trunk/src/geomath.c

/*
 * Copyright (C) 2008 Till Harbaum <till@harbaum.org>.
 *
 * This file is part of GPXView.
 *
 * GPXView is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * GPXView is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GPXView.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "gpxview.h"
#include <math.h>

#define STR_NAN  "----"

typedef struct {
  appdata_t *appdata;

  GtkWidget *lon1, *lat1, *dist1, *dir1;
  GtkWidget *lon2, *lat2;

  GtkWidget *distance, *proj_lat, *proj_lon;
  GtkWidget *middle_lat, *middle_lon;
} math_dialog_state_t;

static gboolean mark(GtkWidget *widget, gboolean valid) {
  gtk_widget_set_state(widget, valid?GTK_STATE_NORMAL:TAG_STATE);
  return valid;
}

/* a entry that is colored red when being "active" */
static GtkWidget *gtk_red_entry_new(void) {
  GdkColor color;
  GtkWidget *widget = gtk_entry_new();
  gdk_color_parse("#ff0000", &color);
  gtk_widget_modify_text(widget, TAG_STATE, &color);
  return widget;
}

/* a comboboxentry that is colored red when being "active" */
static GtkWidget *gtk_red_combo_box_entry_new_text(void) {
  GdkColor color;
  GtkWidget *widget = gtk_combo_box_entry_new_text();
  gdk_color_parse("#ff0000", &color);
  gtk_widget_modify_text(GTK_BIN(widget)->child, TAG_STATE, &color);
  return widget;
}

/* a label that is left aligned */
static GtkWidget *gtk_left_label_new(char *str) {
  GtkWidget *widget = gtk_label_new(str);
  gtk_misc_set_alignment(GTK_MISC(widget), 0.0f, 0.5f);
  return widget;
}

/* a label that is colored red when being "active" */
static GtkWidget *gtk_red_label_new(char *str) {
  GdkColor color;
  GtkWidget *widget = gtk_left_label_new(str);
  gdk_color_parse("#ff0000", &color);
  gtk_widget_modify_fg(widget, TAG_STATE, &color);
  return widget;
}

static GtkWidget *gtk_dir_entry_new(float val) {
  char str[16];
  GtkWidget *w = gtk_red_entry_new();
  
  snprintf(str, sizeof(str), _("%.1f°"), val);
  gtk_entry_set_text(GTK_ENTRY(w), str);

  return w;
}

float pos_lat_eval_combo(GtkWidget *widget) {
  char *p = (char*)gtk_combo_box_get_active_text(GTK_COMBO_BOX(widget));
  float val = pos_parse_lat(p);
  mark(widget, !isnan(val));

  return val;
}

static float distance_eval(GtkWidget *widget, math_dialog_state_t *state) {
  char *p = (char*)gtk_entry_get_text(GTK_ENTRY(widget));
  float val = distance_parse(p, state->appdata->imperial);
  mark(widget, !isnan(val));

  return val;
}

float direction_eval(GtkWidget *widget) {
  char *p = (char*)gtk_entry_get_text(GTK_ENTRY(widget));
  float val;
  if(sscanf(p, _("%f°"), &val) != 1)
    val = NAN;

  mark(widget, !isnan(val));

  return val;
}

static void on_calc_clicked(GtkButton *button, gpointer user_data) {
  math_dialog_state_t *state = (math_dialog_state_t*)user_data;
  pos_t pos1, pos2;
  gboolean pos1_ok = FALSE, pos2_ok = FALSE;
  float dist1;
  gboolean dist1_ok = FALSE;
  float dir1;
  gboolean dir1_ok = FALSE;

  /* parse input */
  pos1.lat = lat_get(state->lat1);
  pos1.lon = lon_get(state->lon1);
  if(!isnan(pos1.lat) && !isnan(pos1.lon)) pos1_ok = TRUE;

  pos2.lat = lat_get(state->lat2);
  pos2.lon = lon_get(state->lon2);
  if(!isnan(pos2.lat) && !isnan(pos2.lon)) pos2_ok = TRUE;

  dist1 = distance_eval(state->dist1, state);
  if(!isnan(dist1)) dist1_ok = TRUE;

  dir1 = direction_eval(state->dir1);
  if(!isnan(dir1)) dir1_ok = TRUE;

  /* ------------------- do all calculations ------------------- */


  /* ------------------- distance of coo1 and coo2  ------------------- */
  if(mark(state->distance, pos1_ok && pos2_ok)) {
    char str[32];
    float dist = gpx_pos_get_distance(pos1, pos2, state->appdata->imperial);  
    distance_str(str, sizeof(str), dist, state->appdata->imperial);

    gtk_label_set_text(GTK_LABEL(state->distance), str);
  } else
    gtk_label_set_text(GTK_LABEL(state->distance), STR_NAN);

  // N 53° 09.033'  W 001° 50.666' 100km / 30° = N 53° 55.616, W001° 04.850
  /* ------------------- coordinate projection ---------------- */
  mark(state->proj_lat, pos1_ok && dist1_ok && dir1_ok);
  if(mark(state->proj_lon, pos1_ok && dist1_ok && dir1_ok)) {
    pos_t pro;

    /* get great circle radius in miles/kilometers */
    float gcrad = state->appdata->imperial?3959.0:6371.0;

    // from: http://www.movable-type.co.uk/scripts/latlong.html
    pro.lat = asin(sin(pos1.lat/180*M_PI) * cos(dist1/gcrad) + 
                   cos(pos1.lat/180*M_PI) * sin(dist1/gcrad) * 
                   cos(dir1/180*M_PI) )/M_PI*180;
    pro.lon = pos1.lon + atan2(sin(dir1/180*M_PI)*sin(dist1/gcrad)*
                               cos(pos1.lat/180*M_PI), 
                               cos(dist1/gcrad)-sin(pos1.lat/180*M_PI)*
                               sin(pro.lat/180*M_PI))/M_PI*180;
    pro.lon = fmodf(pro.lon+180,360) - 180;  // normalise to -180...+180

    char str[16];
    pos_lat_str(str, sizeof(str), pro.lat);
    gtk_label_set_text(GTK_LABEL(state->proj_lat), str);
    pos_lon_str(str, sizeof(str), pro.lon);
    gtk_label_set_text(GTK_LABEL(state->proj_lon), str);

    if(!isnan(pro.lat) && !isnan(pro.lon)) 
      state->appdata->geomath = pro;
  } else {
    gtk_label_set_text(GTK_LABEL(state->proj_lat), STR_NAN);
    gtk_label_set_text(GTK_LABEL(state->proj_lon), STR_NAN);
  }

#if 0
  /* ------------ middle between both points ------------- */
  mark(state->middle_lat, pos1_ok && pos2_ok);
  if(mark(state->middle_lon, pos1_ok && pos2_ok)) {
    pos_t res;

    float dlon = fabs(pos2.lon - pos1.lon)/180*M_PI;

    /* http://mathforum.org/library/drmath/view/51822.html */
    res.lon = 180/M_PI * atan(cos(pos2.lat/180*M_PI)*sin(pos2.lon/180*M_PI)/
     (cos(pos1.lat/180*M_PI)+cos(pos2.lat/180*M_PI)*cos(pos2.lon/180*M_PI)));
    res.lat = 180/M_PI * atan((sin(pos1.lat/180*M_PI)+sin(pos2.lat/180*M_PI))/
        sqrt(pow(cos(pos2.lat/180*M_PI)+cos(pos2.lat/180*M_PI)*cos(dlon),2)+
        pow(cos(pos2.lat/180*M_PI)*sin(dlon),2)));

    char str1[32], str2[32];
    pos_lat_str(str1,sizeof(str1),res.lat);
    pos_lon_str(str2,sizeof(str2),res.lon);
    printf("pos = %s/%s\n", str1, str2);
  } else {
    gtk_label_set_text(GTK_LABEL(state->middle_lat), STR_NAN);
    gtk_label_set_text(GTK_LABEL(state->middle_lon), STR_NAN);
  }
#endif
}

static gint waypoint_changed_event(GtkWidget *widget, gpointer data ) {
  math_dialog_state_t *state = (math_dialog_state_t*)data;
  int wpt_idx = gtk_combo_box_get_active(GTK_COMBO_BOX(widget));
  pos_t *pos = NULL;

  if(wpt_idx < 0)
    return FALSE;

  if(wpt_idx == 0) 
    pos = gps_get_pos(state->appdata);
#ifdef USE_MAEMO
  else if(wpt_idx == 1) {
    pos_t cache_pos = gpx_cache_pos(state->appdata->cur_cache);
    pos = &cache_pos;
  } else {
    wpt_t *wpt = state->appdata->cur_cache->wpt;
    while(wpt_idx > 2) {
      g_assert(wpt != NULL);
      wpt = wpt->next;
      wpt_idx--;
    }
    pos = &wpt->pos;
  }
#endif

  if(pos) {
    char str[32];
    pos_lat_str(str,sizeof(str),pos->lat);
    gtk_entry_set_text(GTK_ENTRY(state->lat1), str);
    pos_lon_str(str,sizeof(str),pos->lon);
    gtk_entry_set_text(GTK_ENTRY(state->lon1), str);
  } else {
    gtk_entry_set_text(GTK_ENTRY(state->lat1), STR_NAN);
    gtk_entry_set_text(GTK_ENTRY(state->lon1), STR_NAN);
  }

  mark(state->lat1, pos != NULL);
  mark(state->lon1, pos != NULL);

  return FALSE;
}

void geomath_dialog(appdata_t *appdata) {
  static pos_t pos1 = { 0.0, 0.0 }, pos2 = { 0.0, 0.0 };
  static float dist1 = 0.0;
  static float dir1 = 0.0;
  static gboolean is_imperial = FALSE;

  math_dialog_state_t state;
  char str[32];

  /* this is quite ugly. It would be nice to run the entire system on */
  /* one specific system (e.g. metric) and only convert for in- and output */
  if(!appdata->imperial && is_imperial)
    dist1 *= 6371.0/3959.0;   /* we just switched to metric */
  if(appdata->imperial && !is_imperial)
    dist1 *= 3959.0/6371.0;   /* we just switched to imperial */
  is_imperial = appdata->imperial;

  state.appdata = appdata;

#ifdef USE_MAEMO
  if(appdata->cur_cache) 
    printf("current cache is %s\n", appdata->cur_cache->id);
  else
    printf("no current cache\n");
#endif

  GtkWidget *dialog = gtk_dialog_new_with_buttons(_("Geomath"),
                          GTK_WINDOW(appdata->window),
                          //      GTK_DIALOG_NO_SEPARATOR | 
                          GTK_DIALOG_MODAL | GTK_DIALOG_DESTROY_WITH_PARENT,
                          GTK_STOCK_CLOSE, GTK_RESPONSE_CLOSE,
                          NULL);

#if defined(USE_MAEMO) && defined(HILDON_HELP)
  hildon_help_dialog_help_enable(GTK_DIALOG(dialog), HELP_ID_GEOMATH, 
                                 appdata->osso_context);
#endif

  gtk_window_set_default_size(GTK_WINDOW(dialog), DIALOG_WIDTH, DIALOG_HEIGHT);

  /* do geomath dialog */
  GtkWidget *hbox = gtk_hbox_new(FALSE, 0);

  /* ------------------------- input area ------------------------- */
  GtkWidget *table = gtk_table_new(5, 3, FALSE);
  gtk_table_set_col_spacing(GTK_TABLE(table), 1, 20);

  gtk_table_attach_defaults(GTK_TABLE(table), gtk_label_new(_("Coordinate 1")),                    1, 2, 0, 1);
  gtk_table_attach_defaults(GTK_TABLE(table), gtk_label_new(_("Coordinate 2")),                    2, 3, 0, 1);
  gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Latitude:")),                  0, 1, 1, 2);

  GtkWidget *cbox = gtk_red_combo_box_entry_new_text();
  gtk_combo_box_append_text(GTK_COMBO_BOX(cbox), _("GPS"));
  
#ifdef USE_MAEMO
  if(appdata->cur_cache) {
    gtk_combo_box_append_text(GTK_COMBO_BOX(cbox), appdata->cur_cache->id);
    wpt_t *wpt = appdata->cur_cache->wpt;
    while(wpt) {
      gtk_combo_box_append_text(GTK_COMBO_BOX(cbox), wpt->id);
      wpt = wpt->next;
    }
  }
#endif
  
  state.lat1 = GTK_BIN(cbox)->child;
  pos_lat_str(str, sizeof(str), pos1.lat);
  gtk_entry_set_text(GTK_ENTRY(state.lat1), str);
  
  gtk_signal_connect(GTK_OBJECT(cbox), "changed",
                     (GtkSignalFunc)waypoint_changed_event, &state);
  gtk_table_attach_defaults(GTK_TABLE(table), cbox, 1,2,1,2);


  gtk_table_attach_defaults(GTK_TABLE(table), state.lat2 = lat_entry_new(pos2.lat),         2, 3, 1, 2);
  gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Longitude:")),             0, 1, 2, 3);
  gtk_table_attach_defaults(GTK_TABLE(table), state.lon1 = lon_entry_new(pos1.lon),         1, 2, 2, 3);
  gtk_table_attach_defaults(GTK_TABLE(table), state.lon2 = lon_entry_new(pos2.lon),         2, 3, 2, 3);
  gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Distance:")),              0, 1, 3, 4);
  gtk_table_attach_defaults(GTK_TABLE(table), state.dist1 = dist_entry_new(dist1, appdata->imperial), 1, 2, 3, 4);
  gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Direction:")),             0, 1, 4, 5);
  gtk_table_attach_defaults(GTK_TABLE(table), state.dir1 = gtk_dir_entry_new(dir1),         1, 2, 4, 5);

  gtk_box_pack_start(GTK_BOX(hbox), table, TRUE, TRUE, 0);

  gtk_box_pack_start(GTK_BOX(GTK_DIALOG(dialog)->vbox), hbox, TRUE, TRUE, 0);

  /* ------------------------- do-it-button ------------------------- */

  hbox = gtk_hbox_new(FALSE, 0);
  GtkWidget *button = gtk_button_new_with_label(_("Calculate!"));
  gtk_box_pack_start(GTK_BOX(hbox), button, TRUE, FALSE, 0);
  gtk_box_pack_start(GTK_BOX(GTK_DIALOG(dialog)->vbox), hbox, TRUE, FALSE, 0);
  g_signal_connect(button, "clicked", (GCallback)on_calc_clicked, &state);

  /* ------------------------- output area ------------------------- */
  
  table = gtk_table_new(3, 3, FALSE);

  gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Distance = ")),
                            0, 1, 0, 1);
  gtk_table_attach_defaults(GTK_TABLE(table), state.distance = gtk_red_label_new(STR_NAN),
                            1, 3, 0, 1);

  gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Projection = ")),
                            0, 1, 1, 2);
  gtk_table_attach_defaults(GTK_TABLE(table), state.proj_lat = gtk_red_label_new(STR_NAN),
                            1, 2, 1, 2);
  gtk_table_attach_defaults(GTK_TABLE(table), state.proj_lon = gtk_red_label_new(STR_NAN),
                            2, 3, 1, 2);
#if 0
  gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Middle = ")),
                            0, 1, 2, 3);
  gtk_table_attach_defaults(GTK_TABLE(table), state.middle_lat = gtk_red_label_new(STR_NAN),
                            1, 2, 2, 3);
  gtk_table_attach_defaults(GTK_TABLE(table), state.middle_lon = gtk_red_label_new(STR_NAN),
                            2, 3, 2, 3);
#endif

  gtk_box_pack_start(GTK_BOX(GTK_DIALOG(dialog)->vbox), table, TRUE, TRUE, 0);
  

  gtk_dialog_set_default_response(GTK_DIALOG(dialog), GTK_RESPONSE_CLOSE);

  gtk_widget_show_all(dialog);
  gtk_dialog_run(GTK_DIALOG(dialog));

  /* copy values back to local static variables so they re-appear if */
  /* the dialog is re-opened, convert illegal values (NAN) to 0 */

  pos1.lat = lat_get(state.lat1); if(isnan(pos1.lat)) pos1.lat=0; 
  pos1.lon = lon_get(state.lon1); if(isnan(pos1.lon)) pos1.lon=0; 
  pos2.lat = lat_get(state.lat2); if(isnan(pos2.lat)) pos2.lat=0; 
  pos2.lon = lon_get(state.lon2); if(isnan(pos2.lon)) pos2.lon=0; 
  dist1 = distance_eval(state.dist1, &state); if(isnan(dist1)) dist1=0; 
  dir1 = direction_eval(state.dir1); if(isnan(dir1)) dir1=0; 

  gtk_widget_destroy(dialog);
}
1	harbaum	1	/*
2			* Copyright (C) 2008 Till Harbaum <till@harbaum.org>.
3			*
4			* This file is part of GPXView.
5			*
6			* GPXView 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 3 of the License, or
9			* (at your option) any later version.
10			*
11			* GPXView 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 GPXView. If not, see <http://www.gnu.org/licenses/>.
18			*/
19
20			#include "gpxview.h"
21			#include <math.h>
22
23			#define STR_NAN "----"
24
25			typedef struct {
26			appdata_t *appdata;
27
28			GtkWidget lon1, lat1, dist1, dir1;
29			GtkWidget lon2, lat2;
30
31			GtkWidget distance, proj_lat, *proj_lon;
32			GtkWidget middle_lat, middle_lon;
33			} math_dialog_state_t;
34
35			static gboolean mark(GtkWidget *widget, gboolean valid) {
36			gtk_widget_set_state(widget, valid?GTK_STATE_NORMAL:TAG_STATE);
37			return valid;
38			}
39
40			/* a entry that is colored red when being "active" */
41			static GtkWidget *gtk_red_entry_new(void) {
42			GdkColor color;
43			GtkWidget *widget = gtk_entry_new();
44			gdk_color_parse("#ff0000", &color);
45			gtk_widget_modify_text(widget, TAG_STATE, &color);
46			return widget;
47			}
48
49			/* a comboboxentry that is colored red when being "active" */
50			static GtkWidget *gtk_red_combo_box_entry_new_text(void) {
51			GdkColor color;
52			GtkWidget *widget = gtk_combo_box_entry_new_text();
53			gdk_color_parse("#ff0000", &color);
54			gtk_widget_modify_text(GTK_BIN(widget)->child, TAG_STATE, &color);
55			return widget;
56			}
57
58			/* a label that is left aligned */
59			static GtkWidget gtk_left_label_new(char str) {
60			GtkWidget *widget = gtk_label_new(str);
61			gtk_misc_set_alignment(GTK_MISC(widget), 0.0f, 0.5f);
62			return widget;
63			}
64
65			/* a label that is colored red when being "active" */
66			static GtkWidget gtk_red_label_new(char str) {
67			GdkColor color;
68			GtkWidget *widget = gtk_left_label_new(str);
69			gdk_color_parse("#ff0000", &color);
70			gtk_widget_modify_fg(widget, TAG_STATE, &color);
71			return widget;
72			}
73
74			static GtkWidget *gtk_dir_entry_new(float val) {
75			char str[16];
76			GtkWidget *w = gtk_red_entry_new();
77
78			snprintf(str, sizeof(str), _("%.1f°"), val);
79			gtk_entry_set_text(GTK_ENTRY(w), str);
80
81			return w;
82			}
83
84			float pos_lat_eval_combo(GtkWidget *widget) {
85			char p = (char)gtk_combo_box_get_active_text(GTK_COMBO_BOX(widget));
86			float val = pos_parse_lat(p);
87			mark(widget, !isnan(val));
88
89			return val;
90			}
91
92			static float distance_eval(GtkWidget widget, math_dialog_state_t state) {
93			char p = (char)gtk_entry_get_text(GTK_ENTRY(widget));
94			float val = distance_parse(p, state->appdata->imperial);
95			mark(widget, !isnan(val));
96
97			return val;
98			}
99
100			float direction_eval(GtkWidget *widget) {
101			char p = (char)gtk_entry_get_text(GTK_ENTRY(widget));
102			float val;
103			if(sscanf(p, _("%f°"), &val) != 1)
104			val = NAN;
105
106			mark(widget, !isnan(val));
107
108			return val;
109			}
110
111			static void on_calc_clicked(GtkButton *button, gpointer user_data) {
112			math_dialog_state_t state = (math_dialog_state_t)user_data;
113			pos_t pos1, pos2;
114			gboolean pos1_ok = FALSE, pos2_ok = FALSE;
115			float dist1;
116			gboolean dist1_ok = FALSE;
117			float dir1;
118			gboolean dir1_ok = FALSE;
119
120			/* parse input */
121			pos1.lat = lat_get(state->lat1);
122			pos1.lon = lon_get(state->lon1);
123			if(!isnan(pos1.lat) && !isnan(pos1.lon)) pos1_ok = TRUE;
124
125			pos2.lat = lat_get(state->lat2);
126			pos2.lon = lon_get(state->lon2);
127			if(!isnan(pos2.lat) && !isnan(pos2.lon)) pos2_ok = TRUE;
128
129			dist1 = distance_eval(state->dist1, state);
130			if(!isnan(dist1)) dist1_ok = TRUE;
131
132			dir1 = direction_eval(state->dir1);
133			if(!isnan(dir1)) dir1_ok = TRUE;
134
135			/* ------------------- do all calculations ------------------- */
136
137
138			/* ------------------- distance of coo1 and coo2 ------------------- */
139			if(mark(state->distance, pos1_ok && pos2_ok)) {
140			char str[32];
141			float dist = gpx_pos_get_distance(pos1, pos2, state->appdata->imperial);
142			distance_str(str, sizeof(str), dist, state->appdata->imperial);
143
144			gtk_label_set_text(GTK_LABEL(state->distance), str);
145			} else
146			gtk_label_set_text(GTK_LABEL(state->distance), STR_NAN);
147
148			// N 53° 09.033' W 001° 50.666' 100km / 30° = N 53° 55.616, W001° 04.850
149			/* ------------------- coordinate projection ---------------- */
150			mark(state->proj_lat, pos1_ok && dist1_ok && dir1_ok);
151			if(mark(state->proj_lon, pos1_ok && dist1_ok && dir1_ok)) {
152			pos_t pro;
153
154			/* get great circle radius in miles/kilometers */
155			float gcrad = state->appdata->imperial?3959.0:6371.0;
156
157			// from: http://www.movable-type.co.uk/scripts/latlong.html
158			pro.lat = asin(sin(pos1.lat/180M_PI) cos(dist1/gcrad) +
159			cos(pos1.lat/180M_PI) sin(dist1/gcrad) *
160			cos(dir1/180M_PI) )/M_PI180;
161			pro.lon = pos1.lon + atan2(sin(dir1/180M_PI)sin(dist1/gcrad)*
162			cos(pos1.lat/180*M_PI),
163			cos(dist1/gcrad)-sin(pos1.lat/180M_PI)
164			sin(pro.lat/180M_PI))/M_PI180;
165			pro.lon = fmodf(pro.lon+180,360) - 180; // normalise to -180...+180
166
167			char str[16];
168			pos_lat_str(str, sizeof(str), pro.lat);
169			gtk_label_set_text(GTK_LABEL(state->proj_lat), str);
170			pos_lon_str(str, sizeof(str), pro.lon);
171			gtk_label_set_text(GTK_LABEL(state->proj_lon), str);
172
173			if(!isnan(pro.lat) && !isnan(pro.lon))
174			state->appdata->geomath = pro;
175			} else {
176			gtk_label_set_text(GTK_LABEL(state->proj_lat), STR_NAN);
177			gtk_label_set_text(GTK_LABEL(state->proj_lon), STR_NAN);
178			}
179
180			#if 0
181			/* ------------ middle between both points ------------- */
182			mark(state->middle_lat, pos1_ok && pos2_ok);
183			if(mark(state->middle_lon, pos1_ok && pos2_ok)) {
184			pos_t res;
185
186			float dlon = fabs(pos2.lon - pos1.lon)/180*M_PI;
187
188			/* http://mathforum.org/library/drmath/view/51822.html */
189			res.lon = 180/M_PI * atan(cos(pos2.lat/180M_PI)sin(pos2.lon/180*M_PI)/
190			(cos(pos1.lat/180M_PI)+cos(pos2.lat/180M_PI)cos(pos2.lon/180M_PI)));
191			res.lat = 180/M_PI * atan((sin(pos1.lat/180M_PI)+sin(pos2.lat/180M_PI))/
192			sqrt(pow(cos(pos2.lat/180M_PI)+cos(pos2.lat/180M_PI)*cos(dlon),2)+
193			pow(cos(pos2.lat/180M_PI)sin(dlon),2)));
194
195			char str1[32], str2[32];
196			pos_lat_str(str1,sizeof(str1),res.lat);
197			pos_lon_str(str2,sizeof(str2),res.lon);
198			printf("pos = %s/%s\n", str1, str2);
199			} else {
200			gtk_label_set_text(GTK_LABEL(state->middle_lat), STR_NAN);
201			gtk_label_set_text(GTK_LABEL(state->middle_lon), STR_NAN);
202			}
203			#endif
204			}
205
206			static gint waypoint_changed_event(GtkWidget *widget, gpointer data ) {
207			math_dialog_state_t state = (math_dialog_state_t)data;
208			int wpt_idx = gtk_combo_box_get_active(GTK_COMBO_BOX(widget));
209			pos_t *pos = NULL;
210
211			if(wpt_idx < 0)
212			return FALSE;
213
214			if(wpt_idx == 0)
215			pos = gps_get_pos(state->appdata);
216			#ifdef USE_MAEMO
217			else if(wpt_idx == 1) {
218			pos_t cache_pos = gpx_cache_pos(state->appdata->cur_cache);
219			pos = &cache_pos;
220			} else {
221			wpt_t *wpt = state->appdata->cur_cache->wpt;
222			while(wpt_idx > 2) {
223			g_assert(wpt != NULL);
224			wpt = wpt->next;
225			wpt_idx--;
226			}
227			pos = &wpt->pos;
228			}
229			#endif
230
231			if(pos) {
232			char str[32];
233			pos_lat_str(str,sizeof(str),pos->lat);
234			gtk_entry_set_text(GTK_ENTRY(state->lat1), str);
235			pos_lon_str(str,sizeof(str),pos->lon);
236			gtk_entry_set_text(GTK_ENTRY(state->lon1), str);
237			} else {
238			gtk_entry_set_text(GTK_ENTRY(state->lat1), STR_NAN);
239			gtk_entry_set_text(GTK_ENTRY(state->lon1), STR_NAN);
240			}
241
242			mark(state->lat1, pos != NULL);
243			mark(state->lon1, pos != NULL);
244
245			return FALSE;
246			}
247
248			void geomath_dialog(appdata_t *appdata) {
249			static pos_t pos1 = { 0.0, 0.0 }, pos2 = { 0.0, 0.0 };
250			static float dist1 = 0.0;
251			static float dir1 = 0.0;
252			static gboolean is_imperial = FALSE;
253
254			math_dialog_state_t state;
255			char str[32];
256
257			/* this is quite ugly. It would be nice to run the entire system on */
258			/* one specific system (e.g. metric) and only convert for in- and output */
259			if(!appdata->imperial && is_imperial)
260			dist1 = 6371.0/3959.0; / we just switched to metric */
261			if(appdata->imperial && !is_imperial)
262			dist1 = 3959.0/6371.0; / we just switched to imperial */
263			is_imperial = appdata->imperial;
264
265			state.appdata = appdata;
266
267			#ifdef USE_MAEMO
268			if(appdata->cur_cache)
269			printf("current cache is %s\n", appdata->cur_cache->id);
270			else
271			printf("no current cache\n");
272			#endif
273
274			GtkWidget *dialog = gtk_dialog_new_with_buttons(_("Geomath"),
275			GTK_WINDOW(appdata->window),
276			// GTK_DIALOG_NO_SEPARATOR \|
277			GTK_DIALOG_MODAL \| GTK_DIALOG_DESTROY_WITH_PARENT,
278			GTK_STOCK_CLOSE, GTK_RESPONSE_CLOSE,
279			NULL);
280
281			#if defined(USE_MAEMO) && defined(HILDON_HELP)
282			hildon_help_dialog_help_enable(GTK_DIALOG(dialog), HELP_ID_GEOMATH,
283			appdata->osso_context);
284			#endif
285
286			gtk_window_set_default_size(GTK_WINDOW(dialog), DIALOG_WIDTH, DIALOG_HEIGHT);
287
288			/* do geomath dialog */
289			GtkWidget *hbox = gtk_hbox_new(FALSE, 0);
290
291			/* ------------------------- input area ------------------------- */
292			GtkWidget *table = gtk_table_new(5, 3, FALSE);
293			gtk_table_set_col_spacing(GTK_TABLE(table), 1, 20);
294
295			gtk_table_attach_defaults(GTK_TABLE(table), gtk_label_new(_("Coordinate 1")), 1, 2, 0, 1);
296			gtk_table_attach_defaults(GTK_TABLE(table), gtk_label_new(_("Coordinate 2")), 2, 3, 0, 1);
297			gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Latitude:")), 0, 1, 1, 2);
298
299			GtkWidget *cbox = gtk_red_combo_box_entry_new_text();
300			gtk_combo_box_append_text(GTK_COMBO_BOX(cbox), _("GPS"));
301
302			#ifdef USE_MAEMO
303			if(appdata->cur_cache) {
304			gtk_combo_box_append_text(GTK_COMBO_BOX(cbox), appdata->cur_cache->id);
305			wpt_t *wpt = appdata->cur_cache->wpt;
306			while(wpt) {
307			gtk_combo_box_append_text(GTK_COMBO_BOX(cbox), wpt->id);
308			wpt = wpt->next;
309			}
310			}
311			#endif
312
313			state.lat1 = GTK_BIN(cbox)->child;
314			pos_lat_str(str, sizeof(str), pos1.lat);
315			gtk_entry_set_text(GTK_ENTRY(state.lat1), str);
316
317			gtk_signal_connect(GTK_OBJECT(cbox), "changed",
318			(GtkSignalFunc)waypoint_changed_event, &state);
319			gtk_table_attach_defaults(GTK_TABLE(table), cbox, 1,2,1,2);
320
321
322			gtk_table_attach_defaults(GTK_TABLE(table), state.lat2 = lat_entry_new(pos2.lat), 2, 3, 1, 2);
323			gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Longitude:")), 0, 1, 2, 3);
324			gtk_table_attach_defaults(GTK_TABLE(table), state.lon1 = lon_entry_new(pos1.lon), 1, 2, 2, 3);
325			gtk_table_attach_defaults(GTK_TABLE(table), state.lon2 = lon_entry_new(pos2.lon), 2, 3, 2, 3);
326			gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Distance:")), 0, 1, 3, 4);
327			gtk_table_attach_defaults(GTK_TABLE(table), state.dist1 = dist_entry_new(dist1, appdata->imperial), 1, 2, 3, 4);
328			gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Direction:")), 0, 1, 4, 5);
329			gtk_table_attach_defaults(GTK_TABLE(table), state.dir1 = gtk_dir_entry_new(dir1), 1, 2, 4, 5);
330
331			gtk_box_pack_start(GTK_BOX(hbox), table, TRUE, TRUE, 0);
332
333			gtk_box_pack_start(GTK_BOX(GTK_DIALOG(dialog)->vbox), hbox, TRUE, TRUE, 0);
334
335			/* ------------------------- do-it-button ------------------------- */
336
337			hbox = gtk_hbox_new(FALSE, 0);
338			GtkWidget *button = gtk_button_new_with_label(_("Calculate!"));
339			gtk_box_pack_start(GTK_BOX(hbox), button, TRUE, FALSE, 0);
340			gtk_box_pack_start(GTK_BOX(GTK_DIALOG(dialog)->vbox), hbox, TRUE, FALSE, 0);
341			g_signal_connect(button, "clicked", (GCallback)on_calc_clicked, &state);
342
343			/* ------------------------- output area ------------------------- */
344
345			table = gtk_table_new(3, 3, FALSE);
346
347			gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Distance = ")),
348			0, 1, 0, 1);
349			gtk_table_attach_defaults(GTK_TABLE(table), state.distance = gtk_red_label_new(STR_NAN),
350			1, 3, 0, 1);
351
352			gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Projection = ")),
353			0, 1, 1, 2);
354			gtk_table_attach_defaults(GTK_TABLE(table), state.proj_lat = gtk_red_label_new(STR_NAN),
355			1, 2, 1, 2);
356			gtk_table_attach_defaults(GTK_TABLE(table), state.proj_lon = gtk_red_label_new(STR_NAN),
357			2, 3, 1, 2);
358			#if 0
359			gtk_table_attach_defaults(GTK_TABLE(table), gtk_left_label_new(_("Middle = ")),
360			0, 1, 2, 3);
361			gtk_table_attach_defaults(GTK_TABLE(table), state.middle_lat = gtk_red_label_new(STR_NAN),
362			1, 2, 2, 3);
363			gtk_table_attach_defaults(GTK_TABLE(table), state.middle_lon = gtk_red_label_new(STR_NAN),
364			2, 3, 2, 3);
365			#endif
366
367			gtk_box_pack_start(GTK_BOX(GTK_DIALOG(dialog)->vbox), table, TRUE, TRUE, 0);
368
369
370			gtk_dialog_set_default_response(GTK_DIALOG(dialog), GTK_RESPONSE_CLOSE);
371
372			gtk_widget_show_all(dialog);
373			gtk_dialog_run(GTK_DIALOG(dialog));
374
375			/* copy values back to local static variables so they re-appear if */
376			/* the dialog is re-opened, convert illegal values (NAN) to 0 */
377
378			pos1.lat = lat_get(state.lat1); if(isnan(pos1.lat)) pos1.lat=0;
379			pos1.lon = lon_get(state.lon1); if(isnan(pos1.lon)) pos1.lon=0;
380			pos2.lat = lat_get(state.lat2); if(isnan(pos2.lat)) pos2.lat=0;
381			pos2.lon = lon_get(state.lon2); if(isnan(pos2.lon)) pos2.lon=0;
382			dist1 = distance_eval(state.dist1, &state); if(isnan(dist1)) dist1=0;
383			dir1 = direction_eval(state.dir1); if(isnan(dir1)) dir1=0;
384
385			gtk_widget_destroy(dialog);
386			}