/*
 * passages.c  -  Draw the connecting passages
 *
 * Advanced Rogue
 * Copyright (C) 1984, 1985, 1986 Michael Morgan, Ken Dalka and AT&T
 * All rights reserved.
 *
 * Based on "Rogue: Exploring the Dungeons of Doom"
 * Copyright (C) 1980, 1981 Michael Toy, Ken Arnold and Glenn Wichman
 * All rights reserved.
 *
 * See the file LICENSE.TXT for full copyright and licensing information.
 */

/*
 * Draw the connecting passages
 *
 * @(#)passages.c	3.4 (Berkeley) 6/15/81
 */

#include <stdlib.h>
#include "curses.h"
#include "rogue.h"

void conn(int r1, int r2);
void door(struct room *rm, coord *cp);

/*
 * do_passages:
 *	Draw all the passages on a level.
 */

void
do_passages(void)
{
    register struct rdes *r1, *r2 = NULL;
    register int i, j;
    register int roomcount;
    static struct rdes
    {
	bool	conn[MAXROOMS];		/* possible to connect to room i? */
	bool	isconn[MAXROOMS];	/* connection been made to room i? */
	bool	ingraph;		/* this room in graph already? */
    } rdes[MAXROOMS] = {
	{ { 0, 1, 0, 1, 0, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 0 },
	{ { 1, 0, 1, 0, 1, 0, 0, 0, 0 }, { 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 0 },
	{ { 0, 1, 0, 0, 0, 1, 0, 0, 0 }, { 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 0 },
	{ { 1, 0, 0, 0, 1, 0, 1, 0, 0 }, { 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 0 },
	{ { 0, 1, 0, 1, 0, 1, 0, 1, 0 }, { 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 0 },
	{ { 0, 0, 1, 0, 1, 0, 0, 0, 1 }, { 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 0 },
	{ { 0, 0, 0, 1, 0, 0, 0, 1, 0 }, { 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 0 },
	{ { 0, 0, 0, 0, 1, 0, 1, 0, 1 }, { 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 0 },
	{ { 0, 0, 0, 0, 0, 1, 0, 1, 0 }, { 0, 0, 0, 0, 0, 0, 0, 0, 0 }, 0 },
    };

    /*
     * reinitialize room graph description
     */
    for (r1 = rdes; r1 <= &rdes[MAXROOMS-1]; r1++)
    {
	for (j = 0; j < MAXROOMS; j++)
	    r1->isconn[j] = FALSE;
	r1->ingraph = FALSE;
    }

    /*
     * starting with one room, connect it to a random adjacent room and
     * then pick a new room to start with.
     */
    roomcount = 1;
    r1 = &rdes[rnd(MAXROOMS)];
    r1->ingraph = TRUE;
    do
    {
	/*
	 * find a room to connect with
	 */
	j = 0;
	for (i = 0; i < MAXROOMS; i++)
	    if (r1->conn[i] && !rdes[i].ingraph && rnd(++j) == 0)
		r2 = &rdes[i];
	/*
	 * if no adjacent rooms are outside the graph, pick a new room
	 * to look from
	 */
	if (j == 0)
	{
	    do
		r1 = &rdes[rnd(MAXROOMS)];
	    until (r1->ingraph);
	}
	/*
	 * otherwise, connect new room to the graph, and draw a tunnel
	 * to it
	 */
	else
	{
	    r2->ingraph = TRUE;
	    i = (int)(r1 - rdes);
	    j = (int)(r2 - rdes);
	    conn(i, j);
	    r1->isconn[j] = TRUE;
	    r2->isconn[i] = TRUE;
	    roomcount++;
	}
    } while (roomcount < MAXROOMS);

    /*
     * attempt to add passages to the graph a random number of times so
     * that there isn't just one unique passage through it.
     */
    for (roomcount = rnd(5); roomcount > 0; roomcount--)
    {
	r1 = &rdes[rnd(MAXROOMS)];	/* a random room to look from */
	/*
	 * find an adjacent room not already connected
	 */
	j = 0;
	for (i = 0; i < MAXROOMS; i++)
	    if (r1->conn[i] && !r1->isconn[i] && rnd(++j) == 0)
		r2 = &rdes[i];
	/*
	 * if there is one, connect it and look for the next added
	 * passage
	 */
	if (j != 0)
	{
	    i = (int)(r1 - rdes);
	    j = (int)(r2 - rdes);
	    conn(i, j);
	    r1->isconn[j] = TRUE;
	    r2->isconn[i] = TRUE;
	}
    }
}

/*
 * conn:
 *	Draw a corridor from a room in a certain direction.
 */

void
conn(int r1, int r2)
{
    register struct room *rpf, *rpt = NULL;
    register signed char rmt;
    register int distance, max_diag, offset, i;
    register int rm;
    int turns[3], turn_dist[3];
    register char direc;
    coord delta, curr, turn_delta, spos, epos;

    if (r1 < r2)
    {
	rm = r1;
	if (r1 + 1 == r2)
	    direc = 'r';
	else
	    direc = 'd';
    }
    else
    {
	rm = r2;
	if (r2 + 1 == r1)
	    direc = 'r';
	else
	    direc = 'd';
    }
    rpf = &rooms[rm];
    /*
     * Set up the movement variables, in two cases:
     * first drawing one down.
     */
    if (direc == 'd')
    {
	rmt = rm + 3;				/* room # of dest */
	rpt = &rooms[rmt];			/* room pointer of dest */
	delta.x = 0;				/* direction of move */
	delta.y = 1;
	spos.x = rpf->r_pos.x;			/* start of move */
	spos.y = rpf->r_pos.y;
	epos.x = rpt->r_pos.x;			/* end of move */
	epos.y = rpt->r_pos.y;
	if (!(rpf->r_flags & ISGONE))		/* if not gone pick door pos */
	{
	    spos.x += rnd(rpf->r_max.x-2)+1;
	    spos.y += rpf->r_max.y-1;
	}
	if (!(rpt->r_flags & ISGONE))
	    epos.x += rnd(rpt->r_max.x-2)+1;
	distance = abs(spos.y - epos.y) - 1;	/* distance to move */
	turn_delta.y = 0;			/* direction to turn */
	turn_delta.x = (spos.x < epos.x ? 1 : -1);
	offset = abs(spos.x - epos.x);	/* how far to turn */
    }
    else if (direc == 'r')			/* setup for moving right */
    {
	rmt = rm + 1;
	rpt = &rooms[rmt];
	delta.x = 1;
	delta.y = 0;
	spos.x = rpf->r_pos.x;
	spos.y = rpf->r_pos.y;
	epos.x = rpt->r_pos.x;
	epos.y = rpt->r_pos.y;
	if (!(rpf->r_flags & ISGONE))
	{
	    spos.x += rpf->r_max.x-1;
	    spos.y += rnd(rpf->r_max.y-2)+1;
	}
	if (!(rpt->r_flags & ISGONE))
	    epos.y += rnd(rpt->r_max.y-2)+1;
	distance = abs(spos.x - epos.x) - 1;
	turn_delta.y = (spos.y < epos.y ? 1 : -1);
	turn_delta.x = 0;
	offset = abs(spos.y - epos.y);
    }
    else
    {
	debug("error in connection tables");
	return;
    }

    /*
     * Draw in the doors on either side of the passage or just put #'s
     * if the rooms are gone.
     */
    if (!(rpf->r_flags & ISGONE)) door(rpf, &spos);
    else
    {
	cmov(spos);
	addch('#');
    }
    if (!(rpt->r_flags & ISGONE)) door(rpt, &epos);
    else
    {
	cmov(epos);
	addch('#');
    }

    /* How far can we move diagonally? */
    max_diag = min(distance, offset);

    /*
     * Decide how many turns we will have.
     */
    for (i=0; i<3; i++) turn_dist[i] = 0;	/* Init distances */
    if (max_diag > 0) {
	int nturns;

	for (i=0, nturns=0; i<3; i++) {
	    if (rnd(3 - i + nturns) == 0) {
		nturns++;
		turns[i] = 0;
	    }
	    else turns[i] = -1;
	}
    }
    else {
	/* Just use a straight line (middle turn) */
	turns[0] = turns[2] = -1;
	turns[1] = 0;
    }

    /*
     * Now decide how long each turn will be (for those selected above).
     */
    while (max_diag > 0) {
	for (i=0; i<3; i++) {
	    if (turns[i] >= 0 && max_diag > 0 && rnd(2) == 0) {
		turn_dist[i]++;
		max_diag--;
	    }
	}
    }
    
    /*
     * If we have extra offset space, add it to the straight turn.
     */
    if (offset > distance) turn_dist[1] += offset - distance;

    /*
     * Decide where we want to make our turns.
     * First calculate the offsets, then use those offsets to calculate
     * the exact position relative to "distance."
     */
    turns[0] = rnd(distance - turn_dist[0] - turn_dist[2]);
    turns[2] = rnd(distance - turn_dist[0] - turn_dist[2] - turns[0]);
    turns[1] = rnd(distance - turn_dist[0] - turn_dist[2] -
		   turns[0] - turns[2]);

    turns[0] = distance - turns[0];
    turns[1] = turns[0] - turn_dist[0] - turns[1];
    turns[2] = turns[1] - turns[2];

    /*
     * Get ready to move...
     */
    curr.x = spos.x;
    curr.y = spos.y;
    while (distance > 0) {
	/*
	 * Move to next row/column
	 */
	curr.x += delta.x;
	curr.y += delta.y;

	/*
	 * Check if we are at a turn place; if so make a turn
	 */
	for (i=0; i<3; i++) {
	    if (distance == turns[i] && turn_dist[i] > 0) {
		/*
		 * If this is the start of a straight path,
		 * we might put in a right-angle turn (33% chance).
		 */
		if (i == 1 && rnd(3) == 0) {
		    cmov(curr);
		    addch(PASSAGE);
		}

		/* Now dig the turn */
		while (turn_dist[i]--) {
		    curr.x += turn_delta.x;
		    curr.y += turn_delta.y;
		    cmov(curr);
		    addch(PASSAGE);
		    if (i != 1) {	/* A diagonal */
			if (--distance > 0) {
			    curr.x += delta.x;
			    curr.y += delta.y;
			}
		    }
		}
	    }
	}

	if (distance > 0) {
	    /*
	     * Dig the passage.
	     */
	    cmov(curr);
	    addch(PASSAGE);
	    distance--;
	}
    }
    curr.x += delta.x;
    curr.y += delta.y;
    if (!ce(curr, epos))
	msg("Warning, connectivity problem (%d, %d) to (%d, %d).",
	    curr.y, curr.x, epos.y, epos.x);
}

/*
 * Add a door or possibly a secret door
 * also enters the door in the exits array of the room.
 */

void
door(struct room *rm, coord *cp)
{
    struct linked_list *newroom;
    coord *exit;

    cmov(*cp);
    addch((rnd(10) < level - 1 && rnd(100) < 20) ? SECRETDOOR : DOOR);

    /* Insert the new room into the linked list of rooms */
    newroom = new_item(sizeof(coord));
    exit = DOORPTR(newroom);
    *exit = *cp;
    attach(rm->r_exit, newroom);
}