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)) );
}
}
}
static void
_mapcoord_to_center_coord ( VikMapSource *self, MapCoord *src, VikCoord *dest )
{
gdouble socalled_mpp;
if (src->scale >= 0)
socalled_mpp = VIK_GZ(src->scale);
else
socalled_mpp = 1.0/VIK_GZ(-src->scale);
dest->mode = VIK_COORD_LATLON;
dest->east_west = ((src->x+0.5) / VIK_GZ(17) * socalled_mpp * 360) - 180;
dest->north_south = DEMERCLAT(180 - ((src->y+0.5) / VIK_GZ(17) * socalled_mpp * 360));
}
