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