root/trunk/src/trap.c

/*
 * File: trap.c
 * Purpose: Trap triggering, selection, and placement
 *
 * Copyright (c) 1997 Ben Harrison, James E. Wilson, Robert A. Koeneke
 *
 * This work is free software; you can redistribute it and/or modify it
 * under the terms of either:
 *
 * a) the GNU General Public License as published by the Free Software
 *    Foundation, version 2, or
 *
 * b) the "Angband licence":
 *    This software may be copied and distributed for educational, research,
 *    and not for profit purposes provided that this copyright and statement
 *    are included in all such copies.  Other copyrights may also apply.
 */
#include "angband.h"


/*
 * Determine if a trap affects the player.
 * Always miss 5% of the time, Always hit 5% of the time.
 * Otherwise, match trap power against player armor.
 */
static bool check_hit(int power)
{
        return test_hit(power, p_ptr->ac + p_ptr->to_a, TRUE);
}


/*
 * Hack -- instantiate a trap
 *
 * XXX XXX XXX This routine should be redone to reflect trap "level".
 * That is, it does not make sense to have spiked pits at 50 feet.
 * Actually, it is not this routine, but the "trap instantiation"
 * code, which should also check for "trap doors" on quest levels.
 */
void pick_trap(int y, int x)
{
        int feat;

        const static int min_level[] =
        {
                2,              /* Trap door */
                2,              /* Open pit */
                2,              /* Spiked pit */
                2,              /* Poison pit */
                3,              /* Summoning rune */
                1,              /* Teleport rune */
                2,              /* Fire rune */
                2,              /* Acid rune */
                2,              /* Slow rune */
                6,              /* Strength dart */
                6,              /* Dexterity dart */
                6,              /* Constitution dart */
                2,              /* Gas blind */
                1,              /* Gas confuse */
                2,              /* Gas poison */
                2,              /* Gas sleep */
        };

        /* Paranoia */
        if (cave_feat[y][x] != FEAT_INVIS) return;

        /* Pick a trap */
        while (1)
        {
                /* Hack -- pick a trap */
                feat = FEAT_TRAP_HEAD + randint0(16);

                /* Check against minimum depth */
                if (min_level[feat - FEAT_TRAP_HEAD] > p_ptr->depth) continue;

                /* Hack -- no trap doors on quest levels */
                if ((feat == FEAT_TRAP_HEAD + 0x00) && is_quest(p_ptr->depth)) continue;

                /* Hack -- no trap doors on the deepest level */
                if ((feat == FEAT_TRAP_HEAD + 0x00) && (p_ptr->depth >= MAX_DEPTH-1)) continue;

                /* Done */
                break;
        }

        /* Activate the trap */
        cave_set_feat(y, x, feat);
}



/*
 * Places a random trap at the given location.
 *
 * The location must be a legal, naked, floor grid.
 *
 * Note that all traps start out as "invisible" and "untyped", and then
 * when they are "discovered" (by detecting them or setting them off),
 * the trap is "instantiated" as a visible, "typed", trap.
 */
void place_trap(int y, int x)
{
        /* Paranoia */
        if (!in_bounds(y, x)) return;

        /* Require empty, clean, floor grid */
        if (!cave_naked_bold(y, x)) return;

        /* Place an invisible trap */
        cave_set_feat(y, x, FEAT_INVIS);
}




/*
 * Handle player hitting a real trap
 */
void hit_trap(int y, int x)
{
        int i, num, dam;

        cptr name = "a trap";


        /* Disturb the player */
        disturb(0, 0);

        /* Analyze XXX XXX XXX */
        switch (cave_feat[y][x])
        {
                case FEAT_TRAP_HEAD + 0x00:
                {
                        msg_print("You fall through a trap door!");
                        if (p_ptr->ffall)
                        {
                                msg_print("You float gently down to the next level.");
                        }
                        else
                        {
                                dam = damroll(2, 8);
                                take_hit(dam, name);
                        }

                        /* New depth */
                        p_ptr->depth++;

                        /* Leaving */
                        p_ptr->leaving = TRUE;
                        
                        /* Don't generate connected stairs */
                        p_ptr->create_down_stair = FALSE;
                        p_ptr->create_up_stair = FALSE;

                        break;
                }

                case FEAT_TRAP_HEAD + 0x01:
                {
                        msg_print("You fall into a pit!");
                        if (p_ptr->ffall)
                        {
                                msg_print("You float gently to the bottom of the pit.");
                        }
                        else
                        {
                                dam = damroll(2, 6);
                                take_hit(dam, name);
                        }
                        break;
                }

                case FEAT_TRAP_HEAD + 0x02:
                {
                        msg_print("You fall into a spiked pit!");

                        if (p_ptr->ffall)
                        {
                                msg_print("You float gently to the floor of the pit.");
                                msg_print("You carefully avoid touching the spikes.");
                        }

                        else
                        {
                                /* Base damage */
                                dam = damroll(2, 6);

                                /* Extra spike damage */
                                if (one_in_(2))
                                {
                                        msg_print("You are impaled!");

                                        dam = dam * 2;
                                        (void)inc_timed(TMD_CUT, randint1(dam));
                                }

                                /* Take the damage */
                                take_hit(dam, name);
                        }
                        break;
                }

                case FEAT_TRAP_HEAD + 0x03:
                {
                        msg_print("You fall into a spiked pit!");

                        if (p_ptr->ffall)
                        {
                                msg_print("You float gently to the floor of the pit.");
                                msg_print("You carefully avoid touching the spikes.");
                        }

                        else
                        {
                                /* Base damage */
                                dam = damroll(2, 6);

                                /* Extra spike damage */
                                if (one_in_(2))
                                {
                                        msg_print("You are impaled on poisonous spikes!");

                                        dam = dam * 2;
                                        (void)inc_timed(TMD_CUT, randint1(dam));

                                        if (p_ptr->resist_pois || p_ptr->timed[TMD_OPP_POIS])
                                        {
                                                msg_print("The poison does not affect you!");
                                        }
                                        else
                                        {
                                                dam = dam * 2;
                                                (void)inc_timed(TMD_POISONED, randint1(dam));
                                        }
                                }

                                /* Take the damage */
                                take_hit(dam, name);
                        }

                        break;
                }

                case FEAT_TRAP_HEAD + 0x04:
                {
                        sound(MSG_SUM_MONSTER);
                        msg_print("You are enveloped in a cloud of smoke!");
                        cave_info[y][x] &= ~(CAVE_MARK);
                        cave_set_feat(y, x, FEAT_FLOOR);
                        num = 2 + randint1(3);
                        for (i = 0; i < num; i++)
                        {
                                (void)summon_specific(y, x, p_ptr->depth, 0);
                        }
                        break;
                }

                case FEAT_TRAP_HEAD + 0x05:
                {
                        msg_print("You hit a teleport trap!");
                        teleport_player(100);
                        break;
                }

                case FEAT_TRAP_HEAD + 0x06:
                {
                        msg_print("You are enveloped in flames!");
                        dam = damroll(4, 6);
                        fire_dam(dam, "a fire trap");
                        break;
                }

                case FEAT_TRAP_HEAD + 0x07:
                {
                        msg_print("You are splashed with acid!");
                        dam = damroll(4, 6);
                        acid_dam(dam, "an acid trap");
                        break;
                }

                case FEAT_TRAP_HEAD + 0x08:
                {
                        if (check_hit(125))
                        {
                                msg_print("A small dart hits you!");
                                dam = damroll(1, 4);
                                take_hit(dam, name);
                                (void)inc_timed(TMD_SLOW, randint0(20) + 20);
                        }
                        else
                        {
                                msg_print("A small dart barely misses you.");
                        }
                        break;
                }

                case FEAT_TRAP_HEAD + 0x09:
                {
                        if (check_hit(125))
                        {
                                msg_print("A small dart hits you!");
                                dam = damroll(1, 4);
                                take_hit(dam, name);
                                (void)do_dec_stat(A_STR, FALSE);
                        }
                        else
                        {
                                msg_print("A small dart barely misses you.");
                        }
                        break;
                }

                case FEAT_TRAP_HEAD + 0x0A:
                {
                        if (check_hit(125))
                        {
                                msg_print("A small dart hits you!");
                                dam = damroll(1, 4);
                                take_hit(dam, name);
                                (void)do_dec_stat(A_DEX, FALSE);
                        }
                        else
                        {
                                msg_print("A small dart barely misses you.");
                        }
                        break;
                }

                case FEAT_TRAP_HEAD + 0x0B:
                {
                        if (check_hit(125))
                        {
                                msg_print("A small dart hits you!");
                                dam = damroll(1, 4);
                                take_hit(dam, name);
                                (void)do_dec_stat(A_CON, FALSE);
                        }
                        else
                        {
                                msg_print("A small dart barely misses you.");
                        }
                        break;
                }

                case FEAT_TRAP_HEAD + 0x0C:
                {
                        msg_print("You are surrounded by a black gas!");
                        if (!p_ptr->resist_blind)
                        {
                                (void)inc_timed(TMD_BLIND, randint0(50) + 25);
                        }
                        break;
                }

                case FEAT_TRAP_HEAD + 0x0D:
                {
                        msg_print("You are surrounded by a gas of scintillating colors!");
                        if (!p_ptr->resist_confu)
                        {
                                (void)inc_timed(TMD_CONFUSED, randint0(20) + 10);
                        }
                        break;
                }

                case FEAT_TRAP_HEAD + 0x0E:
                {
                        msg_print("You are surrounded by a pungent green gas!");
                        if (!p_ptr->resist_pois && !p_ptr->timed[TMD_OPP_POIS])
                        {
                                (void)inc_timed(TMD_POISONED, randint0(20) + 10);
                        }
                        break;
                }

                case FEAT_TRAP_HEAD + 0x0F:
                {
                        msg_print("You are surrounded by a strange white mist!");
                        if (!p_ptr->free_act)
                        {
                                (void)inc_timed(TMD_PARALYZED, randint0(10) + 5);
                        }
                        break;
                }
        }
}