src/vikslippymapsource.c

   1 /* -*- Mode: C; indent-tabs-mode: t; c-basic-offset: 4; tab-width: 4 -*- */
   2 /*
   3  * viking
   4  * Copyright (C) 2009, Guilhem Bonnefille <guilhem.bonnefille@gmail.com>
   5  *
   6  * viking is free software: you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * viking is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  14  * See the GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20  /**
  21   * SECTION:vikslippymapsource
  22   * @short_description: the class for SlippyMap oriented map sources
  23   *
  24   * The #VikSlippyMapSource class handles slippy map oriented map sources.
  25   * The related service is tile oriented, à la Google.
  26   *
  27   * The tiles are in 'google spherical mercator', which is
  28   * basically a mercator projection that assumes a spherical earth.
  29   * http://docs.openlayers.org/library/spherical_mercator.html
  30   *
  31   * Such service is also a type of TMS (Tile Map Service) as defined in
  32   * OSGeo's wiki.
  33   * http://wiki.osgeo.org/wiki/Tile_Map_Service_Specification
  34   * But take care that the Y axis is inverted, ie the origin is at top-left
  35   * corner.
  36   * Following this specification, the protocol handled by this class
  37   * follows the global-mercator profile.
  38   *
  39   * You can also find many interesting information on the OSM's wiki.
  40   * http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames
  41   * http://wiki.openstreetmap.org/wiki/Setting_up_TMS
  42   */
  43
  44 #ifdef HAVE_CONFIG_H
  45 #include "config.h"
  46 #endif
  47
  48 #ifdef HAVE_MATH_H
  49 #include <math.h>
  50 #endif
  51
  52 #include "globals.h"
  53 #include "vikslippymapsource.h"
  54
  55 static gboolean _coord_to_mapcoord ( VikMapSource *self, const VikCoord *src, gdouble xzoom, gdouble yzoom, MapCoord *dest );
  56 static void _mapcoord_to_center_coord ( VikMapSource *self, MapCoord *src, VikCoord *dest );
  57
  58 static gboolean _is_direct_file_access (VikMapSource *self );
  59 static gboolean _supports_download_only_new (VikMapSource *self );
  60
  61 static gchar *_get_uri( VikMapSourceDefault *self, MapCoord *src );
  62 static gchar *_get_hostname( VikMapSourceDefault *self );
  63 static DownloadMapOptions *_get_download_options( VikMapSourceDefault *self );
  64
  65 typedef struct _VikSlippyMapSourcePrivate VikSlippyMapSourcePrivate;
  66 struct _VikSlippyMapSourcePrivate
  67 {
  68   gchar *hostname;
  69   gchar *url;
  70   DownloadMapOptions options;
  71   gboolean is_direct_file_access;
  72 };
  73
  74 #define VIK_SLIPPY_MAP_SOURCE_PRIVATE(o)  (G_TYPE_INSTANCE_GET_PRIVATE ((o), VIK_TYPE_SLIPPY_MAP_SOURCE, VikSlippyMapSourcePrivate))
  75
  76 /* properties */
  77 enum
  78 {
  79   PROP_0,
  80
  81   PROP_HOSTNAME,
  82   PROP_URL,
  83   PROP_REFERER,
  84   PROP_FOLLOW_LOCATION,
  85   PROP_CHECK_FILE_SERVER_TIME,
  86   PROP_USE_ETAG,
  87   PROP_IS_DIRECT_FILE_ACCESS,
  88 };
  89
  90 G_DEFINE_TYPE (VikSlippyMapSource, vik_slippy_map_source, VIK_TYPE_MAP_SOURCE_DEFAULT);
  91
  92 static void
  93 vik_slippy_map_source_init (VikSlippyMapSource *self)
  94 {
  95   /* initialize the object here */
  96   VikSlippyMapSourcePrivate *priv = VIK_SLIPPY_MAP_SOURCE_PRIVATE (self);
  97
  98   priv->hostname = NULL;
  99   priv->url = NULL;
 100   priv->options.referer = NULL;
 101   priv->options.follow_location = 0;
 102   priv->options.check_file = a_check_map_file;
 103   priv->options.check_file_server_time = FALSE;
 104   priv->options.use_etag = FALSE;
 105   priv->is_direct_file_access = FALSE;
 106
 107   g_object_set (G_OBJECT (self),
 108                 "tilesize-x", 256,
 109                 "tilesize-y", 256,
 110                 "drawmode", VIK_VIEWPORT_DRAWMODE_MERCATOR,
 111                 NULL);
 112 }
 113
 114 static void
 115 vik_slippy_map_source_finalize (GObject *object)
 116 {
 117   VikSlippyMapSource *self = VIK_SLIPPY_MAP_SOURCE (object);
 118   VikSlippyMapSourcePrivate *priv = VIK_SLIPPY_MAP_SOURCE_PRIVATE (self);
 119
 120   g_free (priv->hostname);
 121   priv->hostname = NULL;
 122   g_free (priv->url);
 123   priv->url = NULL;
 124   g_free (priv->options.referer);
 125   priv->options.referer = NULL;
 126
 127   G_OBJECT_CLASS (vik_slippy_map_source_parent_class)->finalize (object);
 128 }
 129
 130 static void
 131 vik_slippy_map_source_set_property (GObject      *object,
 132                                     guint         property_id,
 133                                     const GValue *value,
 134                                     GParamSpec   *pspec)
 135 {
 136   VikSlippyMapSource *self = VIK_SLIPPY_MAP_SOURCE (object);
 137   VikSlippyMapSourcePrivate *priv = VIK_SLIPPY_MAP_SOURCE_PRIVATE (self);
 138
 139   switch (property_id)
 140     {
 141     case PROP_HOSTNAME:
 142       g_free (priv->hostname);
 143       priv->hostname = g_value_dup_string (value);
 144       break;
 145
 146     case PROP_URL:
 147       g_free (priv->url);
 148       priv->url = g_value_dup_string (value);
 149       break;
 150
 151     case PROP_REFERER:
 152       g_free (priv->options.referer);
 153       priv->options.referer = g_value_dup_string (value);
 154       break;
 155
 156     case PROP_FOLLOW_LOCATION:
 157       priv->options.follow_location = g_value_get_long (value);
 158       break;
 159
 160     case PROP_CHECK_FILE_SERVER_TIME:
 161       priv->options.check_file_server_time = g_value_get_boolean (value);
 162       break;
 163
 164     case PROP_USE_ETAG:
 165       priv->options.use_etag = g_value_get_boolean (value);
 166       break;
 167
 168     case PROP_IS_DIRECT_FILE_ACCESS:
 169       priv->is_direct_file_access = g_value_get_boolean (value);
 170       break;
 171
 172     default:
 173       /* We don't have any other property... */
 174       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
 175       break;
 176     }
 177 }
 178
 179 static void
 180 vik_slippy_map_source_get_property (GObject    *object,
 181                                     guint       property_id,
 182                                     GValue     *value,
 183                                     GParamSpec *pspec)
 184 {
 185   VikSlippyMapSource *self = VIK_SLIPPY_MAP_SOURCE (object);
 186   VikSlippyMapSourcePrivate *priv = VIK_SLIPPY_MAP_SOURCE_PRIVATE (self);
 187
 188   switch (property_id)
 189     {
 190     case PROP_HOSTNAME:
 191       g_value_set_string (value, priv->hostname);
 192       break;
 193
 194     case PROP_URL:
 195       g_value_set_string (value, priv->url);
 196       break;
 197
 198     case PROP_REFERER:
 199       g_value_set_string (value, priv->options.referer);
 200       break;
 201
 202     case PROP_FOLLOW_LOCATION:
 203       g_value_set_long (value, priv->options.follow_location);
 204       break;
 205
 206     case PROP_CHECK_FILE_SERVER_TIME:
 207       g_value_set_boolean (value, priv->options.check_file_server_time);
 208       break;
 209
 210     case PROP_USE_ETAG:
 211       g_value_set_boolean (value, priv->options.use_etag);
 212       break;
 213
 214     case PROP_IS_DIRECT_FILE_ACCESS:
 215       g_value_set_boolean (value, priv->is_direct_file_access);
 216       break;
 217
 218     default:
 219       /* We don't have any other property... */
 220       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
 221       break;
 222     }
 223 }
 224
 225 static void
 226 vik_slippy_map_source_class_init (VikSlippyMapSourceClass *klass)
 227 {
 228         GObjectClass* object_class = G_OBJECT_CLASS (klass);
 229         VikMapSourceClass* grandparent_class = VIK_MAP_SOURCE_CLASS (klass);
 230         VikMapSourceDefaultClass* parent_class = VIK_MAP_SOURCE_DEFAULT_CLASS (klass);
 231         GParamSpec *pspec = NULL;
 232
 233         object_class->set_property = vik_slippy_map_source_set_property;
 234     object_class->get_property = vik_slippy_map_source_get_property;
 235
 236         /* Overiding methods */
 237         grandparent_class->coord_to_mapcoord =        _coord_to_mapcoord;
 238         grandparent_class->mapcoord_to_center_coord = _mapcoord_to_center_coord;
 239         grandparent_class->is_direct_file_access = _is_direct_file_access;
 240         grandparent_class->supports_download_only_new = _supports_download_only_new;
 241
 242         parent_class->get_uri = _get_uri;
 243         parent_class->get_hostname = _get_hostname;
 244         parent_class->get_download_options = _get_download_options;
 245
 246         pspec = g_param_spec_string ("hostname",
 247                                      "Hostname",
 248                                      "The hostname of the map server",
 249                                      "<no-set>" /* default value */,
 250                                      G_PARAM_READWRITE);
 251         g_object_class_install_property (object_class, PROP_HOSTNAME, pspec);
 252
 253         pspec = g_param_spec_string ("url",
 254                                      "URL",
 255                                      "The template of the tiles' URL",
 256                                      "<no-set>" /* default value */,
 257                                      G_PARAM_READWRITE);
 258         g_object_class_install_property (object_class, PROP_URL, pspec);
 259
 260         pspec = g_param_spec_string ("referer",
 261                                      "Referer",
 262                                      "The REFERER string to use in HTTP request",
 263                                      NULL /* default value */,
 264                                      G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE);
 265         g_object_class_install_property (object_class, PROP_REFERER, pspec);
 266
 267         pspec = g_param_spec_long ("follow-location",
 268                                    "Follow location",
 269                                "Specifies the number of retries to follow a redirect while downloading a page",
 270                                0  /* minimum value */,
 271                                G_MAXLONG /* maximum value */,
 272                                0  /* default value */,
 273                                G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE);
 274         g_object_class_install_property (object_class, PROP_FOLLOW_LOCATION, pspec);
 275
 276         pspec = g_param_spec_boolean ("check-file-server-time",
 277                                       "Check file server time",
 278                                   "Age of current cache before redownloading tile",
 279                                   FALSE  /* default value */,
 280                                   G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE);
 281         g_object_class_install_property (object_class, PROP_CHECK_FILE_SERVER_TIME, pspec);
 282
 283         pspec = g_param_spec_boolean ("use-etag",
 284                                       "Use etag values with server",
 285                                   "Store etag in a file, and send it to server to check if we have the latest file",
 286                                   FALSE  /* default value */,
 287                                   G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE);
 288         g_object_class_install_property (object_class, PROP_USE_ETAG, pspec);
 289
 290         pspec = g_param_spec_boolean ("use-direct-file-access",
 291                                       "Use direct file access",
 292                                       "Use direct file access to OSM like tile images - no need for a webservice",
 293                                   FALSE  /* default value */,
 294                                   G_PARAM_CONSTRUCT_ONLY | G_PARAM_READWRITE);
 295         g_object_class_install_property (object_class, PROP_IS_DIRECT_FILE_ACCESS, pspec);
 296
 297         g_type_class_add_private (klass, sizeof (VikSlippyMapSourcePrivate));
 298
 299         object_class->finalize = vik_slippy_map_source_finalize;
 300 }
 301
 302 /* 1 << (x) is like a 2**(x) */
 303 #define GZ(x) ((1<<(x)))
 304
 305 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),
 306                                            GZ(10), GZ(11), GZ(12), GZ(13), GZ(14), GZ(15), GZ(16), GZ(17) };
 307
 308 static const gint num_scales = (sizeof(scale_mpps) / sizeof(scale_mpps[0]));
 309
 310 static const gdouble scale_neg_mpps[] = { 1.0/GZ(0), 1.0/GZ(1), 1.0/GZ(2), 1.0/GZ(3) };
 311 static const gint num_scales_neg = (sizeof(scale_neg_mpps) / sizeof(scale_neg_mpps[0]));
 312
 313 #define ERROR_MARGIN 0.01
 314 gint
 315 vik_slippy_map_source_zoom_to_scale ( gdouble mpp ) {
 316   gint i;
 317   for ( i = 0; i < num_scales; i++ ) {
 318     if ( ABS(scale_mpps[i] - mpp) < ERROR_MARGIN ) {
 319       return i;
 320     }
 321   }
 322   for ( i = 0; i < num_scales_neg; i++ ) {
 323     if ( ABS(scale_neg_mpps[i] - mpp) < 0.000001 ) {
 324       return -i;
 325     }
 326   }
 327
 328   return 255;
 329 }
 330
 331 gboolean
 332 _is_direct_file_access (VikMapSource *self)
 333 {
 334   g_return_val_if_fail (VIK_IS_SLIPPY_MAP_SOURCE(self), FALSE);
 335
 336   VikSlippyMapSourcePrivate *priv = VIK_SLIPPY_MAP_SOURCE_PRIVATE(self);
 337
 338   return priv->is_direct_file_access;
 339 }
 340
 341 gboolean
 342 _supports_download_only_new (VikMapSource *self)
 343 {
 344   g_return_val_if_fail (VIK_IS_SLIPPY_MAP_SOURCE(self), FALSE);
 345
 346   VikSlippyMapSourcePrivate *priv = VIK_SLIPPY_MAP_SOURCE_PRIVATE(self);
 347
 348   return priv->options.check_file_server_time || priv->options.use_etag;
 349 }
 350
 351 static gboolean
 352 _coord_to_mapcoord ( VikMapSource *self, const VikCoord *src, gdouble xzoom, gdouble yzoom, MapCoord *dest )
 353 {
 354   g_assert ( src->mode == VIK_COORD_LATLON );
 355
 356   if ( xzoom != yzoom )
 357     return FALSE;
 358
 359   dest->scale = vik_slippy_map_source_zoom_to_scale ( xzoom );
 360   if ( dest->scale == 255 )
 361     return FALSE;
 362
 363   dest->x = (src->east_west + 180) / 360 * GZ(17) / xzoom;
 364   dest->y = (180 - MERCLAT(src->north_south)) / 360 * GZ(17) / xzoom;
 365   dest->z = 0;
 366
 367   return TRUE;
 368 }
 369
 370 static void
 371 _mapcoord_to_center_coord ( VikMapSource *self, MapCoord *src, VikCoord *dest )
 372 {
 373   gdouble socalled_mpp;
 374   if (src->scale >= 0)
 375     socalled_mpp = GZ(src->scale);
 376   else
 377     socalled_mpp = 1.0/GZ(-src->scale);
 378   dest->mode = VIK_COORD_LATLON;
 379   dest->east_west = ((src->x+0.5) / GZ(17) * socalled_mpp * 360) - 180;
 380   dest->north_south = DEMERCLAT(180 - ((src->y+0.5) / GZ(17) * socalled_mpp * 360));
 381 }
 382
 383 static gchar *
 384 _get_uri( VikMapSourceDefault *self, MapCoord *src )
 385 {
 386         g_return_val_if_fail (VIK_IS_SLIPPY_MAP_SOURCE(self), NULL);
 387
 388     VikSlippyMapSourcePrivate *priv = VIK_SLIPPY_MAP_SOURCE_PRIVATE(self);
 389         gchar *uri = g_strdup_printf (priv->url, 17 - src->scale, src->x, src->y);
 390         return uri;
 391 }
 392
 393 static gchar *
 394 _get_hostname( VikMapSourceDefault *self )
 395 {
 396         g_return_val_if_fail (VIK_IS_SLIPPY_MAP_SOURCE(self), NULL);
 397
 398     VikSlippyMapSourcePrivate *priv = VIK_SLIPPY_MAP_SOURCE_PRIVATE(self);
 399         return g_strdup( priv->hostname );
 400 }
 401
 402 static DownloadMapOptions *
 403 _get_download_options( VikMapSourceDefault *self )
 404 {
 405         g_return_val_if_fail (VIK_IS_SLIPPY_MAP_SOURCE(self), NULL);
 406
 407         VikSlippyMapSourcePrivate *priv = VIK_SLIPPY_MAP_SOURCE_PRIVATE(self);
 408         return &(priv->options);
 409 }
 410
 411 VikSlippyMapSource *
 412 vik_slippy_map_source_new_with_id (guint8 id, const gchar *label, const gchar *hostname, const gchar *url)
 413 {
 414         return g_object_new(VIK_TYPE_SLIPPY_MAP_SOURCE,
 415                             "id", id, "label", label, "hostname", hostname, "url", url, NULL);
 416 }