src/google.c

   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 #ifdef HAVE_CONFIG_H
  22 #include "config.h"
  23 #endif
  24
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <glib/gi18n.h>
  28 #include <gtk/gtk.h>
  29 #include <math.h>
  30 #include <string.h>
  31 #include "coords.h"
  32 #include "vikcoord.h"
  33 #include "mapcoord.h"
  34 #include "download.h"
  35 #include "curl_download.h"
  36 #include "globals.h"
  37 #include "google.h"
  38 #include "vikmapslayer.h"
  39
  40
  41 static int google_download ( MapCoord *src, const gchar *dest_fn );
  42 static int google_trans_download ( MapCoord *src, const gchar *dest_fn );
  43 static int google_terrain_download ( MapCoord *src, const gchar *dest_fn );
  44 static int google_kh_download ( MapCoord *src, const gchar *dest_fn );
  45 static void google_mapcoord_to_center_coord ( MapCoord *src, VikCoord *dest );
  46 static gboolean google_coord_to_mapcoord ( const VikCoord *src, gdouble xzoom, gdouble yzoom, MapCoord *dest );
  47
  48 static DownloadOptions google_options = { "http://maps.google.com/", 0 };
  49
  50 void google_init () {
  51   VikMapsLayer_MapType google_1 = { 7, 256, 256, VIK_VIEWPORT_DRAWMODE_MERCATOR, google_coord_to_mapcoord, google_mapcoord_to_center_coord, google_download };
  52   VikMapsLayer_MapType google_2 = { 10, 256, 256, VIK_VIEWPORT_DRAWMODE_MERCATOR, google_coord_to_mapcoord, google_mapcoord_to_center_coord, google_trans_download };
  53   VikMapsLayer_MapType google_3 = { 11, 256, 256, VIK_VIEWPORT_DRAWMODE_MERCATOR, google_coord_to_mapcoord, google_mapcoord_to_center_coord, google_kh_download };
  54   VikMapsLayer_MapType google_4 = { 16, 256, 256, VIK_VIEWPORT_DRAWMODE_MERCATOR, google_coord_to_mapcoord, google_mapcoord_to_center_coord, google_terrain_download };
  55
  56   maps_layer_register_type(_("Google Maps"), 7, &google_1);
  57   maps_layer_register_type(_("Transparent Google Maps"), 10, &google_2);
  58   maps_layer_register_type(_("Google Satellite Images"), 11, &google_3);
  59   maps_layer_register_type(_("Google Terrain Maps"), 16, &google_4);
  60 }
  61
  62 /* 1 << (x) is like a 2**(x) */
  63 #define GZ(x) ((1<<x))
  64
  65 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),
  66                                            GZ(10), GZ(11), GZ(12), GZ(13), GZ(14), GZ(15), GZ(16), GZ(17) };
  67
  68 static const gint num_scales = (sizeof(scale_mpps) / sizeof(scale_mpps[0]));
  69
  70 #define ERROR_MARGIN 0.01
  71 guint8 google_zoom ( gdouble mpp ) {
  72   gint i;
  73   for ( i = 0; i < num_scales; i++ ) {
  74     if ( ABS(scale_mpps[i] - mpp) < ERROR_MARGIN )
  75       return i;
  76   }
  77   return 255;
  78 }
  79
  80 typedef enum {
  81         TYPE_GOOGLE_MAPS = 0,
  82         TYPE_GOOGLE_TRANS,
  83         TYPE_GOOGLE_SAT,
  84         TYPE_GOOGLE_TERRAIN,
  85
  86         TYPE_GOOGLE_NUM
  87 } GoogleType;
  88
  89 static gchar *parse_version_number(gchar *text)
  90 {
  91   int i;
  92   gchar *vers;
  93   gchar *s = text;
  94
  95   for (i = 0; (s[i] != '\\') && (i < 8); i++)
  96     ;
  97   if (s[i] != '\\') {
  98     return NULL;
  99   }
 100
 101   return vers = g_strndup(s, i);
 102 }
 103
 104 static const gchar *google_version_number(MapCoord *mapcoord, GoogleType google_type)
 105 {
 106   static gboolean first = TRUE;
 107   static char *vers[] = { "w2.60", "w2t.60", "20", "w2p.60" };
 108   FILE *tmp_file;
 109   int tmp_fd;
 110   gchar *tmpname;
 111   gchar *uri;
 112   VikCoord coord;
 113   gchar *text, *pat, *beg;
 114   GMappedFile *mf;
 115   gsize len;
 116   gchar *gvers, *tvers, *kvers, *terrvers, *tmpvers;
 117   static DownloadOptions dl_options = { "http://maps.google.com/", 0 };
 118   static const char *gvers_pat = "http://mt0.google.com/mt?n\\x3d404\\x26v\\x3d";
 119   static const char *kvers_pat = "http://kh0.google.com/kh?n\\x3d404\\x26v\\x3d";
 120
 121   g_assert(google_type < TYPE_GOOGLE_NUM);
 122
 123   if (!first)
 124     return (vers[google_type]);
 125
 126
 127   first = FALSE;
 128   gvers = tvers = kvers = terrvers = NULL;
 129   if ((tmp_fd = g_file_open_tmp ("vikgvers.XXXXXX", &tmpname, NULL)) == -1) {
 130     g_critical(_("couldn't open temp file %s\n"), tmpname);
 131     exit(1);
 132   }
 133
 134   google_mapcoord_to_center_coord(mapcoord, &coord);
 135   uri = g_strdup_printf("http://maps.google.com/maps?f=q&hl=en&q=%f,%f", coord.north_south, coord.east_west);
 136   tmp_file = fdopen(tmp_fd, "r+");
 137
 138   if (curl_download_uri(uri, tmp_file, &dl_options)) {  /* error */
 139     g_warning(_("Failed downloading %s\n"), tmpname);
 140   } else {
 141     if ((mf = g_mapped_file_new(tmpname, FALSE, NULL)) == NULL) {
 142       g_critical(_("couldn't map temp file\n"));
 143       exit(1);
 144     }
 145     len = g_mapped_file_get_length(mf);
 146     text = g_mapped_file_get_contents(mf);
 147
 148     if ((beg = g_strstr_len(text, len, "GLoadApi")) == NULL) {
 149       g_warning(_("Failed fetching Google numbers (\"GLoadApi\" not found)\n"));
 150       goto failed;
 151     }
 152
 153     pat = beg;
 154     while (!gvers || !tvers ||!terrvers) {
 155       if ((pat = g_strstr_len(pat, &text[len] - pat, gvers_pat)) != NULL) {
 156         pat += strlen(gvers_pat);
 157         if ((tmpvers = parse_version_number(pat)) != NULL) {
 158           if (strstr(tmpvers, "t."))
 159             tvers = tmpvers;
 160           else if (strstr(tmpvers, "p."))
 161             terrvers = tmpvers;
 162           else
 163             gvers = tmpvers;
 164         }
 165       }
 166       else
 167         break;
 168     }
 169
 170     if ((pat = g_strstr_len(beg, &text[len] - beg, kvers_pat)) != NULL)
 171         kvers = parse_version_number(pat + strlen(kvers_pat));
 172
 173     if (gvers && tvers && kvers) {
 174       vers[TYPE_GOOGLE_MAPS] = gvers;
 175       vers[TYPE_GOOGLE_TRANS] = tvers;
 176       vers[TYPE_GOOGLE_SAT] = kvers;
 177       vers[TYPE_GOOGLE_TERRAIN] = terrvers;
 178     }
 179     else
 180       g_warning(_("Failed getting google version numbers"));
 181
 182     if (gvers)
 183       fprintf(stderr, "DEBUG gvers=%s\n", gvers);
 184     if (tvers)
 185       fprintf(stderr, "DEBUG tvers=%s\n", tvers);
 186     if (terrvers)
 187       fprintf(stderr, "DEBUG terrvers=%s\n", terrvers);
 188     if (kvers)
 189       fprintf(stderr, "DEBUG kvers=%s\n", kvers);
 190
 191 failed:
 192     g_mapped_file_free(mf);
 193   }
 194
 195   fclose(tmp_file);
 196   g_free(tmpname);
 197   return (vers[google_type]);
 198 }
 199
 200 gboolean google_coord_to_mapcoord ( const VikCoord *src, gdouble xzoom, gdouble yzoom, MapCoord *dest )
 201 {
 202   g_assert ( src->mode == VIK_COORD_LATLON );
 203
 204   if ( xzoom != yzoom )
 205     return FALSE;
 206
 207   dest->scale = google_zoom ( xzoom );
 208   if ( dest->scale == 255 )
 209     return FALSE;
 210
 211   dest->x = (src->east_west + 180) / 360 * GZ(17) / xzoom;
 212   dest->y = (180 - MERCLAT(src->north_south)) / 360 * GZ(17) / xzoom;
 213   dest->z = 0;
 214
 215   return TRUE;
 216 }
 217
 218 void google_mapcoord_to_center_coord ( MapCoord *src, VikCoord *dest )
 219 {
 220   gdouble socalled_mpp = GZ(src->scale);
 221   dest->mode = VIK_COORD_LATLON;
 222   dest->east_west = ((src->x+0.5) / GZ(17) * socalled_mpp * 360) - 180;
 223   dest->north_south = DEMERCLAT(180 - ((src->y+0.5) / GZ(17) * socalled_mpp * 360));
 224 }
 225
 226 static int real_google_download ( MapCoord *src, const gchar *dest_fn, const char *verstr )
 227 {
 228    int res;
 229    gchar *uri = g_strdup_printf ( "/mt?n=404&v=%s&x=%d&y=%d&zoom=%d", verstr, src->x, src->y, src->scale );
 230    res = a_http_download_get_url ( "mt.google.com", uri, dest_fn, &google_options );
 231    g_free ( uri );
 232    return res;
 233 }
 234
 235 static int google_download ( MapCoord *src, const gchar *dest_fn )
 236 {
 237    const gchar *vers_str = google_version_number(src, TYPE_GOOGLE_MAPS);
 238    return(real_google_download ( src, dest_fn, vers_str ));
 239 }
 240
 241 static int google_trans_download ( MapCoord *src, const gchar *dest_fn )
 242 {
 243    const gchar *vers_str = google_version_number(src, TYPE_GOOGLE_TRANS);
 244    return(real_google_download ( src, dest_fn, vers_str ));
 245 }
 246
 247 static int google_terrain_download ( MapCoord *src, const gchar *dest_fn )
 248 {
 249    const gchar *vers_str = google_version_number(src, TYPE_GOOGLE_TERRAIN);
 250    return(real_google_download ( src, dest_fn, vers_str ));
 251 }
 252
 253 static char *kh_encode(guint32 x, guint32 y, guint8 scale)
 254 {
 255   gchar *buf = g_malloc ( (20-scale)*sizeof(gchar) );
 256   guint32 ya = 1 << (17 - scale);
 257   gint8 i, j;
 258
 259   if (y < 0 || (ya-1 < y)) {
 260     strcpy(buf,"tqq"); /* BAD */
 261     return buf;
 262   }
 263   if (x < 0 || ya-1 < x) {
 264     x %= ya;
 265     if (x < 0)
 266       x += ya;
 267   }
 268
 269   buf[0] = 't';
 270   for (j = 1, i = 16; i >= scale; i--, j++) {
 271     ya /= 2;
 272     if (y < ya) {
 273       if (x < ya)
 274         buf[j]='q';
 275       else {
 276         buf[j]='r';
 277         x -= ya;
 278       }
 279     } else {
 280       if (x < ya) {
 281         buf[j] = 't';
 282         y -= ya;
 283       } else {
 284         buf[j] = 's';
 285         x -= ya;
 286         y -= ya;
 287       }
 288     }
 289   }
 290   buf[j] = '\0';
 291   return buf;
 292 }
 293
 294 static int google_kh_download ( MapCoord *src, const gchar *dest_fn )
 295 {
 296    int res;
 297    gchar *khenc = kh_encode( src->x, src->y, src->scale );
 298    const gchar *vers_str = google_version_number(src, TYPE_GOOGLE_SAT);
 299    gchar *uri = g_strdup_printf ( "/kh?n=404&v=%s&t=%s", vers_str, khenc );
 300    g_free ( khenc );
 301    res = a_http_download_get_url ( "kh.google.com", uri, dest_fn, &google_options );
 302    g_free ( uri );
 303    return(res);
 304 }