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 * 50 newplane(void) 51 { 52 return ((PLANE *) calloc(1, sizeof (PLANE))); 53 } 54 55 void 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 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