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