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mirror of https://git.FreeBSD.org/src.git synced 2024-12-06 09:17:25 +00:00
freebsd/games/atc/list.c
1998-05-09 08:45:53 +00:00

117 lines
3.2 KiB
C

/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Ed James.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* Copyright (c) 1987 by Ed James, UC Berkeley. All rights reserved.
*
* Copy permission is hereby granted provided that this notice is
* retained on all partial or complete copies.
*
* For more info on this and all of my stuff, mail edjames@berkeley.edu.
*/
#ifndef lint
static char sccsid[] = "@(#)list.c 8.1 (Berkeley) 5/31/93";
#endif /* not lint */
#include <stdlib.h>
#include "include.h"
PLANE *
newplane()
{
return ((PLANE *) calloc(1, sizeof (PLANE)));
}
append(l, p)
LIST *l;
PLANE *p;
{
PLANE *q = NULL, *r = NULL;
if (l->head == NULL) {
p->next = p->prev = NULL;
l->head = l->tail = p;
} else {
q = l -> head;
while (q != NULL && q->plane_no < p->plane_no) {
r = q;
q = q -> next;
}
if (q) {
if (r) {
p->prev = r;
r->next = p;
p->next = q;
q->prev = p;
} else {
p->next = q;
p->prev = NULL;
q->prev = p;
l->head = p;
}
} else {
l->tail->next = p;
p->next = NULL;
p->prev = l->tail;
l->tail = p;
}
}
}
delete(l, p)
LIST *l;
PLANE *p;
{
if (l->head == NULL)
loser(p, "deleted a non-existant plane! Get help!");
if (l->head == p && l->tail == p)
l->head = l->tail = NULL;
else if (l->head == p) {
l->head = p->next;
l->head->prev = NULL;
} else if (l->tail == p) {
l->tail = p->prev;
l->tail->next = NULL;
} else {
p->prev->next = p->next;
p->next->prev = p->prev;
}
}