/* for ALTI_TO_MPP */
#include "globals.h"
+#define MERCATOR_FACTOR(x) ( (65536.0 / 180 / (x)) * 256.0 )
+
static gdouble EASTING_OFFSET = 500000.0;
static gint PAD = 10;
-static void viewport_class_init ( VikViewportClass *klass );
-static void viewport_init ( VikViewport *vvp );
static void viewport_finalize ( GObject *gob );
static void viewport_utm_zone_check ( VikViewport *vvp );
GtkDrawingArea drawing_area;
GdkPixmap *scr_buffer;
gint width, height;
+ gint width_2, height_2; // Half of the normal width and height
VikCoord center;
VikCoordMode coord_mode;
gdouble xmpp, ympp;
+ gdouble xmfactor, ymfactor;
GdkPixbuf *alpha_pixbuf;
guint8 alpha_pixbuf_width;
/* subset of coord types. lat lon can be plotted in 2 ways, google or exp. */
VikViewportDrawMode drawmode;
- /* handy conversion factors which make google plotting extremely fast */
- gdouble google_calcx_fact;
- gdouble google_calcy_fact;
- gdouble google_calcx_rev_fact;
- gdouble google_calcy_rev_fact;
-
/* trigger stuff */
gpointer trigger;
GdkPixmap *snapshot_buffer;
return 0.0;
}
+G_DEFINE_TYPE (VikViewport, vik_viewport, GTK_TYPE_DRAWING_AREA)
-GType vik_viewport_get_type (void)
-{
- static GType vvp_type = 0;
-
- if (!vvp_type)
- {
- static const GTypeInfo vvp_info =
- {
- sizeof (VikViewportClass),
- NULL, /* base_init */
- NULL, /* base_finalize */
- (GClassInitFunc) viewport_class_init,
- NULL, /* class_finalize */
- NULL, /* class_data */
- sizeof (VikViewport),
- 0,
- (GInstanceInitFunc) viewport_init,
- };
- vvp_type = g_type_register_static ( GTK_TYPE_DRAWING_AREA, "VikViewport", &vvp_info, 0 );
- }
- return vvp_type;
-}
-
-static void viewport_class_init ( VikViewportClass *klass )
+static void
+vik_viewport_class_init ( VikViewportClass *klass )
{
/* Destructor */
GObjectClass *object_class;
return vv;
}
-static void viewport_init ( VikViewport *vvp )
+static void
+vik_viewport_init ( VikViewport *vvp )
{
viewport_init_ra();
/* TODO: not static */
vvp->xmpp = 4.0;
vvp->ympp = 4.0;
+ vvp->xmfactor = MERCATOR_FACTOR (vvp->xmpp);
+ vvp->ymfactor = MERCATOR_FACTOR (vvp->ympp);
vvp->coord_mode = VIK_COORD_LATLON;
vvp->drawmode = VIK_VIEWPORT_DRAWMODE_MERCATOR;
vvp->center.mode = VIK_COORD_LATLON;
g_signal_connect (G_OBJECT(vvp), "configure_event", G_CALLBACK(vik_viewport_configure), NULL);
+#if GTK_CHECK_VERSION (2,18,0)
+ gtk_widget_set_can_focus ( GTK_WIDGET(vvp), TRUE );
+#else
GTK_WIDGET_SET_FLAGS(vvp, GTK_CAN_FOCUS); /* allow VVP to have focus -- enabling key events, etc */
+#endif
}
GdkColor *vik_viewport_get_background_gdkcolor ( VikViewport *vvp )
GdkGC *rv = NULL;
GdkColor color;
- rv = gdk_gc_new ( GTK_WIDGET(vvp)->window );
+ rv = gdk_gc_new ( gtk_widget_get_window(GTK_WIDGET(vvp)) );
if ( gdk_color_parse ( colorname, &color ) )
gdk_gc_set_rgb_fg_color ( rv, &color );
else
{
GdkGC *rv;
- rv = gdk_gc_new ( GTK_WIDGET(vvp)->window );
+ rv = gdk_gc_new ( gtk_widget_get_window(GTK_WIDGET(vvp)) );
gdk_gc_set_rgb_fg_color ( rv, color );
gdk_gc_set_line_attributes ( rv, thickness, GDK_LINE_SOLID, GDK_CAP_ROUND, GDK_JOIN_ROUND );
return rv;
{
vvp->width = width;
vvp->height = height;
+
+ vvp->width_2 = vvp->width/2;
+ vvp->height_2 = vvp->height/2;
+
if ( vvp->scr_buffer )
g_object_unref ( G_OBJECT ( vvp->scr_buffer ) );
- vvp->scr_buffer = gdk_pixmap_new ( GTK_WIDGET(vvp)->window, vvp->width, vvp->height, -1 );
+ vvp->scr_buffer = gdk_pixmap_new ( gtk_widget_get_window(GTK_WIDGET(vvp)), vvp->width, vvp->height, -1 );
/* TODO trigger: only if this is enabled !!! */
if ( vvp->snapshot_buffer )
g_object_unref ( G_OBJECT ( vvp->snapshot_buffer ) );
- vvp->snapshot_buffer = gdk_pixmap_new ( GTK_WIDGET(vvp)->window, vvp->width, vvp->height, -1 );
+ vvp->snapshot_buffer = gdk_pixmap_new ( gtk_widget_get_window(GTK_WIDGET(vvp)), vvp->width, vvp->height, -1 );
}
vvp->width = GTK_WIDGET(vvp)->allocation.width;
vvp->height = GTK_WIDGET(vvp)->allocation.height;
+ vvp->width_2 = vvp->width/2;
+ vvp->height_2 = vvp->height/2;
+
if ( vvp->scr_buffer )
g_object_unref ( G_OBJECT ( vvp->scr_buffer ) );
- vvp->scr_buffer = gdk_pixmap_new ( GTK_WIDGET(vvp)->window, vvp->width, vvp->height, -1 );
+ vvp->scr_buffer = gdk_pixmap_new ( gtk_widget_get_window(GTK_WIDGET(vvp)), vvp->width, vvp->height, -1 );
/* TODO trigger: only if enabled! */
if ( vvp->snapshot_buffer )
g_object_unref ( G_OBJECT ( vvp->snapshot_buffer ) );
- vvp->snapshot_buffer = gdk_pixmap_new ( GTK_WIDGET(vvp)->window, vvp->width, vvp->height, -1 );
+ vvp->snapshot_buffer = gdk_pixmap_new ( gtk_widget_get_window(GTK_WIDGET(vvp)), vvp->width, vvp->height, -1 );
/* TODO trigger */
/* this is down here so it can get a GC (necessary?) */
VikCoord left, right;
gdouble unit, base, diff, old_unit, old_diff, ratio;
gint odd, len, SCSIZE = 5, HEIGHT=10;
- PangoFontDescription *pfd;
PangoLayout *pl;
gchar s[128];
vik_viewport_draw_line(vvp, vvp->scale_bg_gc,
PAD + len, vvp->height-PAD, PAD + len, vvp->height-PAD-HEIGHT);
/* black scale */
- vik_viewport_draw_line(vvp, GTK_WIDGET(&vvp->drawing_area)->style->black_gc,
+ vik_viewport_draw_line(vvp, gtk_widget_get_style(GTK_WIDGET(&vvp->drawing_area))->black_gc,
PAD, vvp->height-PAD, PAD + len, vvp->height-PAD);
- vik_viewport_draw_line(vvp, GTK_WIDGET(&vvp->drawing_area)->style->black_gc,
+ vik_viewport_draw_line(vvp, gtk_widget_get_style(GTK_WIDGET(&vvp->drawing_area))->black_gc,
PAD, vvp->height-PAD, PAD, vvp->height-PAD-HEIGHT);
- vik_viewport_draw_line(vvp, GTK_WIDGET(&vvp->drawing_area)->style->black_gc,
+ vik_viewport_draw_line(vvp, gtk_widget_get_style(GTK_WIDGET(&vvp->drawing_area))->black_gc,
PAD + len, vvp->height-PAD, PAD + len, vvp->height-PAD-HEIGHT);
if (odd%2) {
int i;
for (i=1; i<5; i++) {
vik_viewport_draw_line(vvp, vvp->scale_bg_gc,
PAD+i*len/5, vvp->height-PAD, PAD+i*len/5, vvp->height-PAD-((i==5)?(2*HEIGHT/3):(HEIGHT/2)));
- vik_viewport_draw_line(vvp, GTK_WIDGET(&vvp->drawing_area)->style->black_gc,
+ vik_viewport_draw_line(vvp, gtk_widget_get_style(GTK_WIDGET(&vvp->drawing_area))->black_gc,
PAD+i*len/5, vvp->height-PAD, PAD+i*len/5, vvp->height-PAD-((i==5)?(2*HEIGHT/3):(HEIGHT/2)));
}
} else {
for (i=1; i<10; i++) {
vik_viewport_draw_line(vvp, vvp->scale_bg_gc,
PAD+i*len/10, vvp->height-PAD, PAD+i*len/10, vvp->height-PAD-((i==5)?(2*HEIGHT/3):(HEIGHT/2)));
- vik_viewport_draw_line(vvp, GTK_WIDGET(&vvp->drawing_area)->style->black_gc,
+ vik_viewport_draw_line(vvp, gtk_widget_get_style(GTK_WIDGET(&vvp->drawing_area))->black_gc,
PAD+i*len/10, vvp->height-PAD, PAD+i*len/10, vvp->height-PAD-((i==5)?(2*HEIGHT/3):(HEIGHT/2)));
}
}
pl = gtk_widget_create_pango_layout (GTK_WIDGET(&vvp->drawing_area), NULL);
- pfd = pango_font_description_from_string ("Sans 8"); // FIXME: settable option? global variable?
- pango_layout_set_font_description (pl, pfd);
- pango_font_description_free (pfd);
+ pango_layout_set_font_description (pl, gtk_widget_get_style(GTK_WIDGET(&vvp->drawing_area))->font_desc);
switch (dist_units) {
case VIK_UNITS_DISTANCE_KILOMETRES:
g_critical("Houston, we've had a problem. distance=%d", dist_units);
}
pango_layout_set_text(pl, s, -1);
- vik_viewport_draw_layout(vvp, GTK_WIDGET(&vvp->drawing_area)->style->black_gc,
+ vik_viewport_draw_layout(vvp, gtk_widget_get_style(GTK_WIDGET(&vvp->drawing_area))->black_gc,
PAD + len + PAD, vvp->height - PAD - 10, pl);
g_object_unref(pl);
pl = NULL;
{
g_return_if_fail ( vvp != NULL );
- PangoFontDescription *pfd;
PangoLayout *pl;
PangoRectangle ink_rect, logical_rect;
gchar s[128] = "";
/* create pango layout */
pl = gtk_widget_create_pango_layout (GTK_WIDGET(&vvp->drawing_area), NULL);
- pfd = pango_font_description_from_string ("Sans 8"); // FIXME: settable option? global variable?
- pango_layout_set_font_description (pl, pfd);
- pango_font_description_free (pfd);
- pfd = NULL;
+ pango_layout_set_font_description (pl, gtk_widget_get_style(GTK_WIDGET(&vvp->drawing_area))->font_desc);
pango_layout_set_alignment ( pl, PANGO_ALIGN_RIGHT );
/* Set the text */
pango_layout_set_text(pl, s, -1);
/* Use maximum of half the viewport width */
- pango_layout_set_width ( pl, ( vvp->width / 2 - PAD ) * PANGO_SCALE );
+ pango_layout_set_width ( pl, ( vvp->width / 2 ) * PANGO_SCALE );
pango_layout_get_pixel_extents(pl, &ink_rect, &logical_rect);
- vik_viewport_draw_layout(vvp, GTK_WIDGET(&vvp->drawing_area)->style->black_gc,
- vvp->width / 2, vvp->height - PAD - logical_rect.height, pl);
+ vik_viewport_draw_layout(vvp, gtk_widget_get_style(GTK_WIDGET(&vvp->drawing_area))->black_gc,
+ vvp->width / 2, vvp->height - logical_rect.height, pl);
/* Free memory */
g_object_unref(pl);
const int gap = 4;
int center_x = vvp->width/2;
int center_y = vvp->height/2;
- GdkGC * black_gc = GTK_WIDGET(&vvp->drawing_area)->style->black_gc;
+ GdkGC * black_gc = gtk_widget_get_style(GTK_WIDGET(&vvp->drawing_area))->black_gc;
/* white back ground */
vik_viewport_draw_line(vvp, vvp->scale_bg_gc, center_x - len, center_y, center_x - gap, center_y);
void vik_viewport_sync ( VikViewport *vvp )
{
g_return_if_fail ( vvp != NULL );
- 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);
+ gdk_draw_drawable(gtk_widget_get_window(GTK_WIDGET(vvp)), gtk_widget_get_style(GTK_WIDGET(vvp))->bg_gc[0], GDK_DRAWABLE(vvp->scr_buffer), 0, 0, 0, 0, vvp->width, vvp->height);
}
void vik_viewport_pan_sync ( VikViewport *vvp, gint x_off, gint y_off )
gint x, y, wid, hei;
g_return_if_fail ( vvp != NULL );
- 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);
+ gdk_draw_drawable(gtk_widget_get_window(GTK_WIDGET(vvp)), gtk_widget_get_style(GTK_WIDGET(vvp))->bg_gc[0], GDK_DRAWABLE(vvp->scr_buffer), 0, 0, x_off, y_off, vvp->width, vvp->height);
if (x_off >= 0) {
x = 0;
void vik_viewport_set_zoom ( VikViewport *vvp, gdouble xympp )
{
g_return_if_fail ( vvp != NULL );
- if ( xympp >= VIK_VIEWPORT_MIN_ZOOM && xympp <= VIK_VIEWPORT_MAX_ZOOM )
+ if ( xympp >= VIK_VIEWPORT_MIN_ZOOM && xympp <= VIK_VIEWPORT_MAX_ZOOM ) {
vvp->xmpp = vvp->ympp = xympp;
+ // Since xmpp & ympp are the same it doesn't matter which one is used here
+ vvp->xmfactor = vvp->ymfactor = MERCATOR_FACTOR(vvp->xmpp);
+ }
if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_UTM )
viewport_utm_zone_check(vvp);
vvp->xmpp /= 2;
vvp->ympp /= 2;
+ vvp->xmfactor = MERCATOR_FACTOR(vvp->xmpp);
+ vvp->ymfactor = MERCATOR_FACTOR(vvp->ympp);
+
viewport_utm_zone_check(vvp);
}
}
vvp->xmpp *= 2;
vvp->ympp *= 2;
+ vvp->xmfactor = MERCATOR_FACTOR(vvp->xmpp);
+ vvp->ymfactor = MERCATOR_FACTOR(vvp->ympp);
+
viewport_utm_zone_check(vvp);
}
}
{
if ( xmpp >= VIK_VIEWPORT_MIN_ZOOM && xmpp <= VIK_VIEWPORT_MAX_ZOOM ) {
vvp->xmpp = xmpp;
+ vvp->ymfactor = MERCATOR_FACTOR(vvp->ympp);
if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_UTM )
viewport_utm_zone_check(vvp);
}
{
if ( ympp >= VIK_VIEWPORT_MIN_ZOOM && ympp <= VIK_VIEWPORT_MAX_ZOOM ) {
vvp->ympp = ympp;
+ vvp->ymfactor = MERCATOR_FACTOR(vvp->ympp);
if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_UTM )
viewport_utm_zone_check(vvp);
}
utm->zone = vvp->center.utm_zone;
utm->letter = vvp->center.utm_letter;
- utm->easting = ( ( x - ( vvp->width / 2) ) * vvp->xmpp ) + vvp->center.east_west;
+ utm->easting = ( ( x - ( vvp->width_2) ) * vvp->xmpp ) + vvp->center.east_west;
zone_delta = floor( (utm->easting - EASTING_OFFSET ) / vvp->utm_zone_width + 0.5 );
utm->zone += zone_delta;
utm->easting -= zone_delta * vvp->utm_zone_width;
- utm->northing = ( ( ( vvp->height / 2) - y ) * vvp->ympp ) + vvp->center.north_south;
+ utm->northing = ( ( ( vvp->height_2) - y ) * vvp->ympp ) + vvp->center.north_south;
} else if ( vvp->coord_mode == VIK_COORD_LATLON ) {
coord->mode = VIK_COORD_LATLON;
if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_LATLON ) {
- coord->east_west = vvp->center.east_west + (180.0 * vvp->xmpp / 65536 / 256 * (x - vvp->width/2));
- coord->north_south = vvp->center.north_south + (180.0 * vvp->ympp / 65536 / 256 * (vvp->height/2 - y));
+ coord->east_west = vvp->center.east_west + (180.0 * vvp->xmpp / 65536 / 256 * (x - vvp->width_2));
+ coord->north_south = vvp->center.north_south + (180.0 * vvp->ympp / 65536 / 256 * (vvp->height_2 - y));
} else if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_EXPEDIA )
- 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);
+ 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);
else if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_MERCATOR ) {
- /* FIXMERCATOR */
- coord->east_west = vvp->center.east_west + (180.0 * vvp->xmpp / 65536 / 256 * (x - vvp->width/2));
- coord->north_south = DEMERCLAT ( MERCLAT(vvp->center.north_south) + (180.0 * vvp->ympp / 65536 / 256 * (vvp->height/2 - y)) );
-
-#if 0
---> THIS IS JUNK HERE.
- *y = vvp->height/2 + (65536.0 / 180 / vvp->ympp * (MERCLAT(center->lat) - MERCLAT(ll->lat)))*256.0;
-
- (*y - vvp->height/2) / 256 / 65536 * 180 * vvp->ympp = (MERCLAT(center->lat) - MERCLAT(ll->lat);
- DML((180.0 * vvp->ympp / 65536 / 256 * (vvp->height/2 - y)) + ML(cl)) = ll
-#endif
+ /* This isn't called with a high frequently so less need to optimize */
+ coord->east_west = vvp->center.east_west + (180.0 * vvp->xmpp / 65536 / 256 * (x - vvp->width_2));
+ coord->north_south = DEMERCLAT ( MERCLAT(vvp->center.north_south) + (180.0 * vvp->ympp / 65536 / 256 * (vvp->height_2 - y)) );
}
}
}
+/*
+ * Since this function is used for every drawn trackpoint - it can get called alot
+ * Thus x & y position factors are calculated once on zoom changes,
+ * avoiding the need to do it here all the time.
+ * For good measure the half width and height values are also pre calculated too.
+ */
void vik_viewport_coord_to_screen ( VikViewport *vvp, const VikCoord *coord, int *x, int *y )
{
static VikCoord tmp;
return;
}
- *x = ( (utm->easting - center->easting) / vvp->xmpp ) + (vvp->width / 2) -
+ *x = ( (utm->easting - center->easting) / vvp->xmpp ) + (vvp->width_2) -
(center->zone - utm->zone ) * vvp->utm_zone_width / vvp->xmpp;
- *y = (vvp->height / 2) - ( (utm->northing - center->northing) / vvp->ympp );
+ *y = (vvp->height_2) - ( (utm->northing - center->northing) / vvp->ympp );
} else if ( vvp->coord_mode == VIK_COORD_LATLON ) {
struct LatLon *center = (struct LatLon *) &(vvp->center);
struct LatLon *ll = (struct LatLon *) coord;
double xx,yy;
if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_LATLON ) {
- /* FIXMERCATOR: Optimize */
- *x = vvp->width/2 + (65536.0 / 180 / vvp->xmpp * (ll->lon - center->lon))*256.0;
- *y = vvp->height/2 + (65536.0 / 180 / vvp->ympp * (center->lat - ll->lat))*256.0;
+ *x = vvp->width_2 + ( MERCATOR_FACTOR(vvp->xmpp) * (ll->lon - center->lon) );
+ *y = vvp->height_2 + ( MERCATOR_FACTOR(vvp->ympp) * (center->lat - ll->lat) );
} else if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_EXPEDIA ) {
- 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 );
+ 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 );
*x = xx; *y = yy;
} else if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_MERCATOR ) {
- /* FIXMERCATOR: Optimize */
- *x = vvp->width/2 + (65536.0 / 180 / vvp->xmpp * (ll->lon - center->lon))*256.0;
- *y = vvp->height/2 + (65536.0 / 180 / vvp->ympp * (MERCLAT(center->lat) - MERCLAT(ll->lat)))*256.0;
+ *x = vvp->width_2 + ( MERCATOR_FACTOR(vvp->xmpp) * (ll->lon - center->lon) );
+ *y = vvp->height_2 + ( MERCATOR_FACTOR(vvp->ympp) * ( MERCLAT(center->lat) - MERCLAT(ll->lat) ) );
}
}
}
gint dest_x, gint dest_y, gint w, gint h )
{
gdk_draw_pixbuf ( vvp->scr_buffer,
-// GTK_WIDGET(vvp)->style->black_gc,
-NULL,
- pixbuf,
+ NULL,
+ pixbuf,
src_x, src_y, dest_x, dest_y, w, h,
GDK_RGB_DITHER_NONE, 0, 0 );
}
lon =
zero_long -
px / (Ra *
- cos (lat * DEG2RAD));
+ cos (DEG2RAD(lat)));
- dif = lat * (1 - (cos ((fabs (lon - zero_long)) * DEG2RAD)));
+ dif = lat * (1 - (cos (DEG2RAD(fabs (lon - zero_long)))));
lat = lat - dif / 1.5;
lon =
zero_long -
px / (Ra *
- cos (lat * DEG2RAD));
+ cos (DEG2RAD(lat)));
*lt = lat;
*lg = lon;
// lt *= rad2deg;
Ra = Radius[90+(gint)lt];
*x = Ra *
- cos (lt*DEG2RAD) * (lg - zero_long);
+ cos (DEG2RAD(lt)) * (lg - zero_long);
*y = Ra * (lt - zero_lat);
- dif = Ra * RAD2DEG * (1 - (cos ((DEG2RAD * (lg - zero_long)))));
+ dif = Ra * RAD2DEG(1 - (cos ((DEG2RAD(lg - zero_long)))));
*y = *y + dif / 1.85;
*x = *x / pixelfact_x;
*y = *y / pixelfact_y;
{
gint i;
for ( i = -90; i <= 90; i++)
- Radius[i+90] = calcR ( (double)i ) * DEG2RAD;
+ Radius[i+90] = calcR ( DEG2RAD((double)i) );
done_before = TRUE;
}
}
* = 0.081082 Eccentricity
*/
- lat = lat * DEG2RAD;
+ lat = DEG2RAD(lat);
sc = sin (lat);
x = a * (1.0 - e2);
z = 1.0 - e2 * sc * sc;
}
}
}
+
+/**
+ * vik_viewport_compute_bearing:
+ * @vp: self object
+ * @x1: screen coord
+ * @y1: screen coord
+ * @x2: screen coord
+ * @y2: screen coord
+ * @angle: bearing in Radian (output)
+ * @baseangle: UTM base angle in Radian (output)
+ *
+ * Compute bearing.
+ */
+void vik_viewport_compute_bearing ( VikViewport *vp, gint x1, gint y1, gint x2, gint y2, gdouble *angle, gdouble *baseangle )
+{
+ gdouble len = sqrt((x1-x2)*(x1-x2) + (y1-y2)*(y1-y2));
+ gdouble dx = (x2-x1)/len*10;
+ gdouble dy = (y2-y1)/len*10;
+
+ *angle = atan2(dy, dx) + M_PI_2;
+
+ if ( vik_viewport_get_drawmode ( vp ) == VIK_VIEWPORT_DRAWMODE_UTM) {
+ VikCoord test;
+ struct LatLon ll;
+ struct UTM u;
+ gint tx, ty;
+
+ vik_viewport_screen_to_coord ( vp, x1, y1, &test );
+ vik_coord_to_latlon ( &test, &ll );
+ ll.lat += vik_viewport_get_ympp ( vp ) * vik_viewport_get_height ( vp ) / 11000.0; // about 11km per degree latitude
+ a_coords_latlon_to_utm ( &ll, &u );
+ vik_coord_load_from_utm ( &test, VIK_VIEWPORT_DRAWMODE_UTM, &u );
+ vik_viewport_coord_to_screen ( vp, &test, &tx, &ty );
+
+ *baseangle = M_PI - atan2(tx-x1, ty-y1);
+ *angle -= *baseangle;
+ }
+
+ if (*angle < 0)
+ *angle += 2*M_PI;
+ if (*angle > 2*M_PI)
+ *angle -= 2*M_PI;
+}
projects / andy / viking.git / blobdiff