2 * viking -- GPS Data and Topo Analyzer, Explorer, and Manager
4 * Copyright (C) 2003-2005, Evan Battaglia <gtoevan@gmx.net>
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.
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.
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
32 /* 1 << (x) is like a 2**(x) */
33 #define GZ(x) ((1<<x))
35 static const gdouble scale_mpps
[] = { GZ(0), GZ(1), GZ(2), GZ(3), GZ(4), GZ(5), GZ(6), GZ(7), GZ(8), GZ(9),
36 GZ(10), GZ(11), GZ(12), GZ(13), GZ(14), GZ(15), GZ(16), GZ(17) };
38 static const gint num_scales
= (sizeof(scale_mpps
) / sizeof(scale_mpps
[0]));
40 #define ERROR_MARGIN 0.01
41 guint8
google_zoom ( gdouble mpp
) {
43 for ( i
= 0; i
< num_scales
; i
++ ) {
44 if ( ABS(scale_mpps
[i
] - mpp
) < ERROR_MARGIN
)
50 gboolean
google_coord_to_mapcoord ( const VikCoord
*src
, gdouble xzoom
, gdouble yzoom
, MapCoord
*dest
)
52 g_assert ( src
->mode
== VIK_COORD_LATLON
);
57 dest
->scale
= google_zoom ( xzoom
);
58 if ( dest
->scale
== 255 )
61 dest
->x
= (src
->east_west
+ 180) / 360 * GZ(17) / xzoom
;
62 dest
->y
= (180 - MERCLAT(src
->north_south
)) / 360 * GZ(17) / xzoom
;
68 void google_mapcoord_to_center_coord ( MapCoord
*src
, VikCoord
*dest
)
70 gdouble socalled_mpp
= GZ(src
->scale
);
71 dest
->mode
= VIK_COORD_LATLON
;
72 dest
->east_west
= ((src
->x
+0.5) / GZ(17) * socalled_mpp
* 360) - 180;
73 dest
->north_south
= DEMERCLAT(180 - ((src
->y
+0.5) / GZ(17) * socalled_mpp
* 360));
76 static void real_google_download ( MapCoord
*src
, const gchar
*dest_fn
, const char *verstr
)
78 gchar
*uri
= g_strdup_printf ( "/mt?v=%s&x=%d&y=%d&zoom=%d", verstr
, src
->x
, src
->y
, src
->scale
);
79 a_http_download_get_url ( "mt.google.com", uri
, dest_fn
);
83 void google_download ( MapCoord
*src
, const gchar
*dest_fn
)
85 real_google_download ( src
, dest_fn
, "w2.5" );
88 void google_trans_download ( MapCoord
*src
, const gchar
*dest_fn
)
90 real_google_download ( src
, dest_fn
, "w2t.1" );
93 static char *kh_encode(guint32 x
, guint32 y
, guint8 scale
)
95 gchar
*buf
= g_malloc ( (20-scale
)*sizeof(gchar
) );
96 guint32 ya
= 1 << (17 - scale
);
99 if (y
< 0 || (ya
-1 < y
)) {
100 strcpy(buf
,"tqq"); /* BAD */
103 if (x
< 0 || ya
-1 < x
) {
110 for (j
= 1, i
= 16; i
>= scale
; i
--, j
++) {
134 void google_kh_download ( MapCoord
*src
, const gchar
*dest_fn
)
136 gchar
*khenc
= kh_encode( src
->x
, src
->y
, src
->scale
);
137 gchar
*uri
= g_strdup_printf ( "/kh?v=3&t=%s", khenc
);
139 a_http_download_get_url ( "kh.google.com", uri
, dest_fn
);