src/vikviewport.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  * Lat/Lon plotting functions calcxy* are from GPSDrive
   7  * GPSDrive Copyright (C) 2001-2004 Fritz Ganter <ganter@ganter.at>
   8  *
   9  * Multiple UTM zone patch by Kit Transue <notlostyet@didactek.com>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  24  *
  25  */
  26
  27 #define DEFAULT_BACKGROUND_COLOR "#CCCCCC"
  28
  29 #include <gtk/gtk.h>
  30 #include <math.h>
  31
  32 #include "coords.h"
  33 #include "vikcoord.h"
  34 #include "vikwindow.h"
  35 #include "vikviewport.h"
  36
  37 #include "mapcoord.h"
  38
  39 /* for ALTI_TO_MPP */
  40 #include "globals.h"
  41 #include "googlemaps.h"
  42 #include "khmaps.h"
  43
  44 static gdouble EASTING_OFFSET = 500000.0;
  45
  46 static void viewport_class_init ( VikViewportClass *klass );
  47 static void viewport_init ( VikViewport *vvp );
  48 static void viewport_finalize ( GObject *gob );
  49 static void viewport_utm_zone_check ( VikViewport *vvp );
  50
  51 static gboolean calcxy(double *x, double *y, double lg, double lt, double zero_long, double zero_lat, double pixelfact_x, double pixelfact_y, gint mapSizeX2, gint mapSizeY2 );
  52 static gboolean calcxy_rev(double *lg, double *lt, gint x, gint y, double zero_long, double zero_lat, double pixelfact_x, double pixelfact_y, gint mapSizeX2, gint mapSizeY2 );
  53 double calcR (double lat);
  54
  55 static double Radius[181];
  56 static void viewport_init_ra();
  57
  58 static GObjectClass *parent_class;
  59
  60 static void viewport_google_rezoom ( VikViewport *vvp );
  61
  62
  63 struct _VikViewport {
  64   GtkDrawingArea drawing_area;
  65   GdkPixmap *scr_buffer;
  66   gint width, height;
  67   VikCoord center;
  68   VikCoordMode coord_mode;
  69   gdouble xmpp, ympp;
  70
  71   GdkPixbuf *alpha_pixbuf;
  72   guint8 alpha_pixbuf_width;
  73   guint8 alpha_pixbuf_height;
  74
  75   gdouble utm_zone_width;
  76   gboolean one_utm_zone;
  77
  78   GdkGC *background_gc;
  79   GdkColor background_color;
  80   GdkGC *scale_bg_gc;
  81   gboolean draw_scale;
  82   gboolean draw_centermark;
  83
  84   /* subset of coord types. lat lon can be plotted in 2 ways, google or exp. */
  85   VikViewportDrawMode drawmode;
  86
  87   /* handy conversion factors which make google plotting extremely fast */
  88   gdouble google_calcx_fact;
  89   gdouble google_calcy_fact;
  90   gdouble google_calcx_rev_fact;
  91   gdouble google_calcy_rev_fact;
  92
  93   /* trigger stuff */
  94   gpointer trigger;
  95   GdkPixmap *snapshot_buffer;
  96   gboolean half_drawn;
  97 };
  98
  99 static gdouble
 100 viewport_utm_zone_width ( VikViewport *vvp )
 101 {
 102   if ( vvp->coord_mode == VIK_COORD_UTM ) {
 103     struct LatLon ll;
 104
 105     /* get latitude of screen bottom */
 106     struct UTM utm = *((struct UTM *)(vik_viewport_get_center ( vvp )));
 107     utm.northing -= vvp -> height * vvp -> ympp / 2;
 108     a_coords_utm_to_latlon ( &utm, &ll );
 109
 110     /* boundary */
 111     ll.lon = (utm.zone - 1) * 6 - 180 ;
 112     a_coords_latlon_to_utm ( &ll, &utm);
 113     return fabs ( utm.easting - EASTING_OFFSET ) * 2;
 114   } else
 115     return 0.0;
 116 }
 117
 118
 119 GType vik_viewport_get_type (void)
 120 {
 121   static GType vvp_type = 0;
 122
 123   if (!vvp_type)
 124   {
 125     static const GTypeInfo vvp_info =
 126     {
 127       sizeof (VikViewportClass),
 128       NULL, /* base_init */
 129       NULL, /* base_finalize */
 130       (GClassInitFunc) viewport_class_init,
 131       NULL, /* class_finalize */
 132       NULL, /* class_data */
 133       sizeof (VikViewport),
 134       0,
 135       (GInstanceInitFunc) viewport_init,
 136     };
 137     vvp_type = g_type_register_static ( GTK_TYPE_DRAWING_AREA, "VikViewport", &vvp_info, 0 );
 138   }
 139   return vvp_type;
 140 }
 141
 142 static void viewport_class_init ( VikViewportClass *klass )
 143 {
 144   /* Destructor */
 145   GObjectClass *object_class;
 146
 147   object_class = G_OBJECT_CLASS (klass);
 148
 149   object_class->finalize = viewport_finalize;
 150
 151   parent_class = g_type_class_peek_parent (klass);
 152 }
 153
 154 VikViewport *vik_viewport_new ()
 155 {
 156   VikViewport *vv = VIK_VIEWPORT ( g_object_new ( VIK_VIEWPORT_TYPE, NULL ) );
 157   return vv;
 158 }
 159
 160 static void viewport_init ( VikViewport *vvp )
 161 {
 162   viewport_init_ra();
 163
 164   /* TODO: not static */
 165   vvp->xmpp = 4.0;
 166   vvp->ympp = 4.0;
 167   vvp->coord_mode = VIK_COORD_LATLON;
 168   vvp->drawmode = VIK_VIEWPORT_DRAWMODE_MERCATOR;
 169   vvp->center.mode = VIK_COORD_LATLON;
 170   vvp->center.north_south = 40.714490;
 171   vvp->center.east_west = -74.007130;
 172   vvp->center.utm_zone = 31;
 173   vvp->center.utm_letter = 'N';
 174   vvp->scr_buffer = NULL;
 175   vvp->alpha_pixbuf = NULL;
 176   vvp->alpha_pixbuf_width = vvp->alpha_pixbuf_height = 0;
 177   vvp->utm_zone_width = 0.0;
 178   vvp->background_gc = NULL;
 179   vvp->scale_bg_gc = NULL;
 180   vvp->draw_scale = TRUE;
 181   vvp->draw_centermark = TRUE;
 182
 183   vvp->trigger = NULL;
 184   vvp->snapshot_buffer = NULL;
 185   vvp->half_drawn = FALSE;
 186
 187   g_signal_connect (G_OBJECT(vvp), "configure_event", G_CALLBACK(vik_viewport_configure), NULL);
 188
 189   GTK_WIDGET_SET_FLAGS(vvp, GTK_CAN_FOCUS); /* allow VVP to have focus -- enabling key events, etc */
 190 }
 191
 192 GdkColor *vik_viewport_get_background_gdkcolor ( VikViewport *vvp )
 193 {
 194   GdkColor *rv = g_malloc ( sizeof ( GdkColor ) );
 195   *rv = vvp->background_color;
 196   return rv;
 197 }
 198
 199 /* returns pointer to internal static storage, changes next time function called, use quickly */
 200 const gchar *vik_viewport_get_background_color ( VikViewport *vvp )
 201 {
 202   static gchar color[8];
 203   g_snprintf(color, sizeof(color), "#%.2x%.2x%.2x", (int)(vvp->background_color.red/256),(int)(vvp->background_color.green/256),(int)(vvp->background_color.blue/256));
 204   return color;
 205 }
 206
 207 void vik_viewport_set_background_color ( VikViewport *vvp, const gchar *colorname )
 208 {
 209   g_assert ( vvp->background_gc );
 210   gdk_color_parse ( colorname, &(vvp->background_color) );
 211   gdk_gc_set_rgb_fg_color ( vvp->background_gc, &(vvp->background_color) );
 212 }
 213
 214 void vik_viewport_set_background_gdkcolor ( VikViewport *vvp, GdkColor *color )
 215 {
 216   g_assert ( vvp->background_gc );
 217   vvp->background_color = *color;
 218   gdk_gc_set_rgb_fg_color ( vvp->background_gc, color );
 219 }
 220
 221
 222 GdkGC *vik_viewport_new_gc ( VikViewport *vvp, const gchar *colorname, gint thickness )
 223 {
 224   GdkGC *rv;
 225   GdkColor color;
 226
 227   rv = gdk_gc_new ( GTK_WIDGET(vvp)->window );
 228   gdk_color_parse ( colorname, &color );
 229   gdk_gc_set_rgb_fg_color ( rv, &color );
 230   gdk_gc_set_line_attributes ( rv, thickness, GDK_LINE_SOLID, GDK_CAP_ROUND, GDK_JOIN_ROUND );
 231   return rv;
 232 }
 233
 234 GdkGC *vik_viewport_new_gc_from_color ( VikViewport *vvp, GdkColor *color, gint thickness )
 235 {
 236   GdkGC *rv;
 237
 238   rv = gdk_gc_new ( GTK_WIDGET(vvp)->window );
 239   gdk_gc_set_rgb_fg_color ( rv, color );
 240   gdk_gc_set_line_attributes ( rv, thickness, GDK_LINE_SOLID, GDK_CAP_ROUND, GDK_JOIN_ROUND );
 241   return rv;
 242 }
 243
 244 void vik_viewport_configure_manually ( VikViewport *vvp, gint width, guint height )
 245 {
 246   vvp->width = width;
 247   vvp->height = height;
 248   if ( vvp->scr_buffer )
 249     g_object_unref ( G_OBJECT ( vvp->scr_buffer ) );
 250   vvp->scr_buffer = gdk_pixmap_new ( GTK_WIDGET(vvp)->window, vvp->width, vvp->height, -1 );
 251
 252   /* TODO trigger: only if this is enabled !!! */
 253   if ( vvp->snapshot_buffer )
 254     g_object_unref ( G_OBJECT ( vvp->snapshot_buffer ) );
 255   vvp->snapshot_buffer = gdk_pixmap_new ( GTK_WIDGET(vvp)->window, vvp->width, vvp->height, -1 );
 256 }
 257
 258
 259 GdkPixmap *vik_viewport_get_pixmap ( VikViewport *vvp )
 260 {
 261   return vvp->scr_buffer;
 262 }
 263
 264 gboolean vik_viewport_configure ( VikViewport *vvp )
 265 {
 266   g_return_val_if_fail ( vvp != NULL, TRUE );
 267
 268   vvp->width = GTK_WIDGET(vvp)->allocation.width;
 269   vvp->height = GTK_WIDGET(vvp)->allocation.height;
 270
 271   if ( vvp->scr_buffer )
 272     g_object_unref ( G_OBJECT ( vvp->scr_buffer ) );
 273
 274   vvp->scr_buffer = gdk_pixmap_new ( GTK_WIDGET(vvp)->window, vvp->width, vvp->height, -1 );
 275
 276   /* TODO trigger: only if enabled! */
 277   if ( vvp->snapshot_buffer )
 278     g_object_unref ( G_OBJECT ( vvp->snapshot_buffer ) );
 279
 280   vvp->snapshot_buffer = gdk_pixmap_new ( GTK_WIDGET(vvp)->window, vvp->width, vvp->height, -1 );
 281   /* TODO trigger */
 282
 283   /* this is down here so it can get a GC (necessary?) */
 284   if ( ! vvp->background_gc )
 285   {
 286     vvp->background_gc = vik_viewport_new_gc ( vvp, "", 1 );
 287     vik_viewport_set_background_color ( vvp, DEFAULT_BACKGROUND_COLOR ); /* set to "backup" color in vvp->background_color */
 288   }
 289   if ( !vvp->scale_bg_gc) {
 290     vvp->scale_bg_gc = vik_viewport_new_gc(vvp, "grey", 3);
 291   }
 292
 293   return FALSE;
 294 }
 295
 296 static void viewport_finalize ( GObject *gob )
 297 {
 298   VikViewport *vvp = VIK_VIEWPORT(gob);
 299
 300   g_return_if_fail ( vvp != NULL );
 301
 302   if ( vvp->scr_buffer )
 303     g_object_unref ( G_OBJECT ( vvp->scr_buffer ) );
 304
 305   if ( vvp->snapshot_buffer )
 306     g_object_unref ( G_OBJECT ( vvp->snapshot_buffer ) );
 307
 308   if ( vvp->alpha_pixbuf )
 309     g_object_unref ( G_OBJECT ( vvp->alpha_pixbuf ) );
 310
 311   if ( vvp->background_gc )
 312     g_object_unref ( G_OBJECT ( vvp->background_gc ) );
 313
 314   if ( vvp->scale_bg_gc ) {
 315     g_object_unref ( G_OBJECT ( vvp->scale_bg_gc ) );
 316     vvp->scale_bg_gc = NULL;
 317   }
 318
 319   G_OBJECT_CLASS(parent_class)->finalize(gob);
 320 }
 321
 322 void vik_viewport_clear ( VikViewport *vvp )
 323 {
 324   g_return_if_fail ( vvp != NULL );
 325   gdk_draw_rectangle(GDK_DRAWABLE(vvp->scr_buffer), vvp->background_gc, TRUE, 0, 0, vvp->width, vvp->height);
 326 }
 327
 328 void vik_viewport_set_draw_scale ( VikViewport *vvp, gboolean draw_scale )
 329 {
 330   vvp->draw_scale = draw_scale;
 331 }
 332
 333 gboolean vik_viewport_get_draw_scale ( VikViewport *vvp )
 334 {
 335   return vvp->draw_scale;
 336 }
 337
 338 void vik_viewport_draw_scale ( VikViewport *vvp )
 339 {
 340   if ( vvp->draw_scale ) {
 341     VikCoord left, right;
 342     gdouble unit, base, diff, old_unit, old_diff, ratio;
 343     gint odd, len, PAD = 10, SCSIZE = 5, HEIGHT=10;
 344     PangoFontDescription *pfd;
 345     PangoLayout *pl;
 346     gchar s[128];
 347
 348     g_return_if_fail ( vvp != NULL );
 349
 350     vik_viewport_screen_to_coord ( vvp, 0, vvp->height, &left );
 351     vik_viewport_screen_to_coord ( vvp, vvp->width/SCSIZE, vvp->height, &right );
 352
 353     base = vik_coord_diff ( &left, &right ); // in meters
 354     ratio = (vvp->width/SCSIZE)/base;
 355
 356     unit = 1;
 357     diff = fabs(base-unit);
 358     old_unit = unit;
 359     old_diff = diff;
 360     odd = 1;
 361     while (diff <= old_diff) {
 362       old_unit = unit;
 363       old_diff = diff;
 364       unit = unit * (odd%2 ? 5 : 2);
 365       diff = fabs(base-unit);
 366       odd++;
 367     }
 368     unit = old_unit;
 369     len = unit * ratio;
 370
 371     /* white background */
 372     vik_viewport_draw_line(vvp, vvp->scale_bg_gc,
 373                          PAD, vvp->height-PAD, PAD + len, vvp->height-PAD);
 374     vik_viewport_draw_line(vvp, vvp->scale_bg_gc,
 375                          PAD, vvp->height-PAD, PAD, vvp->height-PAD-HEIGHT);
 376     vik_viewport_draw_line(vvp, vvp->scale_bg_gc,
 377                          PAD + len, vvp->height-PAD, PAD + len, vvp->height-PAD-HEIGHT);
 378     /* black scale */
 379     vik_viewport_draw_line(vvp, GTK_WIDGET(&vvp->drawing_area)->style->black_gc,
 380                          PAD, vvp->height-PAD, PAD + len, vvp->height-PAD);
 381     vik_viewport_draw_line(vvp, GTK_WIDGET(&vvp->drawing_area)->style->black_gc,
 382                          PAD, vvp->height-PAD, PAD, vvp->height-PAD-HEIGHT);
 383     vik_viewport_draw_line(vvp, GTK_WIDGET(&vvp->drawing_area)->style->black_gc,
 384                          PAD + len, vvp->height-PAD, PAD + len, vvp->height-PAD-HEIGHT);
 385     if (odd%2) {
 386       int i;
 387       for (i=1; i<5; i++) {
 388         vik_viewport_draw_line(vvp, vvp->scale_bg_gc,
 389                              PAD+i*len/5, vvp->height-PAD, PAD+i*len/5, vvp->height-PAD-((i==5)?(2*HEIGHT/3):(HEIGHT/2)));
 390         vik_viewport_draw_line(vvp, GTK_WIDGET(&vvp->drawing_area)->style->black_gc,
 391                              PAD+i*len/5, vvp->height-PAD, PAD+i*len/5, vvp->height-PAD-((i==5)?(2*HEIGHT/3):(HEIGHT/2)));
 392       }
 393     } else {
 394       int i;
 395       for (i=1; i<10; i++) {
 396         vik_viewport_draw_line(vvp, vvp->scale_bg_gc,
 397                              PAD+i*len/10, vvp->height-PAD, PAD+i*len/10, vvp->height-PAD-((i==5)?(2*HEIGHT/3):(HEIGHT/2)));
 398         vik_viewport_draw_line(vvp, GTK_WIDGET(&vvp->drawing_area)->style->black_gc,
 399                              PAD+i*len/10, vvp->height-PAD, PAD+i*len/10, vvp->height-PAD-((i==5)?(2*HEIGHT/3):(HEIGHT/2)));
 400       }
 401     }
 402     pl = gtk_widget_create_pango_layout (GTK_WIDGET(&vvp->drawing_area), NULL);
 403     pfd = pango_font_description_from_string ("Sans 8"); // FIXME: settable option? global variable?
 404     pango_layout_set_font_description (pl, pfd);
 405     pango_font_description_free (pfd);
 406
 407     if (unit >= 1000) {
 408       sprintf(s, "%d km", (int)unit/1000);
 409     } else {
 410       sprintf(s, "%d m", (int)unit);
 411     }
 412     pango_layout_set_text(pl, s, -1);
 413     vik_viewport_draw_layout(vvp, GTK_WIDGET(&vvp->drawing_area)->style->black_gc,
 414                            PAD + len + PAD, vvp->height - PAD - 10, pl);
 415   }
 416 }
 417
 418 void vik_viewport_set_draw_centermark ( VikViewport *vvp, gboolean draw_centermark )
 419 {
 420   vvp->draw_centermark = draw_centermark;
 421 }
 422
 423 gboolean vik_viewport_get_draw_centermark ( VikViewport *vvp )
 424 {
 425   return vvp->draw_centermark;
 426 }
 427
 428 void vik_viewport_draw_centermark ( VikViewport *vvp )
 429 {
 430   if ( !vvp->draw_centermark )
 431     return;
 432
 433   const int len = 30;
 434   const int gap = 4;
 435   int center_x = vvp->width/2;
 436   int center_y = vvp->height/2;
 437   GdkGC * black_gc = GTK_WIDGET(&vvp->drawing_area)->style->black_gc;
 438
 439   /* white back ground */
 440   vik_viewport_draw_line(vvp, vvp->scale_bg_gc, center_x - len, center_y, center_x - gap, center_y);
 441   vik_viewport_draw_line(vvp, vvp->scale_bg_gc, center_x + gap, center_y, center_x + len, center_y);
 442   vik_viewport_draw_line(vvp, vvp->scale_bg_gc, center_x, center_y - len, center_x, center_y - gap);
 443   vik_viewport_draw_line(vvp, vvp->scale_bg_gc, center_x, center_y + gap, center_x, center_y + len);
 444   /* black fore ground */
 445   vik_viewport_draw_line(vvp, black_gc, center_x - len, center_y, center_x - gap, center_y);
 446   vik_viewport_draw_line(vvp, black_gc, center_x + gap, center_y, center_x + len, center_y);
 447   vik_viewport_draw_line(vvp, black_gc, center_x, center_y - len, center_x, center_y - gap);
 448   vik_viewport_draw_line(vvp, black_gc, center_x, center_y + gap, center_x, center_y + len);
 449
 450 }
 451
 452 void vik_viewport_sync ( VikViewport *vvp )
 453 {
 454   g_return_if_fail ( vvp != NULL );
 455   gdk_draw_drawable(GTK_WIDGET(vvp)->window, GTK_WIDGET(vvp)->style->bg_gc[0], GDK_DRAWABLE(vvp->scr_buffer), 0, 0, 0, 0, vvp->width, vvp->height);
 456 }
 457
 458 void vik_viewport_pan_sync ( VikViewport *vvp, gint x_off, gint y_off )
 459 {
 460   gint x, y, wid, hei;
 461
 462   g_return_if_fail ( vvp != NULL );
 463   gdk_draw_drawable(GTK_WIDGET(vvp)->window, GTK_WIDGET(vvp)->style->bg_gc[0], GDK_DRAWABLE(vvp->scr_buffer), 0, 0, x_off, y_off, vvp->width, vvp->height);
 464
 465   if (x_off >= 0) {
 466     x = 0;
 467     wid = x_off;
 468   } else {
 469     x = vvp->width+x_off;
 470     wid = -x_off;
 471   }
 472   if (y_off >= 0) {
 473     y = 0;
 474     hei = y_off;
 475   } else {
 476     y = vvp->height+y_off;
 477     hei = -y_off;
 478   }
 479   gtk_widget_queue_draw_area(GTK_WIDGET(vvp), x, 0, wid, vvp->height);
 480   gtk_widget_queue_draw_area(GTK_WIDGET(vvp), 0, y, vvp->width, hei);
 481 }
 482
 483 void vik_viewport_set_zoom ( VikViewport *vvp, gdouble xympp )
 484 {
 485   g_return_if_fail ( vvp != NULL );
 486   if ( xympp >= VIK_VIEWPORT_MIN_ZOOM && xympp <= VIK_VIEWPORT_MAX_ZOOM )
 487     vvp->xmpp = vvp->ympp = xympp;
 488
 489   if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_UTM )
 490     viewport_utm_zone_check(vvp);
 491   else if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_GOOGLE )
 492     viewport_google_rezoom ( vvp );
 493 }
 494
 495 /* or could do factor */
 496 void vik_viewport_zoom_in ( VikViewport *vvp )
 497 {
 498   g_return_if_fail ( vvp != NULL );
 499   if ( vvp->xmpp >= (VIK_VIEWPORT_MIN_ZOOM*2) && vvp->ympp >= (VIK_VIEWPORT_MIN_ZOOM*2) )
 500   {
 501     vvp->xmpp /= 2;
 502     vvp->ympp /= 2;
 503
 504     if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_GOOGLE )
 505       viewport_google_rezoom ( vvp );
 506
 507     viewport_utm_zone_check(vvp);
 508   }
 509 }
 510
 511 void vik_viewport_zoom_out ( VikViewport *vvp )
 512 {
 513   g_return_if_fail ( vvp != NULL );
 514   if ( vvp->xmpp <= (VIK_VIEWPORT_MAX_ZOOM/2) && vvp->ympp <= (VIK_VIEWPORT_MAX_ZOOM/2) )
 515   {
 516     vvp->xmpp *= 2;
 517     vvp->ympp *= 2;
 518
 519     if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_GOOGLE )
 520       viewport_google_rezoom ( vvp );
 521
 522     viewport_utm_zone_check(vvp);
 523   }
 524 }
 525
 526 gdouble vik_viewport_get_zoom ( VikViewport *vvp )
 527 {
 528   if ( vvp->xmpp == vvp->ympp )
 529     return vvp->xmpp;
 530   return 0.0;
 531 }
 532
 533 gdouble vik_viewport_get_xmpp ( VikViewport *vvp )
 534 {
 535   return vvp->xmpp;
 536 }
 537
 538 gdouble vik_viewport_get_ympp ( VikViewport *vvp )
 539 {
 540   return vvp->ympp;
 541 }
 542
 543 void vik_viewport_set_xmpp ( VikViewport *vvp, gdouble xmpp )
 544 {
 545   if ( xmpp >= VIK_VIEWPORT_MIN_ZOOM && xmpp <= VIK_VIEWPORT_MAX_ZOOM ) {
 546     vvp->xmpp = xmpp;
 547     if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_UTM )
 548       viewport_utm_zone_check(vvp);
 549     if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_GOOGLE )
 550       viewport_google_rezoom ( vvp );
 551   }
 552 }
 553
 554 void vik_viewport_set_ympp ( VikViewport *vvp, gdouble ympp )
 555 {
 556   if ( ympp >= VIK_VIEWPORT_MIN_ZOOM && ympp <= VIK_VIEWPORT_MAX_ZOOM ) {
 557     vvp->ympp = ympp;
 558     if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_UTM )
 559       viewport_utm_zone_check(vvp);
 560     if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_GOOGLE )
 561       viewport_google_rezoom ( vvp );
 562   }
 563 }
 564
 565
 566 const VikCoord *vik_viewport_get_center ( VikViewport *vvp )
 567 {
 568   g_return_val_if_fail ( vvp != NULL, NULL );
 569   return &(vvp->center);
 570 }
 571
 572 /* called every time we update coordinates/zoom */
 573 static void viewport_utm_zone_check ( VikViewport *vvp )
 574 {
 575   if ( vvp->coord_mode == VIK_COORD_UTM )
 576   {
 577     struct UTM utm;
 578     struct LatLon ll;
 579     a_coords_utm_to_latlon ( (struct UTM *) &(vvp->center), &ll );
 580     a_coords_latlon_to_utm ( &ll, &utm );
 581     if ( utm.zone != vvp->center.utm_zone )
 582       *((struct UTM *)(&vvp->center)) = utm;
 583
 584     /* misc. stuff so we don't have to check later */
 585     vvp->utm_zone_width = viewport_utm_zone_width ( vvp );
 586     vvp->one_utm_zone = ( vik_viewport_rightmost_zone(vvp) == vik_viewport_leftmost_zone(vvp) );
 587   }
 588 }
 589
 590 void vik_viewport_set_center_latlon ( VikViewport *vvp, const struct LatLon *ll )
 591 {
 592   vik_coord_load_from_latlon ( &(vvp->center), vvp->coord_mode, ll );
 593   if ( vvp->coord_mode == VIK_COORD_UTM )
 594     viewport_utm_zone_check ( vvp );
 595 }
 596
 597 void vik_viewport_set_center_utm ( VikViewport *vvp, const struct UTM *utm )
 598 {
 599   vik_coord_load_from_utm ( &(vvp->center), vvp->coord_mode, utm );
 600   if ( vvp->coord_mode == VIK_COORD_UTM )
 601     viewport_utm_zone_check ( vvp );
 602 }
 603
 604 void vik_viewport_set_center_coord ( VikViewport *vvp, const VikCoord *coord )
 605 {
 606   vvp->center = *coord;
 607   if ( vvp->coord_mode == VIK_COORD_UTM )
 608     viewport_utm_zone_check ( vvp );
 609 }
 610
 611 void vik_viewport_corners_for_zonen ( VikViewport *vvp, int zone, VikCoord *ul, VikCoord *br )
 612 {
 613   g_return_if_fail ( vvp->coord_mode == VIK_COORD_UTM );
 614
 615   /* get center, then just offset */
 616   vik_viewport_center_for_zonen ( vvp, VIK_UTM(ul), zone );
 617   ul->mode = VIK_COORD_UTM;
 618   *br = *ul;
 619
 620   ul->north_south += (vvp->ympp * vvp->height / 2);
 621   ul->east_west -= (vvp->xmpp * vvp->width / 2);
 622   br->north_south -= (vvp->ympp * vvp->height / 2);
 623   br->east_west += (vvp->xmpp * vvp->width / 2);
 624 }
 625
 626 void vik_viewport_center_for_zonen ( VikViewport *vvp, struct UTM *center, int zone)
 627 {
 628   if ( vvp->coord_mode == VIK_COORD_UTM ) {
 629     *center = *((struct UTM *)(vik_viewport_get_center ( vvp )));
 630     center->easting -= ( zone - center->zone ) * vvp->utm_zone_width;
 631     center->zone = zone;
 632   }
 633 }
 634
 635 gchar vik_viewport_leftmost_zone ( VikViewport *vvp )
 636 {
 637   if ( vvp->coord_mode == VIK_COORD_UTM ) {
 638     VikCoord coord;
 639     g_assert ( vvp != NULL );
 640     vik_viewport_screen_to_coord ( vvp, 0, 0, &coord );
 641     return coord.utm_zone;
 642   }
 643   return '\0';
 644 }
 645
 646 gchar vik_viewport_rightmost_zone ( VikViewport *vvp )
 647 {
 648   if ( vvp->coord_mode == VIK_COORD_UTM ) {
 649     VikCoord coord;
 650     g_assert ( vvp != NULL );
 651     vik_viewport_screen_to_coord ( vvp, vvp->width, 0, &coord );
 652     return coord.utm_zone;
 653   }
 654   return '\0';
 655 }
 656
 657
 658 void vik_viewport_set_center_screen ( VikViewport *vvp, int x, int y )
 659 {
 660   g_return_if_fail ( vvp != NULL );
 661   if ( vvp->coord_mode == VIK_COORD_UTM ) {
 662     /* slightly optimized */
 663     vvp->center.east_west += vvp->xmpp * (x - (vvp->width/2));
 664     vvp->center.north_south += vvp->ympp * ((vvp->height/2) - y);
 665     viewport_utm_zone_check ( vvp );
 666   } else {
 667     VikCoord tmp;
 668     vik_viewport_screen_to_coord ( vvp, x, y, &tmp );
 669     vik_viewport_set_center_coord ( vvp, &tmp );
 670   }
 671 }
 672
 673 gint vik_viewport_get_width( VikViewport *vvp )
 674 {
 675   g_return_val_if_fail ( vvp != NULL, 0 );
 676   return vvp->width;
 677 }
 678
 679 gint vik_viewport_get_height( VikViewport *vvp )
 680 {
 681   g_return_val_if_fail ( vvp != NULL, 0 );
 682   return vvp->height;
 683 }
 684
 685 void vik_viewport_screen_to_coord ( VikViewport *vvp, int x, int y, VikCoord *coord )
 686 {
 687   if ( vvp->coord_mode == VIK_COORD_UTM ) {
 688     int zone_delta;
 689     struct UTM *utm = (struct UTM *) coord;
 690     coord->mode = VIK_COORD_UTM;
 691
 692     g_return_if_fail ( vvp != NULL );
 693
 694     utm->zone = vvp->center.utm_zone;
 695     utm->letter = vvp->center.utm_letter;
 696     utm->easting = ( ( x - ( vvp->width / 2) ) * vvp->xmpp ) + vvp->center.east_west;
 697     zone_delta = floor( (utm->easting - EASTING_OFFSET ) / vvp->utm_zone_width + 0.5 );
 698     utm->zone += zone_delta;
 699     utm->easting -= zone_delta * vvp->utm_zone_width;
 700     utm->northing = ( ( ( vvp->height / 2) - y ) * vvp->ympp ) + vvp->center.north_south;
 701   } else if ( vvp->coord_mode == VIK_COORD_LATLON ) {
 702     coord->mode = VIK_COORD_LATLON;
 703     if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_EXPEDIA )
 704       calcxy_rev(&(coord->east_west), &(coord->north_south), x, y, vvp->center.east_west, vvp->center.north_south, vvp->xmpp * ALTI_TO_MPP, vvp->ympp * ALTI_TO_MPP, vvp->width/2, vvp->height/2);
 705     else if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_GOOGLE ) {
 706       /* google */
 707       coord->east_west = (x - (vvp->width/2)) * vvp->google_calcx_rev_fact + vvp->center.east_west;
 708       coord->north_south = ((vvp->height/2) - y) * vvp->google_calcy_rev_fact + vvp->center.north_south;
 709     } else if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_KH ) {
 710       coord->east_west = vvp->center.east_west + (180.0 * vvp->xmpp / 65536 / 256 * (x - vvp->width/2));
 711       coord->north_south = vvp->center.north_south + (180.0 * vvp->ympp / 65536 / 256 * (vvp->height/2 - y));
 712     } else if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_MERCATOR ) {
 713       /* FIXMERCATOR */
 714       coord->east_west = vvp->center.east_west + (180.0 * vvp->xmpp / 65536 / 256 * (x - vvp->width/2));
 715       coord->north_south = DEMERCLAT ( MERCLAT(vvp->center.north_south) + (180.0 * vvp->ympp / 65536 / 256 * (vvp->height/2 - y)) );
 716
 717 #if 0
 718 -->     THIS IS JUNK HERE.
 719       *y = vvp->height/2 + (65536.0 / 180 / vvp->ympp * (MERCLAT(center->lat) - MERCLAT(ll->lat)))*256.0;
 720
 721       (*y - vvp->height/2) / 256 / 65536 * 180 * vvp->ympp = (MERCLAT(center->lat) - MERCLAT(ll->lat);
 722       DML((180.0 * vvp->ympp / 65536 / 256 * (vvp->height/2 - y)) + ML(cl)) = ll
 723 #endif
 724     }
 725   }
 726 }
 727
 728 void vik_viewport_coord_to_screen ( VikViewport *vvp, const VikCoord *coord, int *x, int *y )
 729 {
 730   static VikCoord tmp;
 731   g_return_if_fail ( vvp != NULL );
 732
 733   if ( coord->mode != vvp->coord_mode )
 734   {
 735     g_warning ( "Have to convert in vik_viewport_coord_to_screen! This should never happen!");
 736     vik_coord_copy_convert ( coord, vvp->coord_mode, &tmp );
 737     coord = &tmp;
 738   }
 739
 740   if ( vvp->coord_mode == VIK_COORD_UTM ) {
 741     struct UTM *center = (struct UTM *) &(vvp->center);
 742     struct UTM *utm = (struct UTM *) coord;
 743     if ( center->zone != utm->zone && vvp->one_utm_zone )
 744     {
 745       *x = *y = VIK_VIEWPORT_UTM_WRONG_ZONE;
 746       return;
 747     }
 748
 749     *x = ( (utm->easting - center->easting) / vvp->xmpp ) + (vvp->width / 2) -
 750           (center->zone - utm->zone ) * vvp->utm_zone_width / vvp->xmpp;
 751     *y = (vvp->height / 2) - ( (utm->northing - center->northing) / vvp->ympp );
 752   } else if ( vvp->coord_mode == VIK_COORD_LATLON ) {
 753     struct LatLon *center = (struct LatLon *) &(vvp->center);
 754     struct LatLon *ll = (struct LatLon *) coord;
 755     double xx,yy;
 756     if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_EXPEDIA ) {
 757       calcxy ( &xx, &yy, center->lon, center->lat, ll->lon, ll->lat, vvp->xmpp * ALTI_TO_MPP, vvp->ympp * ALTI_TO_MPP, vvp->width / 2, vvp->height / 2 );
 758       *x = xx; *y = yy;
 759     } else if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_GOOGLE ) {
 760       /* google */
 761       *x = vvp->google_calcx_fact * (ll->lon - center->lon) + (vvp->width/2);
 762       *y = vvp->google_calcy_fact * (center->lat - ll->lat) + (vvp->height/2);
 763     } else if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_KH ) {
 764       /* subtract, convert to KH coords; blow it up by 256 */
 765       *x = vvp->width/2 + (65536.0 / 180 / vvp->xmpp * (ll->lon - center->lon))*256.0;
 766       *y = vvp->height/2 + (65536.0 / 180 / vvp->ympp * (center->lat - ll->lat))*256.0;
 767     } else if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_MERCATOR ) {
 768       /* FIXMERCATOR: Optimize */
 769       *x = vvp->width/2 + (65536.0 / 180 / vvp->xmpp * (ll->lon - center->lon))*256.0;
 770       *y = vvp->height/2 + (65536.0 / 180 / vvp->ympp * (MERCLAT(center->lat) - MERCLAT(ll->lat)))*256.0;
 771     }
 772   }
 773 }
 774
 775 void a_viewport_clip_line ( gint *x1, gint *y1, gint *x2, gint *y2 )
 776 {
 777   if ( *x1 > 20000 || *x1 < -20000 ) {
 778     gdouble shrinkfactor = ABS(20000.0 / *x1);
 779     *x1 = *x2 + (shrinkfactor * (*x1-*x2));
 780     *y1 = *y2 + (shrinkfactor * (*y1-*y2));
 781   } else if ( *y1 > 20000 || *y1 < -20000 ) {
 782     gdouble shrinkfactor = ABS(20000.0 / *x1);
 783     *x1 = *x2 + (shrinkfactor * (*x1-*x2));
 784     *y1 = *y2 + (shrinkfactor * (*y1-*y2));
 785   } else if ( *x2 > 20000 || *x2 < -20000 ) {
 786     gdouble shrinkfactor = ABS(20000.0 / (gdouble)*x2);
 787     *x2 = *x1 + (shrinkfactor * (*x2-*x1));
 788     *y2 = *y1 + (shrinkfactor * (*y2-*y1));
 789     g_print("%f, %d, %d\n", shrinkfactor, *x2, *y2);
 790   } else if ( *y2 > 20000 || *y2 < -20000 ) {
 791     gdouble shrinkfactor = ABS(20000.0 / (gdouble)*x2);
 792     *x2 = *x1 + (shrinkfactor * (*x2-*x1));
 793     *y2 = *y1 + (shrinkfactor * (*y2-*y1));
 794   }
 795 }
 796
 797 void vik_viewport_draw_line ( VikViewport *vvp, GdkGC *gc, gint x1, gint y1, gint x2, gint y2 )
 798 {
 799   if ( ! ( ( x1 < 0 && x2 < 0 ) || ( y1 < 0 && y2 < 0 ) ||
 800        ( x1 > vvp->width && x2 > vvp->width ) || ( y1 > vvp->height && y2 > vvp->height ) ) ) {
 801     /*** clipping, yeah! ***/
 802     a_viewport_clip_line ( &x1, &y1, &x2, &y2 );
 803     gdk_draw_line ( vvp->scr_buffer, gc, x1, y1, x2, y2);
 804   }
 805 }
 806
 807 void vik_viewport_draw_rectangle ( VikViewport *vvp, GdkGC *gc, gboolean filled, gint x1, gint y1, gint x2, gint y2 )
 808 {
 809   if ( x1 > -10 && x1 < vvp->width + 10 && y1 > -10 && y1 < vvp->height + 10 )
 810     gdk_draw_rectangle ( vvp->scr_buffer, gc, filled, x1, y1, x2, y2);
 811 }
 812
 813 void vik_viewport_draw_string ( VikViewport *vvp, GdkFont *font, GdkGC *gc, gint x1, gint y1, const gchar *string )
 814 {
 815   if ( x1 > -100 && x1 < vvp->width + 100 && y1 > -100 && y1 < vvp->height + 100 )
 816     gdk_draw_string ( vvp->scr_buffer, font, gc, x1, y1, string );
 817 }
 818
 819 /* shouldn't use this -- slow -- change the alpha channel instead. */
 820 void vik_viewport_draw_pixbuf_with_alpha ( VikViewport *vvp, GdkPixbuf *pixbuf, gint alpha,
 821                                            gint src_x, gint src_y, gint dest_x, gint dest_y, gint w, gint h )
 822 {
 823   gint real_dest_x = MAX(dest_x,0);
 824   gint real_dest_y = MAX(dest_y,0);
 825
 826   if ( alpha == 0 )
 827     return; /* don't waste your time */
 828
 829   if ( w > vvp->alpha_pixbuf_width || h > vvp->alpha_pixbuf_height )
 830   {
 831     if ( vvp->alpha_pixbuf )
 832       g_object_unref ( G_OBJECT ( vvp->alpha_pixbuf ) );
 833     vvp->alpha_pixbuf_width = MAX(w,vvp->alpha_pixbuf_width);
 834     vvp->alpha_pixbuf_height = MAX(h,vvp->alpha_pixbuf_height);
 835     vvp->alpha_pixbuf = gdk_pixbuf_new ( GDK_COLORSPACE_RGB, FALSE, 8, vvp->alpha_pixbuf_width, vvp->alpha_pixbuf_height );
 836   }
 837
 838   w = MIN(w,vvp->width - dest_x);
 839   h = MIN(h,vvp->height - dest_y);
 840
 841   /* check that we are drawing within boundaries. */
 842   src_x += (real_dest_x - dest_x);
 843   src_y += (real_dest_y - dest_y);
 844   w -= (real_dest_x - dest_x);
 845   h -= (real_dest_y - dest_y);
 846
 847   gdk_pixbuf_get_from_drawable ( vvp->alpha_pixbuf, vvp->scr_buffer, NULL,
 848                                  real_dest_x, real_dest_y, 0, 0, w, h );
 849
 850   /* do a composite */
 851   gdk_pixbuf_composite ( pixbuf, vvp->alpha_pixbuf, 0, 0, w, h, -src_x, -src_y, 1, 1, 0, alpha );
 852
 853   /* draw pixbuf_tmp */
 854   vik_viewport_draw_pixbuf ( vvp, vvp->alpha_pixbuf, 0, 0, real_dest_x, real_dest_y, w, h );
 855 }
 856
 857 void vik_viewport_draw_pixbuf ( VikViewport *vvp, GdkPixbuf *pixbuf, gint src_x, gint src_y,
 858                               gint dest_x, gint dest_y, gint w, gint h )
 859 {
 860   gdk_draw_pixbuf ( vvp->scr_buffer,
 861 // GTK_WIDGET(vvp)->style->black_gc,
 862 NULL,
 863  pixbuf,
 864                     src_x, src_y, dest_x, dest_y, w, h,
 865                     GDK_RGB_DITHER_NONE, 0, 0 );
 866 }
 867
 868 void vik_viewport_draw_arc ( VikViewport *vvp, GdkGC *gc, gboolean filled, gint x, gint y, gint width, gint height, gint angle1, gint angle2 )
 869 {
 870   gdk_draw_arc ( vvp->scr_buffer, gc, filled, x, y, width, height, angle1, angle2 );
 871 }
 872
 873
 874 void vik_viewport_draw_polygon ( VikViewport *vvp, GdkGC *gc, gboolean filled, GdkPoint *points, gint npoints )
 875 {
 876   gdk_draw_polygon ( vvp->scr_buffer, gc, filled, points, npoints );
 877 }
 878
 879 VikCoordMode vik_viewport_get_coord_mode ( const VikViewport *vvp )
 880 {
 881   g_assert ( vvp );
 882   return vvp->coord_mode;
 883 }
 884
 885 static void viewport_set_coord_mode ( VikViewport *vvp, VikCoordMode mode )
 886 {
 887   g_return_if_fail ( vvp != NULL );
 888   vvp->coord_mode = mode;
 889   vik_coord_convert ( &(vvp->center), mode );
 890 }
 891
 892 /* Thanks GPSDrive */
 893 static gboolean calcxy_rev(double *lg, double *lt, gint x, gint y, double zero_long, double zero_lat, double pixelfact_x, double pixelfact_y, gint mapSizeX2, gint mapSizeY2 )
 894 {
 895   int px, py;
 896   gdouble dif, lat, lon;
 897   double Ra = Radius[90+(gint)zero_lat];
 898
 899   px = (mapSizeX2 - x) * pixelfact_x;
 900   py = (-mapSizeY2 + y) * pixelfact_y;
 901
 902   lat = zero_lat - py / Ra;
 903   lat = zero_lat - py / Ra;
 904   lon =
 905     zero_long -
 906     px / (Ra *
 907          cos (lat * DEG2RAD));
 908
 909   dif = lat * (1 - (cos ((fabs (lon - zero_long)) * DEG2RAD)));
 910   lat = lat - dif / 1.5;
 911   lon =
 912     zero_long -
 913     px / (Ra *
 914               cos (lat * DEG2RAD));
 915
 916   *lt = lat;
 917   *lg = lon;
 918   return (TRUE);
 919 }
 920
 921 /* Thanks GPSDrive */
 922 static gboolean calcxy(double *x, double *y, double lg, double lt, double zero_long, double zero_lat, double pixelfact_x, double pixelfact_y, gint mapSizeX2, gint mapSizeY2 )
 923 {
 924     double dif;
 925     double Ra;
 926     gint mapSizeX = 2 * mapSizeX2;
 927     gint mapSizeY = 2 * mapSizeY2;
 928
 929     g_assert ( lt >= -90.0 && lt <= 90.0 );
 930 //    lg *= rad2deg; // FIXME, optimize equations
 931 //    lt *= rad2deg;
 932     Ra = Radius[90+(gint)lt];
 933     *x = Ra *
 934          cos (lt*DEG2RAD) * (lg - zero_long);
 935     *y = Ra * (lt - zero_lat);
 936     dif = Ra * RAD2DEG * (1 - (cos ((DEG2RAD * (lg - zero_long)))));
 937     *y = *y + dif / 1.85;
 938     *x = *x / pixelfact_x;
 939     *y = *y / pixelfact_y;
 940     *x = mapSizeX2 - *x;
 941     *y += mapSizeY2;
 942     if ((*x < 0)||(*x >= mapSizeX)||(*y < 0)||(*y >= mapSizeY))
 943         return (FALSE);
 944     return (TRUE);
 945 }
 946
 947 static void viewport_init_ra()
 948 {
 949   static gboolean done_before = FALSE;
 950   if ( !done_before )
 951   {
 952     gint i;
 953     for ( i = -90; i <= 90; i++)
 954       Radius[i+90] = calcR ( (double)i ) * DEG2RAD;
 955     done_before = TRUE;
 956   }
 957 }
 958
 959 double calcR (double lat)
 960 {
 961     double a = 6378.137, r, sc, x, y, z;
 962     double e2 = 0.081082 * 0.081082;
 963     /*
 964      * the radius of curvature of an ellipsoidal Earth in the plane of the
 965      * meridian is given by
 966      *
 967      * R' = a * (1 - e^2) / (1 - e^2 * (sin(lat))^2)^(3/2)
 968      *
 969      *
 970      * where a is the equatorial radius, b is the polar radius, and e is
 971      * the eccentricity of the ellipsoid = sqrt(1 - b^2/a^2)
 972      *
 973      * a = 6378 km (3963 mi) Equatorial radius (surface to center distance)
 974      * b = 6356.752 km (3950 mi) Polar radius (surface to center distance) e
 975      * = 0.081082 Eccentricity
 976      */
 977
 978     lat = lat * DEG2RAD;
 979     sc = sin (lat);
 980     x = a * (1.0 - e2);
 981     z = 1.0 - e2 * sc * sc;
 982     y = pow (z, 1.5);
 983     r = x / y;
 984     r = r * 1000.0;
 985     return r;
 986 }
 987
 988 gboolean vik_viewport_is_one_zone ( VikViewport *vvp )
 989 {
 990   return vvp->coord_mode == VIK_COORD_UTM && vvp->one_utm_zone;
 991 }
 992
 993 void vik_viewport_draw_layout ( VikViewport *vvp, GdkGC *gc, gint x, gint y, PangoLayout *layout )
 994 {
 995   if ( x > -100 && x < vvp->width + 100 && y > -100 && y < vvp->height + 100 )
 996     gdk_draw_layout ( vvp->scr_buffer, gc, x, y, layout );
 997 }
 998
 999 void vik_gc_get_fg_color ( GdkGC *gc, GdkColor *dest )
1000 {
1001   static GdkGCValues values;
1002   gdk_gc_get_values ( gc, &values );
1003   gdk_colormap_query_color ( gdk_colormap_get_system(), values.foreground.pixel, dest );
1004 }
1005
1006 GdkFunction vik_gc_get_function ( GdkGC *gc )
1007 {
1008   static GdkGCValues values;
1009   gdk_gc_get_values ( gc, &values );
1010   return values.function;
1011 }
1012
1013 void vik_viewport_set_drawmode ( VikViewport *vvp, VikViewportDrawMode drawmode )
1014 {
1015   vvp->drawmode = drawmode;
1016   if ( drawmode == VIK_VIEWPORT_DRAWMODE_UTM )
1017     viewport_set_coord_mode ( vvp, VIK_COORD_UTM );
1018   else {
1019     viewport_set_coord_mode ( vvp, VIK_COORD_LATLON );
1020     if ( drawmode == VIK_VIEWPORT_DRAWMODE_GOOGLE )
1021       viewport_google_rezoom ( vvp );
1022   }
1023 }
1024
1025 VikViewportDrawMode vik_viewport_get_drawmode ( VikViewport *vvp )
1026 {
1027   return vvp->drawmode;
1028 }
1029
1030 static void viewport_google_rezoom ( VikViewport *vvp )
1031 {
1032   vvp->google_calcx_fact = (GOOGLEMAPS_ZOOM_ONE_MPP * 65536.0 * 0.7716245833877 / vvp->xmpp);
1033   vvp->google_calcy_fact = (GOOGLEMAPS_ZOOM_ONE_MPP * 65536.0 / vvp->ympp);
1034   vvp->google_calcx_rev_fact = 1 / vvp->google_calcx_fact;
1035   vvp->google_calcy_rev_fact = 1 / vvp->google_calcy_fact;
1036 }
1037
1038 /******** triggering *******/
1039 void vik_viewport_set_trigger ( VikViewport *vp, gpointer trigger )
1040 {
1041   vp->trigger = trigger;
1042 }
1043
1044 gpointer vik_viewport_get_trigger ( VikViewport *vp )
1045 {
1046   return vp->trigger;
1047 }
1048
1049 void vik_viewport_snapshot_save ( VikViewport *vp )
1050 {
1051   gdk_draw_drawable ( vp->snapshot_buffer, vp->background_gc, vp->scr_buffer, 0, 0, 0, 0, -1, -1 );
1052 }
1053
1054 void vik_viewport_snapshot_load ( VikViewport *vp )
1055 {
1056   gdk_draw_drawable ( vp->scr_buffer, vp->background_gc, vp->snapshot_buffer, 0, 0, 0, 0, -1, -1 );
1057 }
1058
1059 void vik_viewport_set_half_drawn(VikViewport *vp, gboolean half_drawn)
1060 {
1061   vp->half_drawn = half_drawn;
1062 }
1063
1064 gboolean vik_viewport_get_half_drawn( VikViewport *vp )
1065 {
1066   return vp->half_drawn;
1067 }
1068
1069
1070 const gchar *vik_viewport_get_drawmode_name(VikViewport *vv, VikViewportDrawMode mode)
1071  {
1072   const gchar *name = NULL;
1073   VikWindow *vw = NULL;
1074   GtkWidget *mode_button;
1075   GtkWidget *label;
1076
1077   vw = VIK_WINDOW_FROM_WIDGET(vv);
1078   mode_button = vik_window_get_drawmode_button(vw, mode);
1079   label = gtk_bin_get_child(GTK_BIN(mode_button));
1080
1081   name = gtk_label_get_text ( GTK_LABEL(label) );
1082
1083   return name;
1084
1085 }
1086
1087 void vik_viewport_get_min_max_lat_lon ( VikViewport *vp, gdouble *min_lat, gdouble *max_lat, gdouble *min_lon, gdouble *max_lon )
1088 {
1089   VikCoord tleft, tright, bleft, bright;
1090
1091   vik_viewport_screen_to_coord ( vp, 0, 0, &tleft );
1092   vik_viewport_screen_to_coord ( vp, vik_viewport_get_width(vp), 0, &tright );
1093   vik_viewport_screen_to_coord ( vp, 0, vik_viewport_get_height(vp), &bleft );
1094   vik_viewport_screen_to_coord ( vp, vp->width, vp->height, &bright );
1095
1096   vik_coord_convert(&tleft, VIK_COORD_LATLON);
1097   vik_coord_convert(&tright, VIK_COORD_LATLON);
1098   vik_coord_convert(&bleft, VIK_COORD_LATLON);
1099   vik_coord_convert(&bright, VIK_COORD_LATLON);
1100
1101   *max_lat = MAX(tleft.north_south, tright.north_south);
1102   *min_lat = MIN(bleft.north_south, bright.north_south);
1103   *max_lon = MAX(tright.east_west, bright.east_west);
1104   *min_lon = MIN(tleft.east_west, bleft.east_west);
1105 }