1 /*-
2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Ed James.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)list.c 8.1 (Berkeley) 5/31/93
33 * $FreeBSD: src/games/atc/list.c,v 1.4 1999/11/30 03:48:20 billf Exp $
34 * $DragonFly: src/games/atc/list.c,v 1.4 2007/05/17 08:19:00 swildner Exp $
35 */
36
37 /*
38 * Copyright (c) 1987 by Ed James, UC Berkeley. All rights reserved.
39 *
40 * Copy permission is hereby granted provided that this notice is
41 * retained on all partial or complete copies.
42 *
43 * For more info on this and all of my stuff, mail edjames@berkeley.edu.
44 */
45
46 #include "include.h"
47
48
49 PLANE *
newplane(void)50 newplane(void)
51 {
52 return ((PLANE *) calloc(1, sizeof (PLANE)));
53 }
54
55 void
append(LIST * l,PLANE * p)56 append(LIST *l, PLANE *p)
57 {
58 PLANE *q = NULL, *r = NULL;
59
60 if (l->head == NULL) {
61 p->next = p->prev = NULL;
62 l->head = l->tail = p;
63 } else {
64 q = l -> head;
65
66 while (q != NULL && q->plane_no < p->plane_no) {
67 r = q;
68 q = q -> next;
69 }
70
71 if (q) {
72 if (r) {
73 p->prev = r;
74 r->next = p;
75 p->next = q;
76 q->prev = p;
77 } else {
78 p->next = q;
79 p->prev = NULL;
80 q->prev = p;
81 l->head = p;
82 }
83 } else {
84 l->tail->next = p;
85 p->next = NULL;
86 p->prev = l->tail;
87 l->tail = p;
88 }
89 }
90 }
91
92 void
delete(LIST * l,PLANE * p)93 delete(LIST *l, PLANE *p)
94 {
95 if (l->head == NULL)
96 loser(p, "deleted a non-existent plane! Get help!");
97
98 if (l->head == p && l->tail == p)
99 l->head = l->tail = NULL;
100 else if (l->head == p) {
101 l->head = p->next;
102 l->head->prev = NULL;
103 } else if (l->tail == p) {
104 l->tail = p->prev;
105 l->tail->next = NULL;
106 } else {
107 p->prev->next = p->next;
108 p->next->prev = p->prev;
109 }
110 }
111