[hengband/hengband.git] / src / floor-generate.c

/*!
 * @file generate.c
 * @brief ダンジョンの生成 / Dungeon generation
 * @date 2014/01/04
 * @author
 * Copyright (c) 1997 Ben Harrison, James E. Wilson, Robert A. Koeneke\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
 * 2014 Deskull rearranged comment for Doxygen. \n
 * @details
 * Note that Level generation is *not* an important bottleneck,\n
 * though it can be annoyingly slow on older machines...  Thus\n
 * we emphasize "simplicity" and "correctness" over "speed".\n
 *\n
 * This entire file is only needed for generating levels.\n
 * This may allow smart compilers to only load it when needed.\n
 *\n
 * Consider the "v_info.txt" file for vault generation.\n
 *\n
 * In this file, we use the "special" granite and perma-wall sub-types,\n
 * where "basic" is normal, "inner" is inside a room, "outer" is the\n
 * outer wall of a room, and "solid" is the outer wall of the dungeon\n
 * or any walls that may not be pierced by corridors.  Thus the only\n
 * wall type that may be pierced by a corridor is the "outer granite"\n
 * type.  The "basic granite" type yields the "actual" corridors.\n
 *\n
 * Note that we use the special "solid" granite wall type to prevent\n
 * multiple corridors from piercing a wall in two adjacent locations,\n
 * which would be messy, and we use the special "outer" granite wall\n
 * to indicate which walls "surround" rooms, and may thus be "pierced"\n
 * by corridors entering or leaving the room.\n
 *\n
 * Note that a tunnel which attempts to leave a room near the "edge"\n
 * of the dungeon in a direction toward that edge will cause "silly"\n
 * wall piercings, but will have no permanently incorrect effects,\n
 * as long as the tunnel can *eventually* exit from another side.\n
 * And note that the wall may not come back into the room by the\n
 * hole it left through, so it must bend to the left or right and\n
 * then optionally re-enter the room (at least 2 grids away).  This\n
 * is not a problem since every room that is large enough to block\n
 * the passage of tunnels is also large enough to allow the tunnel\n
 * to pierce the room itself several times.\n
 *\n
 * Note that no two corridors may enter a room through adjacent grids,\n
 * they must either share an entryway or else use entryways at least\n
 * two grids apart.  This prevents "large" (or "silly") doorways.\n
 *\n
 * To create rooms in the dungeon, we first divide the dungeon up\n
 * into "blocks" of 11x11 grids each, and require that all rooms\n
 * occupy a rectangular group of blocks.  As long as each room type\n
 * reserves a sufficient number of blocks, the room building routines\n
 * will not need to check bounds.  Note that most of the normal rooms\n
 * actually only use 23x11 grids, and so reserve 33x11 grids.\n
 *\n
 * Note that the use of 11x11 blocks (instead of the old 33x11 blocks)\n
 * allows more variability in the horizontal placement of rooms, and\n
 * at the same time has the disadvantage that some rooms (two thirds\n
 * of the normal rooms) may be "split" by panel boundaries.  This can\n
 * induce a situation where a player is in a room and part of the room\n
 * is off the screen.  It may be annoying enough to go back to 33x11\n
 * blocks to prevent this visual situation.\n
 *\n
 * Note that the dungeon generation routines are much different (2.7.5)\n
 * and perhaps "DUN_ROOMS" should be less than 50.\n
 *\n
 * Note that it is possible to create a room which is only\n
 * connected to itself, because the "tunnel generation" code allows a\n
 * tunnel to leave a room, wander around, and then re-enter the room.\n
 *\n
 * Note that it is possible to create a set of rooms which\n
 * are only connected to other rooms in that set, since there is nothing\n
 * explicit in the code to prevent this from happening.  But this is less\n
 * likely than the "isolated room" problem, because each room attempts to\n
 * connect to another room, in a giant cycle, thus requiring at least two\n
 * bizarre occurances to create an isolated section of the dungeon.\n
 *\n
 * Note that (2.7.9) monster pits have been split into monster "nests"\n
 * and monster "pits".  The "nests" have a collection of monsters of a\n
 * given type strewn randomly around the room (jelly, animal, or undead),\n
 * while the "pits" have a collection of monsters of a given type placed\n
 * around the room in an organized manner (orc, troll, giant, dragon, or\n
 * demon).  Note that both "nests" and "pits" are now "level dependant",\n
 * and both make 16 "expensive" calls to the "get_mon_num()" function.\n
 *\n
 * Note that the cave grid flags changed in a rather drastic manner\n
 * for Angband 2.8.0 (and 2.7.9+), in particular, dungeon terrain\n
 * features, such as doors and stairs and traps and rubble and walls,\n
 * are all handled as a set of 64 possible "terrain features", and\n
 * not as "fake" objects (440-479) as in pre-2.8.0 versions.\n
 *\n
 * The 64 new "dungeon features" will also be used for "visual display"\n
 * but we must be careful not to allow, for example, the user to display\n
 * hidden traps in a different way from floors, or secret doors in a way\n
 * different from granite walls, or even permanent granite in a different\n
 * way from granite.  \n
 */

#include "angband.h"
#include "generate.h"
#include "grid.h"
#include "rooms.h"
#include "floor-streams.h"
#include "trap.h"

int dun_tun_rnd; 
int dun_tun_chg;
int dun_tun_con;
int dun_tun_pen;
int dun_tun_jct;


/*!
 * Dungeon generation data -- see "cave_gen()"
 */
dun_data *dun;


/*!
 * @brief 上下左右の外壁数をカウントする / Count the number of walls adjacent to the given grid.
 * @param y 基準のy座標
 * @param x 基準のx座標
 * @return 隣接する外壁の数
 * @note Assumes "in_bounds(y, x)"
 * @details We count only granite walls and permanent walls.
 */
static int next_to_walls(POSITION y, POSITION x)
{
        int k = 0;

        if (in_bounds(y + 1, x) && is_extra_bold(y + 1, x)) k++;
        if (in_bounds(y - 1, x) && is_extra_bold(y - 1, x)) k++;
        if (in_bounds(y, x + 1) && is_extra_bold(y, x + 1)) k++;
        if (in_bounds(y, x - 1) && is_extra_bold(y, x - 1)) k++;

        return (k);
}

/*!
 * @brief alloc_stairs()の補助として指定の位置に階段を生成できるかの判定を行う / Helper function for alloc_stairs(). Is this a good location for stairs?
 * @param y 基準のy座標
 * @param x 基準のx座標
 * @param walls 最低減隣接させたい外壁の数
 * @return 階段を生成して問題がないならばTRUEを返す。
 */
static bool alloc_stairs_aux(POSITION y, POSITION x, int walls)
{
        cave_type *c_ptr = &cave[y][x];

        /* Require "naked" floor grid */
        if (!is_floor_grid(c_ptr)) return FALSE;
        if (pattern_tile(y, x)) return FALSE;
        if (c_ptr->o_idx || c_ptr->m_idx) return FALSE;

        /* Require a certain number of adjacent walls */
        if (next_to_walls(y, x) < walls) return FALSE;

        return TRUE;
}


/*!
 * @brief 外壁に隣接させて階段を生成する / Places some staircases near walls
 * @param feat 配置したい地形ID
 * @param num 配置したい階段の数
 * @param walls 最低減隣接させたい外壁の数
 * @return 規定数通りに生成に成功したらTRUEを返す。
 */
static bool alloc_stairs(IDX feat, int num, int walls)
{
        int i;
        int shaft_num = 0;

        feature_type *f_ptr = &f_info[feat];

        if (have_flag(f_ptr->flags, FF_LESS))
        {
                /* No up stairs in town or in ironman mode */
                if (ironman_downward || !dun_level) return TRUE;

                if (dun_level > d_info[dungeon_type].mindepth)
                        shaft_num = (randint1(num+1))/2;
        }
        else if (have_flag(f_ptr->flags, FF_MORE))
        {
                QUEST_IDX q_idx = quest_number(dun_level);

                /* No downstairs on quest levels */
                if (dun_level > 1 && q_idx)
                {
                        monster_race *r_ptr = &r_info[quest[q_idx].r_idx];

                        /* The quest monster(s) is still alive? */
                        if (!(r_ptr->flags1 & RF1_UNIQUE) || 0 < r_ptr->max_num)
                                return TRUE;
                }

                /* No downstairs at the bottom */
                if (dun_level >= d_info[dungeon_type].maxdepth) return TRUE;

                if ((dun_level < d_info[dungeon_type].maxdepth-1) && !quest_number(dun_level+1))
                        shaft_num = (randint1(num)+1)/2;
        }

        /* Paranoia */
        else return FALSE;


        /* Place "num" stairs */
        for (i = 0; i < num; i++)
        {
                while (TRUE)
                {
                        POSITION y, x = 0;
                        cave_type *c_ptr;

                        int candidates = 0;
                        int pick;

                        for (y = 1; y < cur_hgt - 1; y++)
                        {
                                for (x = 1; x < cur_wid - 1; x++)
                                {
                                        if (alloc_stairs_aux(y, x, walls))
                                        {
                                                /* A valid space found */
                                                candidates++;
                                        }
                                }
                        }

                        /* No valid place! */
                        if (!candidates)
                        {
                                /* There are exactly no place! */
                                if (walls <= 0) return FALSE;

                                /* Decrease walls limit, and try again */
                                walls--;
                                continue;
                        }

                        /* Choose a random one */
                        pick = randint1(candidates);

                        for (y = 1; y < cur_hgt - 1; y++)
                        {
                                for (x = 1; x < cur_wid - 1; x++)
                                {
                                        if (alloc_stairs_aux(y, x, walls))
                                        {
                                                pick--;

                                                /* Is this a picked one? */
                                                if (!pick) break;
                                        }
                                }

                                if (!pick) break;
                        }
                        c_ptr = &cave[y][x];

                        /* Clear possible garbage of hidden trap */
                        c_ptr->mimic = 0;

                        /* Clear previous contents, add stairs */
                        c_ptr->feat = (i < shaft_num) ? feat_state(feat, FF_SHAFT) : feat;

                        /* No longer "FLOOR" */
                        c_ptr->info &= ~(CAVE_FLOOR);

                        /* Success */
                        break;
                }
        }
        return TRUE;
}

/*!
 * @brief フロア上のランダム位置に各種オブジェクトを配置する / Allocates some objects (using "place" and "type")
 * @param set 配置したい地形の種類
 * @param typ 配置したいオブジェクトの種類
 * @param num 配置したい数
 * @return 規定数通りに生成に成功したらTRUEを返す。
 */
static void alloc_object(int set, EFFECT_ID typ, int num)
{
        POSITION y = 0, x = 0;
        int k;
        int dummy = 0;
        cave_type *c_ptr;

        /* A small level has few objects. */
        num = num * cur_hgt * cur_wid / (MAX_HGT*MAX_WID) +1;

        /* Place some objects */
        for (k = 0; k < num; k++)
        {
                /* Pick a "legal" spot */
                while (dummy < SAFE_MAX_ATTEMPTS)
                {
                        bool room;

                        dummy++;

                        y = randint0(cur_hgt);
                        x = randint0(cur_wid);

                        c_ptr = &cave[y][x];

                        /* Require "naked" floor grid */
                        if (!is_floor_grid(c_ptr) || c_ptr->o_idx || c_ptr->m_idx) continue;

                        /* Avoid player location */
                        if (player_bold(y, x)) continue;

                        /* Check for "room" */
                        room = (cave[y][x].info & CAVE_ROOM) ? TRUE : FALSE;

                        /* Require corridor? */
                        if ((set == ALLOC_SET_CORR) && room) continue;

                        /* Require room? */
                        if ((set == ALLOC_SET_ROOM) && !room) continue;

                        /* Accept it */
                        break;
                }

                if (dummy >= SAFE_MAX_ATTEMPTS)
                {
                        msg_print_wizard(CHEAT_DUNGEON, _("アイテムの配置に失敗しました。", "Failed to place object."));
                        return;
                }


                /* Place something */
                switch (typ)
                {
                        case ALLOC_TYP_RUBBLE:
                        {
                                place_rubble(y, x);
                                cave[y][x].info &= ~(CAVE_FLOOR);
                                break;
                        }

                        case ALLOC_TYP_TRAP:
                        {
                                place_trap(y, x);
                                cave[y][x].info &= ~(CAVE_FLOOR);
                                break;
                        }

                        case ALLOC_TYP_GOLD:
                        {
                                place_gold(y, x);
                                break;
                        }

                        case ALLOC_TYP_OBJECT:
                        {
                                place_object(y, x, 0L);
                                break;
                        }
                }
        }
}




/*!
 * @brief クエストに関わるモンスターの配置を行う / Place quest monsters
 * @return 成功したならばTRUEを返す
 */
bool place_quest_monsters(void)
{
        int i;

        /* Handle the quest monster placements */
        for (i = 0; i < max_q_idx; i++)
        {
                monster_race *r_ptr;
                BIT_FLAGS mode;
                int j;

                if (quest[i].status != QUEST_STATUS_TAKEN ||
                    (quest[i].type != QUEST_TYPE_KILL_LEVEL &&
                     quest[i].type != QUEST_TYPE_RANDOM) ||
                    quest[i].level != dun_level ||
                    dungeon_type != quest[i].dungeon ||
                    (quest[i].flags & QUEST_FLAG_PRESET))
                {
                        /* Ignore it */
                        continue;
                }

                r_ptr = &r_info[quest[i].r_idx];

                /* Hack -- "unique" monsters must be "unique" */
                if ((r_ptr->flags1 & RF1_UNIQUE) &&
                    (r_ptr->cur_num >= r_ptr->max_num)) continue;

                mode = (PM_NO_KAGE | PM_NO_PET);

                if (!(r_ptr->flags1 & RF1_FRIENDS))
                        mode |= PM_ALLOW_GROUP;

                for (j = 0; j < (quest[i].max_num - quest[i].cur_num); j++)
                {
                        int k;

                        for (k = 0; k < SAFE_MAX_ATTEMPTS; k++)
                        {
                                POSITION x = 0, y = 0;
                                int l;

                                /* Find an empty grid */
                                for (l = SAFE_MAX_ATTEMPTS; l > 0; l--)
                                {
                                        cave_type    *c_ptr;
                                        feature_type *f_ptr;

                                        y = randint0(cur_hgt);
                                        x = randint0(cur_wid);

                                        c_ptr = &cave[y][x];
                                        f_ptr = &f_info[c_ptr->feat];

                                        if (!have_flag(f_ptr->flags, FF_MOVE) && !have_flag(f_ptr->flags, FF_CAN_FLY)) continue;
                                        if (!monster_can_enter(y, x, r_ptr, 0)) continue;
                                        if (distance(y, x, p_ptr->y, p_ptr->x) < 10) continue;
                                        if (c_ptr->info & CAVE_ICKY) continue;
                                        else break;
                                }

                                /* Failed to place */
                                if (!l) return FALSE;

                                /* Try to place the monster */
                                if (place_monster_aux(0, y, x, quest[i].r_idx, mode))
                                {
                                        /* Success */
                                        break;
                                }
                                else
                                {
                                        /* Failure - Try again */
                                        continue;
                                }
                        }

                        /* Failed to place */
                        if (k == SAFE_MAX_ATTEMPTS) return FALSE;
                }
        }

        return TRUE;
}


/*!
 * @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 c_ptr 永久壁を廃止したいマス構造体の参照ポインタ
 * @return なし
 */
static void set_bound_perm_wall(cave_type *c_ptr)
{
        if (bound_walls_perm)
        {
                /* Clear boundary mimic */
                c_ptr->mimic = 0;
        }
        else
        {
                feature_type *f_ptr = &f_info[c_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))
                        c_ptr->feat = feat_state(c_ptr->feat, FF_ENSECRET);

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

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

/*!
 * @brief フロアに洞窟や湖を配置する / Generate various caverns and lakes
 * @details There were moved from cave_gen().
 * @return なし
 */
static void gen_caverns_and_lakes(void)
{
#ifdef ALLOW_CAVERNS_AND_LAKES
        /* Possible "destroyed" level */
        if ((dun_level > 30) && one_in_(DUN_DEST*2) && (small_levels) && (d_info[dungeon_type].flags1 & DF1_DESTROY))
        {
                dun->destroyed = TRUE;

                /* extra rubble around the place looks cool */
                build_lake(one_in_(2) ? LAKE_T_CAVE : LAKE_T_EARTH_VAULT);
        }

        /* Make a lake some of the time */
        if (one_in_(LAKE_LEVEL) && !dun->empty_level && !dun->destroyed &&
            (d_info[dungeon_type].flags1 & DF1_LAKE_MASK))
        {
                int count = 0;
                if (d_info[dungeon_type].flags1 & DF1_LAKE_WATER) count += 3;
                if (d_info[dungeon_type].flags1 & DF1_LAKE_LAVA) count += 3;
                if (d_info[dungeon_type].flags1 & DF1_LAKE_RUBBLE) count += 3;
                if (d_info[dungeon_type].flags1 & DF1_LAKE_TREE) count += 3;

                if (d_info[dungeon_type].flags1 & DF1_LAKE_LAVA)
                {
                        /* Lake of Lava */
                        if ((dun_level > 80) && (randint0(count) < 2)) dun->laketype = LAKE_T_LAVA;
                        count -= 2;

                        /* Lake of Lava2 */
                        if (!dun->laketype && (dun_level > 80) && one_in_(count)) dun->laketype = LAKE_T_FIRE_VAULT;
                        count--;
                }

                if ((d_info[dungeon_type].flags1 & DF1_LAKE_WATER) && !dun->laketype)
                {
                        /* Lake of Water */
                        if ((dun_level > 50) && randint0(count) < 2) dun->laketype = LAKE_T_WATER;
                        count -= 2;

                        /* Lake of Water2 */
                        if (!dun->laketype && (dun_level > 50) && one_in_(count)) dun->laketype = LAKE_T_WATER_VAULT;
                        count--;
                }

                if ((d_info[dungeon_type].flags1 & DF1_LAKE_RUBBLE) && !dun->laketype)
                {
                        /* Lake of rubble */
                        if ((dun_level > 35) && (randint0(count) < 2)) dun->laketype = LAKE_T_CAVE;
                        count -= 2;

                        /* Lake of rubble2 */
                        if (!dun->laketype && (dun_level > 35) && one_in_(count)) dun->laketype = LAKE_T_EARTH_VAULT;
                        count--;
                }

                /* Lake of tree */
                if ((dun_level > 5) && (d_info[dungeon_type].flags1 & DF1_LAKE_TREE) && !dun->laketype) dun->laketype = LAKE_T_AIR_VAULT;

                if (dun->laketype)
                {
                        msg_print_wizard(CHEAT_DUNGEON, _("湖を生成します。", "Lake on the level."));
                        build_lake(dun->laketype);
                }
        }

        if ((dun_level > DUN_CAVERN) && !dun->empty_level &&
            (d_info[dungeon_type].flags1 & DF1_CAVERN) &&
            !dun->laketype && !dun->destroyed && (randint1(1000) < dun_level))
        {
                dun->cavern = TRUE;

                /* make a large fractal cave in the middle of the dungeon */

                msg_print_wizard(CHEAT_DUNGEON, _("洞窟を生成。", "Cavern on level."));
                build_cavern();
        }
#endif /* ALLOW_CAVERNS_AND_LAKES */

        /* Hack -- No destroyed "quest" levels */
        if (quest_number(dun_level)) dun->destroyed = FALSE;
}


/*!
 * @brief ダンジョン生成のメインルーチン / Generate a new dungeon level
 * @details Note that "dun_body" adds about 4000 bytes of memory to the stack.
 * @return ダンジョン生成が全て無事に成功したらTRUEを返す。
 */
static bool cave_gen(void)
{
        int i, k, y, x;

        dun_data dun_body;

        /* Global data */
        dun = &dun_body;

        dun->destroyed = FALSE;
        dun->empty_level = FALSE;
        dun->cavern = FALSE;
        dun->laketype = 0;

        /* Fill the arrays of floors and walls in the good proportions */
        set_floor_and_wall(dungeon_type);

        /* Prepare allocation table */
        get_mon_num_prep(get_monster_hook(), NULL);

        /* Randomize the dungeon creation values */
        dun_tun_rnd = rand_range(DUN_TUN_RND_MIN, DUN_TUN_RND_MAX);
        dun_tun_chg = rand_range(DUN_TUN_CHG_MIN, DUN_TUN_CHG_MAX);
        dun_tun_con = rand_range(DUN_TUN_CON_MIN, DUN_TUN_CON_MAX);
        dun_tun_pen = rand_range(DUN_TUN_PEN_MIN, DUN_TUN_PEN_MAX);
        dun_tun_jct = rand_range(DUN_TUN_JCT_MIN, DUN_TUN_JCT_MAX);

        /* Actual maximum number of rooms on this level */
        dun->row_rooms = cur_hgt / BLOCK_HGT;
        dun->col_rooms = cur_wid / BLOCK_WID;

        /* Initialize the room table */
        for (y = 0; y < dun->row_rooms; y++)
        {
                for (x = 0; x < dun->col_rooms; x++)
                {
                        dun->room_map[y][x] = FALSE;
                }
        }

        /* No rooms yet */
        dun->cent_n = 0;

        /* Empty arena levels */
        if (ironman_empty_levels || ((d_info[dungeon_type].flags1 & DF1_ARENA) && (empty_levels && one_in_(EMPTY_LEVEL))))
        {
                dun->empty_level = TRUE;
                msg_print_wizard(CHEAT_DUNGEON, _("アリーナレベルを生成。", "Arena level."));
        }

        if (dun->empty_level)
        {
                /* Start with floors */
                for (y = 0; y < cur_hgt; y++)
                {
                        for (x = 0; x < cur_wid; x++)
                        {
                                place_floor_bold(y, x);
                        }
                }

                /* Special boundary walls -- Top and bottom */
                for (x = 0; x < cur_wid; x++)
                {
                        place_extra_bold(0, x);
                        place_extra_bold(cur_hgt - 1, x);
                }

                /* Special boundary walls -- Left and right */
                for (y = 1; y < (cur_hgt - 1); y++)
                {
                        place_extra_bold(y, 0);
                        place_extra_bold(y, cur_wid - 1);
                }
        }
        else
        {
                /* Start with walls */
                for (y = 0; y < cur_hgt; y++)
                {
                        for (x = 0; x < cur_wid; x++)
                        {
                                place_extra_bold(y, x);
                        }
                }
        }


        /* Generate various caverns and lakes */
        gen_caverns_and_lakes();


        /* Build maze */
        if (d_info[dungeon_type].flags1 & DF1_MAZE)
        {
                build_maze_vault(cur_wid/2-1, cur_hgt/2-1, cur_wid-4, cur_hgt-4, FALSE);

                /* Place 3 or 4 down stairs near some walls */
                if (!alloc_stairs(feat_down_stair, rand_range(2, 3), 3)) return FALSE;

                /* Place 1 or 2 up stairs near some walls */
                if (!alloc_stairs(feat_up_stair, 1, 3)) return FALSE;
        }

        /* Build some rooms */
        else
        {
                int tunnel_fail_count = 0;

                /*
                 * Build each type of room in turn until we cannot build any more.
                 */
                if (!generate_rooms()) return FALSE;


                /* Make a hole in the dungeon roof sometimes at level 1 */
                if (dun_level == 1)
                {
                        while (one_in_(DUN_MOS_DEN))
                        {
                                place_trees(randint1(cur_wid - 2), randint1(cur_hgt - 2));
                        }
                }

                /* Destroy the level if necessary */
                if (dun->destroyed) destroy_level();

                /* Hack -- Add some rivers */
                if (one_in_(3) && (randint1(dun_level) > 5))
                {
                        IDX feat1 = 0, feat2 = 0;

                        /* Choose water or lava */
                        if ((randint1(MAX_DEPTH * 2) - 1 > dun_level) && (d_info[dungeon_type].flags1 & DF1_WATER_RIVER))
                        {
                                feat1 = feat_deep_water;
                                feat2 = feat_shallow_water;
                        }
                        else if  (d_info[dungeon_type].flags1 & DF1_LAVA_RIVER)
                        {
                                feat1 = feat_deep_lava;
                                feat2 = feat_shallow_lava;
                        }
                        else feat1 = 0;

                        if (feat1)
                        {
                                feature_type *f_ptr = &f_info[feat1];

                                /* Only add river if matches lake type or if have no lake at all */
                                if (((dun->laketype == LAKE_T_LAVA) && have_flag(f_ptr->flags, FF_LAVA)) ||
                                    ((dun->laketype == LAKE_T_WATER) && have_flag(f_ptr->flags, FF_WATER)) ||
                                     !dun->laketype)
                                {
                                        add_river(feat1, feat2);
                                }
                        }
                }

                /* Hack -- Scramble the room order */
                for (i = 0; i < dun->cent_n; i++)
                {
                        int ty, tx;
                        int pick = rand_range(0, i);

                        ty = dun->cent[i].y;
                        tx = dun->cent[i].x;
                        dun->cent[i].y = dun->cent[pick].y;
                        dun->cent[i].x = dun->cent[pick].x;
                        dun->cent[pick].y = ty;
                        dun->cent[pick].x = tx;
                }

                /* Start with no tunnel doors */
                dun->door_n = 0;

                /* Hack -- connect the first room to the last room */
                y = dun->cent[dun->cent_n-1].y;
                x = dun->cent[dun->cent_n-1].x;

                /* Connect all the rooms together */
                for (i = 0; i < dun->cent_n; i++)
                {
                        int j;

                        /* Reset the arrays */
                        dun->tunn_n = 0;
                        dun->wall_n = 0;

                        /* Connect the room to the previous room */
                        if (randint1(dun_level) > d_info[dungeon_type].tunnel_percent)
                        {
                                /* make cave-like tunnel */
                                (void)build_tunnel2(dun->cent[i].x, dun->cent[i].y, x, y, 2, 2);
                        }
                        else
                        {
                                /* make normal tunnel */
                                if (!build_tunnel(dun->cent[i].y, dun->cent[i].x, y, x)) tunnel_fail_count++;
                        }

                        if (tunnel_fail_count >= 2) return FALSE;

                        /* Turn the tunnel into corridor */
                        for (j = 0; j < dun->tunn_n; j++)
                        {
                                cave_type *c_ptr;
                                feature_type *f_ptr;
                                y = dun->tunn[j].y;
                                x = dun->tunn[j].x;
                                c_ptr = &cave[y][x];
                                f_ptr = &f_info[c_ptr->feat];

                                /* Clear previous contents (if not a lake), add a floor */
                                if (!have_flag(f_ptr->flags, FF_MOVE) || (!have_flag(f_ptr->flags, FF_WATER) && !have_flag(f_ptr->flags, FF_LAVA)))
                                {
                                        /* Clear mimic type */
                                        c_ptr->mimic = 0;

                                        place_floor_grid(c_ptr);
                                }
                        }

                        /* Apply the piercings that we found */
                        for (j = 0; j < dun->wall_n; j++)
                        {
                                cave_type *c_ptr;
                                y = dun->wall[j].y;
                                x = dun->wall[j].x;
                                c_ptr = &cave[y][x];

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

                                /* Clear previous contents, add up floor */
                                place_floor_grid(c_ptr);

                                /* Occasional doorway */
                                if ((randint0(100) < dun_tun_pen) && !(d_info[dungeon_type].flags1 & DF1_NO_DOORS))
                                {
                                        /* Place a random door */
                                        place_random_door(y, x, TRUE);
                                }
                        }

                        /* Remember the "previous" room */
                        y = dun->cent[i].y;
                        x = dun->cent[i].x;
                }

                /* Place intersection doors */
                for (i = 0; i < dun->door_n; i++)
                {
                        /* Extract junction location */
                        y = dun->door[i].y;
                        x = dun->door[i].x;

                        /* Try placing doors */
                        try_door(y, x - 1);
                        try_door(y, x + 1);
                        try_door(y - 1, x);
                        try_door(y + 1, x);
                }

                /* Place 3 or 4 down stairs near some walls */
                if (!alloc_stairs(feat_down_stair, rand_range(3, 4), 3)) return FALSE;

                /* Place 1 or 2 up stairs near some walls */
                if (!alloc_stairs(feat_up_stair, rand_range(1, 2), 3)) return FALSE;
        }

        if (!dun->laketype)
        {
                if (d_info[dungeon_type].stream2)
                {
                        /* Hack -- Add some quartz streamers */
                        for (i = 0; i < DUN_STR_QUA; i++)
                        {
                                build_streamer(d_info[dungeon_type].stream2, DUN_STR_QC);
                        }
                }

                if (d_info[dungeon_type].stream1)
                {
                        /* Hack -- Add some magma streamers */
                        for (i = 0; i < DUN_STR_MAG; i++)
                        {
                                build_streamer(d_info[dungeon_type].stream1, DUN_STR_MC);
                        }
                }
        }

        /* Special boundary walls -- Top and bottom */
        for (x = 0; x < cur_wid; x++)
        {
                set_bound_perm_wall(&cave[0][x]);
                set_bound_perm_wall(&cave[cur_hgt - 1][x]);
        }

        /* Special boundary walls -- Left and right */
        for (y = 1; y < (cur_hgt - 1); y++)
        {
                set_bound_perm_wall(&cave[y][0]);
                set_bound_perm_wall(&cave[y][cur_wid - 1]);
        }

        /* Determine the character location */
        if (!new_player_spot()) return FALSE;

        if (!place_quest_monsters()) return FALSE;

        /* Basic "amount" */
        k = (dun_level / 3);
        if (k > 10) k = 10;
        if (k < 2) k = 2;

        /* Pick a base number of monsters */
        i = d_info[dungeon_type].min_m_alloc_level;

        /* To make small levels a bit more playable */
        if (cur_hgt < MAX_HGT || cur_wid < MAX_WID)
        {
                int small_tester = i;

                i = (i * cur_hgt) / MAX_HGT;
                i = (i * cur_wid) / MAX_WID;
                i += 1;

                if (i > small_tester) i = small_tester;
                else msg_format_wizard(CHEAT_DUNGEON,
                        _("モンスター数基本値を %d から %d に減らします", "Reduced monsters base from %d to %d"), small_tester, i);

        }

        i += randint1(8);

        /* Put some monsters in the dungeon */
        for (i = i + k; i > 0; i--)
        {
                (void)alloc_monster(0, PM_ALLOW_SLEEP);
        }

        /* Place some traps in the dungeon */
        alloc_object(ALLOC_SET_BOTH, ALLOC_TYP_TRAP, randint1(k));

        /* Put some rubble in corridors (except NO_CAVE dungeon (Castle)) */
        if (!(d_info[dungeon_type].flags1 & DF1_NO_CAVE)) alloc_object(ALLOC_SET_CORR, ALLOC_TYP_RUBBLE, randint1(k));

        /* Mega Hack -- No object at first level of deeper dungeon */
        if (p_ptr->enter_dungeon && dun_level > 1)
        {
                /* No stair scum! */
                object_level = 1;
        }

        /* Put some objects in rooms */
        alloc_object(ALLOC_SET_ROOM, ALLOC_TYP_OBJECT, randnor(DUN_AMT_ROOM, 3));

        /* Put some objects/gold in the dungeon */
        alloc_object(ALLOC_SET_BOTH, ALLOC_TYP_OBJECT, randnor(DUN_AMT_ITEM, 3));
        alloc_object(ALLOC_SET_BOTH, ALLOC_TYP_GOLD, randnor(DUN_AMT_GOLD, 3));

        /* Set back to default */
        object_level = base_level;

        /* Put the Guardian */
        if (!alloc_guardian(TRUE)) return FALSE;

        if (dun->empty_level && (!one_in_(DARK_EMPTY) || (randint1(100) > dun_level)) && !(d_info[dungeon_type].flags1 & DF1_DARKNESS))
        {
                /* Lite the cave */
                for (y = 0; y < cur_hgt; y++)
                {
                        for (x = 0; x < cur_wid; x++)
                        {
                                cave[y][x].info |= (CAVE_GLOW);
                        }
                }
        }

        return TRUE;
}

/*!
 * @brief 闘技場用のアリーナ地形を作成する / Builds the arena after it is entered -KMW-
 * @return なし
 */
static void build_arena(void)
{
        POSITION yval, y_height, y_depth, xval, x_left, x_right;
        register int i, j;

        yval = SCREEN_HGT / 2;
        xval = SCREEN_WID / 2;
        y_height = yval - 10;
        y_depth = yval + 10;
        x_left = xval - 32;
        x_right = xval + 32;

        for (i = y_height; i <= y_height + 5; i++)
                for (j = x_left; j <= x_right; j++)
                {
                        place_extra_perm_bold(i, j);
                        cave[i][j].info |= (CAVE_GLOW | CAVE_MARK);
                }
        for (i = y_depth; i >= y_depth - 5; i--)
                for (j = x_left; j <= x_right; j++)
                {
                        place_extra_perm_bold(i, j);
                        cave[i][j].info |= (CAVE_GLOW | CAVE_MARK);
                }
        for (j = x_left; j <= x_left + 17; j++)
                for (i = y_height; i <= y_depth; i++)
                {
                        place_extra_perm_bold(i, j);
                        cave[i][j].info |= (CAVE_GLOW | CAVE_MARK);
                }
        for (j = x_right; j >= x_right - 17; j--)
                for (i = y_height; i <= y_depth; i++)
                {
                        place_extra_perm_bold(i, j);
                        cave[i][j].info |= (CAVE_GLOW | CAVE_MARK);
                }

        place_extra_perm_bold(y_height+6, x_left+18);
        cave[y_height+6][x_left+18].info |= (CAVE_GLOW | CAVE_MARK);
        place_extra_perm_bold(y_depth-6, x_left+18);
        cave[y_depth-6][x_left+18].info |= (CAVE_GLOW | CAVE_MARK);
        place_extra_perm_bold(y_height+6, x_right-18);
        cave[y_height+6][x_right-18].info |= (CAVE_GLOW | CAVE_MARK);
        place_extra_perm_bold(y_depth-6, x_right-18);
        cave[y_depth-6][x_right-18].info |= (CAVE_GLOW | CAVE_MARK);

        i = y_height + 5;
        j = xval;
        cave[i][j].feat = f_tag_to_index("ARENA_GATE");
        cave[i][j].info |= (CAVE_GLOW | CAVE_MARK);
        player_place(i, j);
}

/*!
 * @brief 闘技場への入場処理 / Town logic flow for generation of arena -KMW-
 * @return なし
 */
static void arena_gen(void)
{
        POSITION y, x;
        POSITION qy = 0;
        POSITION qx = 0;

        /* Smallest area */
        cur_hgt = SCREEN_HGT;
        cur_wid = SCREEN_WID;

        /* Start with solid walls */
        for (y = 0; y < MAX_HGT; y++)
        {
                for (x = 0; x < MAX_WID; x++)
                {
                        /* Create "solid" perma-wall */
                        place_solid_perm_bold(y, x);

                        /* Illuminate and memorize the walls */
                        cave[y][x].info |= (CAVE_GLOW | CAVE_MARK);
                }
        }

        /* Then place some floors */
        for (y = qy + 1; y < qy + SCREEN_HGT - 1; y++)
        {
                for (x = qx + 1; x < qx + SCREEN_WID - 1; x++)
                {
                        /* Create empty floor */
                        cave[y][x].feat = feat_floor;
                }
        }

        build_arena();

        if(!place_monster_aux(0, p_ptr->y + 5, p_ptr->x, arena_info[p_ptr->arena_number].r_idx, (PM_NO_KAGE | PM_NO_PET)))
        {
                p_ptr->exit_bldg = TRUE;
                p_ptr->arena_number++;
                msg_print(_("相手は欠場した。あなたの不戦勝だ。", "The enemy is unable appear. You won by default."));
        }

}

/*!
 * @brief モンスター闘技場のフロア生成 / Builds the arena after it is entered -KMW-
 * @return なし
 */
static void build_battle(void)
{
        POSITION yval, y_height, y_depth, xval, x_left, x_right;
        register int i, j;

        yval = SCREEN_HGT / 2;
        xval = SCREEN_WID / 2;
        y_height = yval - 10;
        y_depth = yval + 10;
        x_left = xval - 32;
        x_right = xval + 32;

        for (i = y_height; i <= y_height + 5; i++)
                for (j = x_left; j <= x_right; j++)
                {
                        place_extra_perm_bold(i, j);
                        cave[i][j].info |= (CAVE_GLOW | CAVE_MARK);
                }
        for (i = y_depth; i >= y_depth - 3; i--)
                for (j = x_left; j <= x_right; j++)
                {
                        place_extra_perm_bold(i, j);
                        cave[i][j].info |= (CAVE_GLOW | CAVE_MARK);
                }
        for (j = x_left; j <= x_left + 17; j++)
                for (i = y_height; i <= y_depth; i++)
                {
                        place_extra_perm_bold(i, j);
                        cave[i][j].info |= (CAVE_GLOW | CAVE_MARK);
                }
        for (j = x_right; j >= x_right - 17; j--)
                for (i = y_height; i <= y_depth; i++)
                {
                        place_extra_perm_bold(i, j);
                        cave[i][j].info |= (CAVE_GLOW | CAVE_MARK);
                }

        place_extra_perm_bold(y_height+6, x_left+18);
        cave[y_height+6][x_left+18].info |= (CAVE_GLOW | CAVE_MARK);
        place_extra_perm_bold(y_depth-4, x_left+18);
        cave[y_depth-4][x_left+18].info |= (CAVE_GLOW | CAVE_MARK);
        place_extra_perm_bold(y_height+6, x_right-18);
        cave[y_height+6][x_right-18].info |= (CAVE_GLOW | CAVE_MARK);
        place_extra_perm_bold(y_depth-4, x_right-18);
        cave[y_depth-4][x_right-18].info |= (CAVE_GLOW | CAVE_MARK);

        for (i = y_height + 1; i <= y_height + 5; i++)
                for (j = x_left + 20 + 2 * (y_height + 5 - i); j <= x_right - 20 - 2 * (y_height + 5 - i); j++)
                {
                        cave[i][j].feat = feat_permanent_glass_wall;
                }

        i = y_height + 1;
        j = xval;
        cave[i][j].feat = f_tag_to_index("BUILDING_3");
        cave[i][j].info |= (CAVE_GLOW | CAVE_MARK);
        player_place(i, j);
}

/*!
 * @brief モンスター闘技場への導入処理 / Town logic flow for generation of arena -KMW-
 * @return なし
 */
static void battle_gen(void)
{
        POSITION y, x;
        MONSTER_IDX i;
        POSITION qy = 0;
        POSITION qx = 0;

        /* Start with solid walls */
        for (y = 0; y < MAX_HGT; y++)
        {
                for (x = 0; x < MAX_WID; x++)
                {
                        /* Create "solid" perma-wall */
                        place_solid_perm_bold(y, x);

                        /* Illuminate and memorize the walls */
                        cave[y][x].info |= (CAVE_GLOW | CAVE_MARK);
                }
        }

        /* Then place some floors */
        for (y = qy + 1; y < qy + SCREEN_HGT - 1; y++)
        {
                for (x = qx + 1; x < qx + SCREEN_WID - 1; x++)
                {
                        /* Create empty floor */
                        cave[y][x].feat = feat_floor;
                }
        }

        build_battle();

        for(i = 0; i < 4; i++)
        {
                place_monster_aux(0, p_ptr->y + 8 + (i/2)*4, p_ptr->x - 2 + (i%2)*4, battle_mon[i],
                                  (PM_NO_KAGE | PM_NO_PET));
                set_friendly(&m_list[cave[p_ptr->y+8+(i/2)*4][p_ptr->x-2+(i%2)*4].m_idx]);
        }
        for(i = 1; i < m_max; i++)
        {
                monster_type *m_ptr = &m_list[i];

                if (!m_ptr->r_idx) continue;

                /* Hack -- Detect monster */
                m_ptr->mflag2 |= (MFLAG2_MARK | MFLAG2_SHOW);
                update_monster(i, FALSE);
        }
}

/*!
 * @brief 固定マップクエストのフロア生成 / Generate a quest level
 * @return なし
 */
static void quest_gen(void)
{
        POSITION x, y;


        /* Start with perm walls */
        for (y = 0; y < cur_hgt; y++)
        {
                for (x = 0; x < cur_wid; x++)
                {
                        place_solid_perm_bold(y, x);
                }
        }

        /* Set the quest level */
        base_level = quest[p_ptr->inside_quest].level;
        dun_level = base_level;
        object_level = base_level;
        monster_level = base_level;

        if (record_stair) do_cmd_write_nikki(NIKKI_TO_QUEST, p_ptr->inside_quest, NULL);

        /* Prepare allocation table */
        get_mon_num_prep(get_monster_hook(), NULL);

        init_flags = INIT_CREATE_DUNGEON;

        process_dungeon_file("q_info.txt", 0, 0, MAX_HGT, MAX_WID);
}

/*!
 * @brief ダンジョン時のランダムフロア生成 / Make a real level
 * @return フロアの生成に成功したらTRUE
 */
static bool level_gen(cptr *why)
{
        int level_height, level_width;

        if ((always_small_levels || ironman_small_levels ||
            (one_in_(SMALL_LEVEL) && small_levels) ||
             (d_info[dungeon_type].flags1 & DF1_BEGINNER) ||
            (d_info[dungeon_type].flags1 & DF1_SMALLEST)) &&
            !(d_info[dungeon_type].flags1 & DF1_BIG))
        {
                if (d_info[dungeon_type].flags1 & DF1_SMALLEST)
                {
                        level_height = 1;
                        level_width = 1;
                }
                else if (d_info[dungeon_type].flags1 & DF1_BEGINNER)
                {
                        level_height = 2;
                        level_width = 2;
                }
                else
                {
                        do
                        {
                                level_height = randint1(MAX_HGT/SCREEN_HGT);
                                level_width = randint1(MAX_WID/SCREEN_WID);
                        }
                        while ((level_height == MAX_HGT/SCREEN_HGT) &&
                                   (level_width == MAX_WID/SCREEN_WID));
                }

                cur_hgt = level_height * SCREEN_HGT;
                cur_wid = level_width * SCREEN_WID;

                /* Assume illegal panel */
                panel_row_min = cur_hgt;
                panel_col_min = cur_wid;

                msg_format_wizard(CHEAT_DUNGEON,
                        _("小さなフロア: X:%d, Y:%d", "A 'small' dungeon level: X:%d, Y:%d."),
                        cur_wid, cur_hgt);
        }
        else
        {
                /* Big dungeon */
                cur_hgt = MAX_HGT;
                cur_wid = MAX_WID;

                /* Assume illegal panel */
                panel_row_min = cur_hgt;
                panel_col_min = cur_wid;
        }

        /* Make a dungeon */
        if (!cave_gen())
        {
#ifdef JP
*why = "ダンジョン生成に失敗";
#else
                *why = "could not place player";
#endif

                return FALSE;
        }
        else return TRUE;
}

/*!
 * @brief フロアに存在する全マスの記憶状態を初期化する / Wipe all unnecessary flags after cave generation
 * @return なし
 */
void wipe_generate_cave_flags(void)
{
        POSITION x, y;

        for (y = 0; y < cur_hgt; y++)
        {
                for (x = 0; x < cur_wid; x++)
                {
                        /* Wipe unused flags */
                        cave[y][x].info &= ~(CAVE_MASK);
                }
        }

        if (dun_level)
        {
                for (y = 1; y < cur_hgt - 1; y++)
                {
                        for (x = 1; x < cur_wid - 1; x++)
                        {
                                /* There might be trap */
                                cave[y][x].info |= CAVE_UNSAFE;
                        }
                }
        }
}

/*!
 * @brief フロアの全情報を初期化する / Clear and empty the cave
 * @return なし
 */
void clear_cave(void)
{
        POSITION x, y;
        int i;

        /* Very simplified version of wipe_o_list() */
        (void)C_WIPE(o_list, o_max, object_type);
        o_max = 1;
        o_cnt = 0;

        /* Very simplified version of wipe_m_list() */
        for (i = 1; i < max_r_idx; i++)
                r_info[i].cur_num = 0;
        (void)C_WIPE(m_list, m_max, monster_type);
        m_max = 1;
        m_cnt = 0;
        for (i = 0; i < MAX_MTIMED; i++) mproc_max[i] = 0;

        /* Pre-calc cur_num of pets in party_mon[] */
        precalc_cur_num_of_pet();


        /* Start with a blank cave */
        for (y = 0; y < MAX_HGT; y++)
        {
                for (x = 0; x < MAX_WID; x++)
                {
                        cave_type *c_ptr = &cave[y][x];

                        /* No flags */
                        c_ptr->info = 0;

                        /* No features */
                        c_ptr->feat = 0;

                        /* No objects */
                        c_ptr->o_idx = 0;

                        /* No monsters */
                        c_ptr->m_idx = 0;

                        /* No special */
                        c_ptr->special = 0;

                        /* No mimic */
                        c_ptr->mimic = 0;

                        /* No flow */
                        c_ptr->cost = 0;
                        c_ptr->dist = 0;
                        c_ptr->when = 0;
                }
        }

        /* Mega-Hack -- no player yet */
        p_ptr->x = p_ptr->y = 0;

        /* Set the base level */
        base_level = dun_level;

        /* Reset the monster generation level */
        monster_level = base_level;

        /* Reset the object generation level */
        object_level = base_level;
}


/*!
 * ダンジョンのランダムフロアを生成する / Generates a random dungeon level -RAK-
 * @return なし
 * @note Hack -- regenerate any "overflow" levels
 */
void generate_cave(void)
{
        int num;

        /* Fill the arrays of floors and walls in the good proportions */
        set_floor_and_wall(dungeon_type);

        /* Generate */
        for (num = 0; TRUE; num++)
        {
                bool okay = TRUE;

                cptr why = NULL;

                /* Clear and empty the cave */
                clear_cave();

                /* Build the arena -KMW- */
                if (p_ptr->inside_arena)
                {
                        /* Small arena */
                        arena_gen();
                }

                /* Build the battle -KMW- */
                else if (p_ptr->inside_battle)
                {
                        /* Small arena */
                        battle_gen();
                }

                else if (p_ptr->inside_quest)
                {
                        quest_gen();
                }

                /* Build the town */
                else if (!dun_level)
                {
                        /* Make the wilderness */
                        if (p_ptr->wild_mode) wilderness_gen_small();
                        else wilderness_gen();
                }

                /* Build a real level */
                else
                {
                        okay = level_gen(&why);
                }


                /* Prevent object over-flow */
                if (o_max >= max_o_idx)
                {
#ifdef JP
why = "アイテムが多すぎる";
#else
                        why = "too many objects";
#endif


                        okay = FALSE;
                }
                /* Prevent monster over-flow */
                else if (m_max >= max_m_idx)
                {
#ifdef JP
why = "モンスターが多すぎる";
#else
                        why = "too many monsters";
#endif


                        okay = FALSE;
                }

                /* Accept */
                if (okay) break;

#ifdef JP
if (why) msg_format("生成やり直し(%s)", why);
#else
                if (why) msg_format("Generation restarted (%s)", why);
#endif


                /* Wipe the objects */
                wipe_o_list();

                /* Wipe the monsters */
                wipe_m_list();
        }

        /* Glow deep lava and building entrances */
        glow_deep_lava_and_bldg();

        /* Reset flag */
        p_ptr->enter_dungeon = FALSE;

        wipe_generate_cave_flags();
}

/*!
* @brief 部屋間のトンネルを生成する / Constructs a tunnel between two points
* @param row1 始点Y座標
* @param col1 始点X座標
* @param row2 終点Y座標
* @param col2 終点X座標
* @return 生成に成功したらTRUEを返す
* @details
* This function must be called BEFORE any streamers are created,\n
* since we use the special "granite wall" sub-types to keep track\n
* of legal places for corridors to pierce rooms.\n
*\n
* We use "door_flag" to prevent excessive construction of doors\n
* along overlapping corridors.\n
*\n
* We queue the tunnel grids to prevent door creation along a corridor\n
* which intersects itself.\n
*\n
* We queue the wall piercing grids to prevent a corridor from leaving\n
* a room and then coming back in through the same entrance.\n
*\n
* We "pierce" grids which are "outer" walls of rooms, and when we\n
* do so, we change all adjacent "outer" walls of rooms into "solid"\n
* walls so that no two corridors may use adjacent grids for exits.\n
*\n
* The "solid" wall check prevents corridors from "chopping" the\n
* corners of rooms off, as well as "silly" door placement, and\n
* "excessively wide" room entrances.\n
*\n
* Kind of walls:\n
*   extra -- walls\n
*   inner -- inner room walls\n
*   outer -- outer room walls\n
*   solid -- solid room walls\n
*/
bool build_tunnel(POSITION row1, POSITION col1, POSITION row2, POSITION col2)
{
        POSITION y, x;
        POSITION tmp_row, tmp_col;
        DIRECTION row_dir, col_dir;
        POSITION start_row, start_col;
        int main_loop_count = 0;

        bool door_flag = FALSE;

        cave_type *c_ptr;

        /* Save the starting location */
        start_row = row1;
        start_col = col1;

        /* Start out in the correct direction */
        correct_dir(&row_dir, &col_dir, row1, col1, row2, col2);

        /* Keep going until done (or bored) */
        while ((row1 != row2) || (col1 != col2))
        {
                /* Mega-Hack -- Paranoia -- prevent infinite loops */
                if (main_loop_count++ > 2000) return FALSE;

                /* Allow bends in the tunnel */
                if (randint0(100) < dun_tun_chg)
                {
                        /* Acquire the correct direction */
                        correct_dir(&row_dir, &col_dir, row1, col1, row2, col2);

                        /* Random direction */
                        if (randint0(100) < dun_tun_rnd)
                        {
                                rand_dir(&row_dir, &col_dir);
                        }
                }

                /* Get the next location */
                tmp_row = row1 + row_dir;
                tmp_col = col1 + col_dir;


                /* Extremely Important -- do not leave the dungeon */
                while (!in_bounds(tmp_row, tmp_col))
                {
                        /* Acquire the correct direction */
                        correct_dir(&row_dir, &col_dir, row1, col1, row2, col2);

                        /* Random direction */
                        if (randint0(100) < dun_tun_rnd)
                        {
                                rand_dir(&row_dir, &col_dir);
                        }

                        /* Get the next location */
                        tmp_row = row1 + row_dir;
                        tmp_col = col1 + col_dir;
                }


                /* Access the location */
                c_ptr = &cave[tmp_row][tmp_col];

                /* Avoid "solid" walls */
                if (is_solid_grid(c_ptr)) continue;

                /* Pierce "outer" walls of rooms */
                if (is_outer_grid(c_ptr))
                {
                        /* Acquire the "next" location */
                        y = tmp_row + row_dir;
                        x = tmp_col + col_dir;

                        /* Hack -- Avoid outer/solid walls */
                        if (is_outer_bold(y, x)) continue;
                        if (is_solid_bold(y, x)) continue;

                        /* Accept this location */
                        row1 = (POSITION)tmp_row;
                        col1 = (POSITION)tmp_col;

                        /* Save the wall location */
                        if (dun->wall_n < WALL_MAX)
                        {
                                dun->wall[dun->wall_n].y = row1;
                                dun->wall[dun->wall_n].x = col1;
                                dun->wall_n++;
                        }
                        else return FALSE;

                        /* Forbid re-entry near this piercing */
                        for (y = row1 - 1; y <= row1 + 1; y++)
                        {
                                for (x = col1 - 1; x <= col1 + 1; x++)
                                {
                                        /* Convert adjacent "outer" walls as "solid" walls */
                                        if (is_outer_bold(y, x))
                                        {
                                                /* Change the wall to a "solid" wall */
                                                place_solid_noperm_bold(y, x);
                                        }
                                }
                        }
                }

                /* Travel quickly through rooms */
                else if (c_ptr->info & (CAVE_ROOM))
                {
                        /* Accept the location */
                        row1 = tmp_row;
                        col1 = tmp_col;
                }

                /* Tunnel through all other walls */
                else if (is_extra_grid(c_ptr) || is_inner_grid(c_ptr) || is_solid_grid(c_ptr))
                {
                        /* Accept this location */
                        row1 = tmp_row;
                        col1 = tmp_col;

                        /* Save the tunnel location */
                        if (dun->tunn_n < TUNN_MAX)
                        {
                                dun->tunn[dun->tunn_n].y = row1;
                                dun->tunn[dun->tunn_n].x = col1;
                                dun->tunn_n++;
                        }
                        else return FALSE;

                        /* Allow door in next grid */
                        door_flag = FALSE;
                }

                /* Handle corridor intersections or overlaps */
                else
                {
                        /* Accept the location */
                        row1 = tmp_row;
                        col1 = tmp_col;

                        /* Collect legal door locations */
                        if (!door_flag)
                        {
                                /* Save the door location */
                                if (dun->door_n < DOOR_MAX)
                                {
                                        dun->door[dun->door_n].y = row1;
                                        dun->door[dun->door_n].x = col1;
                                        dun->door_n++;
                                }
                                else return FALSE;

                                /* No door in next grid */
                                door_flag = TRUE;
                        }

                        /* Hack -- allow pre-emptive tunnel termination */
                        if (randint0(100) >= dun_tun_con)
                        {
                                /* Distance between row1 and start_row */
                                tmp_row = row1 - start_row;
                                if (tmp_row < 0) tmp_row = (-tmp_row);

                                /* Distance between col1 and start_col */
                                tmp_col = col1 - start_col;
                                if (tmp_col < 0) tmp_col = (-tmp_col);

                                /* Terminate the tunnel */
                                if ((tmp_row > 10) || (tmp_col > 10)) break;
                        }
                }
        }

        return TRUE;
}


/*!
* @brief トンネル生成のための基準点を指定する。
* @param x 基準点を指定するX座標の参照ポインタ、適時値が修正される。
* @param y 基準点を指定するY座標の参照ポインタ、適時値が修正される。
* @param affectwall (調査中)
* @return なし
* @details
* This routine adds the square to the tunnel\n
* It also checks for SOLID walls - and returns a nearby\n
* non-SOLID square in (x,y) so that a simple avoiding\n
* routine can be used. The returned boolean value reflects\n
* whether or not this routine hit a SOLID wall.\n
*\n
* "affectwall" toggles whether or not this new square affects\n
* the boundaries of rooms. - This is used by the catacomb\n
* routine.\n
* @todo 特に詳細な処理の意味を調査すべし
*/
static bool set_tunnel(POSITION *x, POSITION *y, bool affectwall)
{
        int i, j, dx, dy;

        cave_type *c_ptr = &cave[*y][*x];

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

        if (is_inner_grid(c_ptr))
        {
                return TRUE;
        }

        if (is_extra_bold(*y, *x))
        {
                /* Save the tunnel location */
                if (dun->tunn_n < TUNN_MAX)
                {
                        dun->tunn[dun->tunn_n].y = *y;
                        dun->tunn[dun->tunn_n].x = *x;
                        dun->tunn_n++;

                        return TRUE;
                }
                else return FALSE;
        }

        if (is_floor_bold(*y, *x))
        {
                /* Don't do anything */
                return TRUE;
        }

        if (is_outer_grid(c_ptr) && affectwall)
        {
                /* Save the wall location */
                if (dun->wall_n < WALL_MAX)
                {
                        dun->wall[dun->wall_n].y = *y;
                        dun->wall[dun->wall_n].x = *x;
                        dun->wall_n++;
                }
                else return FALSE;

                /* Forbid re-entry near this piercing */
                for (j = *y - 1; j <= *y + 1; j++)
                {
                        for (i = *x - 1; i <= *x + 1; i++)
                        {
                                /* Convert adjacent "outer" walls as "solid" walls */
                                if (is_outer_bold(j, i))
                                {
                                        /* Change the wall to a "solid" wall */
                                        place_solid_noperm_bold(j, i);
                                }
                        }
                }

                /* Clear mimic type */
                cave[*y][*x].mimic = 0;

                place_floor_bold(*y, *x);

                return TRUE;
        }

        if (is_solid_grid(c_ptr) && affectwall)
        {
                /* cannot place tunnel here - use a square to the side */

                /* find usable square and return value in (x,y) */

                i = 50;

                dy = 0;
                dx = 0;
                while ((i > 0) && is_solid_bold(*y + dy, *x + dx))
                {
                        dy = randint0(3) - 1;
                        dx = randint0(3) - 1;

                        if (!in_bounds(*y + dy, *x + dx))
                        {
                                dx = 0;
                                dy = 0;
                        }

                        i--;
                }

                if (i == 0)
                {
                        /* Failed for some reason: hack - ignore the solidness */
                        place_outer_grid(c_ptr);
                        dx = 0;
                        dy = 0;
                }

                /* Give new, acceptable coordinate. */
                *x = *x + dx;
                *y = *y + dy;

                return FALSE;
        }

        return TRUE;
}


/*!
* @brief 外壁を削って「カタコンベ状」の通路を作成する / This routine creates the catacomb-like tunnels by removing extra rock.
* @param x 基準点のX座標
* @param y 基準点のY座標
* @return なし
* @details
* Note that this routine is only called on "even" squares - so it gives
* a natural checkerboard pattern.
*/
static void create_cata_tunnel(POSITION x, POSITION y)
{
        POSITION x1, y1;

        /* Build tunnel */
        x1 = x - 1;
        y1 = y;
        set_tunnel(&x1, &y1, FALSE);

        x1 = x + 1;
        y1 = y;
        set_tunnel(&x1, &y1, FALSE);

        x1 = x;
        y1 = y - 1;
        set_tunnel(&x1, &y1, FALSE);

        x1 = x;
        y1 = y + 1;
        set_tunnel(&x1, &y1, FALSE);
}


/*!
* @brief トンネル生成処理（詳細調査中）/ This routine does the bulk of the work in creating the new types of tunnels.
* @return なし
* @todo 詳細用調査
* @details
* It is designed to use very simple algorithms to go from (x1,y1) to (x2,y2)\n
* It doesn't need to add any complexity - straight lines are fine.\n
* The SOLID walls are avoided by a recursive algorithm which tries random ways\n
* around the obstical until it works.  The number of itterations is counted, and it\n
* this gets too large the routine exits. This should stop any crashes - but may leave\n
* small gaps in the tunnel where there are too many SOLID walls.\n
*\n
* Type 1 tunnels are extremely simple - straight line from A to B.  This is only used\n
* as a part of the dodge SOLID walls algorithm.\n
*\n
* Type 2 tunnels are made of two straight lines at right angles. When this is used with\n
* short line segments it gives the "cavelike" tunnels seen deeper in the dungeon.\n
*\n
* Type 3 tunnels are made of two straight lines like type 2, but with extra rock removed.\n
* This, when used with longer line segments gives the "catacomb-like" tunnels seen near\n
* the surface.\n
*/
static void short_seg_hack(POSITION x1, POSITION y1, POSITION x2, POSITION y2, int type, int count, bool *fail)
{
        int i;
        POSITION x, y;
        int length;

        /* Check for early exit */
        if (!(*fail)) return;

        length = distance(x1, y1, x2, y2);

        count++;

        if ((type == 1) && (length != 0))
        {

                for (i = 0; i <= length; i++)
                {
                        x = x1 + i * (x2 - x1) / length;
                        y = y1 + i * (y2 - y1) / length;
                        if (!set_tunnel(&x, &y, TRUE))
                        {
                                if (count > 50)
                                {
                                        /* This isn't working - probably have an infinite loop */
                                        *fail = FALSE;
                                        return;
                                }

                                /* solid wall - so try to go around */
                                short_seg_hack(x, y, x1 + (i - 1) * (x2 - x1) / length, y1 + (i - 1) * (y2 - y1) / length, 1, count, fail);
                                short_seg_hack(x, y, x1 + (i + 1) * (x2 - x1) / length, y1 + (i + 1) * (y2 - y1) / length, 1, count, fail);
                        }
                }
        }
        else if ((type == 2) || (type == 3))
        {
                if (x1 < x2)
                {
                        for (i = x1; i <= x2; i++)
                        {
                                x = i;
                                y = y1;
                                if (!set_tunnel(&x, &y, TRUE))
                                {
                                        /* solid wall - so try to go around */
                                        short_seg_hack(x, y, i - 1, y1, 1, count, fail);
                                        short_seg_hack(x, y, i + 1, y1, 1, count, fail);
                                }
                                if ((type == 3) && ((x + y) % 2))
                                {
                                        create_cata_tunnel(i, y1);
                                }
                        }
                }
                else
                {
                        for (i = x2; i <= x1; i++)
                        {
                                x = i;
                                y = y1;
                                if (!set_tunnel(&x, &y, TRUE))
                                {
                                        /* solid wall - so try to go around */
                                        short_seg_hack(x, y, i - 1, y1, 1, count, fail);
                                        short_seg_hack(x, y, i + 1, y1, 1, count, fail);
                                }
                                if ((type == 3) && ((x + y) % 2))
                                {
                                        create_cata_tunnel(i, y1);
                                }
                        }

                }
                if (y1 < y2)
                {
                        for (i = y1; i <= y2; i++)
                        {
                                x = x2;
                                y = i;
                                if (!set_tunnel(&x, &y, TRUE))
                                {
                                        /* solid wall - so try to go around */
                                        short_seg_hack(x, y, x2, i - 1, 1, count, fail);
                                        short_seg_hack(x, y, x2, i + 1, 1, count, fail);
                                }
                                if ((type == 3) && ((x + y) % 2))
                                {
                                        create_cata_tunnel(x2, i);
                                }
                        }
                }
                else
                {
                        for (i = y2; i <= y1; i++)
                        {
                                x = x2;
                                y = i;
                                if (!set_tunnel(&x, &y, TRUE))
                                {
                                        /* solid wall - so try to go around */
                                        short_seg_hack(x, y, x2, i - 1, 1, count, fail);
                                        short_seg_hack(x, y, x2, i + 1, 1, count, fail);
                                }
                                if ((type == 3) && ((x + y) % 2))
                                {
                                        create_cata_tunnel(x2, i);
                                }
                        }
                }
        }
}


/*!
* @brief 特定の壁(永久壁など)を避けながら部屋間の通路を作成する / This routine maps a path from (x1, y1) to (x2, y2) avoiding SOLID walls.
* @return なし
* @todo 詳細要調査
* @details
* Permanent rock is ignored in this path finding- sometimes there is no\n
* path around anyway -so there will be a crash if we try to find one.\n
* This routine is much like the river creation routine in Zangband.\n
* It works by dividing a line segment into two.  The segments are divided\n
* until they are less than "cutoff" - when the corresponding routine from\n
* "short_seg_hack" is called.\n
* Note it is VERY important that the "stop if hit another passage" logic\n
* stays as is.  Without this the dungeon turns into Swiss Cheese...\n
*/
bool build_tunnel2(POSITION x1, POSITION y1, POSITION x2, POSITION y2, int type, int cutoff)
{
        POSITION x3, y3, dx, dy;
        POSITION changex, changey;
        int length;
        int i;
        bool retval, firstsuccede;
        cave_type *c_ptr;

        length = distance(x1, y1, x2, y2);

        if (length > cutoff)
        {
                /*
                * Divide path in half and call routine twice.
                */
                dx = (x2 - x1) / 2;
                dy = (y2 - y1) / 2;

                /* perturbation perpendicular to path */
                changex = (randint0(abs(dy) + 2) * 2 - abs(dy) - 1) / 2;
                changey = (randint0(abs(dx) + 2) * 2 - abs(dx) - 1) / 2;

                /* Work out "mid" ponit */
                x3 = x1 + dx + changex;
                y3 = y1 + dy + changey;

                /* See if in bounds - if not - do not perturb point */
                if (!in_bounds(y3, x3))
                {
                        x3 = (x1 + x2) / 2;
                        y3 = (y1 + y2) / 2;
                }
                /* cache c_ptr */
                c_ptr = &cave[y3][x3];
                if (is_solid_grid(c_ptr))
                {
                        /* move midpoint a bit to avoid problem. */

                        i = 50;

                        dy = 0;
                        dx = 0;
                        while ((i > 0) && is_solid_bold(y3 + dy, x3 + dx))
                        {
                                dy = randint0(3) - 1;
                                dx = randint0(3) - 1;
                                if (!in_bounds(y3 + dy, x3 + dx))
                                {
                                        dx = 0;
                                        dy = 0;
                                }
                                i--;
                        }

                        if (i == 0)
                        {
                                /* Failed for some reason: hack - ignore the solidness */
                                place_outer_bold(y3, x3);
                                dx = 0;
                                dy = 0;
                        }
                        y3 += dy;
                        x3 += dx;
                        c_ptr = &cave[y3][x3];
                }

                if (is_floor_grid(c_ptr))
                {
                        if (build_tunnel2(x1, y1, x3, y3, type, cutoff))
                        {
                                if ((cave[y3][x3].info & CAVE_ROOM) || (randint1(100) > 95))
                                {
                                        /* do second half only if works + if have hit a room */
                                        retval = build_tunnel2(x3, y3, x2, y2, type, cutoff);
                                }
                                else
                                {
                                        /* have hit another tunnel - make a set of doors here */
                                        retval = FALSE;

                                        /* Save the door location */
                                        if (dun->door_n < DOOR_MAX)
                                        {
                                                dun->door[dun->door_n].y = (POSITION)y3;
                                                dun->door[dun->door_n].x = (POSITION)x3;
                                                dun->door_n++;
                                        }
                                        else return FALSE;
                                }
                                firstsuccede = TRUE;
                        }
                        else
                        {
                                /* false- didn't work all the way */
                                retval = FALSE;
                                firstsuccede = FALSE;
                        }
                }
                else
                {
                        /* tunnel through walls */
                        if (build_tunnel2(x1, y1, (POSITION)x3, (POSITION)y3, type, cutoff))
                        {
                                retval = build_tunnel2((POSITION)x3, (POSITION)y3, x2, y2, type, cutoff);
                                firstsuccede = TRUE;
                        }
                        else
                        {
                                /* false- didn't work all the way */
                                retval = FALSE;
                                firstsuccede = FALSE;
                        }
                }
                if (firstsuccede)
                {
                        /* only do this if the first half has worked */
                        set_tunnel(&x3, &y3, TRUE);
                }
                /* return value calculated above */
                return retval;
        }
        else
        {
                /* Do a short segment */
                retval = TRUE;
                short_seg_hack(x1, y1, x2, y2, type, 0, &retval);

                /* Hack - ignore return value so avoid infinite loops */
                return TRUE;
        }
}