/*
 * Portions of this file are copyright Rebirth contributors and licensed as
 * described in COPYING.txt.
 * Portions of this file are copyright Parallax Software and licensed
 * according to the Parallax license below.
 * See COPYING.txt for license details.

THE COMPUTER CODE CONTAINED HEREIN IS THE SOLE PROPERTY OF PARALLAX
SOFTWARE CORPORATION ("PARALLAX").  PARALLAX, IN DISTRIBUTING THE CODE TO
END-USERS, AND SUBJECT TO ALL OF THE TERMS AND CONDITIONS HEREIN, GRANTS A
ROYALTY-FREE, PERPETUAL LICENSE TO SUCH END-USERS FOR USE BY SUCH END-USERS
IN USING, DISPLAYING,  AND CREATING DERIVATIVE WORKS THEREOF, SO LONG AS
SUCH USE, DISPLAY OR CREATION IS FOR NON-COMMERCIAL, ROYALTY OR REVENUE
FREE PURPOSES.  IN NO EVENT SHALL THE END-USER USE THE COMPUTER CODE
CONTAINED HEREIN FOR REVENUE-BEARING PURPOSES.  THE END-USER UNDERSTANDS
AND AGREES TO THE TERMS HEREIN AND ACCEPTS THE SAME BY USE OF THIS FILE.
COPYRIGHT 1993-1999 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
*/

/*
 *
 * Code for rendering & otherwise dealing with explosions
 *
 */

#include <algorithm>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "dxxerror.h"
#include "maths.h"
#include "vecmat.h"
#include "gr.h"
#include "3d.h"

#include "inferno.h"
#include "object.h"
#include "vclip.h"
#include "game.h"
#include "robot.h"
#include "sounds.h"
#include "player.h"
#include "gauges.h"
#include "powerup.h"
#include "bm.h"
#include "ai.h"
#include "weapon.h"
#include "fireball.h"
#include "collide.h"
#include "newmenu.h"
#include "gameseq.h"
#include "physics.h"
#include "scores.h"
#include "laser.h"
#include "wall.h"
#include "multi.h"
#include "endlevel.h"
#include "timer.h"
#include "fuelcen.h"
#include "playsave.h"
#include "cntrlcen.h"
#include "gameseg.h"
#include "automap.h"
#include "byteutil.h"

#include "compiler-range_for.h"
#include "highest_valid.h"
#include "partial_range.h"
#include "segiter.h"

using std::min;

#define EXPLOSION_SCALE (F1_0*5/2)		//explosion is the obj size times this 

//--unused-- ubyte	Frame_processed[MAX_OBJECTS];

namespace dsx {

#if defined(DXX_BUILD_DESCENT_II)
fix	Flash_effect=0;
static const int	PK1=1, PK2=8;
#endif

static objptridx_t object_create_explosion_sub(const objptridx_t objp, const vsegptridx_t segnum, const vms_vector &position, fix size, int vclip_type, fix maxdamage, fix maxdistance, fix maxforce, const cobjptridx_t parent )
{
	auto obj = obj_create( OBJ_FIREBALL,vclip_type,segnum,position,&vmd_identity_matrix,size,
					CT_EXPLOSION,MT_NONE,RT_FIREBALL);

	if (obj == object_none) {
		return obj;
	}

	//now set explosion-specific data

	obj->lifeleft = Vclip[vclip_type ].play_time;
	obj->ctype.expl_info.spawn_time = -1;
	obj->ctype.expl_info.delete_objnum = object_none;
	obj->ctype.expl_info.delete_time = -1;

	if (maxdamage > 0) {
		fix force;
		vms_vector pos_hit, vforce;
		fix damage;
		// -- now legal for badass explosions on a wall. Assert(objp != NULL);

		range_for (const auto &&obj0p, highest_valid(vobjptridx))
		{
			//	Weapons used to be affected by badass explosions, but this introduces serious problems.
			//	When a smart bomb blows up, if one of its children goes right towards a nearby wall, it will
			//	blow up, blowing up all the children.  So I remove it.  MK, 09/11/94

#if defined(DXX_BUILD_DESCENT_I)
			if ( (obj0p->type == OBJ_CNTRLCEN) ||
				(obj0p->type==OBJ_PLAYER) ||
				(
					obj0p->type == OBJ_ROBOT &&
					parent != object_none &&
					(parent->type != OBJ_ROBOT || get_robot_id(parent) != obj0p->id)
				)
			)
#elif defined(DXX_BUILD_DESCENT_II)
			if ( !(obj0p==objp) &&
				!(obj0p->flags&OF_SHOULD_BE_DEAD) &&
				((obj0p->type==OBJ_WEAPON && (is_proximity_bomb_or_smart_mine_or_placed_mine(get_weapon_id(obj0p)))) ||
				 (obj0p->type == OBJ_CNTRLCEN) ||
				 (obj0p->type==OBJ_PLAYER) ||
				(
					obj0p->type == OBJ_ROBOT &&
					parent != object_none &&
					(parent->type != OBJ_ROBOT || get_robot_id(parent) != obj0p->id)
				)
				 ))
#endif
			{
				const auto dist = vm_vec_dist_quick( obj0p->pos, obj->pos );
				// Make damage be from 'maxdamage' to 0.0, where 0.0 is 'maxdistance' away;
				if ( dist < maxdistance ) {
					if (object_to_object_visibility(obj, obj0p, FQ_TRANSWALL)) {

						damage = maxdamage - fixmuldiv( dist, maxdamage, maxdistance );
						force = maxforce - fixmuldiv( dist, maxforce, maxdistance );

						// Find the force vector on the object
						vm_vec_normalized_dir_quick( vforce, obj0p->pos, obj->pos );
						vm_vec_scale(vforce, force );
	
						// Find where the point of impact is... ( pos_hit )
						vm_vec_scale(vm_vec_sub(pos_hit, obj->pos, obj0p->pos), fixdiv(obj0p->size, obj0p->size + dist));
	
						switch ( obj0p->type )	{
#if defined(DXX_BUILD_DESCENT_II)
							case OBJ_WEAPON:
								phys_apply_force(obj0p,vforce);

								if (is_proximity_bomb_or_smart_mine(get_weapon_id(obj0p)))
								{		//prox bombs have chance of blowing up
									if (fixmul(dist,force) > i2f(8000)) {
										obj0p->flags |= OF_SHOULD_BE_DEAD;
										explode_badass_weapon(obj0p, obj0p->pos);
									}
								}
								break;
#endif
							case OBJ_ROBOT:
								{
								phys_apply_force(obj0p,vforce);
#if defined(DXX_BUILD_DESCENT_II)
								//	If not a boss, stun for 2 seconds at 32 force, 1 second at 16 force
								if ((objp != object_none) && (!Robot_info[get_robot_id(obj0p)].boss_flag) && (Weapon_info[get_weapon_id(objp)].flash)) {
									ai_static	*aip = &obj0p->ctype.ai_info;
									int			force_val = f2i(fixdiv(vm_vec_mag_quick(vforce) * Weapon_info[get_weapon_id(objp)].flash, FrameTime)/128) + 2;

									if (obj->ctype.ai_info.SKIP_AI_COUNT * FrameTime < F1_0) {
										aip->SKIP_AI_COUNT += force_val;
										obj0p->mtype.phys_info.rotthrust.x = ((d_rand() - 16384) * force_val)/16;
										obj0p->mtype.phys_info.rotthrust.y = ((d_rand() - 16384) * force_val)/16;
										obj0p->mtype.phys_info.rotthrust.z = ((d_rand() - 16384) * force_val)/16;
										obj0p->mtype.phys_info.flags |= PF_USES_THRUST;

										//@@if (Robot_info[obj0p->id].companion)
										//@@	buddy_message("Daisy, Daisy, Give me...");
									} else
										aip->SKIP_AI_COUNT--;
								}
#endif

								//	When a robot gets whacked by a badass force, he looks towards it because robots tend to get blasted from behind.
								{
									vms_vector neg_vforce;
									neg_vforce.x = vforce.x * -2 * (7 - Difficulty_level)/8;
									neg_vforce.y = vforce.y * -2 * (7 - Difficulty_level)/8;
									neg_vforce.z = vforce.z * -2 * (7 - Difficulty_level)/8;
									phys_apply_rot(obj0p,neg_vforce);
								}
								if ( obj0p->shields >= 0 ) {
#if defined(DXX_BUILD_DESCENT_II)
									const auto &robot_info = Robot_info[get_robot_id(obj0p)];
									if (robot_info.boss_flag >= BOSS_D2 && Boss_invulnerable_matter[robot_info.boss_flag - BOSS_D2])
											damage /= 4;
#endif
									if (apply_damage_to_robot(obj0p, damage, parent))
										if ((objp != object_none) && (parent == get_local_player().objnum))
											add_points_to_score(Robot_info[get_robot_id(obj0p)].score_value);
								}
#if defined(DXX_BUILD_DESCENT_II)
								if (objp != object_none && Robot_info[get_robot_id(obj0p)].companion && !Weapon_info[get_weapon_id(objp)].flash)
								{
									static const char ouch_str[] = "ouch! " "ouch! " "ouch! " "ouch! ";
									int	count;

									count = f2i(damage/8);
									if (count > 4)
										count = 4;
									else if (count <= 0)
										count = 1;
									buddy_message_str(&ouch_str[(4 - count) * 6]);
								}
#endif
								break;
								}
							case OBJ_CNTRLCEN:
								if (parent != object_none && obj0p->shields >= 0)
								{
									apply_damage_to_controlcen(obj0p, damage, parent );
								}
								break;
							case OBJ_PLAYER:	{
								cobjptridx_t killer = object_none;
								vms_vector	vforce2;
#if defined(DXX_BUILD_DESCENT_II)
								//	Hack! Warning! Test code!
								if (objp != object_none && Weapon_info[get_weapon_id(objp)].flash && get_player_id(obj0p) == Player_num)
								{
									int	fe;

									fe = min(F1_0 * 4, force*Weapon_info[get_weapon_id(objp)].flash / 32);	//	For four seconds or less

									if (objp->ctype.laser_info.parent_signature == ConsoleObject->signature) {
										fe /= 2;
										force /= 2;
									}
									if (force > F1_0) {
										Flash_effect = fe;
										PALETTE_FLASH_ADD(PK1 + f2i(PK2*force), PK1 + f2i(PK2*force), PK1 + f2i(PK2*force));
									}
								}
#endif
								if ((objp != object_none) && (Game_mode & GM_MULTI) && (objp->type == OBJ_PLAYER)) {
									killer = objp;
								}
								vforce2 = vforce;
								if (parent != object_none ) {
									killer = parent;
									if (killer != ConsoleObject)		// if someone else whacks you, cut force by 2x
										vforce2.x /= 2;	vforce2.y /= 2;	vforce2.z /= 2;
								}
								vforce2.x /= 2;	vforce2.y /= 2;	vforce2.z /= 2;

								phys_apply_force(obj0p,vforce);
								phys_apply_rot(obj0p,vforce2);
#if defined(DXX_BUILD_DESCENT_II)
								if (Difficulty_level == 0)
									damage /= 4;
#endif
								if ( obj0p->shields >= 0 )
									apply_damage_to_player(obj0p, killer, damage, 1 );
							}
								break;

							default:
								Int3();	//	Illegal object type
						}	// end switch
					} else {
						;
					}	// end if (object_to_object_visibility...
				}	// end if (dist < maxdistance)
			}
		}	// end for
	}	// end if (maxdamage...

	return obj;

}

void object_create_muzzle_flash(const vsegptridx_t segnum, const vms_vector &position, fix size, int vclip_type )
{
	object_create_explosion_sub(object_none, segnum, position, size, vclip_type, 0, 0, 0, object_none );
}

objptridx_t object_create_explosion(const vsegptridx_t segnum, const vms_vector &position, fix size, int vclip_type )
{
	return object_create_explosion_sub(object_none, segnum, position, size, vclip_type, 0, 0, 0, object_none );
}

objptridx_t object_create_badass_explosion(const objptridx_t objp, const vsegptridx_t segnum, const vms_vector &position, fix size, int vclip_type, fix maxdamage, fix maxdistance, fix maxforce, const cobjptridx_t parent )
{
	const objptridx_t rval = object_create_explosion_sub(objp, segnum, position, size, vclip_type, maxdamage, maxdistance, maxforce, parent );

	if ((objp != object_none) && (objp->type == OBJ_WEAPON))
		create_weapon_smart_children(objp);
	return rval;
}

//blows up a badass weapon, creating the badass explosion
//return the explosion object
void explode_badass_weapon(const vobjptridx_t obj,const vms_vector &pos)
{
	const auto weapon_id = get_weapon_id(obj);
	const weapon_info *wi = &Weapon_info[weapon_id];

	Assert(wi->damage_radius);
#if defined(DXX_BUILD_DESCENT_II)
	if (weapon_id == weapon_id_type::EARTHSHAKER_ID || weapon_id == weapon_id_type::ROBOT_EARTHSHAKER_ID)
		smega_rock_stuff();
#endif
	digi_link_sound_to_object(SOUND_BADASS_EXPLOSION, obj, 0, F1_0);

	object_create_badass_explosion(obj, obj->segnum, pos,
	                                      wi->impact_size,
	                                      wi->robot_hit_vclip,
	                                      wi->strength[Difficulty_level],
	                                      wi->damage_radius,wi->strength[Difficulty_level],
	                                      objptridx(obj->ctype.laser_info.parent_num));

}

static void explode_badass_object(const vobjptridx_t objp, fix damage, fix distance, fix force)
{
	const objptridx_t rval = object_create_badass_explosion(objp, objp->segnum, objp->pos, objp->size,
					get_explosion_vclip(objp, explosion_vclip_stage::s0),
					damage, distance, force,
					objp);
	if (rval != object_none)
		digi_link_sound_to_object(SOUND_BADASS_EXPLOSION, rval, 0, F1_0);
}

//blows up the player with a badass explosion
//return the explosion object
void explode_badass_player(const vobjptridx_t objp)
{
	explode_badass_object(objp, F1_0*50, F1_0*40, F1_0*150);
}


#define DEBRIS_LIFE (f1_0 * (PERSISTENT_DEBRIS?60:2))		//lifespan in seconds

static void object_create_debris(const vobjptr_t parent, int subobj_num)
{
	Assert((parent->type == OBJ_ROBOT) || (parent->type == OBJ_PLAYER)  );

	auto obj = obj_create(OBJ_DEBRIS,0,parent->segnum,parent->pos,
				&parent->orient,Polygon_models[parent->rtype.pobj_info.model_num].submodel_rads[subobj_num],
				CT_DEBRIS,MT_PHYSICS,RT_POLYOBJ);

	if ((obj == object_none ) && (Highest_object_index >= MAX_OBJECTS-1)) {
//		Int3(); // this happens often and is normal :-)
		return;
	}
	if ( obj == object_none )
		return;				// Not enough debris slots!

	Assert(subobj_num < 32);

	//Set polygon-object-specific data

	obj->rtype.pobj_info.model_num = parent->rtype.pobj_info.model_num;
	obj->rtype.pobj_info.subobj_flags = 1<<subobj_num;
	obj->rtype.pobj_info.tmap_override = parent->rtype.pobj_info.tmap_override;

	//Set physics data for this object

	obj->mtype.phys_info.velocity.x = D_RAND_MAX/2 - d_rand();
	obj->mtype.phys_info.velocity.y = D_RAND_MAX/2 - d_rand();
	obj->mtype.phys_info.velocity.z = D_RAND_MAX/2 - d_rand();
	vm_vec_normalize_quick(obj->mtype.phys_info.velocity);
	vm_vec_scale(obj->mtype.phys_info.velocity,i2f(10 + (30 * d_rand() / D_RAND_MAX)));

	vm_vec_add2(obj->mtype.phys_info.velocity,parent->mtype.phys_info.velocity);

	// -- used to be: Notice, not random! vm_vec_make(&obj->mtype.phys_info.rotvel,10*0x2000/3,10*0x4000/3,10*0x7000/3);
	obj->mtype.phys_info.rotvel = {d_rand() + 0x1000, d_rand()*2 + 0x4000, d_rand()*3 + 0x2000};
	vm_vec_zero(obj->mtype.phys_info.rotthrust);

	obj->lifeleft = 3*DEBRIS_LIFE/4 + fixmul(d_rand(), DEBRIS_LIFE);	//	Some randomness, so they don't all go away at the same time.

	obj->mtype.phys_info.mass = fixmuldiv(parent->mtype.phys_info.mass,obj->size,parent->size);
	obj->mtype.phys_info.drag = 0; //fl2f(0.2);		//parent->mtype.phys_info.drag;

	if (PERSISTENT_DEBRIS)
	{
		obj->mtype.phys_info.flags |= PF_BOUNCE;
		obj->mtype.phys_info.drag = 128;
	}
}

void draw_fireball(const vobjptridx_t obj)
{
	if ( obj->lifeleft > 0 )
		draw_vclip_object(obj,obj->lifeleft,0, get_fireball_id(obj));
}

// --------------------------------------------------------------------------------------------------------------------
//	Return true if there is a door here and it is openable
//	It is assumed that the player has all keys.
static int door_is_openable_by_player(const vcsegptr_t segp, int sidenum)
{
	int	wall_type;

	auto wall_num = segp->sides[sidenum].wall_num;
	wall_type = Walls[wall_num].type;

	if (wall_num == wall_none)
		return 0;						//	no wall here.

	//	Can't open locked doors.
	if (((wall_type == WALL_DOOR) && (Walls[wall_num].flags & WALL_DOOR_LOCKED)) || (wall_type == WALL_CLOSED))
		return 0;

	return 1;

}

#define	QUEUE_SIZE	64

// --------------------------------------------------------------------------------------------------------------------
//	Return a segment %i segments away from initial segment.
//	Returns -1 if can't find a segment that distance away.
segidx_t pick_connected_segment(const vcobjptr_t objp, int max_depth)
{
	using std::swap;
	int		i;
	int		cur_depth;
	int		start_seg;
	int		head, tail;
	array<segnum_t, QUEUE_SIZE * 2> seg_queue{};
	sbyte   depth[MAX_SEGMENTS];
	sbyte   side_rand[MAX_SIDES_PER_SEGMENT];

	visited_segment_bitarray_t visited;
	memset(depth, 0, Highest_segment_index+1);

	start_seg = objp->segnum;
	head = 0;
	tail = 0;
	seg_queue[head++] = start_seg;

	cur_depth = 0;

	for (i=0; i<MAX_SIDES_PER_SEGMENT; i++)
		side_rand[i] = i;

	//	Now, randomize a bit to start, so we don't always get started in the same direction.
	for (i=0; i<4; i++) {
		int	ind1;

		ind1 = (d_rand() * MAX_SIDES_PER_SEGMENT) >> 15;
		swap(side_rand[ind1], side_rand[i]);
	}

	while (tail != head) {
		int		sidenum, count;
		int		ind1, ind2;

		if (cur_depth >= max_depth) {
			return seg_queue[tail];
		}

		const auto &&segp = vcsegptr(seg_queue[tail++]);
		tail &= QUEUE_SIZE-1;

		//	to make random, switch a pair of entries in side_rand.
		ind1 = (d_rand() * MAX_SIDES_PER_SEGMENT) >> 15;
		ind2 = (d_rand() * MAX_SIDES_PER_SEGMENT) >> 15;
		swap(side_rand[ind1], side_rand[ind2]);
		count = 0;
		for (sidenum=ind1; count<MAX_SIDES_PER_SEGMENT; count++) {
			int	snrand;

			if (sidenum == MAX_SIDES_PER_SEGMENT)
				sidenum = 0;

			snrand = side_rand[sidenum];
			auto wall_num = segp->sides[snrand].wall_num;
			sidenum++;

			if ((wall_num == wall_none || door_is_openable_by_player(segp, snrand)) && IS_CHILD(segp->children[snrand]))
			{
				if (!visited[segp->children[snrand]]) {
					seg_queue[head++] = segp->children[snrand];
					visited[segp->children[snrand]] = true;
					depth[segp->children[snrand]] = cur_depth+1;
					head &= QUEUE_SIZE-1;
					if (head > tail) {
						if (head == tail + QUEUE_SIZE-1)
							Int3();	//	queue overflow.  Make it bigger!
					} else
						if (head+QUEUE_SIZE == tail + QUEUE_SIZE-1)
							Int3();	//	queue overflow.  Make it bigger!
				}
			}
		}

		if (seg_queue[tail] > Highest_segment_index)
		{
			// -- Int3();	//	Something bad has happened.  Queue is trashed.  --MK, 12/13/94
			return segment_none;
		}
		cur_depth = depth[seg_queue[tail]];
	}
	return segment_none;
}

#if defined(DXX_BUILD_DESCENT_I)
#define BASE_NET_DROP_DEPTH 10
#elif defined(DXX_BUILD_DESCENT_II)
#define BASE_NET_DROP_DEPTH 8
#endif

//	------------------------------------------------------------------------------------------------------
//	Choose segment to drop a powerup in.
//	For all active net players, try to create a N segment path from the player.  If possible, return that
//	segment.  If not possible, try another player.  After a few tries, use a random segment.
//	Don't drop if control center in segment.
static segnum_t choose_drop_segment()
{
	playernum_t	pnum = 0;
	int	cur_drop_depth;
	int	count;
	vms_vector *player_pos;

	d_srand((fix)timer_query());

	cur_drop_depth = BASE_NET_DROP_DEPTH + ((d_rand() * BASE_NET_DROP_DEPTH*2) >> 15);

	player_pos = &get_local_plrobj().pos;
	const auto player_seg = get_local_plrobj().segnum;

	segnum_t	segnum = segment_none;
	while ((segnum == segment_none) && (cur_drop_depth > BASE_NET_DROP_DEPTH/2)) {
		pnum = (d_rand() * N_players) >> 15;
		count = 0;
#if defined(DXX_BUILD_DESCENT_I)
		while ((count < N_players) && ((Players[pnum].connected == CONNECT_DISCONNECTED) || (pnum==Player_num)))
#elif defined(DXX_BUILD_DESCENT_II)
		while ((count < N_players) && ((Players[pnum].connected == CONNECT_DISCONNECTED) || (pnum==Player_num) || ((Game_mode & (GM_TEAM|GM_CAPTURE)) && (get_team(pnum)==get_team(Player_num)))))
#endif
		{
			pnum = (pnum+1)%N_players;
			count++;
		}

		if (count == N_players) {
			//if can't valid non-player person, use the player
			pnum = Player_num;
		}

		segnum = pick_connected_segment(vcobjptr(Players[pnum].objnum), cur_drop_depth);
		if (segnum == segment_none)
		{
			cur_drop_depth--;
			continue;
		}
		if (Segments[segnum].special == SEGMENT_IS_CONTROLCEN)
		{
			segnum = segment_none;
		}
		else {	//don't drop in any children of control centers
			int i;
			for (i=0;i<6;i++) {
				auto ch = Segments[segnum].children[i];
				if (IS_CHILD(ch) && Segments[ch].special == SEGMENT_IS_CONTROLCEN) {
					segnum = segment_none;
					break;
				}
			}
		}

		//bail if not far enough from original position
		if (segnum != segment_none) {
			const auto &&tempv = compute_segment_center(vcsegptr(segnum));
			if (find_connected_distance(*player_pos,player_seg,tempv,segnum,-1,WID_FLY_FLAG) < i2f(20)*cur_drop_depth) {
				segnum = segment_none;
			}
		}

		cur_drop_depth--;
	}

	if (segnum == segment_none) {
		cur_drop_depth = BASE_NET_DROP_DEPTH;
		while (cur_drop_depth > 0 && segnum == segment_none) // before dropping in random segment, try to find ANY segment which is connected to the player responsible for the drop so object will not spawn in inaccessible areas
		{
			segnum = pick_connected_segment(vcobjptr(get_local_player().objnum), --cur_drop_depth);
			if (segnum != segment_none && vcsegptr(segnum)->special == SEGMENT_IS_CONTROLCEN)
				segnum = segment_none;
		}
		return ((segnum == segment_none)?((d_rand() * Highest_segment_index) >> 15):segnum); // basically it should be impossible segnum == -1 now... but oh well...
	} else
		return segnum;

}

//	------------------------------------------------------------------------------------------------------
//	Drop cloak powerup if in a network game.
void maybe_drop_net_powerup(powerup_type_t powerup_type)
{
	if ((Game_mode & GM_MULTI) && !(Game_mode & GM_MULTI_COOP)) {
		if (Game_mode & GM_NETWORK)
		{
			if (!PowerupCaps.can_add_powerup(powerup_type))
				return;
		}

		if (Control_center_destroyed || (Network_status == NETSTAT_ENDLEVEL))
			return;

//--old-- 		segnum = (d_rand() * Highest_segment_index) >> 15;
//--old-- 		Assert((segnum >= 0) && (segnum <= Highest_segment_index));
//--old-- 		if (segnum < 0)
//--old-- 			segnum = -segnum;
//--old-- 		while (segnum > Highest_segment_index)
//--old-- 			segnum /= 2;

		Net_create_loc = 0;
		const auto &&objnum = call_object_create_egg(vobjptr(get_local_player().objnum), 1, OBJ_POWERUP, powerup_type);

		if (objnum == object_none)
			return;

		const auto &&segnum = choose_drop_segment();
		const auto &&new_pos = pick_random_point_in_seg(vcsegptr(segnum));
		multi_send_create_powerup(powerup_type, segnum, objnum, new_pos);
		objnum->pos = new_pos;
		vm_vec_zero(objnum->mtype.phys_info.velocity);
		obj_relink(objnum, segnum);

		object_create_explosion(segnum, new_pos, i2f(5), VCLIP_POWERUP_DISAPPEARANCE );
	}
}

//	------------------------------------------------------------------------------------------------------
//	Return true if current segment contains some object.
static csegptr_t segment_contains_powerup(const vcsegptr_t segnum, const powerup_type_t obj_id)
{
	range_for (const auto objp, objects_in(segnum))
		if (objp->type == OBJ_POWERUP && get_powerup_id(objp) == obj_id)
			return segnum;
	return segment_none;
}

//	------------------------------------------------------------------------------------------------------
static csegptr_t powerup_nearby_aux(const vcsegptr_t segnum, powerup_type_t object_id, uint_fast32_t depth)
{
	if (auto r = segment_contains_powerup(segnum, object_id))
		return r;
	if (! -- depth)
		return segment_none;
	range_for (const auto seg2, segnum->children)
	{
		if (seg2 != segment_none)
			if (auto r = powerup_nearby_aux(vcsegptr(seg2), object_id, depth))
				return r;
	}
	return segment_none;
}


//	------------------------------------------------------------------------------------------------------
//	Return true if some powerup is nearby (within 3 segments).
static csegptr_t weapon_nearby(const vobjptr_t objp, powerup_type_t weapon_id)
{
	return powerup_nearby_aux(vcsegptr(objp->segnum), weapon_id, 2);
}

//	------------------------------------------------------------------------------------------------------
void maybe_replace_powerup_with_energy(const vobjptr_t del_obj)
{
	int	weapon_index=-1;

	if (del_obj->contains_type != OBJ_POWERUP)
		return;

	if (del_obj->contains_id == POW_CLOAK) {
		if (weapon_nearby(del_obj, static_cast<powerup_type_t>(del_obj->contains_id)) != nullptr)
		{
			del_obj->contains_count = 0;
		}
		return;
	}
	switch (del_obj->contains_id) {
		case POW_VULCAN_WEAPON:
			weapon_index = primary_weapon_index_t::VULCAN_INDEX;
			break;
		case POW_SPREADFIRE_WEAPON:
			weapon_index = primary_weapon_index_t::SPREADFIRE_INDEX;
			break;
		case POW_PLASMA_WEAPON:
			weapon_index = primary_weapon_index_t::PLASMA_INDEX;
			break;
		case POW_FUSION_WEAPON:
			weapon_index = primary_weapon_index_t::FUSION_INDEX;
			break;
#if defined(DXX_BUILD_DESCENT_II)
		case POW_GAUSS_WEAPON:
			weapon_index = primary_weapon_index_t::GAUSS_INDEX;
			break;
		case POW_HELIX_WEAPON:
			weapon_index = primary_weapon_index_t::HELIX_INDEX;
			break;
		case POW_PHOENIX_WEAPON:
			weapon_index = primary_weapon_index_t::PHOENIX_INDEX;
			break;
		case POW_OMEGA_WEAPON:
			weapon_index = primary_weapon_index_t::OMEGA_INDEX;
			break;
#endif
	}

	//	Don't drop vulcan ammo if player maxed out.
	if ((weapon_index_uses_vulcan_ammo(weapon_index) || (del_obj->contains_id == POW_VULCAN_AMMO)) && (get_local_player_vulcan_ammo() >= VULCAN_AMMO_MAX))
		del_obj->contains_count = 0;
	else if (weapon_index != -1) {
		if (player_has_primary_weapon(weapon_index).has_weapon() || weapon_nearby(del_obj, static_cast<powerup_type_t>(del_obj->contains_id)) != nullptr)
		{
			if (d_rand() > 16384) {
#if defined(DXX_BUILD_DESCENT_I)
				del_obj->contains_count = 1;
#endif
				del_obj->contains_type = OBJ_POWERUP;
				if (weapon_index_uses_vulcan_ammo(weapon_index)) {
					del_obj->contains_id = POW_VULCAN_AMMO;
				}
				else {
					del_obj->contains_id = POW_ENERGY;
				}
			} else {
#if defined(DXX_BUILD_DESCENT_I)
				del_obj->contains_count = 0;
#elif defined(DXX_BUILD_DESCENT_II)
				del_obj->contains_type = OBJ_POWERUP;
				del_obj->contains_id = POW_SHIELD_BOOST;
#endif
			}
		}
	} else if (del_obj->contains_id == POW_QUAD_FIRE)
		if ((get_local_player_flags() & PLAYER_FLAGS_QUAD_LASERS) || weapon_nearby(del_obj, static_cast<powerup_type_t>(del_obj->contains_id)) != nullptr)
		{
			if (d_rand() > 16384) {
#if defined(DXX_BUILD_DESCENT_I)
				del_obj->contains_count = 1;
#endif
				del_obj->contains_type = OBJ_POWERUP;
				del_obj->contains_id = POW_ENERGY;
			} else {
#if defined(DXX_BUILD_DESCENT_I)
				del_obj->contains_count = 0;
#elif defined(DXX_BUILD_DESCENT_II)
				del_obj->contains_type = OBJ_POWERUP;
				del_obj->contains_id = POW_SHIELD_BOOST;
#endif
			}
		}

	//	If this robot was gated in by the boss and it now contains energy, make it contain nothing,
	//	else the room gets full of energy.
	if ( (del_obj->matcen_creator == BOSS_GATE_MATCEN_NUM) && (del_obj->contains_id == POW_ENERGY) && (del_obj->contains_type == OBJ_POWERUP) ) {
		del_obj->contains_count = 0;
	}

	// Change multiplayer extra-lives into invulnerability
	if ((Game_mode & GM_MULTI) && (del_obj->contains_id == POW_EXTRA_LIFE))
	{
		del_obj->contains_id = POW_INVULNERABILITY;
	}
}

#if defined(DXX_BUILD_DESCENT_I)
static
#endif
objptridx_t drop_powerup(int type, int id, int num, const vms_vector &init_vel, const vms_vector &pos, const vsegptridx_t segnum)
{
	objptridx_t	objnum = object_none;
	vms_vector	new_pos;
   int             count;

	switch (type) {
		case OBJ_POWERUP:
			for (count=0; count<num; count++) {
				int	rand_scale;
				auto new_velocity = init_vel;
				const auto old_mag = vm_vec_mag_quick(init_vel);

				//	We want powerups to move more in network mode.
				if ((Game_mode & GM_MULTI) && !(Game_mode & GM_MULTI_ROBOTS)) {
					rand_scale = 4;
					//	extra life powerups are converted to invulnerability in multiplayer, for what is an extra life, anyway?
					if (id == POW_EXTRA_LIFE)
						id = POW_INVULNERABILITY;
				} else
					rand_scale = 2;

				new_velocity.x += fixmul(old_mag+F1_0*32, d_rand()*rand_scale - 16384*rand_scale);
				new_velocity.y += fixmul(old_mag+F1_0*32, d_rand()*rand_scale - 16384*rand_scale);
				new_velocity.z += fixmul(old_mag+F1_0*32, d_rand()*rand_scale - 16384*rand_scale);

				// Give keys zero velocity so they can be tracked better in multi

				if ((Game_mode & GM_MULTI) && (id >= POW_KEY_BLUE) && (id <= POW_KEY_GOLD))
					vm_vec_zero(new_velocity);

				new_pos = pos;
//				new_pos.x += (d_rand()-16384)*8;
//				new_pos.y += (d_rand()-16384)*8;
//				new_pos.z += (d_rand()-16384)*8;

				if (Game_mode & GM_MULTI)
				{	
					if (Net_create_loc >= MAX_NET_CREATE_OBJECTS)
					{
						return object_none;
					}
#if defined(DXX_BUILD_DESCENT_II)
					if ((Game_mode & GM_NETWORK) && Network_status == NETSTAT_ENDLEVEL)
					 return object_none;
#endif
				}
				auto		obj = obj_create( OBJ_POWERUP, id, segnum, new_pos, &vmd_identity_matrix, Powerup_info[id].size, CT_POWERUP, MT_PHYSICS, RT_POWERUP);
				objnum = obj;

				if (objnum == object_none ) {
					Int3();
					return objnum;
				}

				if (Game_mode & GM_MULTI)
				{
					Net_create_objnums[Net_create_loc++] = objnum;
				}
				obj->mtype.phys_info.velocity = new_velocity;

				obj->mtype.phys_info.drag = 512;	//1024;
				obj->mtype.phys_info.mass = F1_0;

				obj->mtype.phys_info.flags = PF_BOUNCE;

				obj->rtype.vclip_info.vclip_num = Powerup_info[get_powerup_id(obj)].vclip_num;
				obj->rtype.vclip_info.frametime = Vclip[obj->rtype.vclip_info.vclip_num].frame_time;
				obj->rtype.vclip_info.framenum = 0;

				switch (get_powerup_id(obj)) {
					case POW_MISSILE_1:
					case POW_MISSILE_4:
					case POW_SHIELD_BOOST:
					case POW_ENERGY:
						obj->lifeleft = (d_rand() + F1_0*3) * 64;		//	Lives for 3 to 3.5 binary minutes (a binary minute is 64 seconds)
						if (Game_mode & GM_MULTI)
							obj->lifeleft /= 2;
						break;
					default:
//						if (Game_mode & GM_MULTI)
//							obj->lifeleft = (d_rand() + F1_0*3) * 64;		//	Lives for 5 to 5.5 binary minutes (a binary minute is 64 seconds)
						break;
				}
			}
			break;

		case OBJ_ROBOT:
			for (count=0; count<num; count++) {
				int	rand_scale;
				auto new_velocity = vm_vec_normalized_quick(init_vel);
				const auto old_mag = vm_vec_mag_quick(init_vel);

				//	We want powerups to move more in network mode.
//				if (Game_mode & GM_MULTI)
//					rand_scale = 4;
//				else
					rand_scale = 2;

				new_velocity.x += (d_rand()-16384)*2;
				new_velocity.y += (d_rand()-16384)*2;
				new_velocity.z += (d_rand()-16384)*2;

				vm_vec_normalize_quick(new_velocity);
				vm_vec_scale(new_velocity, (F1_0*32 + old_mag) * rand_scale);
				new_pos = pos;
				//	This is dangerous, could be outside mine.
//				new_pos.x += (d_rand()-16384)*8;
//				new_pos.y += (d_rand()-16384)*7;
//				new_pos.z += (d_rand()-16384)*6;

#if defined(DXX_BUILD_DESCENT_I)
				auto obj = obj_create(OBJ_ROBOT, id, segnum, new_pos, &vmd_identity_matrix, Polygon_models[Robot_info[ObjId[type]].model_num].rad, CT_AI, MT_PHYSICS, RT_POLYOBJ);
#elif defined(DXX_BUILD_DESCENT_II)
				auto obj = obj_create(OBJ_ROBOT, id, segnum, new_pos, &vmd_identity_matrix, Polygon_models[Robot_info[id].model_num].rad, CT_AI, MT_PHYSICS, RT_POLYOBJ);
#endif

				objnum = obj;
				if ( objnum == object_none ) {
					Int3();
					return objnum;
				}

				if (Game_mode & GM_MULTI)
				{
					Net_create_objnums[Net_create_loc++] = objnum;
				}
				//Set polygon-object-specific data

				obj->rtype.pobj_info.model_num = Robot_info[get_robot_id(obj)].model_num;
				obj->rtype.pobj_info.subobj_flags = 0;

				//set Physics info
		
				obj->mtype.phys_info.velocity = new_velocity;

				obj->mtype.phys_info.mass = Robot_info[get_robot_id(obj)].mass;
				obj->mtype.phys_info.drag = Robot_info[get_robot_id(obj)].drag;

				obj->mtype.phys_info.flags |= (PF_LEVELLING);

				obj->shields = Robot_info[get_robot_id(obj)].strength;

				obj->ctype.ai_info.behavior = ai_behavior::AIB_NORMAL;
				ai_local		*ailp = &obj->ctype.ai_info.ail;
				ailp->player_awareness_type = player_awareness_type_t::PA_WEAPON_ROBOT_COLLISION;
				ailp->player_awareness_time = F1_0*3;
				obj->ctype.ai_info.CURRENT_STATE = AIS_LOCK;
				obj->ctype.ai_info.GOAL_STATE = AIS_LOCK;
				obj->ctype.ai_info.REMOTE_OWNER = -1;
			}

#if defined(DXX_BUILD_DESCENT_II)
			// At JasenW's request, robots which contain robots
			// sometimes drop shields.
			if (d_rand() > 16384)
				drop_powerup(OBJ_POWERUP, POW_SHIELD_BOOST, 1, init_vel, pos, segnum);
#endif
			break;

		default:
			Error("Error: Illegal type (%i) in object spawning.\n", type);
	}

	return objnum;
}

#if defined(DXX_BUILD_DESCENT_II)
static bool skip_create_egg_powerup(powerup_type_t powerup)
{
	fix current;
	if (powerup == POW_SHIELD_BOOST)
		current = get_local_player_shields();
	else if (powerup == POW_ENERGY)
		current = get_local_player_energy();
	else
		return false;
	int limit;
	if (current >= i2f(150))
		limit = 8192;
	else if (current >= i2f(100))
		limit = 16384;
	else
		return false;
	return d_rand() > limit;
}
#endif

// ----------------------------------------------------------------------------
// Returns created object number.
// If object dropped by player, set flag.
static objptridx_t object_create_player_egg(int type, int id, int num, const vms_vector &init_vel, const vms_vector &pos, const vsegptridx_t segnum)
{
	const auto rval = drop_powerup(type, id, num, init_vel, pos, segnum);
#if defined(DXX_BUILD_DESCENT_II)
	if (rval != object_none)
		rval->flags |= OF_PLAYER_DROPPED;
#endif
	return rval;
}

objptridx_t object_create_robot_egg(int type, int id, int num, const vms_vector &init_vel, const vms_vector &pos, const vsegptridx_t segnum)
{
#if defined(DXX_BUILD_DESCENT_II)
	if (!(Game_mode & GM_MULTI))
	{
		if (type == OBJ_POWERUP)
		{
			if (skip_create_egg_powerup(static_cast<powerup_type_t>(id)))
				return object_none;
		}
	}
#endif
	const auto rval = drop_powerup(type, id, num, init_vel, pos, segnum);
#if defined(DXX_BUILD_DESCENT_II)
	if (rval != object_none)
	{
		if (type == OBJ_POWERUP)
		{
			if (id == POW_VULCAN_WEAPON || id == POW_GAUSS_WEAPON)
				rval->ctype.powerup_info.count = VULCAN_WEAPON_AMMO_AMOUNT;
			else if (id == POW_OMEGA_WEAPON)
				rval->ctype.powerup_info.count = MAX_OMEGA_CHARGE;
		}
	}
#endif
	return rval;
}

objptridx_t object_create_robot_egg(const vobjptr_t objp)
{
	return object_create_robot_egg(objp->contains_type, objp->contains_id, objp->contains_count, objp->mtype.phys_info.velocity, objp->pos, objp->segnum);
}

// -- extern int Items_destroyed;

//	-------------------------------------------------------------------------------------------------------
//	Put count objects of type type (eg, powerup), id = id (eg, energy) into *objp, then drop them!  Yippee!
//	Returns created object number.
objptridx_t call_object_create_egg(const vobjptr_t objp, int count, int type, int id)
{
	if (count > 0) {
		return object_create_player_egg(type, id, count, objp->mtype.phys_info.velocity, objp->pos, objp->segnum);
	}

	return object_none;
}

//what vclip does this explode with?
int get_explosion_vclip(const vcobjptr_t obj, explosion_vclip_stage stage)
{
	if (obj->type==OBJ_ROBOT) {
		const auto vclip_ptr = stage == explosion_vclip_stage::s0
			? &robot_info::exp1_vclip_num
			: &robot_info::exp2_vclip_num;
		const auto vclip_num = Robot_info[get_robot_id(obj)].*vclip_ptr;
		if (vclip_num > -1)
			return vclip_num;
	}
	else if (obj->type==OBJ_PLAYER && Player_ship->expl_vclip_num>-1)
			return Player_ship->expl_vclip_num;

	return VCLIP_SMALL_EXPLOSION;		//default
}

//blow up a polygon model
static void explode_model(const vobjptr_t obj)
{
	Assert(obj->render_type == RT_POLYOBJ);

	const auto poly_model_num = obj->rtype.pobj_info.model_num;
	const auto dying_model_num = Dying_modelnums[poly_model_num];
	const auto model_num = (dying_model_num != -1)
		? (obj->rtype.pobj_info.model_num = dying_model_num)
		: poly_model_num;
	const auto n_models = Polygon_models[model_num].n_models;
	if (n_models > 1) {
		for (unsigned i = 1; i < n_models; ++i)
#if defined(DXX_BUILD_DESCENT_II)
			if (!(i == 5 && obj->type == OBJ_ROBOT && get_robot_id(obj) == 44))	//energy sucker energy part
#endif
				object_create_debris(obj,i);

		//make parent object only draw center part
		obj->rtype.pobj_info.subobj_flags=1;
	}
}

//if the object has a destroyed model, switch to it.  Otherwise, delete it.
static void maybe_delete_object(const vobjptr_t del_obj)
{
	if (Dead_modelnums[del_obj->rtype.pobj_info.model_num] != -1) {
		del_obj->rtype.pobj_info.model_num = Dead_modelnums[del_obj->rtype.pobj_info.model_num];
		del_obj->flags |= OF_DESTROYED;
	}
	else {		//normal, multi-stage explosion
		if (del_obj->type == OBJ_PLAYER)
			del_obj->render_type = RT_NONE;
		else
			del_obj->flags |= OF_SHOULD_BE_DEAD;
	}
}

//	-------------------------------------------------------------------------------------------------------
//blow up an object.  Takes the object to destroy, and the point of impact
void explode_object(const vobjptridx_t hitobj,fix delay_time)
{
	if (hitobj->flags & OF_EXPLODING) return;

	if (delay_time) {		//wait a little while before creating explosion
		//create a placeholder object to do the delay, with id==-1
		auto obj = obj_create( OBJ_FIREBALL,-1,hitobj->segnum,hitobj->pos,&vmd_identity_matrix,0,
						CT_EXPLOSION,MT_NONE,RT_NONE);
		if (obj == object_none ) {
			maybe_delete_object(hitobj);		//no explosion, die instantly
			Int3();
			return;
		}
		//now set explosion-specific data
	
		obj->lifeleft = delay_time;
		obj->ctype.expl_info.delete_objnum = hitobj;
		obj->ctype.expl_info.delete_time = -1;
		obj->ctype.expl_info.spawn_time = 0;

	}
	else {
		int vclip_num;

		vclip_num = get_explosion_vclip(hitobj, explosion_vclip_stage::s0);

		auto expl_obj = object_create_explosion(hitobj->segnum, hitobj->pos, fixmul(hitobj->size,EXPLOSION_SCALE), vclip_num );
	
		if (! expl_obj) {
			maybe_delete_object(hitobj);		//no explosion, die instantly
			return;
		}

		//don't make debris explosions have physics, because they often
		//happen when the debris has hit the wall, so the fireball is trying
		//to move into the wall, which shows off FVI problems.   	
		if (hitobj->type!=OBJ_DEBRIS && hitobj->movement_type==MT_PHYSICS) {
			expl_obj->movement_type = MT_PHYSICS;
			expl_obj->mtype.phys_info = hitobj->mtype.phys_info;
		}
	
		if (hitobj->render_type==RT_POLYOBJ && hitobj->type!=OBJ_DEBRIS)
			explode_model(hitobj);

		maybe_delete_object(hitobj);
	}

	hitobj->flags |= OF_EXPLODING;		//say that this is blowing up
	hitobj->control_type = CT_NONE;		//become inert while exploding

}


//do whatever needs to be done for this piece of debris for this frame
void do_debris_frame(const vobjptridx_t obj)
{
	Assert(obj->control_type == CT_DEBRIS);

	if (obj->lifeleft < 0)
		explode_object(obj,0);

}

//do whatever needs to be done for this explosion for this frame
void do_explosion_sequence(const vobjptr_t obj)
{
	Assert(obj->control_type == CT_EXPLOSION);

	//See if we should die of old age
	if (obj->lifeleft <= 0 ) 	{	// We died of old age
		obj->flags |= OF_SHOULD_BE_DEAD;
		obj->lifeleft = 0;
	}

	//See if we should create a secondary explosion
	if (obj->lifeleft <= obj->ctype.expl_info.spawn_time) {
		auto del_obj = vobjptridx(obj->ctype.expl_info.delete_objnum);
		auto &spawn_pos = del_obj->pos;
		Assert(del_obj->type==OBJ_ROBOT || del_obj->type==OBJ_CLUTTER || del_obj->type==OBJ_CNTRLCEN || del_obj->type == OBJ_PLAYER);
		Assert(del_obj->segnum != segment_none);

		const auto &&expl_obj = [&]{
			const auto vclip_num = get_explosion_vclip(del_obj, explosion_vclip_stage::s1);
#if defined(DXX_BUILD_DESCENT_II)
			if (del_obj->type == OBJ_ROBOT)
			{
				const auto &ri = Robot_info[get_robot_id(del_obj)];
				if (ri.badass)
					return object_create_badass_explosion(object_none, del_obj->segnum, spawn_pos, fixmul(del_obj->size, EXPLOSION_SCALE), vclip_num, F1_0 * ri.badass, i2f(4) * ri.badass, i2f(35) * ri.badass, object_none);
			}
#endif
			return object_create_explosion(del_obj->segnum, spawn_pos, fixmul(del_obj->size, EXPLOSION_SCALE), vclip_num);
		}();

		if ((del_obj->contains_count > 0) && !(Game_mode & GM_MULTI)) { // Multiplayer handled outside of this code!!
			//	If dropping a weapon that the player has, drop energy instead, unless it's vulcan, in which case drop vulcan ammo.
			if (del_obj->contains_type == OBJ_POWERUP)
				maybe_replace_powerup_with_energy(del_obj);
			object_create_robot_egg(del_obj);
		} else if ((del_obj->type == OBJ_ROBOT) && !(Game_mode & GM_MULTI)) { // Multiplayer handled outside this code!!
			robot_info	*robptr = &Robot_info[get_robot_id(del_obj)];
			if (robptr->contains_count) {
				if (((d_rand() * 16) >> 15) < robptr->contains_prob) {
					del_obj->contains_count = ((d_rand() * robptr->contains_count) >> 15) + 1;
					del_obj->contains_type = robptr->contains_type;
					del_obj->contains_id = robptr->contains_id;
					maybe_replace_powerup_with_energy(del_obj);
					object_create_robot_egg(del_obj);
				}
			}
#if defined(DXX_BUILD_DESCENT_II)
			if (robot_is_thief(robptr))
				drop_stolen_items(del_obj);

			if (robot_is_companion(robptr)) {
				DropBuddyMarker(del_obj);
			}
#endif
		}

		const robot_info *robptr = &Robot_info[get_robot_id(del_obj)];
		if ( robptr->exp2_sound_num > -1 )
			digi_link_sound_to_pos( robptr->exp2_sound_num, del_obj->segnum, 0, spawn_pos, 0, F1_0 );
			//PLAY_SOUND_3D( Robot_info[del_obj->id].exp2_sound_num, spawn_pos, del_obj->segnum  );

		obj->ctype.expl_info.spawn_time = -1;

		//make debris
		if (del_obj->render_type==RT_POLYOBJ)
			explode_model(del_obj);		//explode a polygon model

		//set some parm in explosion
		//If num_objects < MAX_USED_OBJECTS, expl_obj could be set to dead before this setting causing the delete_obj not to be removed. If so, directly delete del_obj
		if (expl_obj && !(expl_obj->flags & OF_SHOULD_BE_DEAD))
		{
			if (del_obj->movement_type == MT_PHYSICS) {
				expl_obj->movement_type = MT_PHYSICS;
				expl_obj->mtype.phys_info = del_obj->mtype.phys_info;
			}

			expl_obj->ctype.expl_info.delete_time = expl_obj->lifeleft/2;
			expl_obj->ctype.expl_info.delete_objnum = del_obj;
		}
		else {
			maybe_delete_object(del_obj);
		}

	}

	//See if we should delete an object
	if (obj->lifeleft <= obj->ctype.expl_info.delete_time) {
		const auto &&del_obj = vobjptr(obj->ctype.expl_info.delete_objnum);
		obj->ctype.expl_info.delete_time = -1;
		maybe_delete_object(del_obj);
	}
}

#define EXPL_WALL_TIME					(f1_0)
#define EXPL_WALL_TOTAL_FIREBALLS	32
#if defined(DXX_BUILD_DESCENT_I)
#define EXPL_WALL_FIREBALL_SIZE 		0x48000	//smallest size
#elif defined(DXX_BUILD_DESCENT_II)
#define EXPL_WALL_FIREBALL_SIZE 		(0x48000*6/10)	//smallest size
#endif

}

namespace dcx {

array<expl_wall, MAX_EXPLODING_WALLS> expl_wall_list;

void init_exploding_walls()
{
	range_for (auto &i, expl_wall_list)
		i.segnum = segment_none;
}

}

namespace dsx {

//explode the given wall
void explode_wall(const vsegptridx_t segnum,int sidenum)
{
	//find a free slot
	const auto e = end(expl_wall_list);
	const auto predicate = [](expl_wall &w) {
		return w.segnum == segment_none;
	};
	const auto i = std::find_if(begin(expl_wall_list), e, predicate);
	if (i == e)
	{		//didn't find slot.
		Int3();
		return;
	}

	auto &w = *i;
	w.segnum	= segnum;
	w.sidenum	= sidenum;
	w.time		= 0;

	//play one long sound for whole door wall explosion
	const auto pos = compute_center_point_on_side(segnum,sidenum);
	digi_link_sound_to_pos( SOUND_EXPLODING_WALL,segnum, sidenum, pos, 0, F1_0 );

}

//handle walls for this frame
//note: this wall code assumes the wall is not triangulated
void do_exploding_wall_frame()
{
	range_for (auto &i, expl_wall_list)
	{
		auto segnum = i.segnum;

		if (segnum != segment_none) {
			int sidenum = i.sidenum;
			fix oldfrac,newfrac;
			int old_count,new_count,e;		//n,

			oldfrac = fixdiv(i.time,EXPL_WALL_TIME);

			i.time += FrameTime;
			if (i.time > EXPL_WALL_TIME)
				i.time = EXPL_WALL_TIME;

			const auto seg = vsegptridx(segnum);
			if (i.time>(EXPL_WALL_TIME*3)/4) {
				int a,n;
				a = Walls[seg->sides[sidenum].wall_num].clip_num;
				n = WallAnims[a].num_frames;

				const auto &&csegp = seg.absolute_sibling(seg->children[sidenum]);
				auto cside = find_connect_side(seg, csegp);

				wall_set_tmap_num(seg,sidenum,csegp,cside,a,n-1);

				Walls[seg->sides[sidenum].wall_num].flags |= WALL_BLASTED;
				Walls[csegp->sides[cside].wall_num].flags |= WALL_BLASTED;

			}

			newfrac = fixdiv(i.time,EXPL_WALL_TIME);

			old_count = f2i(EXPL_WALL_TOTAL_FIREBALLS * fixmul(oldfrac,oldfrac));
			new_count = f2i(EXPL_WALL_TOTAL_FIREBALLS * fixmul(newfrac,newfrac));

			//n = new_count - old_count;

			//now create all the next explosions

			for (e=old_count;e<new_count;e++) {
				fix			size;

				//calc expl position

				const auto vertnum_list = get_side_verts(seg,sidenum);

				const auto &v0 = Vertices[vertnum_list[0]];
				const auto &v1 = Vertices[vertnum_list[1]];
				const auto &v2 = Vertices[vertnum_list[2]];

				const auto vv0 = vm_vec_sub(v0,v1);
				const auto vv1 = vm_vec_sub(v2,v1);

				auto pos = vm_vec_scale_add(v1,vv0,d_rand()*2);
				vm_vec_scale_add2(pos,vv1,d_rand()*2);

				size = EXPL_WALL_FIREBALL_SIZE + (2*EXPL_WALL_FIREBALL_SIZE * e / EXPL_WALL_TOTAL_FIREBALLS);

				//fireballs start away from door, with subsequent ones getting closer
				vm_vec_scale_add2(pos, vcsegptr(segnum)->sides[sidenum].normals[0], size * (EXPL_WALL_TOTAL_FIREBALLS - e) / EXPL_WALL_TOTAL_FIREBALLS);

				if (e & 3)		//3 of 4 are normal
					object_create_explosion(i.segnum,pos,size,VCLIP_SMALL_EXPLOSION);
				else
					object_create_badass_explosion( object_none, i.segnum, pos,
					size,
					VCLIP_SMALL_EXPLOSION,
					i2f(4),		// damage strength
					i2f(20),		//	damage radius
					i2f(50),		//	damage force
					object_none		//	parent id
					);
			}
			if (i.time >= EXPL_WALL_TIME)
				i.segnum = segment_none;	//flag this slot as free
		}
	}

}

#if defined(DXX_BUILD_DESCENT_II)
//creates afterburner blobs behind the specified object
void drop_afterburner_blobs(const vobjptr_t obj, int count, fix size_scale, fix lifetime)
{
	auto pos_left = vm_vec_scale_add(obj->pos, obj->orient.fvec, -obj->size);
	vm_vec_scale_add2(pos_left, obj->orient.rvec, -obj->size/4);
	const auto pos_right = vm_vec_scale_add(pos_left, obj->orient.rvec, obj->size/2);

	if (count == 1)
		vm_vec_avg(pos_left, pos_left, pos_right);

	auto segnum = find_point_seg(pos_left, obj->segnum);
	if (segnum != segment_none)
		object_create_explosion(segnum, pos_left, size_scale, VCLIP_AFTERBURNER_BLOB );

	if (count > 1) {
		segnum = find_point_seg(pos_right, obj->segnum);
		if (segnum != segment_none) {
			auto blob_obj = object_create_explosion(segnum, pos_right, size_scale, VCLIP_AFTERBURNER_BLOB );
			if (lifetime != -1 && blob_obj != object_none)
				blob_obj->lifeleft = lifetime;
		}
	}
}

/*
 * reads n expl_wall structs from a PHYSFS_file and swaps if specified
 */
void expl_wall_read_n_swap(PHYSFS_file *fp, int swap, partial_range_t<expl_wall *> r)
{
	range_for (auto &e, r)
	{
		disk_expl_wall d;
		PHYSFS_read(fp, &d, sizeof(d), 1);
		if (swap)
		{
			d.segnum = SWAPINT(d.segnum);
			d.sidenum = SWAPINT(d.sidenum);
			d.time = SWAPINT(d.time);
		}
		e.segnum = d.segnum;
		e.sidenum = d.sidenum;
		e.time = d.time;
	}
}
#endif
}