src/expedia.c

   1 /*
   2  * viking -- GPS Data and Topo Analyzer, Explorer, and Manager
   3  *
   4  * Copyright (C) 2005, Evan Battaglia <viking@greentorch.org>
   5  *
   6  * Some formulas or perhaps even code derived from GPSDrive
   7  * GPSDrive Copyright (C) 2001-2004 Fritz Ganter <ganter@ganter.at>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  *
  23  */
  24
  25 #include <gtk/gtk.h>
  26 #include <math.h>
  27 #include "globals.h"
  28 #include "coords.h"
  29 #include "vikcoord.h"
  30 #include "mapcoord.h"
  31 #include "http.h"
  32
  33
  34 #define EXPEDIA_SITE "expedia.com"
  35 #define MPP_MARGIN_OF_ERROR 0.01
  36 #define DEGREES_TO_RADS 0.0174532925
  37 #define HEIGHT_OF_LAT_DEGREE (111318.84502/ALTI_TO_MPP)
  38 #define HEIGHT_OF_LAT_MINUTE (1855.3140837/ALTI_TO_MPP)
  39 #define WIDTH_BUFFER 0
  40 #define HEIGHT_BUFFER 25
  41 #define REAL_WIDTH_BUFFER 1
  42 #define REAL_HEIGHT_BUFFER 26
  43
  44 /* first buffer is to cut off the expedia/microsoft logo. Annoying little buggers ;) */
  45 /* second is to allow for a 1-pixel overlap on each side. this is a good thing (tm) */
  46
  47 static const guint expedia_altis[]              = { 1, 2, 4, 8, 16, 32, 64, 128, 256, 512 };
  48 /* square this number to find out how many per square degree. */
  49 static const gdouble expedia_altis_degree_freq[]  = { 120, 60, 30, 15, 8, 4, 2, 1, 1, 1 };
  50 static const guint expedia_altis_count = sizeof(expedia_altis) / sizeof(expedia_altis[0]);
  51
  52 gdouble expedia_altis_freq ( gint alti )
  53 {
  54   static gint i;
  55   for ( i = 0; i < expedia_altis_count; i++ )
  56     if ( expedia_altis[i] == alti )
  57       return expedia_altis_degree_freq [ i ];
  58
  59   g_error ( "Invalid expedia altitude" );
  60   return 0;
  61 }
  62
  63 /* returns -1 if none of the above. */
  64 gint expedia_zoom_to_alti ( gdouble zoom )
  65 {
  66   guint i;
  67   for ( i = 0; i < expedia_altis_count; i++ )
  68     if ( fabs(expedia_altis[i] - zoom) / zoom < MPP_MARGIN_OF_ERROR )
  69       return expedia_altis[i];
  70   return -1;
  71 }
  72
  73 /*
  74 gint expedia_pseudo_zone ( gint alti, gint x, gint y )
  75 {
  76   return (int) (x/expedia_altis_freq(alti)*180) + (int) (y/expedia_altis_freq(alti)*90);
  77 }
  78 */
  79
  80 void expedia_snip ( const gchar *file )
  81 {
  82   /* Load the pixbuf */
  83   GError *gx = NULL;
  84   GdkPixbuf *old, *cropped;
  85   gint width, height;
  86
  87   old = gdk_pixbuf_new_from_file ( file, &gx );
  88   if (gx)
  89   {
  90     g_warning ( "Couldn't open EXPEDIA image file (right after successful download! Please report and delete image file!): %s", gx->message );
  91     g_error_free ( gx );
  92     return;
  93   }
  94
  95   width = gdk_pixbuf_get_width ( old );
  96   height = gdk_pixbuf_get_height ( old );
  97
  98   cropped = gdk_pixbuf_new_subpixbuf ( old, WIDTH_BUFFER, HEIGHT_BUFFER,
  99                               width - 2*WIDTH_BUFFER, height - 2*HEIGHT_BUFFER );
 100
 101   gdk_pixbuf_save ( cropped, file, "png", NULL, NULL, &gx );
 102   if ( gx ) {
 103     g_warning ( "Couldn't save EXPEDIA image file (right after successful download! Please report and delete image file!): %s", gx->message );
 104     g_error_free ( gx );
 105   }
 106
 107   g_object_unref ( cropped );
 108   g_object_unref ( old );
 109 }
 110
 111 /* if degree_freeq = 60 -> nearest minute (in middle) */
 112 /* everything starts at -90,-180 -> 0,0. then increments by (1/degree_freq) */
 113 gboolean expedia_coord_to_mapcoord ( const VikCoord *src, gdouble xzoom, gdouble yzoom, MapCoord *dest )
 114 {
 115   gint alti;
 116
 117   g_assert ( src->mode == VIK_COORD_LATLON );
 118
 119   if ( xzoom != yzoom )
 120     return FALSE;
 121
 122   alti = expedia_zoom_to_alti ( xzoom );
 123   if ( alti != -1 )
 124   {
 125     dest->scale = alti;
 126     dest->x = (int) (((src->east_west+180) * expedia_altis_freq(alti))+0.5);
 127     dest->y = (int) (((src->north_south+90) * expedia_altis_freq(alti))+0.5);
 128     /* + 0.5 to round off and not floor */
 129
 130     /* just to space out tiles on the filesystem */
 131     dest->z = 0;
 132     return TRUE;
 133   }
 134   return FALSE;
 135 }
 136
 137 void expedia_xy_to_latlon_middle ( gint alti, gint x, gint y, struct LatLon *ll )
 138 {
 139   ll->lon = (((gdouble)x) / expedia_altis_freq(alti)) - 180;
 140   ll->lat = (((gdouble)y) / expedia_altis_freq(alti)) - 90;
 141 }
 142
 143 void expedia_mapcoord_to_center_coord ( MapCoord *src, VikCoord *dest )
 144 {
 145   dest->mode = VIK_COORD_LATLON;
 146   dest->east_west = (((gdouble)src->x) / expedia_altis_freq(src->scale)) - 180;
 147   dest->north_south = (((gdouble)src->y) / expedia_altis_freq(src->scale)) - 90;
 148 }
 149
 150 void expedia_download ( MapCoord *src, const gchar *dest_fn )
 151 {
 152   gint height, width;
 153   struct LatLon ll;
 154   gchar *uri;
 155
 156   expedia_xy_to_latlon_middle ( src->scale, src->x, src->y, &ll );
 157
 158   height = HEIGHT_OF_LAT_DEGREE / expedia_altis_freq(src->scale) / (src->scale);
 159   width = height * cos ( ll.lat * DEGREES_TO_RADS );
 160
 161   height += 2*REAL_HEIGHT_BUFFER;
 162   width  += 2*REAL_WIDTH_BUFFER;
 163
 164   uri = g_strdup_printf ( "/pub/agent.dll?qscr=mrdt&ID=3XNsF.&CenP=%lf,%lf&Lang=%s&Alti=%d&Size=%d,%d&Offs=0.000000,0.000000&BCheck&tpid=1",
 165                ll.lat, ll.lon, (ll.lon > -30) ? "EUR0809" : "USA0409", src->scale, width, height );
 166
 167   a_http_download_get_url_nohostname ( "expedia.com", uri, dest_fn );
 168
 169   expedia_snip ( dest_fn );
 170 }
 171
 172