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1 | /* | |
2 | * viking -- GPS Data and Topo Analyzer, Explorer, and Manager | |
3 | * | |
4 | * Copyright (C) 2003-2005, Evan Battaglia <gtoevan@gmx.net> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
19 | * | |
20 | */ | |
21 | ||
22 | #include <gtk/gtk.h> | |
23 | #include <math.h> | |
24 | #include "coords.h" | |
25 | #include "vikcoord.h" | |
26 | #include "mapcoord.h" | |
27 | #include "http.h" | |
28 | ||
29 | #include "googlemaps.h" | |
30 | ||
31 | /* 1 << (x-1) is like a 2**(x-1) */ | |
32 | #define GZ(x) ((1<<(x-1))*GOOGLEMAPS_ZOOM_ONE_MPP) | |
33 | ||
34 | static const gdouble scale_mpps[] = { GZ(1)/2, GZ(1), GZ(2), GZ(3), GZ(4), GZ(5), GZ(6), GZ(7), GZ(8), GZ(9), | |
35 | GZ(10), GZ(11), GZ(12), GZ(13), GZ(14), GZ(15) }; | |
36 | ||
37 | static const gint num_scales = (sizeof(scale_mpps) / sizeof(scale_mpps[0])) - 1; | |
38 | ||
39 | #define ERROR_MARGIN 0.01 | |
40 | guint8 googlemaps_zoom ( gdouble mpp ) { | |
41 | gint i; | |
42 | for ( i = 0; i <= num_scales; i++ ) { | |
43 | if ( ABS(scale_mpps[i] - mpp) < ERROR_MARGIN ) | |
44 | return i; | |
45 | } | |
46 | return 255; | |
47 | } | |
48 | ||
49 | gboolean googlemaps_coord_to_mapcoord ( const VikCoord *src, gdouble xzoom, gdouble yzoom, MapCoord *dest ) | |
50 | { | |
51 | g_assert ( src->mode == VIK_COORD_LATLON ); | |
52 | ||
53 | if ( xzoom != yzoom ) | |
54 | return FALSE; | |
55 | ||
56 | dest->scale = googlemaps_zoom ( xzoom ); | |
57 | if ( dest->scale == 255 ) | |
58 | return FALSE; | |
59 | ||
60 | dest->x = (gint) floor ( floor ((src->east_west + 98.35) * (131072 >> dest->scale) * 0.77162458338772) / 128); | |
61 | dest->y = (gint) floor ( floor ((39.5 - src->north_south) * (131072 >> dest->scale)) / 128); | |
62 | dest->z = 0; | |
63 | return TRUE; | |
64 | } | |
65 | ||
66 | void googlemaps_mapcoord_to_center_coord ( MapCoord *src, VikCoord *dest ) | |
67 | { | |
68 | dest->mode = VIK_COORD_LATLON; | |
69 | dest->north_south = 39.5 - (1.0/(131072 >> src->scale) * (src->y+0.5) * 128); | |
70 | dest->east_west = 1.0 / (131072 >> src->scale) * (src->x+0.5) / 0.77162458338772 * 128 - 98.35; | |
71 | } | |
72 | ||
73 | void googlemaps_download ( MapCoord *src, const gchar *dest_fn ) | |
74 | { | |
75 | gchar *uri = g_strdup_printf ( "/mt?v=.3&x=%d&y=%d&zoom=%d", src->x, src->y, src->scale ); | |
76 | a_http_download_get_url ( "mt.google.com", uri, dest_fn ); | |
77 | g_free ( uri ); | |
78 | } |