void vik_viewport_screen_to_coord ( VikViewport *vvp, int x, int y, VikCoord *coord )
{
g_return_if_fail ( vvp != NULL );
if ( vvp->coord_mode == VIK_COORD_UTM ) {
int zone_delta;
struct UTM *utm = (struct UTM *) coord;
coord->mode = VIK_COORD_UTM;
utm->zone = vvp->center.utm_zone;
utm->letter = vvp->center.utm_letter;
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;
} 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));
} 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);
else if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_MERCATOR ) {
/* 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;
g_return_if_fail ( vvp != NULL );
if ( coord->mode != vvp->coord_mode )
{
g_warning ( "Have to convert in vik_viewport_coord_to_screen! This should never happen!");
vik_coord_copy_convert ( coord, vvp->coord_mode, &tmp );
coord = &tmp;
}
if ( vvp->coord_mode == VIK_COORD_UTM ) {
struct UTM *center = (struct UTM *) &(vvp->center);
struct UTM *utm = (struct UTM *) coord;
if ( center->zone != utm->zone && vvp->one_utm_zone )
{
*x = *y = VIK_VIEWPORT_UTM_WRONG_ZONE;
return;
}
*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 );
} 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 ) {
*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 );
*x = xx; *y = yy;
} else if ( vvp->drawmode == VIK_VIEWPORT_DRAWMODE_MERCATOR ) {
*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) ) );
}
}
}
static gboolean
_coord_to_mapcoord ( VikMapSource *self, const VikCoord *src, gdouble xzoom, gdouble yzoom, MapCoord *dest )
{
g_assert ( src->mode == VIK_COORD_LATLON );
if ( xzoom != yzoom )
return FALSE;
dest->scale = map_utils_mpp_to_scale ( xzoom );
if ( dest->scale == 255 )
return FALSE;
dest->x = (src->east_west + 180) / 360 * VIK_GZ(17) / xzoom;
dest->y = (180 - MERCLAT(src->north_south)) / 360 * VIK_GZ(17) / xzoom;
dest->z = 0;
return TRUE;
}