain */
        if (have_flag(f_ptr->flags, FF_GLOW) && !(d_info[p_ptr->dungeon_idx].flags1 & DF1_DARKNESS))
        {
                DIRECTION i;
                POSITION yy, xx;
                grid_type *cc_ptr;

                for (i = 0; i < 9; i++)
                {
                        yy = y + ddy_ddd[i];
                        xx = x + ddx_ddd[i];
                        if (!in_bounds2(yy, xx)) continue;
                        cc_ptr = &current_floor_ptr->grid_array[yy][xx];
                        cc_ptr->info |= CAVE_GLOW;

                        if (player_has_los_grid(cc_ptr))
                        {
                                if (cc_ptr->m_idx) update_monster(cc_ptr->m_idx, FALSE);

                                note_spot(yy, xx);

                                lite_spot(yy, xx);
                        }

                        update_local_illumination(yy, xx);
                }

                if (p_ptr->special_defense & NINJA_S_STEALTH)
                {
                        if (current_floor_ptr->grid_array[p_ptr->y][p_ptr->x].info & CAVE_GLOW) set_superstealth(FALSE);
                }
        }
}


FEAT_IDX conv_dungeon_feat(FEAT_IDX newfeat)
{
        feature_type *f_ptr = &f_info[newfeat];

        if (have_flag(f_ptr->flags, FF_CONVERT))
        {
                switch (f_ptr->subtype)
                {
                case CONVERT_TYPE_FLOOR:
                        return feat_ground_type[randint0(100)];
                case CONVERT_TYPE_WALL:
                        return feat_wall_type[randint0(100)];
                case CONVERT_TYPE_INNER:
                        return feat_wall_inner;
                case CONVERT_TYPE_OUTER:
                        return feat_wall_outer;
                case CONVERT_TYPE_SOLID:
                        return feat_wall_solid;
                case CONVERT_TYPE_STREAM1:
                        return d_info[p_ptr->dungeon_idx].stream1;
                case CONVERT_TYPE_STREAM2:
                        return d_info[p_ptr->dungeon_idx].stream2;
                default:
                        return newfeat;
                }
        }
        else return newfeat;
}


/*
 * Take a feature, determine what that feature becomes
 * through applying the given action.
 */
FEAT_IDX feat_state(FEAT_IDX feat, int action)
{
        feature_type *f_ptr = &f_info[feat];
        int i;

        /* Get the new feature */
        for (i = 0; i < MAX_FEAT_STATES; i++)
        {
                if (f_ptr->state[i].action == action) return conv_dungeon_feat(f_ptr->state[i].result);
        }

        if (have_flag(f_ptr->flags, FF_PERMANENT)) return feat;

        return (feature_action_flags[action] & FAF_DESTROY) ? conv_dungeon_feat(f_ptr->destroyed) : feat;
}

/*
 * Takes a location and action and changes the feature at that
 * location through applying the given action.
 */
void cave_alter_feat(POSITION y, POSITION x, int action)
{
        /* Set old feature */
        FEAT_IDX oldfeat = current_floor_ptr->grid_array[y][x].feat;

        /* Get the new feat */
        FEAT_IDX newfeat = feat_state(oldfeat, action);

        /* No change */
        if (newfeat == oldfeat) return;

        /* Set the new feature */
        cave_set_feat(y, x, newfeat);

        if (!(feature_action_flags[action] & FAF_NO_DROP))
        {
                feature_type *old_f_ptr = &f_info[oldfeat];
                feature_type *f_ptr = &f_info[newfeat];
                bool found = FALSE;

                /* Handle gold */
                if (have_flag(old_f_ptr->flags, FF_HAS_GOLD) && !have_flag(f_ptr->flags, FF_HAS_GOLD))
                {
                        /* Place some gold */
                        place_gold(y, x);
                        found = TRUE;
                }

                /* Handle item */
                if (have_flag(old_f_ptr->flags, FF_HAS_ITEM) && !have_flag(f_ptr->flags, FF_HAS_ITEM) && (randint0(100) < (15 - current_floor_ptr->dun_level / 2)))
                {
                        /* Place object */
                        place_object(y, x, 0L);
                        found = TRUE;
                }

                if (found && character_dungeon && player_can_see_bold(y, x))
                {
                        msg_print(_("何かを発見した！", "You have found something!"));
                }
        }

        if (feature_action_flags[action] & FAF_CRASH_GLASS)
        {
                feature_type *old_f_ptr = &f_info[oldfeat];

                if (have_flag(old_f_ptr->flags, FF_GLASS) && character_dungeon)
                {
                        project(PROJECT_WHO_GLASS_SHARDS, 1, y, x, MIN(current_floor_ptr->dun_level, 100) / 4, GF_SHARDS,
                                (PROJECT_GRID | PROJECT_ITEM | PROJECT_KILL | PROJECT_HIDE | PROJECT_JUMP | PROJECT_NO_HANGEKI), -1);
                }
        }
}


/* Remove a mirror */
void remove_mirror(POSITION y, POSITION x)
{
        grid_type *g_ptr = &current_floor_ptr->grid_array[y][x];

        /* Remove the mirror */
        g_ptr->info &= ~(CAVE_OBJECT);
        g_ptr->mimic = 0;

        if (d_info[p_ptr->dungeon_idx].flags1 & DF1_DARKNESS)
        {
                g_ptr->info &= ~(CAVE_GLOW);
                if (!view_torch_grids) g_ptr->info &= ~(CAVE_MARK);
                if (g_ptr->m_idx) update_monster(g_ptr->m_idx, FALSE);

                update_local_illumination(y, x);
        }

        note_spot(y, x);

        lite_spot(y, x);
}


/*
 *  Return TRUE if there is a mirror on the grid.
 */
bool is_mirror_grid(grid_type *g_ptr)
{
        if ((g_ptr->info & CAVE_OBJECT) && have_flag(f_info[g_ptr->mimic].flags, FF_MIRROR))
                return TRUE;
        else
                return FALSE;
}


/*
 *  Return TRUE if there is a mirror on the grid.
 */
bool is_glyph_grid(grid_type *g_ptr)
{
        if ((g_ptr->info & CAVE_OBJECT) && have_flag(f_info[g_ptr->mimic].flags, FF_GLYPH))
                return TRUE;
        else
                return FALSE;
}


/*
 *  Return TRUE if there is a mirror on the grid.
 */
bool is_explosive_rune_grid(grid_type *g_ptr)
{
        if ((g_ptr->info & CAVE_OBJECT) && have_flag(f_info[g_ptr->mimic].flags, FF_MINOR_GLYPH))
                return TRUE;
        else
                return FALSE;
}

/*!
* @brief 指定されたマスがモンスターのテレポート可能先かどうかを判定する。
* @param m_idx モンスターID
* @param y 移動先Y座標
* @param x 移動先X座標
* @param mode オプション
* @return テレポート先として妥当ならばtrue
*/
bool cave_monster_teleportable_bold(MONSTER_IDX m_idx, POSITION y, POSITION x, BIT_FLAGS mode)
{
        monster_type *m_ptr = &current_floor_ptr->m_list[m_idx];
        grid_type    *g_ptr = &current_floor_ptr->grid_array[y][x];
        feature_type *f_ptr = &f_info[g_ptr->feat];

        /* Require "teleportable" space */
        if (!have_flag(f_ptr->flags, FF_TELEPORTABLE)) return FALSE;

        if (g_ptr->m_idx && (g_ptr->m_idx != m_idx)) return FALSE;
        if (player_bold(y, x)) return FALSE;

        /* Hack -- no teleport onto glyph of warding */
        if (is_glyph_grid(g_ptr)) return FALSE;
        if (is_explosive_rune_grid(g_ptr)) return FALSE;

        if (!(mode & TELEPORT_PASSIVE))
        {
                if (!monster_can_cross_terrain(g_ptr->feat, &r_info[m_ptr->r_idx], 0)) return FALSE;
        }

        return TRUE;
}

/*!
* @brief 指定されたマスにプレイヤーがテレポート可能かどうかを判定する。
* @param y 移動先Y座標
* @param x 移動先X座標
* @param mode オプション
* @return テレポート先として妥当ならばtrue
*/
bool cave_player_teleportable_bold(POSITION y, POSITION x, BIT_FLAGS mode)
{
        grid_type    *g_ptr = &current_floor_ptr->grid_array[y][x];
        feature_type *f_ptr = &f_info[g_ptr->feat];

        /* Require "teleportable" space */
        if (!have_flag(f_ptr->flags, FF_TELEPORTABLE)) return FALSE;

        /* No magical teleporting into vaults and such */
        if (!(mode & TELEPORT_NONMAGICAL) && (g_ptr->info & CAVE_ICKY)) return FALSE;

        if (g_ptr->m_idx && (g_ptr->m_idx != p_ptr->riding)) return FALSE;

        /* don't teleport on a trap. */
        if (have_flag(f_ptr->flags, FF_HIT_TRAP)) return FALSE;

        if (!(mode & TELEPORT_PASSIVE))
        {
                if (!player_can_enter(g_ptr->feat, 0)) return FALSE;

                if (have_flag(f_ptr->flags, FF_WATER) && have_flag(f_ptr->flags, FF_DEEP))
                {
                        if (!p_ptr->levitation && !p_ptr->can_swim) return FALSE;
                }

                if (have_flag(f_ptr->flags, FF_LAVA) && !p_ptr->immune_fire && !IS_INVULN())
                {
                        /* Always forbid deep lava */
                        if (have_flag(f_ptr->flags, FF_DEEP)) return FALSE;

                        /* Forbid shallow lava when the player don't have levitation */
                        if (!p_ptr->levitation) return FALSE;
                }

        }

        return TRUE;
}

/*!
 * @brief 地形は開くものであって、かつ開かれているかを返す /
 * Attempt to open the given chest at the given location
 * @param feat 地形ID
 * @return 開いた地形である場合TRUEを返す /  Return TRUE if the given feature is an open door
 */
bool is_open(FEAT_IDX feat)
{
        return have_flag(f_info[feat].flags, FF_CLOSE) && (feat != feat_state(feat, FF_CLOSE));
}

/*!
 * @brief プレイヤーが地形踏破可能かを返す
 * @param feature 判定したい地形ID
 * @param mode 移動に関するオプションフラグ
 * @return 移動可能ならばTRUEを返す
 */
bool player_can_enter(FEAT_IDX feature, BIT_FLAGS16 mode)
{
        feature_type *f_ptr = &f_info[feature];

        if (p_ptr->riding) return monster_can_cross_terrain(feature, &r_info[current_floor_ptr->m_list[p_ptr->riding].r_idx], mode | CEM_RIDING);

        if (have_flag(f_ptr->flags, FF_PATTERN))
        {
                if (!(mode & CEM_P_CAN_ENTER_PATTERN)) return FALSE;
        }

        if (have_flag(f_ptr->flags, FF_CAN_FLY) && p_ptr->levitation) return TRUE;
        if (have_flag(f_ptr->flags, FF_CAN_SWIM) && p_ptr->can_swim) return TRUE;
        if (have_flag(f_ptr->flags, FF_CAN_PASS) && p_ptr->pass_wall) return TRUE;

        if (!have_flag(f_ptr->flags, FF_MOVE)) return FALSE;

        return TRUE;
}