dxx-rebirth/main/wall.c

/*
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 1993-1998 PARALLAX SOFTWARE CORPORATION.  ALL RIGHTS RESERVED.
*/

/*
 *
 * Destroyable wall stuff
 *
 */


#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <string.h>
#include "gr.h"
#include "wall.h"
#include "switch.h"
#include "inferno.h"
#ifdef EDITOR
#include "editor/editor.h"
#endif
#include "segment.h"
#include "error.h"
#include "gameseg.h"
#include "game.h"
#include "bm.h"
#include "vclip.h"
#include "player.h"
#include "gauges.h"
#include "text.h"
#include "fireball.h"
#include "textures.h"
#include "sounds.h"
#include "newdemo.h"
#include "multi.h"
#include "gameseq.h"
#include "byteswap.h"

void kill_stuck_objects(int wallnum);

//	Special door on boss level which is locked if not in multiplayer...sorry for this awful solution --MK.
#define	BOSS_LOCKED_DOOR_LEVEL	7
#define	BOSS_LOCKED_DOOR_SEG		595
#define	BOSS_LOCKED_DOOR_SIDE	5

wall Walls[MAX_WALLS];					// Master walls array
int Num_walls=0;							// Number of walls

wclip WallAnims[MAX_WALL_ANIMS];		// Wall animations
int Num_wall_anims;
//--unused-- int walls_bm_num[MAX_WALL_ANIMS];

//door Doors[MAX_DOORS];					//	Master doors array

active_door ActiveDoors[MAX_DOORS];
int Num_open_doors;						// Number of open doors

//--unused-- grs_bitmap *wall_title_bms[MAX_WALL_ANIMS];

//#define BM_FLAG_TRANSPARENT			1
//#define BM_FLAG_SUPER_TRANSPARENT	2

#ifdef EDITOR
char	Wall_names[7][10] = {
	"NORMAL   ",
	"BLASTABLE",
	"DOOR     ",
	"ILLUSION ",
	"OPEN     ",
	"CLOSED   ",
	"EXTERNAL "
};
#endif

// This function determines whether the current segment/side is transparent
//		1 = YES
//		0 = NO
int check_transparency( segment * seg, int side )
{
	if ( (seg->sides[side].tmap_num2 & 0x3FFF) == 0) {
		if (GameBitmaps[Textures[seg->sides[side].tmap_num].index].bm_flags & BM_FLAG_TRANSPARENT )
			return 1;
		else
			return 0;
		}

	if (GameBitmaps[Textures[seg->sides[side].tmap_num2 & 0x3FFF ].index].bm_flags & BM_FLAG_SUPER_TRANSPARENT )
		return 1;
	else
		return 0;
}

//-----------------------------------------------------------------
// This function checks whether we can fly through the given side.
//	In other words, whether or not we have a 'doorway'
//	 Flags:
//		WID_FLY_FLAG				1
//		WID_RENDER_FLAG			2
//		WID_RENDPAST_FLAG			4
//	 Return values:
//		WID_WALL						2	// 0/1/0		wall	
//		WID_TRANSPARENT_WALL		6	//	0/1/1		transparent wall
//		WID_ILLUSORY_WALL			3	//	1/1/0		illusory wall
//		WID_TRANSILLUSORY_WALL	7	//	1/1/1		transparent illusory wall
//		WID_NO_WALL					5	//	1/0/1		no wall, can fly through

int wall_is_doorway ( segment * seg, int side )
{
	int flags, type;
	int state;
//--Covered by macro	// No child.
//--Covered by macro	if (seg->children[side] == -1)
//--Covered by macro		return WID_WALL;

//--Covered by macro	if (seg->children[side] == -2)
//--Covered by macro		return WID_EXTERNAL_FLAG;

//--Covered by macro // No wall present.
//--Covered by macro	if (seg->sides[side].wall_num == -1)
//--Covered by macro		return WID_NO_WALL;

	Assert(seg-Segments>=0 && seg-Segments<=Highest_segment_index);
	Assert(side>=0 && side<6);

	type = Walls[seg->sides[side].wall_num].type;
	flags = Walls[seg->sides[side].wall_num].flags;

	if (type == WALL_OPEN)
		return WID_NO_WALL;

	if (type == WALL_ILLUSION) {
		if (Walls[seg->sides[side].wall_num].flags & WALL_ILLUSION_OFF)
			return WID_NO_WALL;
		else {
			if (check_transparency( seg, side)) {
				return WID_TRANSILLUSORY_WALL;
		 	}else
				return WID_ILLUSORY_WALL;
		}
	}

	if (type == WALL_BLASTABLE) {
	 	if (flags & WALL_BLASTED)
			return WID_TRANSILLUSORY_WALL;

		if (check_transparency( seg, side))
			return WID_TRANSPARENT_WALL;
		else
			return WID_WALL;
	}	
	
	if (flags & WALL_DOOR_OPENED)
		return WID_TRANSILLUSORY_WALL;
	
	state = Walls[seg->sides[side].wall_num].state;
	if ((type == WALL_DOOR) && (state == WALL_DOOR_OPENING))
		return WID_TRANSPARENT_WALL;
	
// If none of the above flags are set, there is no doorway.
	if (check_transparency( seg, side))
		return WID_TRANSPARENT_WALL;
	else
		return WID_WALL; // There are children behind the door.
}

#ifdef EDITOR
//-----------------------------------------------------------------
// Initializes all the walls (in other words, no special walls)
void wall_init()
{
	int i;
	
	Num_walls = 0;
	for (i=0;i<MAX_WALLS;i++) {
		Walls[i].segnum = Walls[i].sidenum = -1;
		Walls[i].type = WALL_NORMAL;
		Walls[i].flags = 0;
		Walls[i].hps = 0;
		Walls[i].trigger = -1;
		Walls[i].clip_num = -1;
		Walls[i].linked_wall = -1;
		}
	Num_open_doors = 0;

}

//-----------------------------------------------------------------
// Initializes one wall.
void wall_reset(segment *seg, int side)
{
	int i;
	
	i = seg->sides[side].wall_num;

	if (i==-1) {
		return;
	}

	Walls[i].segnum = seg-Segments;
	Walls[i].sidenum = side;
	Walls[i].type = WALL_NORMAL;
	Walls[i].flags = 0;
	Walls[i].hps = 0;
	Walls[i].trigger = -1;
	Walls[i].clip_num = -1;
	Walls[i].linked_wall = -1;
}
#endif

//set the tmap_num or tmap_num2 field for a wall/door
void wall_set_tmap_num(segment *seg,int side,segment *csegp,int cside,int anim_num,int frame_num)
{
	wclip *anim = &WallAnims[anim_num];
	int tmap = anim->frames[frame_num];

	if ( Newdemo_state==ND_STATE_PLAYBACK ) return;

	if (anim->flags & WCF_TMAP1)	{
		if (tmap != seg->sides[side].tmap_num || tmap != csegp->sides[cside].tmap_num)
		{
			seg->sides[side].tmap_num = csegp->sides[cside].tmap_num = tmap;
			if ( Newdemo_state == ND_STATE_RECORDING )
				newdemo_record_wall_set_tmap_num1(seg-Segments,side,csegp-Segments,cside,tmap);
		}
	} else	{
		Assert(tmap!=0 && seg->sides[side].tmap_num2!=0);
		if (tmap != seg->sides[side].tmap_num2 || tmap != csegp->sides[cside].tmap_num2)
		{
			seg->sides[side].tmap_num2 = csegp->sides[cside].tmap_num2 = tmap;
			if ( Newdemo_state == ND_STATE_RECORDING )
				newdemo_record_wall_set_tmap_num2(seg-Segments,side,csegp-Segments,cside,tmap);
		}
	}
}


// -------------------------------------------------------------------------------
//when the wall has used all its hitpoints, this will destroy it
void blast_blastable_wall(segment *seg, int side)
{
	int Connectside;
	segment *csegp;
	int a, n;

	Assert(seg->sides[side].wall_num != -1);

	csegp = &Segments[seg->children[side]];
	Connectside = find_connect_side(seg, csegp);
	Assert(Connectside != -1);

	kill_stuck_objects(seg->sides[side].wall_num);
	kill_stuck_objects(csegp->sides[Connectside].wall_num);

	a = Walls[seg->sides[side].wall_num].clip_num;
	n = WallAnims[a].num_frames;

	if (!(WallAnims[Walls[seg->sides[side].wall_num].clip_num].flags & WCF_EXPLODES))
		wall_set_tmap_num(seg,side,csegp,Connectside,a,n-1);

	Walls[seg->sides[side].wall_num].flags |= WALL_BLASTED;
	Walls[csegp->sides[Connectside].wall_num].flags |= WALL_BLASTED;

	//if this is an exploding wall, explode it
	if (WallAnims[Walls[seg->sides[side].wall_num].clip_num].flags & WCF_EXPLODES)
		explode_wall(seg-Segments,side);
}


//-----------------------------------------------------------------
// Destroys a blastable wall.
void wall_destroy(segment *seg, int side)
{
	Assert(seg->sides[side].wall_num != -1);
	Assert(seg-Segments != 0);

	if (Walls[seg->sides[side].wall_num].type == WALL_BLASTABLE)
		blast_blastable_wall( seg, side );
	else
		Error("Hey bub, you are trying to destroy an indestructable wall.");
}

//-----------------------------------------------------------------
// Deteriorate appearance of wall. (Changes bitmap (paste-ons))
void wall_damage(segment *seg, int side, fix damage)
{
	int a, i, n;

	if (seg->sides[side].wall_num == -1) {
		return;
	}

	if (Walls[seg->sides[side].wall_num].type != WALL_BLASTABLE)
		return;
	
	if (!(Walls[seg->sides[side].wall_num].flags & WALL_BLASTED))
		{
		int Connectside;
		segment *csegp;

		csegp = &Segments[seg->children[side]];
		Connectside = find_connect_side(seg, csegp);
		Assert(Connectside != -1);
		
		Walls[seg->sides[side].wall_num].hps -= damage;
		Walls[csegp->sides[Connectside].wall_num].hps -= damage;
			
		a = Walls[seg->sides[side].wall_num].clip_num;
		n = WallAnims[a].num_frames;
		
		if (Walls[seg->sides[side].wall_num].hps < WALL_HPS*1/n) {
			blast_blastable_wall( seg, side );			
			#ifdef NETWORK
			if (Game_mode & GM_MULTI)
				multi_send_door_open(seg-Segments, side);
			#endif
		}
		else
			for (i=0;i<n;i++)
				if (Walls[seg->sides[side].wall_num].hps < WALL_HPS*(n-i)/n) {
					wall_set_tmap_num(seg,side,csegp,Connectside,a,i);
				}
		}
}


//-----------------------------------------------------------------
// Opens a door
void wall_open_door(segment *seg, int side)
{
	wall *w;
	active_door *d;
	int Connectside=0, wall_num=0, cwall_num=0;
	segment *csegp;

	Assert(seg->sides[side].wall_num != -1); 	//Opening door on illegal wall

	w = &Walls[seg->sides[side].wall_num];
	wall_num = w - Walls;
	//kill_stuck_objects(seg->sides[side].wall_num);

	if ((w->state == WALL_DOOR_OPENING) ||		//already opening
		 (w->state == WALL_DOOR_WAITING))	//open, waiting to close
		return;

	if (w->state == WALL_DOOR_CLOSING) {		//closing, so reuse door

		int i;
	
		d = NULL;

		for (i=0;i<Num_open_doors;i++) {		//find door

			d = &ActiveDoors[i];
	
			if (d->front_wallnum[0]==w-Walls || d->back_wallnum[0]==wall_num ||
				 (d->n_parts==2 && (d->front_wallnum[1]==wall_num || d->back_wallnum[1]==wall_num)))
				break;
		}

		if (i>=Num_open_doors) // likely in demo playback or multiplayer
		{
			d = &ActiveDoors[Num_open_doors];
			d->time = 0;
			Num_open_doors++;
			Assert( Num_open_doors < MAX_DOORS );
		}
		else
		{
			Assert( d!=NULL ); // Get John!

			d->time = WallAnims[w->clip_num].play_time - d->time;

			if (d->time < 0)
				d->time = 0;
		}
	
	}
	else {											//create new door
		Assert(w->state == WALL_DOOR_CLOSED);
		d = &ActiveDoors[Num_open_doors];
		d->time = 0;
		Num_open_doors++;
		Assert( Num_open_doors < MAX_DOORS );
	}


	w->state = WALL_DOOR_OPENING;

	// So that door can't be shot while opening
	csegp = &Segments[seg->children[side]];
	Connectside = find_connect_side(seg, csegp);
	if (Connectside >= 0)
	{
		cwall_num = csegp->sides[Connectside].wall_num;
		if (cwall_num > -1)
		{
			Walls[cwall_num].state = WALL_DOOR_OPENING;
			d->back_wallnum[0] = cwall_num;
		}
		d->front_wallnum[0] = seg->sides[side].wall_num;
	}
	else
		con_printf(CON_URGENT, "Illegal Connectside %i in wall_open_door. Trying to hop over. Please check your level!\n", side);

	Assert( seg-Segments != -1);

	if (Newdemo_state == ND_STATE_RECORDING) {
		newdemo_record_door_opening(seg-Segments, side);
	}

	if (w->linked_wall != -1) {
		wall *w2;
		segment *seg2;

		w2		= &Walls[w->linked_wall];
		seg2	= &Segments[w2->segnum];

		Assert(w2->linked_wall == seg->sides[side].wall_num);
		//Assert(!(w2->flags & WALL_DOOR_OPENING  ||  w2->flags & WALL_DOOR_OPENED));

		w2->state = WALL_DOOR_OPENING;

		csegp = &Segments[seg2->children[w2->sidenum]];
		Connectside = find_connect_side(seg2, csegp);
		Assert(Connectside != -1);
		if (cwall_num > -1)
			Walls[cwall_num].state = WALL_DOOR_OPENING;

		d->n_parts = 2;
		d->front_wallnum[1] = w->linked_wall;
		d->back_wallnum[1] = cwall_num;
	}
	else
		d->n_parts = 1;


	if ( Newdemo_state != ND_STATE_PLAYBACK )
	{
		// NOTE THE LINK TO ABOVE!!!!
		vms_vector cp;
		compute_center_point_on_side(&cp, seg, side );
		if (WallAnims[w->clip_num].open_sound > -1 )
			digi_link_sound_to_pos( WallAnims[w->clip_num].open_sound, seg-Segments, side, &cp, 0, F1_0 );

	}
}

//-----------------------------------------------------------------
// This function closes the specified door and restores the closed
//  door texture.  This is called when the animation is done
void wall_close_door(int door_num)
{
	int p;
	active_door *d;
	int i;

	d = &ActiveDoors[door_num];

	for (p=0;p<d->n_parts;p++) {
		wall *w;
		int Connectside, side;
		segment *csegp, *seg;
	
		w = &Walls[d->front_wallnum[p]];

		seg = &Segments[w->segnum];
		side = w->sidenum;
	
		Assert(seg->sides[side].wall_num != -1);		//Closing door on illegal wall
		
		csegp = &Segments[seg->children[side]];
		Connectside = find_connect_side(seg, csegp);
		Assert(Connectside != -1);
	
		Walls[seg->sides[side].wall_num].state = WALL_DOOR_CLOSED;
		Walls[csegp->sides[Connectside].wall_num].state = WALL_DOOR_CLOSED;
	
		wall_set_tmap_num(seg,side,csegp,Connectside,w->clip_num,0);

	}
	
	for (i=door_num;i<Num_open_doors;i++)
		ActiveDoors[i] = ActiveDoors[i+1];

	Num_open_doors--;

}


//-----------------------------------------------------------------
// Animates opening of a door.
// Called in the game loop.
void do_door_open(int door_num)
{
	int p;
	active_door *d;

// 	Assert(door_num != -1);		//Trying to do_door_open on illegal door
	if (door_num == -1)
		return;
	
	d = &ActiveDoors[door_num];

	for (p=0;p<d->n_parts;p++) {
		wall *w;
		int Connectside, side;
		segment *csegp, *seg;
		fix time_elapsed, time_total, one_frame;
		int i, n;
	
		w = &Walls[d->front_wallnum[p]];
		kill_stuck_objects(d->front_wallnum[p]);
		kill_stuck_objects(d->back_wallnum[p]);

		seg = &Segments[w->segnum];
		side = w->sidenum;
	
// 		Assert(seg->sides[side].wall_num != -1);		//Trying to do_door_open on illegal wall
		if (seg->sides[side].wall_num == -1)
		{
			con_printf(CON_URGENT, "Trying to do_door_open on illegal wall %i. Please check your level!\n",side);
			continue;
		}
	
		csegp = &Segments[seg->children[side]];
		Connectside = find_connect_side(seg, csegp);
		Assert(Connectside != -1);

		d->time += FrameTime;
	
		time_elapsed = d->time;
		n = WallAnims[w->clip_num].num_frames;
		time_total = WallAnims[w->clip_num].play_time;
	
		one_frame = time_total/n;	
	
		i = time_elapsed/one_frame;
	
		if (i < n)
			wall_set_tmap_num(seg,side,csegp,Connectside,w->clip_num,i);
	
		if (i> n/2) {
			Walls[seg->sides[side].wall_num].flags |= WALL_DOOR_OPENED;
			Walls[csegp->sides[Connectside].wall_num].flags |= WALL_DOOR_OPENED;
		}
	
		if (i >= n-1) {
			wall_set_tmap_num(seg,side,csegp,Connectside,w->clip_num,n-1);

			// If our door is not automatic just remove it from the list.
			if (!(Walls[seg->sides[side].wall_num].flags & WALL_DOOR_AUTO)) {
				for (i=door_num;i<Num_open_doors;i++)
					ActiveDoors[i] = ActiveDoors[i+1];
				Num_open_doors--;
			}
			else {

				Walls[seg->sides[side].wall_num].state = WALL_DOOR_WAITING;
				Walls[csegp->sides[Connectside].wall_num].state = WALL_DOOR_WAITING;

				ActiveDoors[Num_open_doors].time = 0;	//counts up
			}
		}

	}

}

//-----------------------------------------------------------------
// This function closes the specified door and restores the closed
//  door texture.  This is called when the animation is done
void wall_close_door_num(int door_num)
{
	int p;
	active_door *d;
	int i, cwall_num;
	
	d = &ActiveDoors[door_num];
	
	for (p=0;p<d->n_parts;p++) {
		wall *w;
		int Connectside, side;
		segment *csegp, *seg;
		
		w = &Walls[d->front_wallnum[p]];
		
		seg = &Segments[w->segnum];
		side = w->sidenum;
		
		Assert(seg->sides[side].wall_num != -1);		//Closing door on illegal wall
		
		csegp = &Segments[seg->children[side]];
		Connectside = find_connect_side(seg, csegp);
		Assert(Connectside != -1);
		cwall_num = csegp->sides[Connectside].wall_num;
		Walls[seg->sides[side].wall_num].state = WALL_DOOR_CLOSED;
		if (cwall_num > -1)
			Walls[cwall_num].state = WALL_DOOR_CLOSED;
		
		wall_set_tmap_num(seg,side,csegp,Connectside,w->clip_num,0);
		
	}
	
	for (i=door_num;i<Num_open_doors;i++)
		ActiveDoors[i] = ActiveDoors[i+1];
	
	Num_open_doors--;
	
}

int check_poke(int objnum,int segnum,int side)
{
	object *obj = &Objects[objnum];

	//note: don't let objects with zero size block door

        if (obj->size && get_seg_masks(&obj->pos,segnum,obj->size,__FILE__,__LINE__).sidemask & (1<<side))
		return 1;		//pokes through side!
	else
		return 0;		//does not!

}


//-----------------------------------------------------------------
// Animates and processes the closing of a door.
// Called from the game loop.
void do_door_close(int door_num)
{
	int p;
	active_door *d;
	wall *w;

	Assert(door_num != -1);		//Trying to do_door_open on illegal door
	
	d = &ActiveDoors[door_num];

	w = &Walls[d->front_wallnum[0]];

	//check for objects in doorway before closing
	if (w->flags & WALL_DOOR_AUTO)
		for (p=0;p<d->n_parts;p++) {
			int Connectside, side;
			segment *csegp, *seg;
			int objnum;
		
			seg = &Segments[w->segnum];
			side = w->sidenum;
		
			csegp = &Segments[seg->children[side]];
			Connectside = find_connect_side(seg, csegp);
			Assert(Connectside != -1);

			//go through each object in each of two segments, and see if
			//it pokes into the connecting seg

			for (objnum=seg->objects;objnum!=-1;objnum=Objects[objnum].next)
				if (check_poke(objnum,seg-Segments,side))
					return;		//abort!

			for (objnum=csegp->objects;objnum!=-1;objnum=Objects[objnum].next)
				if (check_poke(objnum,csegp-Segments,Connectside))
					return;		//abort!
		}

	for (p=0;p<d->n_parts;p++) {
		wall *w;
		int Connectside, side;
		segment *csegp, *seg;
		fix time_elapsed, time_total, one_frame;
		int i, n;
	
		w = &Walls[d->front_wallnum[p]];

		seg = &Segments[w->segnum];
		side = w->sidenum;
	
		if (seg->sides[side].wall_num == -1) {
			return;
		}
	
		//if here, must be auto door
		Assert(Walls[seg->sides[side].wall_num].flags & WALL_DOOR_AUTO);		
	
		// Otherwise, close it.
		csegp = &Segments[seg->children[side]];
		Connectside = find_connect_side(seg, csegp);
		Assert(Connectside != -1);
	

		if ( Newdemo_state != ND_STATE_PLAYBACK )
			// NOTE THE LINK TO ABOVE!!
			if (p==0)	//only play one sound for linked doors
				if ( d->time==0 )	{		//first time
					vms_vector cp;
					compute_center_point_on_side(&cp, seg, side );
					if (WallAnims[w->clip_num].close_sound  > -1 )
						digi_link_sound_to_pos( WallAnims[Walls[seg->sides[side].wall_num].clip_num].close_sound, seg-Segments, side, &cp, 0, F1_0 );
				}
	
		d->time += FrameTime;

		time_elapsed = d->time;
		n = WallAnims[w->clip_num].num_frames;
		time_total = WallAnims[w->clip_num].play_time;
	
		one_frame = time_total/n;	
	
		i = n-time_elapsed/one_frame-1;
	
		if (i < n/2) {
			Walls[seg->sides[side].wall_num].flags &= ~WALL_DOOR_OPENED;
			Walls[csegp->sides[Connectside].wall_num].flags &= ~WALL_DOOR_OPENED;
		}
	
		// Animate door.
		if (i > 0) {
			wall_set_tmap_num(seg,side,csegp,Connectside,w->clip_num,i);

			Walls[seg->sides[side].wall_num].state = WALL_DOOR_CLOSING;
			Walls[csegp->sides[Connectside].wall_num].state = WALL_DOOR_CLOSING;

			ActiveDoors[Num_open_doors].time = 0;		//counts up

		} else
			wall_close_door(door_num);
	}
}


//-----------------------------------------------------------------
// Turns off an illusionary wall (This will be used primarily for
//  wall switches or triggers that can turn on/off illusionary walls.)
void wall_illusion_off(segment *seg, int side)
{
	segment *csegp;
	int cside;

	csegp = &Segments[seg->children[side]];
	cside = find_connect_side(seg, csegp);
	Assert(cside != -1);

	if (seg->sides[side].wall_num == -1) {
		return;
	}

	Walls[seg->sides[side].wall_num].flags |= WALL_ILLUSION_OFF;
	Walls[csegp->sides[cside].wall_num].flags |= WALL_ILLUSION_OFF;
}

//-----------------------------------------------------------------
// Turns on an illusionary wall (This will be used primarily for
//  wall switches or triggers that can turn on/off illusionary walls.)
void wall_illusion_on(segment *seg, int side)
{
	segment *csegp;
	int cside;

	csegp = &Segments[seg->children[side]];
	cside = find_connect_side(seg, csegp);
	Assert(cside != -1);

	if (seg->sides[side].wall_num == -1) {
		return;
	}

	Walls[seg->sides[side].wall_num].flags &= ~WALL_ILLUSION_OFF;
	Walls[csegp->sides[cside].wall_num].flags &= ~WALL_ILLUSION_OFF;
}

//	-----------------------------------------------------------------------------
//	Allowed to open the normally locked special boss door if in multiplayer mode.
int special_boss_opening_allowed(int segnum, int sidenum)
{
	if (Game_mode & GM_MULTI)
		return (Current_level_num == BOSS_LOCKED_DOOR_LEVEL) && (segnum == BOSS_LOCKED_DOOR_SEG) && (sidenum == BOSS_LOCKED_DOOR_SIDE);
	else
		return 0;
}

//-----------------------------------------------------------------
// Determines what happens when a wall is shot
//returns info about wall.  see wall.h for codes
//obj is the object that hit...either a weapon or the player himself
//playernum is the number the player who hit the wall or fired the weapon,
//or -1 if a robot fired the weapon
int wall_hit_process(segment *seg, int side, fix damage, int playernum, object *obj )
{
	wall	*w;
	fix	show_message;

	Assert (seg-Segments != -1);

	// If it is not a "wall" then just return.
	if ( seg->sides[side].wall_num < 0 )
		return WHP_NOT_SPECIAL;

	w = &Walls[seg->sides[side].wall_num];

	if ( Newdemo_state == ND_STATE_RECORDING )
		newdemo_record_wall_hit_process( seg-Segments, side, damage, playernum );

	if (w->type == WALL_BLASTABLE) {
		wall_damage(seg, side, damage);
		return WHP_BLASTABLE;
	}

	if (playernum != Player_num)	//return if was robot fire
		return WHP_NOT_SPECIAL;

	Assert( playernum > -1 );
	
	//	Determine whether player is facing door he hit.  If not, don't say negative
	//	messages because he probably didn't intentionally hit the door.
	if (obj->type == OBJ_PLAYER)
		show_message = (vm_vec_dot(&obj->orient.fvec, &obj->mtype.phys_info.velocity) > 0);
	else
		show_message = 1;

	if (w->keys == KEY_BLUE)
		if (!(Players[playernum].flags & PLAYER_FLAGS_BLUE_KEY)) {
			if ( playernum==Player_num )
				if (show_message)
					HUD_init_message(HM_DEFAULT, "%s %s",TXT_BLUE,TXT_ACCESS_DENIED);
			return WHP_NO_KEY;
		}

	if (w->keys == KEY_RED)
		if (!(Players[playernum].flags & PLAYER_FLAGS_RED_KEY)) {
			if ( playernum==Player_num )
				if (show_message)
					HUD_init_message(HM_DEFAULT, "%s %s",TXT_RED,TXT_ACCESS_DENIED);
			return WHP_NO_KEY;
		}
	
	if (w->keys == KEY_GOLD)
		if (!(Players[playernum].flags & PLAYER_FLAGS_GOLD_KEY)) {
			if ( playernum==Player_num )
				if (show_message)
					HUD_init_message(HM_DEFAULT, "%s %s",TXT_YELLOW,TXT_ACCESS_DENIED);
			return WHP_NO_KEY;
		}

	if (w->type == WALL_DOOR)
	{
		if ((w->flags & WALL_DOOR_LOCKED ) && !(special_boss_opening_allowed(seg-Segments, side)) ) {
			if ( playernum==Player_num )
				if (show_message)
					HUD_init_message(HM_DEFAULT, "%s", TXT_CANT_OPEN_DOOR);
			return WHP_NO_KEY;
		}
		else {
			if (w->state != WALL_DOOR_OPENING)
			{
				wall_open_door(seg, side);
			#ifdef NETWORK
				if (Game_mode & GM_MULTI)
					multi_send_door_open(seg-Segments, side);
			#endif
			}
			return WHP_DOOR;
			
		}
	}
	return WHP_NOT_SPECIAL;		//default is treat like normal wall
}

//-----------------------------------------------------------------
// Opens doors/destroys wall/shuts off triggers.
void wall_toggle(int segnum, int side)
{
	int wall_num; 

	if (segnum < 0 || segnum > Highest_segment_index || side < 0 || side >= MAX_SIDES_PER_SEGMENT)
	{
#ifndef NDEBUG
		Warning("Can't toggle side %d (%i) of\nsegment %d (%i)!\n", side, MAX_SIDES_PER_SEGMENT, segnum, Highest_segment_index);
#endif
		return;
	}

	wall_num = Segments[segnum].sides[side].wall_num;

	if (wall_num == -1) {
		return;
	}

	if ( Newdemo_state == ND_STATE_RECORDING )
		newdemo_record_wall_toggle(segnum, side );

	if (Walls[wall_num].type == WALL_BLASTABLE)
		wall_destroy(&Segments[segnum], side);

	if ((Walls[wall_num].type == WALL_DOOR) && (Walls[wall_num].state == WALL_DOOR_CLOSED))
		wall_open_door(&Segments[segnum], side);
}


//-----------------------------------------------------------------
// Tidy up Walls array for load/save purposes.
void reset_walls()
{
	int i;

	if (Num_walls < 0) {
		return;
	}

	for (i=Num_walls;i<MAX_WALLS;i++) {
		Walls[i].type = WALL_NORMAL;
		Walls[i].flags = 0;
		Walls[i].hps = 0;
		Walls[i].trigger = -1;
		Walls[i].clip_num = -1;
		}
}

void wall_frame_process()
{
	int i;

	for (i=0;i<Num_open_doors;i++) {
		active_door *d;
		wall *w;

		d = &ActiveDoors[i];
		w = &Walls[d->front_wallnum[0]];

		if (w->state == WALL_DOOR_OPENING)
			do_door_open(i);
		else if (w->state == WALL_DOOR_CLOSING)
			do_door_close(i);
		else if (w->state == WALL_DOOR_WAITING) {
			d->time += FrameTime;

			// set flags to fix occasional netgame problem where door is waiting to close but open flag isn't set
			// NOTE: Taken from D2 source. Should not be necessary as multi_do_door_open() is more simple than in D2 but add anyways as it's a *good* fallback...
			w->flags |= WALL_DOOR_OPENED;
			if (d->back_wallnum[0] > -1)
				Walls[d->back_wallnum[0]].flags |= WALL_DOOR_OPENED;

			if (d->time > DOOR_WAIT_TIME) {
				w->state = WALL_DOOR_CLOSING;
				d->time = 0;
			}
		}
	}
}

int	Num_stuck_objects=0;

stuckobj	Stuck_objects[MAX_STUCK_OBJECTS];

//	An object got stuck in a door (like a flare).
//	Add global entry.
void add_stuck_object(object *objp, int segnum, int sidenum)
{
	int	i;
	int	wallnum;

	wallnum = Segments[segnum].sides[sidenum].wall_num;

	if (wallnum != -1) {
		if (Walls[wallnum].flags & WALL_BLASTED)
			objp->flags |= OF_SHOULD_BE_DEAD;

		for (i=0; i<MAX_STUCK_OBJECTS; i++) {
			if (Stuck_objects[i].wallnum == -1) {
				Stuck_objects[i].wallnum = wallnum;
				Stuck_objects[i].objnum = objp-Objects;
				Stuck_objects[i].signature = objp->signature;
				Num_stuck_objects++;
				break;
			}
		}
	}



}

//	--------------------------------------------------------------------------------------------------
//	Look at the list of stuck objects, clean up in case an object has gone away, but not been removed here.
//	Removes up to one/frame.
void remove_obsolete_stuck_objects(void)
{
	int	objnum;

	objnum = d_tick_count % MAX_STUCK_OBJECTS;

	if (Stuck_objects[objnum].wallnum != -1)
		if ((Stuck_objects[objnum].wallnum == 0) || (Objects[Stuck_objects[objnum].objnum].signature != Stuck_objects[objnum].signature)) {
			Num_stuck_objects--;
			Stuck_objects[objnum].wallnum = -1;
		}

}

//	----------------------------------------------------------------------------------------------------
//	Door with wall index wallnum is opening, kill all objects stuck in it.
void kill_stuck_objects(int wallnum)
{
	int	i;

	if (Num_stuck_objects == 0)
		return;

	Num_stuck_objects=0;

	for (i=0; i<MAX_STUCK_OBJECTS; i++)
		if (Stuck_objects[i].wallnum == wallnum) {
			if (Objects[Stuck_objects[i].objnum].type == OBJ_WEAPON) {
				Objects[Stuck_objects[i].objnum].lifeleft = F1_0/4;
			}
			Stuck_objects[i].wallnum = -1;
		} else if (Stuck_objects[i].wallnum != -1)
			Num_stuck_objects++;
}

/*
 * reads a wclip structure from a PHYSFS_file
 */
int wclip_read_n(wclip *wc, int n, PHYSFS_file *fp)
{
	int i, j;

	for (i = 0; i < n; i++) {
		WallAnims[i].play_time = PHYSFSX_readFix(fp);;
		WallAnims[i].num_frames = PHYSFSX_readShort(fp);;
		for (j = 0; j < MAX_CLIP_FRAMES; j++)
			WallAnims[i].frames[j] = PHYSFSX_readShort(fp);
		WallAnims[i].open_sound = PHYSFSX_readShort(fp);
		WallAnims[i].close_sound = PHYSFSX_readShort(fp);
		WallAnims[i].flags = PHYSFSX_readShort(fp);
		PHYSFS_read(fp, WallAnims[i].filename, 13, 1);
		WallAnims[i].pad = PHYSFSX_readByte(fp);
	}
	return i;
}

/*
 * reads a v16_wall structure from a PHYSFS_file
 */
extern void v16_wall_read(v16_wall *w, PHYSFS_file *fp)
{
	w->type = PHYSFSX_readByte(fp);
	w->flags = PHYSFSX_readByte(fp);
	w->hps = PHYSFSX_readFix(fp);
	w->trigger = PHYSFSX_readByte(fp);
	w->clip_num = PHYSFSX_readByte(fp);
	w->keys = PHYSFSX_readByte(fp);
}

/*
 * reads a v19_wall structure from a PHYSFS_file
 */
extern void v19_wall_read(v19_wall *w, PHYSFS_file *fp)
{
	w->segnum = PHYSFSX_readInt(fp);
	w->sidenum = PHYSFSX_readInt(fp);
	w->type = PHYSFSX_readByte(fp);
	w->flags = PHYSFSX_readByte(fp);
	w->hps = PHYSFSX_readFix(fp);
	w->trigger = PHYSFSX_readByte(fp);
	w->clip_num = PHYSFSX_readByte(fp);
	w->keys = PHYSFSX_readByte(fp);
	w->linked_wall = PHYSFSX_readInt(fp);
}

/*
 * reads a wall structure from a PHYSFS_file
 */
extern void wall_read(wall *w, PHYSFS_file *fp)
{
	w->segnum = PHYSFSX_readInt(fp);
	w->sidenum = PHYSFSX_readInt(fp);
	w->hps = PHYSFSX_readFix(fp);
	w->linked_wall = PHYSFSX_readInt(fp);
	w->type = PHYSFSX_readByte(fp);
	w->flags = PHYSFSX_readByte(fp);
	w->state = PHYSFSX_readByte(fp);
	w->trigger = PHYSFSX_readByte(fp);
	w->clip_num = PHYSFSX_readByte(fp);
	w->keys = PHYSFSX_readByte(fp);
	/*w->controlling_trigger =*/ PHYSFSX_readByte(fp);
	/*w->cloak_value =*/ PHYSFSX_readByte(fp);
}

void wall_swap(wall *w, int swap)
{
	if (!swap)
		return;
	
	w->segnum = SWAPINT(w->segnum);
	w->sidenum = SWAPINT(w->sidenum);
	w->hps = SWAPINT(w->hps);
	w->linked_wall = SWAPINT(w->linked_wall);
}

/*
 * reads n wall structs from a PHYSFS_file and swaps if specified
 */
void wall_read_n_swap(wall *w, int n, int swap, PHYSFS_file *fp)
{
	int i;
	
	PHYSFS_read(fp, w, sizeof(wall), n);
	
	if (swap)
		for (i = 0; i < n; i++)
			wall_swap(&w[i], swap);
}

/*
 * reads a v19_door structure from a PHYSFS_file
 */
extern void v19_door_read(v19_door *d, PHYSFS_file *fp)
{
	d->n_parts = PHYSFSX_readInt(fp);
	d->seg[0] = PHYSFSX_readShort(fp);
	d->seg[1] = PHYSFSX_readShort(fp);
	d->side[0] = PHYSFSX_readShort(fp);
	d->side[1] = PHYSFSX_readShort(fp);
	d->type[0] = PHYSFSX_readShort(fp);
	d->type[1] = PHYSFSX_readShort(fp);
	d->open = PHYSFSX_readFix(fp);
}

/*
 * reads an active_door structure from a PHYSFS_file
 */
extern void active_door_read(active_door *ad, PHYSFS_file *fp)
{
	ad->n_parts = PHYSFSX_readInt(fp);
	ad->front_wallnum[0] = PHYSFSX_readShort(fp);
	ad->front_wallnum[1] = PHYSFSX_readShort(fp);
	ad->back_wallnum[0] = PHYSFSX_readShort(fp);
	ad->back_wallnum[1] = PHYSFSX_readShort(fp);
	ad->time = PHYSFSX_readFix(fp);
}

void active_door_swap(active_door *ad, int swap)
{
	if (!swap)
		return;
	
	ad->n_parts = SWAPINT(ad->n_parts);
	ad->front_wallnum[0] = SWAPSHORT(ad->front_wallnum[0]);
	ad->front_wallnum[1] = SWAPSHORT(ad->front_wallnum[1]);
	ad->back_wallnum[0] = SWAPSHORT(ad->back_wallnum[0]);
	ad->back_wallnum[1] = SWAPSHORT(ad->back_wallnum[1]);
	ad->time = SWAPINT(ad->time);
}

/*
 * reads n active_door structs from a PHYSFS_file and swaps if specified
 */
void active_door_read_n_swap(active_door *ad, int n, int swap, PHYSFS_file *fp)
{
	int i;
	
	PHYSFS_read(fp, ad, sizeof(active_door), n);
	
	if (swap)
		for (i = 0; i < n; i++)
			active_door_swap(&ad[i], swap);
}

void wall_write(wall *w, short version, PHYSFS_file *fp)
{
	if (version >= 17)
	{
		PHYSFS_writeSLE32(fp, w->segnum);
		PHYSFS_writeSLE32(fp, w->sidenum);
	}

	if (version >= 20)
	{
		PHYSFSX_writeFix(fp, w->hps);
		PHYSFS_writeSLE32(fp, w->linked_wall);
	}
	
	PHYSFSX_writeU8(fp, w->type);
	PHYSFSX_writeU8(fp, w->flags);
	
	if (version < 20)
		PHYSFSX_writeFix(fp, w->hps);
	else
		PHYSFSX_writeU8(fp, w->state);
	
	PHYSFSX_writeU8(fp, w->trigger);
	PHYSFSX_writeU8(fp, w->clip_num);
	PHYSFSX_writeU8(fp, w->keys);
	
	if (version >= 20)
	{
		PHYSFSX_writeU8(fp, 0);	// w->controlling_trigger
		PHYSFSX_writeU8(fp, 0);	// w->cloak_value
	}
	else if (version >= 17)
		PHYSFS_writeSLE32(fp, w->linked_wall);
}