src/gpx.cc

   1 /* gpx.cc
   2  * Export from Aven as GPX.
   3  */
   4 /* Copyright (C) 2012 Olaf Kähler
   5  * Copyright (C) 2012-2024 Olly Betts
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  20  */
  21
  22 #include <config.h>
  23
  24 #include "gpx.h"
  25
  26 #include "export.h" // For LABELS, etc
  27
  28 #include <stdio.h>
  29 #include <string>
  30 #include <time.h>
  31 #include <math.h>
  32
  33 #include "useful.h"
  34 #include <proj.h>
  35
  36 #include "aven.h"
  37 #include "message.h"
  38
  39 using namespace std;
  40
  41 #define WGS84_DATUM_STRING "EPSG:4326"
  42
  43 static void
  44 html_escape(FILE *fh, const char *s)
  45 {
  46     while (*s) {
  47         switch (*s) {
  48             case '<':
  49                 fputs("&lt;", fh);
  50                 break;
  51             case '>':
  52                 fputs("&gt;", fh);
  53                 break;
  54             case '&':
  55                 fputs("&amp;", fh);
  56                 break;
  57             default:
  58                 PUTC(*s, fh);
  59         }
  60         ++s;
  61     }
  62 }
  63
  64 static void discarding_proj_logger(void *, int, const char *) { }
  65
  66 GPX::GPX(const char * input_datum)
  67 {
  68     /* Prevent stderr spew from PROJ. */
  69     proj_log_func(PJ_DEFAULT_CTX, nullptr, discarding_proj_logger);
  70
  71     pj = proj_create_crs_to_crs(PJ_DEFAULT_CTX,
  72                                 input_datum, WGS84_DATUM_STRING,
  73                                 NULL);
  74
  75     if (pj) {
  76         // Normalise the output order so x is longitude and y latitude - by
  77         // default new PROJ has them switched for EPSG:4326 which just seems
  78         // confusing.
  79         PJ* pj_norm = proj_normalize_for_visualization(PJ_DEFAULT_CTX, pj);
  80         proj_destroy(pj);
  81         pj = pj_norm;
  82     }
  83
  84     if (!pj) {
  85         wxString m = wmsg(/*Failed to initialise input coordinate system “%s”*/287);
  86         m = wxString::Format(m.c_str(), input_datum);
  87         throw m;
  88     }
  89 }
  90
  91 GPX::~GPX()
  92 {
  93     if (pj)
  94         proj_destroy(pj);
  95     free((void*)trk_name);
  96 }
  97
  98 const int *
  99 GPX::passes() const
 100 {
 101     static const int default_passes[] = { LABELS|ENTS|FIXES|EXPORTS, LEGS|SURF, 0 };
 102     return default_passes;
 103 }
 104
 105 /* Initialise GPX routines. */
 106 void GPX::header(const char * title, const char *, time_t datestamp_numeric,
 107                  double, double, double, double, double, double)
 108 {
 109     fputs(
 110 "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
 111 "<gpx version=\"1.0\" creator=\"" PACKAGE_STRING " (aven) - https://survex.com/\""
 112 " xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\""
 113 " xmlns=\"http://www.topografix.com/GPX/1/0\""
 114 " xsi:schemaLocation=\"http://www.topografix.com/GPX/1/0"
 115 " http://www.topografix.com/GPX/1/0/gpx.xsd\">\n", fh);
 116     if (title) {
 117         fputs("<name>", fh);
 118         html_escape(fh, title);
 119         fputs("</name>\n", fh);
 120         trk_name = strdup(title);
 121     }
 122     if (datestamp_numeric != time_t(-1)) {
 123         struct tm * tm = gmtime(&datestamp_numeric);
 124         if (tm) {
 125             char buf[32];
 126             if (strftime(buf, sizeof(buf), "%Y-%m-%dT%H:%M:%SZ", tm)) {
 127                 fputs("<time>", fh);
 128                 fputs(buf, fh);
 129                 fputs("</time>\n", fh);
 130             }
 131         }
 132     }
 133     // FIXME: optional in GPX, but perhaps useful:
 134     // <bounds minlat="..." minlon="..." maxlat="..." maxlon="..." />
 135     // NB Not necessarily the same as the bounds in survex coords translated
 136     // to WGS84 lat+long...
 137 }
 138
 139 void
 140 GPX::line(const img_point *p1, const img_point *p, unsigned /*flags*/, bool fPendingMove)
 141 {
 142     if (fPendingMove) {
 143         if (in_trkseg) {
 144             fputs("</trkseg><trkseg>\n", fh);
 145         } else {
 146             fputs("<trk>", fh);
 147             if (trk_name) {
 148                 fputs("<name>", fh);
 149                 html_escape(fh, trk_name);
 150                 fputs("</name>", fh);
 151             }
 152             fputs("<trkseg>\n", fh);
 153             in_trkseg = true;
 154         }
 155         PJ_COORD coord{{p1->x, p1->y, p1->z, HUGE_VAL}};
 156         coord = proj_trans(pj, PJ_FWD, coord);
 157         if (coord.xyzt.x == HUGE_VAL ||
 158             coord.xyzt.y == HUGE_VAL ||
 159             coord.xyzt.z == HUGE_VAL) {
 160             // FIXME report errors
 161         }
 162         // %.8f is at worst just over 1mm.
 163         fprintf(fh, "<trkpt lon=\"%.8f\" lat=\"%.8f\"><ele>%.2f</ele></trkpt>\n",
 164                 coord.xyzt.x,
 165                 coord.xyzt.y,
 166                 coord.xyzt.z);
 167     }
 168
 169     PJ_COORD coord{{p->x, p->y, p->z, HUGE_VAL}};
 170     coord = proj_trans(pj, PJ_FWD, coord);
 171     if (coord.xyzt.x == HUGE_VAL ||
 172         coord.xyzt.y == HUGE_VAL ||
 173         coord.xyzt.z == HUGE_VAL) {
 174         // FIXME report errors
 175     }
 176     // %.8f is at worst just over 1mm.
 177     fprintf(fh, "<trkpt lon=\"%.8f\" lat=\"%.8f\"><ele>%.2f</ele></trkpt>\n",
 178             coord.xyzt.x,
 179             coord.xyzt.y,
 180             coord.xyzt.z);
 181 }
 182
 183 void
 184 GPX::label(const img_point *p, const wxString& str, int /*sflags*/, int type)
 185 {
 186     const char* s = str.utf8_str();
 187     PJ_COORD coord{{p->x, p->y, p->z, HUGE_VAL}};
 188     coord = proj_trans(pj, PJ_FWD, coord);
 189     if (coord.xyzt.x == HUGE_VAL ||
 190         coord.xyzt.y == HUGE_VAL ||
 191         coord.xyzt.z == HUGE_VAL) {
 192         // FIXME report errors
 193     }
 194     // %.8f is at worst just over 1mm.
 195     fprintf(fh, "<wpt lon=\"%.8f\" lat=\"%.8f\"><ele>%.2f</ele><name>",
 196             coord.xyzt.x,
 197             coord.xyzt.y,
 198             coord.xyzt.z);
 199     html_escape(fh, s);
 200     fputs("</name>", fh);
 201     // Add a "pin" symbol with colour matching what aven shows.
 202     switch (type) {
 203         case FIXES:
 204             fputs("<sym>Pin, Red</sym>", fh);
 205             break;
 206         case EXPORTS:
 207             fputs("<sym>Pin, Blue</sym>", fh);
 208             break;
 209         case ENTS:
 210             fputs("<sym>Pin, Green</sym>", fh);
 211             break;
 212     }
 213     fputs("</wpt>\n", fh);
 214 }
 215
 216 void
 217 GPX::footer()
 218 {
 219     if (in_trkseg)
 220         fputs("</trkseg></trk>\n", fh);
 221     fputs("</gpx>\n", fh);
 222 }