trunk/src/segments.c

/***************************************
 $Header: /home/amb/CVS/routino/src/segments.c,v 1.31 2009-02-07 15:56:07 amb Exp $

 Segment data type functions.
 ******************/ /******************
 Written by Andrew M. Bishop

 This file Copyright 2008,2009 Andrew M. Bishop
 It may be distributed under the GNU Public License, version 2, or
 any higher version.  See section COPYING of the GNU Public license
 for conditions under which this file may be redistributed.
 ***************************************/


#include <assert.h>
#include <math.h>
#include <string.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* SaveSegmentList 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);

 if(!data)
    return(NULL);

 /* 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+(off_t)segments->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.
  ++++++++++++++++++++++++++++++++++++++*/

Segment *NextSegment(Segments* segments,Segment *segment,index_t node)
{
 index_t next;

 if(NODE(segment->node1)==node)
    next=segment->next1;
 else
    next=segment->next2;

 if(next==~0)
    return(NULL);
 else
    return(LookupSegment(segments,next));
}
 
 
/*++++++++++++++++++++++++++++++++++++++
  Calculate the distance between two locations.

  float Distance Returns the distance between the locations.

  float lat1 The latitude of the first location.

  float lon1 The longitude of the first location.

  float lat2 The latitude of the second location.

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

float Distance(float lat1,float lon1,float lat2,float lon2)
{
 double radiant = M_PI / 180;

 double dlon = radiant * (lon1 - lon2);
 double dlat = radiant * (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 * radiant) * cos (lat2 * radiant) * a2 * a2;
 sa = sqrt (a);
 if (sa <= 1.0)
   {c = 2 * asin (sa);}
 else
   {c = 2 * asin (1.0);}
 d = 6378.137 * c;

 return 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    speed=profile->speed[HIGHWAY(way->type)];
 distance_t distance=DISTANCE(segment->distance);

 return distance_speed_to_duration(distance,speed);
}
1	/***************************************
2	$Header: /home/amb/CVS/routino/src/segments.c,v 1.31 2009-02-07 15:56:07 amb Exp $
3
4	Segment data type functions.
5	****************/ /****************
6	Written by Andrew M. Bishop
7
8	This file Copyright 2008,2009 Andrew M. Bishop
9	It may be distributed under the GNU Public License, version 2, or
10	any higher version. See section COPYING of the GNU Public license
11	for conditions under which this file may be redistributed.
12	***************************************/
13
14
15	#include <assert.h>
16	#include <math.h>
17	#include <string.h>
18	#include <stdlib.h>
19
20	#include "types.h"
21	#include "functions.h"
22	#include "nodes.h"
23	#include "segments.h"
24	#include "ways.h"
25	#include "profiles.h"
26
27
28	/*++++++++++++++++++++++++++++++++++++++
29	Load in a segment list from a file.
30
31	Segments* SaveSegmentList Returns the segment list that has just been loaded.
32
33	const char *filename The name of the file to load.
34	++++++++++++++++++++++++++++++++++++++*/
35
36	Segments LoadSegmentList(const char filename)
37	{
38	void *data;
39	Segments *segments;
40
41	segments=(Segments*)malloc(sizeof(Segments));
42
43	data=MapFile(filename);
44
45	if(!data)
46	return(NULL);
47
48	/* Copy the Segments structure from the loaded data */
49
50	segments=((Segments*)data);
51
52	/* Adjust the pointers in the Segments structure. */
53
54	segments->data=data;
55	segments->segments=(Segment*)(data+(off_t)segments->segments);
56
57	return(segments);
58	}
59
60
61	/*++++++++++++++++++++++++++++++++++++++
62	Find the next segment with a particular starting node.
63
64	Segment *NextSegment Returns a pointer to the next segment with the same id.
65
66	Segments* segments The set of segments to process.
67
68	Segment *segment The current segment.
69	++++++++++++++++++++++++++++++++++++++*/
70
71	Segment NextSegment(Segments segments,Segment *segment,index_t node)
72	{
73	index_t next;
74
75	if(NODE(segment->node1)==node)
76	next=segment->next1;
77	else
78	next=segment->next2;
79
80	if(next==~0)
81	return(NULL);
82	else
83	return(LookupSegment(segments,next));
84	}
85
86
87	/*++++++++++++++++++++++++++++++++++++++
88	Calculate the distance between two locations.
89
90	float Distance Returns the distance between the locations.
91
92	float lat1 The latitude of the first location.
93
94	float lon1 The longitude of the first location.
95
96	float lat2 The latitude of the second location.
97
98	float lon2 The longitude of the second location.
99	++++++++++++++++++++++++++++++++++++++*/
100
101	float Distance(float lat1,float lon1,float lat2,float lon2)
102	{
103	double radiant = M_PI / 180;
104
105	double dlon = radiant * (lon1 - lon2);
106	double dlat = radiant * (lat1 - lat2);
107
108	double a1,a2,a,sa,c,d;
109
110	if(dlon==0 && dlat==0)
111	return 0;
112
113	a1 = sin (dlat / 2);
114	a2 = sin (dlon / 2);
115	a = (a1 * a1) + cos (lat1 * radiant) * cos (lat2 * radiant) * a2 * a2;
116	sa = sqrt (a);
117	if (sa <= 1.0)
118	{c = 2 * asin (sa);}
119	else
120	{c = 2 * asin (1.0);}
121	d = 6378.137 * c;
122
123	return d;
124	}
125
126
127	/*++++++++++++++++++++++++++++++++++++++
128	Calculate the duration of segment.
129
130	duration_t Duration Returns the duration of travel between the nodes.
131
132	Segment *segment The segment to traverse.
133
134	Way *way The way that the segment belongs to.
135
136	Profile *profile The profile of the transport being used.
137	++++++++++++++++++++++++++++++++++++++*/
138
139	duration_t Duration(Segment segment,Way way,Profile *profile)
140	{
141	speed_t speed=profile->speed[HIGHWAY(way->type)];
142	distance_t distance=DISTANCE(segment->distance);
143
144	return distance_speed_to_duration(distance,speed);
145	}