trunk/src/segments.c

/***************************************
 $Header: /home/amb/CVS/routino/src/segments.c,v 1.45 2010-04-28 17:27:02 amb Exp $

 Segment data type functions.

 Part of the Routino routing software.
 ******************/ /******************
 This file Copyright 2008-2010 Andrew M. Bishop

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU Affero General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU Affero General Public License for more details.

 You should have received a copy of the GNU Affero General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
 ***************************************/


#include <sys/types.h>
#include <stdlib.h>

#include "types.h"
#include "functions.h"
#include "nodes.h"
#include "segments.h"
#include "ways.h"
#include "profiles.h"


/*++++++++++++++++++++++++++++++++++++++
  Load in a segment list from a file.

  Segments* LoadSegmentList Returns the segment list that has just been loaded.

  const char *filename The name of the file to load.
  ++++++++++++++++++++++++++++++++++++++*/

Segments *LoadSegmentList(const char *filename)
{
 void *data;
 Segments *segments;

 segments=(Segments*)malloc(sizeof(Segments));

 data=MapFile(filename);

 /* Copy the Segments structure from the loaded data */

 *segments=*((Segments*)data);

 /* Adjust the pointers in the Segments structure. */

 segments->data=data;
 segments->segments=(Segment*)(data+sizeof(Segments));

 return(segments);
}


/*++++++++++++++++++++++++++++++++++++++
  Find the next segment with a particular starting node.

  Segment *NextSegment Returns a pointer to the next segment with the same id.

  Segments* segments The set of segments to process.

  Segment *segment The current segment.

  index_t node The current node.
  ++++++++++++++++++++++++++++++++++++++*/

Segment *NextSegment(Segments* segments,Segment *segment,index_t node)
{
 if(segment->node1==node)
   {
    segment++;
    if((segment-segments->segments)>=segments->number || segment->node1!=node)
       return(NULL);
    else
       return(segment);
   }
 else
   {
    if(segment->next2==NO_NODE)
       return(NULL);
    else
       return(LookupSegment(segments,segment->next2));
   }
}
 
 
/*++++++++++++++++++++++++++++++++++++++
  Calculate the distance between two locations.

  distance_t Distance Returns the distance between the locations.

  double lat1 The latitude of the first location.

  double lon1 The longitude of the first location.

  double lat2 The latitude of the second location.

  double lon2 The longitude of the second location.
  ++++++++++++++++++++++++++++++++++++++*/

distance_t Distance(double lat1,double lon1,double lat2,double lon2)
{
 double dlon = lon1 - lon2;
 double dlat = lat1 - lat2;

 double a1,a2,a,sa,c,d;

 if(dlon==0 && dlat==0)
   return 0;

 a1 = sin (dlat / 2);
 a2 = sin (dlon / 2);
 a = (a1 * a1) + cos (lat1) * cos (lat2) * a2 * a2;
 sa = sqrt (a);
 if (sa <= 1.0)
   {c = 2 * asin (sa);}
 else
   {c = 2 * asin (1.0);}
 d = 6378.137 * c;

 return km_to_distance(d);
}


/*++++++++++++++++++++++++++++++++++++++
  Calculate the duration of segment.

  duration_t Duration Returns the duration of travel between the nodes.

  Segment *segment The segment to traverse.

  Way *way The way that the segment belongs to.

  Profile *profile The profile of the transport being used.
  ++++++++++++++++++++++++++++++++++++++*/

duration_t Duration(Segment *segment,Way *way,Profile *profile)
{
 speed_t    speed1=way->speed;
 speed_t    speed2=profile->speed[HIGHWAY(way->type)];
 distance_t distance=DISTANCE(segment->distance);

 if(speed1==0)
   {
    if(speed2==0)
       return(hours_to_duration(10));
    else
       return distance_speed_to_duration(distance,speed2);
   }
 else /* if(speed1!=0) */
   {
    if(speed2==0)
       return distance_speed_to_duration(distance,speed1);
    else if(speed1<=speed2)
       return distance_speed_to_duration(distance,speed1);
    else
       return distance_speed_to_duration(distance,speed2);
   }
}
1	/***************************************
2	$Header: /home/amb/CVS/routino/src/segments.c,v 1.45 2010-04-28 17:27:02 amb Exp $
3
4	Segment data type functions.
5
6	Part of the Routino routing software.
7	****************/ /****************
8	This file Copyright 2008-2010 Andrew M. Bishop
9
10	This program is free software: you can redistribute it and/or modify
11	it under the terms of the GNU Affero General Public License as published by
12	the Free Software Foundation, either version 3 of the License, or
13	(at your option) any later version.
14
15	This program is distributed in the hope that it will be useful,
16	but WITHOUT ANY WARRANTY; without even the implied warranty of
17	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18	GNU Affero General Public License for more details.
19
20	You should have received a copy of the GNU Affero General Public License
21	along with this program. If not, see <http://www.gnu.org/licenses/>.
22	***************************************/
23
24
25	#include <sys/types.h>
26	#include <stdlib.h>
27
28	#include "types.h"
29	#include "functions.h"
30	#include "nodes.h"
31	#include "segments.h"
32	#include "ways.h"
33	#include "profiles.h"
34
35
36	/*++++++++++++++++++++++++++++++++++++++
37	Load in a segment list from a file.
38
39	Segments* LoadSegmentList Returns the segment list that has just been loaded.
40
41	const char *filename The name of the file to load.
42	++++++++++++++++++++++++++++++++++++++*/
43
44	Segments LoadSegmentList(const char filename)
45	{
46	void *data;
47	Segments *segments;
48
49	segments=(Segments*)malloc(sizeof(Segments));
50
51	data=MapFile(filename);
52
53	/* Copy the Segments structure from the loaded data */
54
55	segments=((Segments*)data);
56
57	/* Adjust the pointers in the Segments structure. */
58
59	segments->data=data;
60	segments->segments=(Segment*)(data+sizeof(Segments));
61
62	return(segments);
63	}
64
65
66	/*++++++++++++++++++++++++++++++++++++++
67	Find the next segment with a particular starting node.
68
69	Segment *NextSegment Returns a pointer to the next segment with the same id.
70
71	Segments* segments The set of segments to process.
72
73	Segment *segment The current segment.
74
75	index_t node The current node.
76	++++++++++++++++++++++++++++++++++++++*/
77
78	Segment NextSegment(Segments segments,Segment *segment,index_t node)
79	{
80	if(segment->node1==node)
81	{
82	segment++;
83	if((segment-segments->segments)>=segments->number \|\| segment->node1!=node)
84	return(NULL);
85	else
86	return(segment);
87	}
88	else
89	{
90	if(segment->next2==NO_NODE)
91	return(NULL);
92	else
93	return(LookupSegment(segments,segment->next2));
94	}
95	}
96
97
98	/*++++++++++++++++++++++++++++++++++++++
99	Calculate the distance between two locations.
100
101	distance_t Distance Returns the distance between the locations.
102
103	double lat1 The latitude of the first location.
104
105	double lon1 The longitude of the first location.
106
107	double lat2 The latitude of the second location.
108
109	double lon2 The longitude of the second location.
110	++++++++++++++++++++++++++++++++++++++*/
111
112	distance_t Distance(double lat1,double lon1,double lat2,double lon2)
113	{
114	double dlon = lon1 - lon2;
115	double dlat = lat1 - lat2;
116
117	double a1,a2,a,sa,c,d;
118
119	if(dlon==0 && dlat==0)
120	return 0;
121
122	a1 = sin (dlat / 2);
123	a2 = sin (dlon / 2);
124	a = (a1 * a1) + cos (lat1) * cos (lat2) * a2 * a2;
125	sa = sqrt (a);
126	if (sa <= 1.0)
127	{c = 2 * asin (sa);}
128	else
129	{c = 2 * asin (1.0);}
130	d = 6378.137 * c;
131
132	return km_to_distance(d);
133	}
134
135
136	/*++++++++++++++++++++++++++++++++++++++
137	Calculate the duration of segment.
138
139	duration_t Duration Returns the duration of travel between the nodes.
140
141	Segment *segment The segment to traverse.
142
143	Way *way The way that the segment belongs to.
144
145	Profile *profile The profile of the transport being used.
146	++++++++++++++++++++++++++++++++++++++*/
147
148	duration_t Duration(Segment segment,Way way,Profile *profile)
149	{
150	speed_t speed1=way->speed;
151	speed_t speed2=profile->speed[HIGHWAY(way->type)];
152	distance_t distance=DISTANCE(segment->distance);
153
154	if(speed1==0)
155	{
156	if(speed2==0)
157	return(hours_to_duration(10));
158	else
159	return distance_speed_to_duration(distance,speed2);
160	}
161	else /* if(speed1!=0) */
162	{
163	if(speed2==0)
164	return distance_speed_to_duration(distance,speed1);
165	else if(speed1<=speed2)
166	return distance_speed_to_duration(distance,speed1);
167	else
168	return distance_speed_to_duration(distance,speed2);
169	}
170	}