/*
 *  File:       cloud.cc
 *  Summary:    Functions related to clouds.
 *  Written by: Brent Ross
 *
 *  Creating a cloud module so all the cloud stuff can be isolated.
 */

#include "AppHdr.h"

#include <algorithm>

#include "externs.h"

#include "areas.h"
#include "branch.h"
#include "cloud.h"
#include "colour.h"
#include "coord.h"
#include "coordit.h"
#include "dungeon.h"
#include "fprop.h"
#include "mapmark.h"
#include "ouch.h"
#include "player.h"
#include "random.h"
#include "spells4.h"
#include "stuff.h"
#include "env.h"
#include "terrain.h"
#ifdef USE_TILE
#include "tiledef-gui.h"
#include "tiledef-main.h"
#endif
#include "mutation.h"

static int _actual_spread_rate(cloud_type type, int spread_rate)
{
    if (spread_rate >= 0)
        return spread_rate;

    switch (type)
    {
    case CLOUD_GLOOM:
        return 50;
    case CLOUD_STEAM:
    case CLOUD_GREY_SMOKE:
    case CLOUD_BLACK_SMOKE:
        return 22;
    case CLOUD_RAIN:
        return 11;
    default:
        return 0;
    }
}

#ifdef DEBUG
static bool _killer_whose_match(kill_category whose, killer_type killer)
{
    switch (whose)
    {
        case KC_YOU:
            return (killer == KILL_YOU_MISSILE || killer == KILL_YOU_CONF);

        case KC_FRIENDLY:
            return (killer == KILL_MON_MISSILE || killer == KILL_YOU_CONF);

        case KC_OTHER:
            return (killer == KILL_MON_MISSILE || killer == KILL_MISCAST
                    || killer == KILL_MISC);

        case KC_NCATEGORIES:
            ASSERT(false);
    }
    return (false);
}
#endif

static void _new_cloud( int cloud, cloud_type type, const coord_def& p,
                        int decay, kill_category whose, killer_type killer,
                        unsigned char spread_rate, int colour, std::string name,
                        std::string tile)
{
    ASSERT( env.cloud[cloud].type == CLOUD_NONE );
    ASSERT(_killer_whose_match(whose, killer));

    cloud_struct& c = env.cloud[cloud];

    c.type        = type;
    c.decay       = decay;
    c.pos         = p;
    c.whose       = whose;
    c.killer      = killer;
    c.spread_rate = spread_rate;
    c.colour      = colour;
    c.name        = name;
#ifdef USE_TILE
    if (!tile.empty())
    {
        unsigned int index;
        if (!tile_main_index(tile.c_str(), index))
        {
            mprf(MSGCH_ERROR, "Invalid tile requested for cloud: '%s'.", tile.c_str());
            tile = "";
        }
    }
#endif
    c.tile        = tile;
    env.cgrid(p)  = cloud;
    env.cloud_no++;
}

static void _place_new_cloud(cloud_type cltype, const coord_def& p, int decay,
                             kill_category whose, killer_type killer,
                             int spread_rate = -1, int colour = -1,
                             std::string name = "",
                             std::string tile = "")
{
    if (env.cloud_no >= MAX_CLOUDS)
        return;

    // Find slot for cloud.
    for (int ci = 0; ci < MAX_CLOUDS; ci++)
    {
        if (env.cloud[ci].type == CLOUD_NONE)   // i.e., is empty
        {
            _new_cloud( ci, cltype, p, decay, whose, killer, spread_rate, colour,
                        name, tile );
            break;
        }
    }
}

static int _spread_cloud(const cloud_struct &cloud)
{
    const int spreadch = cloud.decay > 30? 80 :
                         cloud.decay > 20? 50 :
                                           30;
    int extra_decay = 0;
    for ( adjacent_iterator ai(cloud.pos); ai; ++ai )
    {
        if (random2(100) >= spreadch)
            continue;

        if (!in_bounds(*ai)
            || env.cgrid(*ai) != EMPTY_CLOUD
            || feat_is_solid(grd(*ai))
            || is_sanctuary(*ai) && !is_harmless_cloud(cloud.type))
        {
            continue;
        }

        int newdecay = cloud.decay / 2 + 1;
        if (newdecay >= cloud.decay)
            newdecay = cloud.decay - 1;

        _place_new_cloud( cloud.type, *ai, newdecay, cloud.whose, cloud.killer,
                          cloud.spread_rate, cloud.colour, cloud.name, cloud.tile );

        extra_decay += 8;
    }

    return (extra_decay);
}

static void _spread_fire(const cloud_struct &cloud)
{
    int make_flames = one_chance_in(5);

    for ( adjacent_iterator ai(cloud.pos); ai; ++ai )
    {
        if (!in_bounds(*ai)
            || env.cgrid(*ai) != EMPTY_CLOUD
            || is_sanctuary(*ai))
            continue;

        // burning trees produce flames all around
        if (!cell_is_solid(*ai) && make_flames)
            _place_new_cloud( CLOUD_FIRE, *ai, cloud.decay/2+1, cloud.whose,
                              cloud.killer, cloud.spread_rate, cloud.colour,
                              cloud.name, cloud.tile );

        // forest fire doesn't spread in all directions at once,
        // every neighbouring square gets a separate roll
        if (grd(*ai) == DNGN_TREES && one_chance_in(20))
        {
            if (you.see_cell(*ai))
                mpr("The forest fire spreads!");
            grd(*ai) = dgn_tree_base_feature_at(*ai);
            _place_new_cloud( cloud.type, *ai, random2(30)+25, cloud.whose,
                              cloud.killer, cloud.spread_rate, cloud.colour,
                              cloud.name, cloud.tile );
        }

    }
}

static void _cloud_fire_interacts_with_terrain(const cloud_struct &cloud)
{
    for (adjacent_iterator ai(cloud.pos); ai; ++ai)
    {
        const coord_def p(*ai);
        if (feat_is_watery(grd(p)) && env.cgrid(p) == EMPTY_CLOUD)
        {
            _place_new_cloud(CLOUD_STEAM, p, cloud.decay / 2 + 1,
                             cloud.whose, cloud.killer);
        }
    }
}

void cloud_interacts_with_terrain(const cloud_struct &cloud)
{
    if (cloud.type == CLOUD_FIRE || cloud.type == CLOUD_FOREST_FIRE)
        _cloud_fire_interacts_with_terrain(cloud);
}

static void _dissipate_cloud(int cloudidx, int dissipate)
{
    cloud_struct &cloud = env.cloud[cloudidx];
    // Apply calculated rate to the actual cloud.
    cloud.decay -= dissipate;

    if (cloud.type == CLOUD_FOREST_FIRE)
        _spread_fire(cloud);
    else if (x_chance_in_y(cloud.spread_rate, 100))
    {
        cloud.spread_rate -= div_rand_round(cloud.spread_rate, 10);
        cloud.decay       -= _spread_cloud(cloud);
    }

    // Check for total dissipation and handle accordingly.
    if (cloud.decay < 1)
        delete_cloud(cloudidx);
}

void manage_clouds()
{
    for (int i = 0; i < MAX_CLOUDS; ++i)
    {
        cloud_struct& cloud = env.cloud[i];

        if (cloud.type == CLOUD_NONE)
            continue;

        int dissipate = you.time_taken;

        // Fire clouds dissipate faster over water,
        // rain and cold clouds dissipate faster over lava.
        if (cloud.type == CLOUD_FIRE && grd(cloud.pos) == DNGN_DEEP_WATER)
            dissipate *= 4;
        else if ((cloud.type == CLOUD_COLD || cloud.type == CLOUD_RAIN)
                 && grd(cloud.pos) == DNGN_LAVA)
            dissipate *= 4;
        else if (cloud.type == CLOUD_GLOOM)
        {
            int count = 0;
            for (adjacent_iterator ai(cloud.pos); ai; ++ai)
                if (env.cgrid(*ai) != EMPTY_CLOUD)
                    if (env.cloud[env.cgrid(*ai)].type == CLOUD_GLOOM)
                        count++;

            if (!haloers(cloud.pos).empty() && !silenced(cloud.pos))
                count = 0;

            if (count < 4)
                dissipate *= 50;
            else
                dissipate /= 20;
        }

        cloud_interacts_with_terrain(cloud);
        expose_items_to_element(cloud2beam(cloud.type), cloud.pos, 2);

        _dissipate_cloud(i, dissipate);
    }
}

void delete_cloud( int cloud )
{
    cloud_struct& c = env.cloud[cloud];
    if (c.type != CLOUD_NONE)
    {
        if (c.type == CLOUD_RAIN)
        {
            // Rain clouds can occasionally leave shallow water or deepen it:
            // If we're near lava, chance of leaving water is lower;
            // if we're near deep water already, chance of leaving water
            // is slightly higher.
            if (one_chance_in((5 + count_neighbours(c.pos, DNGN_LAVA)) -
                                   count_neighbours(c.pos, DNGN_DEEP_WATER)))
            {
                dungeon_feature_type feat;

                if (grd(c.pos) == DNGN_FLOOR)
                    feat = DNGN_SHALLOW_WATER;
                else if (grd(c.pos) == DNGN_SHALLOW_WATER && you.pos() != c.pos
                        && one_chance_in(3))
                    // Don't drown the player!
                    feat = DNGN_DEEP_WATER;
                else
                    feat = grd(c.pos);

                if (grd(c.pos) != feat)
                {
                    if (you.pos() == c.pos)
                        mpr("The rain has left you waist-deep in water!");
                    dungeon_terrain_changed(c.pos, feat);
                }
            }
        }
        c.type        = CLOUD_NONE;
        c.decay       = 0;
        c.whose       = KC_OTHER;
        c.killer      = KILL_NONE;
        c.spread_rate = 0;
        c.colour      = -1;
        c.name        = "";
        c.tile        = "";

        env.cgrid(c.pos) = EMPTY_CLOUD;
        c.pos.reset();
        env.cloud_no--;
    }
}

// The current use of this function is for shifting in the abyss, so
// that clouds get moved along with the rest of the map.
void move_cloud( int cloud, const coord_def& newpos )
{
    if (cloud != EMPTY_CLOUD)
    {
        const coord_def oldpos = env.cloud[cloud].pos;
        env.cgrid(oldpos) = EMPTY_CLOUD;
        env.cgrid(newpos) = cloud;
        env.cloud[cloud].pos = newpos;
    }
}

// Places a cloud with the given stats assuming one doesn't already
// exist at that point.
void check_place_cloud( cloud_type cl_type, const coord_def& p, int lifetime,
                        kill_category whose, int spread_rate, int colour,
                        std::string name, std::string tile)
{
    check_place_cloud(cl_type, p, lifetime, whose,
                      cloud_struct::whose_to_killer(whose), spread_rate, colour,
                      name, tile);
}

// Places a cloud with the given stats assuming one doesn't already
// exist at that point.
void check_place_cloud( cloud_type cl_type, const coord_def& p, int lifetime,
                        killer_type killer, int spread_rate, int colour,
                        std::string name, std::string tile)
{
    check_place_cloud(cl_type, p, lifetime,
                      cloud_struct::killer_to_whose(killer), killer,
                      spread_rate, colour, name, tile);
}

// Places a cloud with the given stats assuming one doesn't already
// exist at that point.
void check_place_cloud( cloud_type cl_type, const coord_def& p, int lifetime,
                        kill_category whose, killer_type killer,
                        int spread_rate, int colour, std::string name,
                        std::string tile)
{
    if (!in_bounds(p) || env.cgrid(p) != EMPTY_CLOUD)
        return;

    place_cloud( cl_type, p, lifetime, whose, killer, spread_rate, colour,
                 name, tile );
}

int steam_cloud_damage(const cloud_struct &cloud)
{
    return steam_cloud_damage(cloud.decay);
}

int steam_cloud_damage(int decay)
{
    decay = std::min(decay, 60);
    decay = std::max(decay, 10);

    // Damage in range 3 - 16.
    return ((decay * 13 + 20) / 50);
}

//   Places a cloud with the given stats. May delete old clouds to
//   make way if there are too many on level. Will overwrite an old
//   cloud under some circumstances.
void place_cloud(cloud_type cl_type, const coord_def& ctarget, int cl_range,
                 kill_category whose, int _spread_rate, int colour,
                 std::string name, std::string tile)
{
    place_cloud(cl_type, ctarget, cl_range, whose,
                cloud_struct::whose_to_killer(whose), _spread_rate,
                colour, name, tile);
}

//   Places a cloud with the given stats. May delete old clouds to
//   make way if there are too many on level. Will overwrite an old
//   cloud under some circumstances.
void place_cloud(cloud_type cl_type, const coord_def& ctarget, int cl_range,
                 killer_type killer, int _spread_rate, int colour,
                 std::string name, std::string tile)
{
    place_cloud(cl_type, ctarget, cl_range,
                cloud_struct::killer_to_whose(killer), killer, _spread_rate,
                colour, name, tile);
}

bool cloud_is_inferior(cloud_type inf, cloud_type superior)
{
    return (inf == CLOUD_STINK && superior == CLOUD_POISON);
}

//   Places a cloud with the given stats. May delete old clouds to
//   make way if there are too many on level. Will overwrite an old
//   cloud under some circumstances.
void place_cloud(cloud_type cl_type, const coord_def& ctarget, int cl_range,
                 kill_category whose, killer_type killer, int _spread_rate,
                 int colour, std::string name, std::string tile)
{
    if (is_sanctuary(ctarget) && !is_harmless_cloud(cl_type))
        return;

    int cl_new = -1;

    const int target_cgrid = env.cgrid(ctarget);
    if (target_cgrid != EMPTY_CLOUD)
    {
        // There's already a cloud here. See if we can overwrite it.
        cloud_struct& old_cloud = env.cloud[target_cgrid];
        if (old_cloud.type >= CLOUD_GREY_SMOKE && old_cloud.type <= CLOUD_STEAM
            || cloud_is_inferior(old_cloud.type, cl_type)
            || old_cloud.type == CLOUD_BLACK_SMOKE
            || old_cloud.type == CLOUD_MIST
            || old_cloud.decay <= 20) // soon gone
        {
            // Delete this cloud and replace it.
            cl_new = target_cgrid;
            delete_cloud(target_cgrid);
        }
        else                    // Guess not.
            return;
    }

    const int spread_rate = _actual_spread_rate(cl_type, _spread_rate);

    // Too many clouds.
    if (env.cloud_no >= MAX_CLOUDS)
    {
        // Default to random in case there's no low quality clouds.
        int cl_del = random2(MAX_CLOUDS);

        for (int ci = 0; ci < MAX_CLOUDS; ci++)
        {
            cloud_struct& cloud = env.cloud[ci];
            if (cloud.type >= CLOUD_GREY_SMOKE && cloud.type <= CLOUD_STEAM
                || cloud.type == CLOUD_BLACK_SMOKE
                || cloud.type == CLOUD_MIST
                || cloud.decay <= 20) // soon gone
            {
                cl_del = ci;
                break;
            }
        }

        delete_cloud(cl_del);
        cl_new = cl_del;
    }

    // Create new cloud.
    if (cl_new != -1)
    {
        _new_cloud( cl_new, cl_type, ctarget, cl_range * 10,
                    whose, killer, spread_rate, colour, name, tile );
    }
    else
    {
        // Find slot for cloud.
        for (int ci = 0; ci < MAX_CLOUDS; ci++)
        {
            if (env.cloud[ci].type == CLOUD_NONE)   // ie is empty
            {
                _new_cloud( ci, cl_type, ctarget, cl_range * 10,
                            whose, killer, spread_rate, colour, name, tile );
                break;
            }
        }
    }
}

bool is_opaque_cloud(unsigned char cloud_idx)
{
    if (cloud_idx == EMPTY_CLOUD)
        return (false);

    const int ctype = env.cloud[cloud_idx].type;
    return (ctype >= CLOUD_OPAQUE_FIRST && ctype <= CLOUD_OPAQUE_LAST);
}

cloud_type cloud_type_at(const coord_def &c)
{
    const int cloudno = env.cgrid(c);
    return (cloudno == EMPTY_CLOUD ? CLOUD_NONE
                                   : env.cloud[cloudno].type);
}

cloud_type random_smoke_type()
{
    // including black to keep variety
    switch ( random2(4) )
    {
    case 0: return CLOUD_GREY_SMOKE;
    case 1: return CLOUD_BLUE_SMOKE;
    case 2: return CLOUD_BLACK_SMOKE;
    case 3: return CLOUD_PURPLE_SMOKE;
    }
    return CLOUD_DEBUGGING;
}

cloud_type beam2cloud(beam_type flavour)
{
    switch (flavour)
    {
    default:
    case BEAM_NONE:
        return CLOUD_NONE;
    case BEAM_FIRE:
    case BEAM_POTION_FIRE:
        return CLOUD_FIRE;
    case BEAM_POTION_STINKING_CLOUD:
        return CLOUD_STINK;
    case BEAM_COLD:
    case BEAM_POTION_COLD:
        return CLOUD_COLD;
    case BEAM_POISON:
    case BEAM_POTION_POISON:
        return CLOUD_POISON;
    case BEAM_POTION_BLACK_SMOKE:
        return CLOUD_BLACK_SMOKE;
    case BEAM_POTION_GREY_SMOKE:
        return CLOUD_GREY_SMOKE;
    case BEAM_POTION_BLUE_SMOKE:
        return CLOUD_BLUE_SMOKE;
    case BEAM_POTION_PURPLE_SMOKE:
        return CLOUD_PURPLE_SMOKE;
    case BEAM_STEAM:
    case BEAM_POTION_STEAM:
        return CLOUD_STEAM;
    case BEAM_MIASMA:
    case BEAM_POTION_MIASMA:
        return CLOUD_MIASMA;
    case BEAM_CHAOS:
        return CLOUD_CHAOS;
    case BEAM_POTION_RAIN:
        return CLOUD_RAIN;
    case BEAM_POTION_MUTAGENIC:
        return CLOUD_MUTAGENIC;
    case BEAM_GLOOM:
        return CLOUD_GLOOM;
    case BEAM_RANDOM:
        return CLOUD_RANDOM;
    }
}

beam_type cloud2beam(cloud_type flavour)
{
    switch (flavour)
    {
    default:
    case CLOUD_NONE:         return BEAM_NONE;
    case CLOUD_FIRE:         return BEAM_FIRE;
    case CLOUD_FOREST_FIRE:  return BEAM_FIRE;
    case CLOUD_STINK:        return BEAM_POTION_STINKING_CLOUD;
    case CLOUD_COLD:         return BEAM_COLD;
    case CLOUD_POISON:       return BEAM_POISON;
    case CLOUD_BLACK_SMOKE:  return BEAM_POTION_BLACK_SMOKE;
    case CLOUD_GREY_SMOKE:   return BEAM_POTION_GREY_SMOKE;
    case CLOUD_BLUE_SMOKE:   return BEAM_POTION_BLUE_SMOKE;
    case CLOUD_PURPLE_SMOKE: return BEAM_POTION_PURPLE_SMOKE;
    case CLOUD_STEAM:        return BEAM_STEAM;
    case CLOUD_MIASMA:       return BEAM_MIASMA;
    case CLOUD_CHAOS:        return BEAM_CHAOS;
    case CLOUD_RAIN:         return BEAM_POTION_RAIN;
    case CLOUD_MUTAGENIC:    return BEAM_POTION_MUTAGENIC;
    case CLOUD_GLOOM:        return BEAM_GLOOM;
    case CLOUD_RANDOM:       return BEAM_RANDOM;
    }
}

// Returns by how much damage gets divided due to elemental resistances.
// Damage is reduced to, level 1 -> 1/2, level 2 -> 1/3, level 3 -> 1/5, or
// for "boolean" attacks (which use bonus_res = 1, sticky flame/electricity)
// to level 1 -> 1/3, level 2 -> 1/4, or level 3 -> 1/6.
// With the old formula (1 + resist * resist) this used to be
// 1/2, 1/5, 1/10 (normal) and 1/3, 1/6, 1/11 (boolean), respectively.
int resist_fraction(int resist, int bonus_res)
{
    return ((3*resist + 1)/2 + bonus_res);
}

// NOTE: Keep in sync with in_a_cloud()
int max_cloud_damage(cloud_type cl_type, int power)
{
    int speed  = player_speed();
    int dam    = 0;
    int resist = 0;

    switch (cl_type)
    {
    case CLOUD_FIRE:
    case CLOUD_FOREST_FIRE:
        if (you.duration[DUR_FIRE_SHIELD])
            return (0);
        resist = player_res_fire();

        // Intentional fall-throuigh
    case CLOUD_COLD:
        if (you.mutation[MUT_PASSIVE_FREEZE])
            return (0);
        if (cl_type == CLOUD_COLD)
            resist = player_res_cold();

        if (resist <= 0)
        {
            dam += 32 * speed / 10;

            if (resist < 0)
                dam += 16 * speed / 10;
        }
        else
        {
            dam += 32 * speed / 10;
            dam /= resist_fraction(resist);
        }
        break;

    case CLOUD_STINK:
        if (player_res_poison())
            return (0);

        dam += 2 * speed / 10;
        break;

    case CLOUD_POISON:
        if (player_res_poison())
            return (0);

        dam += 9 * speed / 10;
        break;

    case CLOUD_STEAM:
    {
        ASSERT(power >= 0);

        if (player_res_steam() > 0 || power == 0)
            return (0);

        const int base_dam = steam_cloud_damage(power * 10);
        dam += (base_dam - 1) * speed / 10;

        const int res_fire = player_res_fire();
        if (res_fire < 0)
            dam += base_dam / 2 * speed / 10;
        else if (res_fire)
            dam /= 1 + (res_fire / 2);

        break;
    }

    case CLOUD_MIASMA:
        if (you.res_rotting())
            return (0);

        dam += 11 * speed / 10;
        break;

    default:
        break;
    }

    if (dam < 0)
        dam = 0;

    return (dam);
}

// NOTE: Keep in sync with max_cloud_damage()
void in_a_cloud()
{
    int cl = env.cgrid(you.pos());
    int hurted = 0;
    int resist;
    std::string name = env.cloud[cl].name;

    if (you.duration[DUR_CONDENSATION_SHIELD] > 0)
        remove_condensation_shield();

    switch (env.cloud[cl].type)
    {
    case CLOUD_FIRE:
    case CLOUD_FOREST_FIRE:
        if (you.duration[DUR_FIRE_SHIELD])
            return;

        mprf("You are engulfed in %s!", !name.empty() ? name.c_str() : "roaring flames");

        resist = player_res_fire();

        if (resist <= 0)
        {
            hurted += ((random2avg(23, 3) + 10) * you.time_taken) / 10;

            if (resist < 0)
                hurted += ((random2avg(14, 2) + 3) * you.time_taken) / 10;

            hurted -= random2(you.armour_class());

            if (hurted < 0)
                hurted = 0;
            else
                ouch(hurted, cl, KILLED_BY_CLOUD, "flame");
        }
        else
        {
            canned_msg(MSG_YOU_RESIST);
            hurted += ((random2avg(23, 3) + 10) * you.time_taken) / 10;
            hurted /= resist_fraction(resist);
            ouch(hurted, cl, KILLED_BY_CLOUD, "flame");
        }
        expose_player_to_element(BEAM_FIRE, 7);
        break;

    case CLOUD_STINK:
        // If you don't have to breathe, unaffected
        mprf("You are engulfed in %s!", !name.empty() ? name.c_str() : "noxious fumes");

        if (player_res_poison())
            break;

        hurted += (random2(3) * you.time_taken) / 10;
        if (hurted < 1)
            hurted = 0;
        else
            ouch((hurted * you.time_taken) / 10, cl, KILLED_BY_CLOUD,
                 "noxious fumes");

        if (1 + random2(27) >= you.experience_level)
        {
            mpr("You choke on the stench!");
            // effectively one or two turns, since it will be
            // decremented right away
            confuse_player( (coinflip() ? 3 : 2) );
        }
        break;

    case CLOUD_COLD:
        if (you.mutation[MUT_PASSIVE_FREEZE])
            break;

        mprf("You are engulfed in %s!", !name.empty() ? name.c_str() : "freezing vapours");

        resist = player_res_cold();

        if (resist <= 0)
        {
            hurted += ((random2avg(23, 3) + 10) * you.time_taken) / 10;

            if (resist < 0)
                hurted += ((random2avg(14, 2) + 3) * you.time_taken) / 10;

            hurted -= random2(you.armour_class());
            if (hurted < 0)
                hurted = 0;

            ouch(hurted, cl, KILLED_BY_CLOUD, "freezing vapour");
        }
        else
        {
            canned_msg(MSG_YOU_RESIST);
            hurted += ((random2avg(23, 3) + 10) * you.time_taken) / 10;
            hurted /= resist_fraction(resist);
            ouch(hurted, cl, KILLED_BY_CLOUD, "freezing vapour");
        }
        expose_player_to_element(BEAM_COLD, 7);
        break;

    case CLOUD_POISON:
        // If you don't have to breathe, unaffected
        mprf("You are engulfed in %s!", !name.empty() ? name.c_str() : "poison gas");

        if (!player_res_poison())
        {
            ouch((random2(10) * you.time_taken) / 10, cl, KILLED_BY_CLOUD,
                 "poison gas");
            poison_player(1);
        }
        break;

    case CLOUD_GREY_SMOKE:
    case CLOUD_BLUE_SMOKE:
    case CLOUD_TLOC_ENERGY:
    case CLOUD_PURPLE_SMOKE:
    case CLOUD_BLACK_SMOKE:
        mprf("You are engulfed in %s!", !name.empty() ? name.c_str() : "a cloud of smoke");

        break;

    case CLOUD_STEAM:
    {
        mprf("You are engulfed in %s!", !name.empty() ? name.c_str() : "a cloud of scalding steam");

        if (player_res_steam() > 0)
        {
            mpr("It doesn't seem to affect you.");
            return;
        }

        const int base_dam = steam_cloud_damage(env.cloud[cl]);
        hurted += (random2avg(base_dam, 2) * you.time_taken) / 10;

        const int res_fire = player_res_fire();
        if (res_fire < 0)
            hurted += (random2(base_dam / 2 + 1) * you.time_taken) / 10;
        else if (res_fire)
            hurted /= 1 + (res_fire / 2);

        if (hurted < 0)
            hurted = 0;

        ouch(hurted, cl, KILLED_BY_CLOUD, "steam");
        break;
    }

    case CLOUD_MIASMA:
        mprf("You are engulfed in %s!", !name.empty() ? name.c_str() : "a dark miasma");

        if (you.res_rotting())
            return;

        miasma_player();

        hurted += (random2avg(12, 3) * you.time_taken) / 10;    // 3

        if (hurted < 0)
            hurted = 0;

        ouch(hurted, cl, KILLED_BY_CLOUD, "foul pestilence");
        break;

    case CLOUD_RAIN:
        if (you.duration[DUR_FIRE_SHIELD])
            you.duration[DUR_FIRE_SHIELD] = 1;

        if (you.misled())
        {
            mpr("The rain washes away illusions!", MSGCH_DURATION);
            you.duration[DUR_MISLED] = 0;
        }

        if (name.empty() || name == "the rain")
            mpr("You are standing in the rain.");
        else
            mprf("You are engulfed in %s.", name.c_str());

        break;

    case CLOUD_MUTAGENIC:
        mprf("You are engulfed in %s!", !name.empty() ? name.c_str() : "a mutagenic fog");

        if (coinflip())
        {
            mpr("Strange energies course through your body.");
            if (one_chance_in(3))
                you.mutate();
            else
                give_bad_mutation();
        }
        break;

    case CLOUD_GLOOM:
        mprf("You are engulfed in %s!", !name.empty() ? name.c_str() : "a thick gloom");

        break;

    default:
        break;
    }

    return;
}                               // end in_a_cloud()

bool is_damaging_cloud(cloud_type type, bool temp)
{
    switch (type)
    {
    // always harmful...
    case CLOUD_FIRE:
    case CLOUD_FOREST_FIRE:
        // ... unless a Ring of Flames is up and it's a fire cloud.
        if (temp && you.duration[DUR_FIRE_SHIELD])
            return (false);
    case CLOUD_CHAOS:
        return (true);
    case CLOUD_COLD:
        return (!you.mutation[MUT_PASSIVE_FREEZE]);

    // Only harmful if the player doesn't have the necessary resistances.
    // Takes into account what the player can *know* and what s/he can
    // also expect to be the case a few turns later (ignores spells).
    case CLOUD_STINK:
    case CLOUD_POISON:
        return (!player_res_poison(false, temp));
    case CLOUD_STEAM:
        return (player_res_steam(false, temp) <= 0);
    case CLOUD_MIASMA:
        return (!you.res_rotting());
    case CLOUD_MUTAGENIC:
        return (you.can_mutate());

    default:
        // Smoke, never harmful.
        return (false);
    }
}

bool is_harmless_cloud(cloud_type type)
{
    switch (type)
    {
    case CLOUD_NONE:
    case CLOUD_BLACK_SMOKE:
    case CLOUD_GREY_SMOKE:
    case CLOUD_BLUE_SMOKE:
    case CLOUD_PURPLE_SMOKE:
    case CLOUD_TLOC_ENERGY:
    case CLOUD_MIST:
    case CLOUD_RAIN:
    case CLOUD_MAGIC_TRAIL:
    case CLOUD_GLOOM:
    case CLOUD_DEBUGGING:
        return (true);
    default:
        return (false);
    }
}

bool in_what_cloud(cloud_type type)
{
    int cl = env.cgrid(you.pos());

    if (env.cgrid(you.pos()) == EMPTY_CLOUD)
        return (false);

    if (env.cloud[cl].type == type)
        return (true);

    return (false);
}

cloud_type in_what_cloud()
{
    int cl = env.cgrid(you.pos());

    if (env.cgrid(you.pos()) == EMPTY_CLOUD)
        return (CLOUD_NONE);

    return (env.cloud[cl].type);
}

std::string cloud_name(int cloudno)
{
    if (!env.cloud[cloudno].name.empty())
        return (env.cloud[cloudno].name);
    else
        return cloud_name(env.cloud[cloudno].type);
}

std::string cloud_name(cloud_type type)
{
    switch (type)
    {
    case CLOUD_FIRE:
        return "flame";
    case CLOUD_FOREST_FIRE:
        return "fire";
    case CLOUD_STINK:
        return "noxious fumes";
    case CLOUD_COLD:
        return "freezing vapour";
    case CLOUD_POISON:
        return "poison gases";
    case CLOUD_GREY_SMOKE:
        return "grey smoke";
    case CLOUD_BLUE_SMOKE:
        return "blue smoke";
    case CLOUD_PURPLE_SMOKE:
        return "purple smoke";
    case CLOUD_TLOC_ENERGY:
        return "translocational energy";
    case CLOUD_STEAM:
        return "steam";
    case CLOUD_MIASMA:
        return "foul pestilence";
    case CLOUD_BLACK_SMOKE:
        return "black smoke";
    case CLOUD_MIST:
        return "thin mist";
    case CLOUD_CHAOS:
        return "seething chaos";
    case CLOUD_RAIN:
        return "rain";
    case CLOUD_MUTAGENIC:
        return "mutagenic fog";
    case CLOUD_MAGIC_TRAIL:
        return "magical condensation";
    case CLOUD_GLOOM:
        return "gloom";
    default:
        return "buggy goodness";
    }
}

////////////////////////////////////////////////////////////////////////
// cloud_struct

kill_category cloud_struct::killer_to_whose(killer_type killer)
{
    switch (killer)
    {
        case KILL_YOU:
        case KILL_YOU_MISSILE:
        case KILL_YOU_CONF:
            return (KC_YOU);

        case KILL_MON:
        case KILL_MON_MISSILE:
        case KILL_MISC:
            return (KC_OTHER);

        default:
            ASSERT(false);
    }
    return (KC_OTHER);
}

killer_type cloud_struct::whose_to_killer(kill_category whose)
{
    switch (whose)
    {
        case KC_YOU:         return(KILL_YOU_MISSILE);
        case KC_FRIENDLY:    return(KILL_MON_MISSILE);
        case KC_OTHER:       return(KILL_MISC);
        case KC_NCATEGORIES: ASSERT(false);
    }
    return (KILL_NONE);
}

void cloud_struct::set_whose(kill_category _whose)
{
    whose  = _whose;
    killer = whose_to_killer(whose);
}

void cloud_struct::set_killer(killer_type _killer)
{
    killer = _killer;
    whose  = killer_to_whose(killer);

    switch (killer)
    {
        case KILL_YOU:
            killer = KILL_YOU_MISSILE;
            break;

        case KILL_MON:
            killer = KILL_MON_MISSILE;
            break;

        default:
            break;
     }
}

int get_cloud_colour(int cloudno)
{
    int which_colour = LIGHTGREY;
    if (env.cloud[cloudno].colour != -1)
        return (env.cloud[cloudno].colour);

    switch (env.cloud[cloudno].type)
    {
    case CLOUD_FIRE:
    case CLOUD_FOREST_FIRE:
        if (env.cloud[cloudno].decay <= 20)
            which_colour = RED;
        else if (env.cloud[cloudno].decay <= 40)
            which_colour = LIGHTRED;
        else if (one_chance_in(4))
            which_colour = RED;
        else if (one_chance_in(4))
            which_colour = LIGHTRED;
        else
            which_colour = YELLOW;
        break;

    case CLOUD_STINK:
        which_colour = GREEN;
        break;

    case CLOUD_COLD:
        if (env.cloud[cloudno].decay <= 20)
            which_colour = BLUE;
        else if (env.cloud[cloudno].decay <= 40)
            which_colour = LIGHTBLUE;
        else if (one_chance_in(4))
            which_colour = BLUE;
        else if (one_chance_in(4))
            which_colour = LIGHTBLUE;
        else
            which_colour = WHITE;
        break;

    case CLOUD_POISON:
        which_colour = (one_chance_in(3) ? LIGHTGREEN : GREEN);
        break;

    case CLOUD_BLUE_SMOKE:
        which_colour = LIGHTBLUE;
        break;

    case CLOUD_PURPLE_SMOKE:
    case CLOUD_TLOC_ENERGY:
    case CLOUD_GLOOM:
        which_colour = MAGENTA;
        break;

    case CLOUD_MIASMA:
    case CLOUD_BLACK_SMOKE:
        which_colour = DARKGREY;
        break;

    case CLOUD_RAIN:
    case CLOUD_MIST:
        which_colour = ETC_MIST;
        break;

    case CLOUD_CHAOS:
        which_colour = ETC_RANDOM;
        break;

    case CLOUD_MUTAGENIC:
        which_colour = ETC_MUTAGENIC;
        break;

    case CLOUD_MAGIC_TRAIL:
        which_colour = ETC_MAGIC;
        break;

    default:
        which_colour = LIGHTGREY;
        break;
    }
    return (which_colour);
}

//////////////////////////////////////////////////////////////////////////
// Fog machine stuff

void place_fog_machine(fog_machine_type fm_type, cloud_type cl_type,
                       int x, int y, int size, int power)
{
    ASSERT(fm_type >= FM_GEYSER && fm_type < NUM_FOG_MACHINE_TYPES);
    ASSERT(cl_type > CLOUD_NONE && (cl_type < CLOUD_RANDOM
                                    || cl_type == CLOUD_DEBUGGING));
    ASSERT(size  >= 1);
    ASSERT(power >= 1);

    const char* fog_types[] = {
        "geyser",
        "spread",
        "brownian"
    };

    try
    {
        char buf [160];
        sprintf(buf, "lua_mapless:fog_machine_%s(\"%s\", %d, %d)",
                fog_types[fm_type], cloud_name(cl_type).c_str(),
                size, power);

        map_marker *mark = map_lua_marker::parse_marker(buf, "");

        if (mark == NULL)
        {
            mprf(MSGCH_DIAGNOSTICS, "Unable to parse fog machine from '%s'",
                 buf);
            return;
        }

        mark->pos = coord_def(x, y);
        env.markers.add(mark);
    }
    catch (const std::string &err)
    {
        mprf(MSGCH_ERROR, "Error while making fog machine: %s",
             err.c_str());
    }
}

void place_fog_machine(fog_machine_data data, int x, int y)
{
    place_fog_machine(data.fm_type, data.cl_type, x, y, data.size,
                      data.power);
}

bool valid_fog_machine_data(fog_machine_data data)
{
    if (data.fm_type < FM_GEYSER ||  data.fm_type >= NUM_FOG_MACHINE_TYPES)
        return (false);

    if (data.cl_type <= CLOUD_NONE || (data.cl_type >= CLOUD_RANDOM
                                       && data.cl_type != CLOUD_DEBUGGING))
        return (false);

    if (data.size < 1 || data.power < 1)
        return (false);

    return (true);
}

int num_fogs_for_place(int level_number, const level_id &place)
{
    if (level_number == -1)
        level_number = place.absdepth();

    switch (place.level_type)
    {
    case LEVEL_DUNGEON:
    {
        Branch &branch = branches[place.branch];
        ASSERT((branch.num_fogs_function == NULL
                && branch.rand_fog_function == NULL)
               || (branch.num_fogs_function != NULL
                   && branch.rand_fog_function != NULL));

        if (branch.num_fogs_function == NULL)
            return 0;

        return branch.num_fogs_function(level_number);
    }
    case LEVEL_ABYSS:
        return fogs_abyss_number(level_number);
    case LEVEL_PANDEMONIUM:
        return fogs_pan_number(level_number);
    case LEVEL_LABYRINTH:
        return fogs_lab_number(level_number);
    default:
        return 0;
    }

    return 0;
}

fog_machine_data random_fog_for_place(int level_number, const level_id &place)
{
    fog_machine_data data = {NUM_FOG_MACHINE_TYPES, CLOUD_NONE, -1, -1};

    if (level_number == -1)
        level_number = place.absdepth();

    switch (place.level_type)
    {
    case LEVEL_DUNGEON:
    {
        Branch &branch = branches[place.branch];
        ASSERT(branch.num_fogs_function != NULL
                && branch.rand_fog_function != NULL);
        branch.rand_fog_function(level_number, data);
        return data;
    }
    case LEVEL_ABYSS:
        return fogs_abyss_type(level_number);
    case LEVEL_PANDEMONIUM:
        return fogs_pan_type(level_number);
    case LEVEL_LABYRINTH:
        return fogs_lab_type(level_number);
    default:
        ASSERT(false);
        return data;
    }

    ASSERT(false);
    return data;
}

int fogs_pan_number(int level_number)
{
    return 0;
}

fog_machine_data fogs_pan_type(int level_number)
{
    fog_machine_data data = {NUM_FOG_MACHINE_TYPES, CLOUD_NONE, -1, -1};

    return data;
}

int fogs_abyss_number(int level_number)
{
    return 0;
}

fog_machine_data fogs_abyss_type(int level_number)
{
    fog_machine_data data = {NUM_FOG_MACHINE_TYPES, CLOUD_NONE, -1, -1};

    return data;
}

int fogs_lab_number(int level_number)
{
    return 0;
}

fog_machine_data fogs_lab_type(int level_number)
{
    fog_machine_data data = {NUM_FOG_MACHINE_TYPES, CLOUD_NONE, -1, -1};

    return data;
}