/*
 *	movem.c (move monster)		Larn is copyrighted 1986 by Noah Morgan.
 * $FreeBSD: src/games/larn/movem.c,v 1.4 1999/11/16 02:57:23 billf Exp $
 * $DragonFly: src/games/larn/movem.c,v 1.3 2006/08/26 17:05:05 pavalos Exp $
 *
 *	Here are the functions in this file:
 *
 *	movemonst()		Routine to move the monsters toward the player
 *	movemt(x,y)		Function to move a monster at (x,y) -- must determine where
 *	mmove(x,y,xd,yd)	Function to actually perform the monster movement
 *	movsphere() 		Function to look for and move spheres of annihilation
 */
#include "header.h"

static void	movemt(int, int);
static void	mmove(int, int, int, int);
static void	movsphere(void);

/*
 *	movemonst()		Routine to move the monsters toward the player
 *
 *	This routine has the responsibility to determine which monsters are to
 *	move, and call movemt() to do the move.
 *	Returns no value.
 */
static short w1[9],w1x[9],w1y[9];
static int tmp1,tmp2,tmp3,tmp4,distance;

void
movemonst(void)
	{
	int i,j;
	if (c[TIMESTOP]) return;	/* no action if time is stopped */
	if (c[HASTESELF])  if ((c[HASTESELF]&1)==0)  return;
	if (spheres) movsphere();	/* move the spheres of annihilation if any */
	if (c[HOLDMONST])  return;	/* no action if monsters are held */

	if (c[AGGRAVATE])	/* determine window of monsters to move */
	  {
	  tmp1=playery-5; tmp2=playery+6; tmp3=playerx-10; tmp4=playerx+11;
	  distance=40; /* depth of intelligent monster movement */
	  }
	else
	  {
	  tmp1=playery-3; tmp2=playery+4; tmp3=playerx-5; tmp4=playerx+6;
	  distance=17; /* depth of intelligent monster movement */
	  }

	if (level == 0) /* if on outside level monsters can move in perimeter */
		{
		if (tmp1 < 0) tmp1=0;		 if (tmp2 > MAXY) tmp2=MAXY;
		if (tmp3 < 0) tmp3=0;		 if (tmp4 > MAXX) tmp4=MAXX;
		}
	else /* if in a dungeon monsters can't be on the perimeter (wall there) */
		{
		if (tmp1 < 1) tmp1=1;		 if (tmp2 > MAXY-1) tmp2=MAXY-1;
		if (tmp3 < 1) tmp3=1;		 if (tmp4 > MAXX-1) tmp4=MAXX-1;
		}

	for (j=tmp1; j<tmp2; j++) /* now reset monster moved flags */
		for (i=tmp3; i<tmp4; i++)
			moved[i][j] = 0;
    moved[lasthx][lasthy]=0;

	if (c[AGGRAVATE] || !c[STEALTH]) /* who gets moved? split for efficiency */
	  {
	  for (j=tmp1; j<tmp2; j++) /* look thru all locations in window */
	    for (i=tmp3; i<tmp4; i++)
		  if (mitem[i][j])	/* if there is a monster to move */
		    if (moved[i][j]==0)	/* if it has not already been moved */
			  movemt(i,j);	/* go and move the monster */
	  }
	else /* not aggravated and not stealth */
	  {
	  for (j=tmp1; j<tmp2; j++) /* look thru all locations in window */
	    for (i=tmp3; i<tmp4; i++)
		  if (mitem[i][j])	/* if there is a monster to move */
		    if (moved[i][j]==0)	/* if it has not already been moved */
			  if (stealth[i][j])	/* if it is asleep due to stealth */
			    movemt(i,j);	/* go and move the monster */
	  }

	if (mitem[lasthx][lasthy]) /* now move monster last hit by player if not already moved */
		{
	    if (moved[lasthx][lasthy]==0)	/* if it has not already been moved */
			{
			movemt(lasthx,lasthy);
			lasthx = w1x[0];   lasthy = w1y[0];
			}
		}
	}

/*
 *	movemt(x,y)		Function to move a monster at (x,y) -- must determine where
 *		int x,y;
 *
 *	This routine is responsible for determining where one monster at (x,y) will
 *	move to.  Enter with the monsters coordinates in (x,y).
 *	Returns no value.
 */
static int tmpitem,xl,xh,yl,yh;

static void
movemt(int i, int j)
	{
	int k,m,z,tmp,xtmp,ytmp,monst;
	switch(monst=mitem[i][j])  /* for half speed monsters */
		{
		case TROGLODYTE:  case HOBGOBLIN:  case METAMORPH:  case XVART:
		case INVISIBLESTALKER:  case ICELIZARD: if ((gtime & 1) == 1) return;
		};

	if (c[SCAREMONST]) /* choose destination randomly if scared */
		{
		if ((xl = i+rnd(3)-2) < 0) xl=0;  if (xl >= MAXX) xl=MAXX-1;
		if ((yl = j+rnd(3)-2) < 0) yl=0;  if (yl >= MAXY) yl=MAXY-1;
		if ((tmp=item[xl][yl]) != OWALL)
		  if (mitem[xl][yl] == 0)
			if ((mitem[i][j] != VAMPIRE) || (tmpitem != OMIRROR))
			  if (tmp != OCLOSEDDOOR)		mmove(i,j,xl,yl);
		return;
		}

	if (monster[monst].intelligence > 10-c[HARDGAME]) /* if smart monster */
/* intelligent movement here -- first setup screen array */
	  {
	  xl=tmp3-2; yl=tmp1-2; xh=tmp4+2;  yh=tmp2+2;
	  vxy(&xl,&yl);  vxy(&xh,&yh);
	  for (k=yl; k<yh; k++)
	    for (m=xl; m<xh; m++)
		  {
		  switch(item[m][k])
			{
		  	case OWALL: case OPIT: case OTRAPARROW: case ODARTRAP:
			case OCLOSEDDOOR: case OTRAPDOOR: case OTELEPORTER:
				smm:	  screen[m][k]=127;  break;
			case OMIRROR: if (mitem[m][k]==VAMPIRE) goto smm;
			default:  screen[m][k]=  0;  break;
			};
		  }
	  screen[playerx][playery]=1;

/* now perform proximity ripple from playerx,playery to monster */
	  xl=tmp3-1; yl=tmp1-1; xh=tmp4+1;  yh=tmp2+1;
	  vxy(&xl,&yl);  vxy(&xh,&yh);
	  for (tmp=1; tmp<distance; tmp++)	/* only up to 20 squares away */
	    for (k=yl; k<yh; k++)
	      for (m=xl; m<xh; m++)
		    if (screen[m][k]==tmp) /* if find proximity n advance it */
			  for (z=1; z<9; z++) /* go around in a circle */
			    {
			    if (screen[xtmp=m+diroffx[z]][ytmp=k+diroffy[z]]==0)
				  screen[xtmp][ytmp]=tmp+1;
			    if (xtmp==i && ytmp==j) goto out;
			    }

out:  if (tmp<distance) /* did find connectivity */
		/* now select lowest value around playerx,playery */
		for (z=1; z<9; z++) /* go around in a circle */
		  if (screen[xl=i+diroffx[z]][yl=j+diroffy[z]]==tmp)
			if (!mitem[xl][yl]) { mmove(i,j,w1x[0]=xl,w1y[0]=yl); return; }
	  }

	/* dumb monsters move here */
	xl=i-1;  yl=j-1;  xh=i+2;  yh=j+2;
	if (i<playerx) xl++; else if (i>playerx) --xh;
	if (j<playery) yl++; else if (j>playery) --yh;
	for (k=0; k<9; k++) w1[k] = 10000;

	for (k=xl; k<xh; k++)
		for (m=yl; m<yh; m++) /* for each square compute distance to player */
			{
			tmp = k-i+4+3*(m-j);
			tmpitem = item[k][m];
			if (tmpitem!=OWALL || (k==playerx && m==playery))
			 if (mitem[k][m]==0)
			  if ((mitem[i][j] != VAMPIRE) || (tmpitem != OMIRROR))
				 if (tmpitem!=OCLOSEDDOOR)
					{
					w1[tmp] = (playerx-k)*(playerx-k)+(playery-m)*(playery-m);
					w1x[tmp] = k;  w1y[tmp] = m;
					}
			}

	tmp = 0;
	for (k=1; k<9; k++)  if (w1[tmp] > w1[k])  tmp=k;

	if (w1[tmp] < 10000)
		if ((i!=w1x[tmp]) || (j!=w1y[tmp]))
			mmove(i,j,w1x[tmp],w1y[tmp]);
	}

/*
 *	mmove(x,y,xd,yd)	Function to actually perform the monster movement
 *		int x,y,xd,yd;
 *
 *	Enter with the from coordinates in (x,y) and the destination coordinates
 *	in (xd,yd).
 */
static void
mmove(int aa, int bb, int cc, int dd)
	{
	int tmp,i,flag;
	const char *who = NULL, *p;
	flag=0;	/* set to 1 if monster hit by arrow trap */
	if ((cc==playerx) && (dd==playery))
		{
		hitplayer(aa,bb);  moved[aa][bb] = 1;  return;
		}
	i=item[cc][dd];
	if ((i==OPIT) || (i==OTRAPDOOR))
	  switch(mitem[aa][bb])
		{
		case SPIRITNAGA:	case PLATINUMDRAGON:	case WRAITH:
		case VAMPIRE:		case SILVERDRAGON:		case POLTERGEIST:
		case DEMONLORD:		case DEMONLORD+1:		case DEMONLORD+2:
		case DEMONLORD+3:	case DEMONLORD+4:		case DEMONLORD+5:
		case DEMONLORD+6:	case DEMONPRINCE:	break;

		default:	mitem[aa][bb]=0; /* fell in a pit or trapdoor */
		};
	tmp = mitem[cc][dd] = mitem[aa][bb];
	if (i==OANNIHILATION)
		{
		if (tmp>=DEMONLORD+3) /* demons dispel spheres */
			{
			cursors();
			lprintf("\nThe %s dispels the sphere!",monster[tmp].name);
			rmsphere(cc,dd);	/* delete the sphere */
			}
		else i=tmp=mitem[cc][dd]=0;
		}
	stealth[cc][dd]=1;
	if ((hitp[cc][dd] = hitp[aa][bb]) < 0) hitp[cc][dd]=1;
	mitem[aa][bb] = 0;				moved[cc][dd] = 1;
	if (tmp == LEPRECHAUN)
		switch(i)
			{
			case OGOLDPILE:  case OMAXGOLD:  case OKGOLD:  case ODGOLD:
			case ODIAMOND:   case ORUBY:     case OEMERALD: case OSAPPHIRE:
					item[cc][dd] = 0; /* leprechaun takes gold */
			};

	if (tmp == TROLL)  /* if a troll regenerate him */
		if ((gtime & 1) == 0)
			if (monster[tmp].hitpoints > hitp[cc][dd])  hitp[cc][dd]++;

	if (i==OTRAPARROW)	/* arrow hits monster */
		{ who = "An arrow";  if ((hitp[cc][dd] -= rnd(10)+level) <= 0)
			{ mitem[cc][dd]=0;  flag=2; } else flag=1; }
	if (i==ODARTRAP)	/* dart hits monster */
		{ who = "A dart";  if ((hitp[cc][dd] -= rnd(6)) <= 0)
			{ mitem[cc][dd]=0;  flag=2; } else flag=1; }
	if (i==OTELEPORTER)	/* monster hits teleport trap */
		{ flag=3; fillmonst(mitem[cc][dd]);  mitem[cc][dd]=0; }
	if (c[BLINDCOUNT]) return;	/* if blind don't show where monsters are	*/
	if (know[cc][dd] & 1)
		{
		p=0;
		if (flag) cursors();
		switch(flag)
		  {
		  case 1: p="\n%s hits the %s";  break;
		  case 2: p="\n%s hits and kills the %s";  break;
		  case 3: p="\nThe %s%s gets teleported"; who="";  break;
		  };
		if (p) { lprintf(p,who,monster[tmp].name); beep(); }
		}
	if (know[aa][bb] & 1)   show1cell(aa,bb);
	if (know[cc][dd] & 1)   show1cell(cc,dd);
	}

/*
 *	movsphere() 	Function to look for and move spheres of annihilation
 *
 *	This function works on the sphere linked list, first duplicating the list
 *	(the act of moving changes the list), then processing each sphere in order
 *	to move it.  They eat anything in their way, including stairs, volcanic
 *	shafts, potions, etc, except for upper level demons, who can dispel
 *	spheres.
 *	No value is returned.
 */
#define SPHMAX 20	/* maximum number of spheres movsphere can handle */
static void
movsphere(void)
	{
	int x,y,dir,len;
	struct sphere *sp,*sp2;
	struct sphere sph[SPHMAX];

	/* first duplicate sphere list */
	for (sp=0,x=0,sp2=spheres; sp2; sp2=sp2->p)	/* look through sphere list */
	  if (sp2->lev == level)	/* only if this level */
		{
		sph[x] = *sp2;	sph[x++].p = 0;  /* copy the struct */
		if (x>1)  sph[x-2].p = &sph[x-1]; /* link pointers */
		}
	if (x) sp= sph;	/* if any spheres, point to them */
		else return;	/* no spheres */

	for (sp=sph; sp; sp=sp->p)	/* look through sphere list */
		{
		x = sp->x;	  y = sp->y;
		if (item[x][y]!=OANNIHILATION) continue;	/* not really there */
		if (--(sp->lifetime) < 0)	/* has sphere run out of gas? */
			{
			rmsphere(x,y); /* delete sphere */
			continue;
			}
		switch(rnd((int)max(7,c[INTELLIGENCE]>>1))) /* time to move the sphere */
			{
			case 1:
			case 2:		/* change direction to a random one */
						sp->dir = rnd(8);
			default:	/* move in normal direction */
						dir = sp->dir;		len = sp->lifetime;
						rmsphere(x,y);
						newsphere(x+diroffx[dir],y+diroffy[dir],dir,len);
			};
		}
	}
