src/osm.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
  22 #include <gtk/gtk.h>
  23 #include <math.h>
  24 #include "viking.h"
  25 #include "coords.h"
  26 #include "vikcoord.h"
  27 #include "mapcoord.h"
  28 #include "http.h"
  29 #include "vikmapslayer.h"
  30
  31 #include "osm.h"
  32
  33 static guint8 osm_zoom ( gdouble mpp );
  34
  35 static gboolean osm_coord_to_mapcoord ( const VikCoord *src, gdouble xzoom, gdouble yzoom, MapCoord *dest );
  36 static void osm_mapcoord_to_center_coord ( MapCoord *src, VikCoord *dest );
  37 static int osm_maplint_download ( MapCoord *src, const gchar *dest_fn );
  38 static int osm_mapnik_download ( MapCoord *src, const gchar *dest_fn );
  39 static int osm_osmarender_download ( MapCoord *src, const gchar *dest_fn );
  40
  41 static DownloadOptions osm_options = { 1, NULL };
  42
  43 /* initialisation */
  44 void osm_init () {
  45   VikMapsLayer_MapType osmarender_type = { 12, 256, 256, VIK_VIEWPORT_DRAWMODE_MERCATOR, osm_coord_to_mapcoord, osm_mapcoord_to_center_coord, osm_osmarender_download };
  46   VikMapsLayer_MapType mapnik_type = { 13, 256, 256, VIK_VIEWPORT_DRAWMODE_MERCATOR, osm_coord_to_mapcoord, osm_mapcoord_to_center_coord, osm_mapnik_download };  VikMapsLayer_MapType maplint_type = { 14, 256, 256, VIK_VIEWPORT_DRAWMODE_MERCATOR, osm_coord_to_mapcoord, osm_mapcoord_to_center_coord, osm_maplint_download };
  47
  48   maps_layer_register_type("OpenStreetMap (Osmarender)", 12, &osmarender_type);
  49   maps_layer_register_type("OpenStreetMap (Mapnik)", 13, &mapnik_type);
  50   maps_layer_register_type("OpenStreetMap (Maplint)", 14, &maplint_type);
  51 }
  52
  53 /* 1 << (x) is like a 2**(x) */
  54 #define GZ(x) (1<<(x))
  55
  56 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),
  57                                       GZ(10), GZ(11), GZ(12), GZ(13), GZ(14), GZ(15), GZ(16), GZ(17) };
  58
  59 static const gint num_scales = (sizeof(scale_mpps) / sizeof(scale_mpps[0]));
  60
  61 #define ERROR_MARGIN 0.01
  62 guint8 osm_zoom ( gdouble mpp ) {
  63   gint i;
  64   for ( i = 0; i < num_scales; i++ ) {
  65     if ( ABS(scale_mpps[i] - mpp) < ERROR_MARGIN )
  66       return i;
  67   }
  68   return 255;
  69 }
  70
  71 static gboolean osm_coord_to_mapcoord ( const VikCoord *src, gdouble xzoom, gdouble yzoom, MapCoord *dest )
  72 {
  73   g_assert ( src->mode == VIK_COORD_LATLON );
  74
  75   if ( xzoom != yzoom )
  76     return FALSE;
  77
  78   dest->scale = osm_zoom ( xzoom );
  79   if ( dest->scale == 255 )
  80     return FALSE;
  81
  82   dest->x = (src->east_west + 180) / 360 * GZ(17) / xzoom;
  83   dest->y = (180 - MERCLAT(src->north_south)) / 360 * GZ(17) / xzoom;
  84   dest->z = 0;
  85   return TRUE;
  86 }
  87
  88 static void osm_mapcoord_to_center_coord ( MapCoord *src, VikCoord *dest )
  89 {
  90   gdouble socalled_mpp = GZ(src->scale);
  91   dest->mode = VIK_COORD_LATLON;
  92   dest->east_west = ((src->x+0.5) / GZ(17) * socalled_mpp * 360) - 180;
  93   dest->north_south = DEMERCLAT(180 - ((src->y+0.5) / GZ(17) * socalled_mpp * 360));
  94 }
  95
  96 /* Maplint tiles
  97  * Ex: http://dev.openstreetmap.org/~ojw/Tiles/maplint.php/10/517/375.png
  98  */
  99 static int osm_maplint_download ( MapCoord *src, const gchar *dest_fn )
 100 {
 101    int res = -1;
 102    gchar *uri = g_strdup_printf ( "/~ojw/Tiles/maplint.php/%d/%d/%d.png", 17-src->scale, src->x, src->y );
 103    res = a_http_download_get_url ( "dev.openstreetmap.org", uri, dest_fn, &osm_options );
 104    g_free ( uri );
 105    return res;
 106 }
 107
 108 static int osm_mapnik_download ( MapCoord *src, const gchar *dest_fn )
 109 {
 110    int res = -1;
 111    gchar *uri = g_strdup_printf ( "/osamrender/%d/%d/%d.png", 17-src->scale, src->x, src->y );
 112    res = a_http_download_get_url ( "tile.openstreetmap.org", uri, dest_fn, &osm_options );
 113    g_free ( uri );
 114    return res;
 115 }
 116
 117 static int osm_osmarender_download ( MapCoord *src, const gchar *dest_fn )
 118 {
 119    int res = -1;
 120    gchar *uri = g_strdup_printf ( "/~ojw/Tiles/tile.php/%d/%d/%d.png", 17-src->scale, src->x, src->y );
 121    res = a_http_download_get_url ( "dev.openstreetmap.org", uri, dest_fn, &osm_options );
 122    g_free ( uri );
 123    return res;
 124 }