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. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)list.c 8.1 (Berkeley) 5/31/93 37 * $FreeBSD: src/games/atc/list.c,v 1.4 1999/11/30 03:48:20 billf Exp $ 38 * $DragonFly: src/games/atc/list.c,v 1.4 2007/05/17 08:19:00 swildner Exp $ 39 */ 40 41 /* 42 * Copyright (c) 1987 by Ed James, UC Berkeley. All rights reserved. 43 * 44 * Copy permission is hereby granted provided that this notice is 45 * retained on all partial or complete copies. 46 * 47 * For more info on this and all of my stuff, mail edjames@berkeley.edu. 48 */ 49 50 #include "include.h" 51 52 53 PLANE * 54 newplane(void) 55 { 56 return ((PLANE *) calloc(1, sizeof (PLANE))); 57 } 58 59 void 60 append(LIST *l, PLANE *p) 61 { 62 PLANE *q = NULL, *r = NULL; 63 64 if (l->head == NULL) { 65 p->next = p->prev = NULL; 66 l->head = l->tail = p; 67 } else { 68 q = l -> head; 69 70 while (q != NULL && q->plane_no < p->plane_no) { 71 r = q; 72 q = q -> next; 73 } 74 75 if (q) { 76 if (r) { 77 p->prev = r; 78 r->next = p; 79 p->next = q; 80 q->prev = p; 81 } else { 82 p->next = q; 83 p->prev = NULL; 84 q->prev = p; 85 l->head = p; 86 } 87 } else { 88 l->tail->next = p; 89 p->next = NULL; 90 p->prev = l->tail; 91 l->tail = p; 92 } 93 } 94 } 95 96 void 97 delete(LIST *l, PLANE *p) 98 { 99 if (l->head == NULL) 100 loser(p, "deleted a non-existent plane! Get help!"); 101 102 if (l->head == p && l->tail == p) 103 l->head = l->tail = NULL; 104 else if (l->head == p) { 105 l->head = p->next; 106 l->head->prev = NULL; 107 } else if (l->tail == p) { 108 l->tail = p->prev; 109 l->tail->next = NULL; 110 } else { 111 p->prev->next = p->next; 112 p->next->prev = p->prev; 113 } 114 } 115