1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
|
/**
* Navit, a modular navigation system.
* Copyright (C) 2005-2008 Navit Team
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the
* Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#include <string.h>
#include <glib.h>
#include "coord.h"
#include "debug.h"
#include "projection.h"
struct projection_name {
enum projection projection;
char *name;
};
struct projection_name projection_names[]={
{projection_none, ""},
{projection_mg, "mg"},
{projection_garmin, "garmin"},
{projection_utm, "utm"},
};
static int
utmref_letter(char l)
{
if (l < 'a' || l == 'i' || l == 'o')
return -1;
if (l < 'i')
return l-'a';
if (l < 'o')
return l-'a'-1;
if (l <= 'z')
return l-'a'-2;
return -1;
}
/**
* Look up a projection by name.
*
* @param name name of projection to look up (values from projection_names, and UTM projections)
* @utm_offset Only for UTM projections: Used to return the offset for the UTM projection
* @returns projection, or projection_none if no projection could be determined
*/
enum projection
projection_from_name(const char *name, struct coord *utm_offset)
{
int i;
int zone,baserow;
char ns,zone_field,square_x,square_y;
for (i=0 ; i < sizeof(projection_names)/sizeof(struct projection_name) ; i++) {
if (! strcmp(projection_names[i].name, name))
return projection_names[i].projection;
}
if (utm_offset) {
if (sscanf(name,"utm%d%c",&zone,&ns) == 2 && zone > 0 && zone <= 60 && (ns == 'n' || ns == 's')) {
utm_offset->x=zone*1000000;
utm_offset->y=(ns == 's' ? -10000000:0);
return projection_utm;
}
if (sscanf(name,"utmref%d%c%c%c",&zone,&zone_field,&square_x,&square_y)) {
i=utmref_letter(zone_field);
if (i < 2 || i > 21) {
dbg(lvl_error,"invalid zone field '%c' in '%s'\n",zone_field,name);
return projection_none;
}
i-=12;
dbg(lvl_debug,"zone_field %d\n",i);
baserow=i*887.6/100;
utm_offset->x=zone*1000000;
i=utmref_letter(square_x);
utm_offset->x+=((i%8)+1)*100000;
i=utmref_letter(square_y);
dbg(lvl_debug,"baserow %d\n",baserow);
if (!(zone % 2))
i-=5;
dbg(lvl_debug,"i=%d\n",i);
i=(i-baserow+100)%20+baserow;
utm_offset->y=i*100000;
return projection_utm;
}
}
return projection_none;
}
char *
projection_to_name(enum projection proj)
{
int i;
for (i=0 ; i < sizeof(projection_names)/sizeof(struct projection_name) ; i++) {
if (projection_names[i].projection == proj)
return projection_names[i].name;
}
return NULL;
}
|
