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Show the path marker on the great circle segment line

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This commit is contained in:
Martin Tůma 2018-09-15 10:41:00 +02:00
parent b867ce9a7f
commit eda5046518
1 changed files with 24 additions and 3 deletions
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27
src/GUI/pathitem.cpp
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@ -11,6 +11,11 @@
#define GEOGRAPHICAL_MILE 1855.3248
static unsigned segments(qreal distance)
{
return ceil(distance / GEOGRAPHICAL_MILE);
}
PathItem::PathItem(const Path &path, Map *map, QGraphicsItem *parent)
: QGraphicsObject(parent)
{
@ -50,7 +55,7 @@ void PathItem::updatePainterPath(Map *map)
for (int i = 1; i < _path.size(); i++) {
const PathPoint &p1 = _path.at(i-1);
const PathPoint &p2 = _path.at(i);
unsigned n = ceil((p2.distance() - p1.distance()) / GEOGRAPHICAL_MILE);
unsigned n = segments(p2.distance() - p1.distance());
if (n > 1) {
Coordinates c1(p1.coordinates());
@ -176,9 +181,25 @@ QPointF PathItem::position(qreal x) const
p1 = _path.at(mid-1).distance(); p2 = _path.at(mid).distance();
}
if ((unsigned)qAbs(c1.lon() - c2.lon())) {
unsigned n = segments(p2 - p1);
if (n > 1) {
GreatCircle gc(c1, c2);
return _map->ll2xy(gc.pointAt((x - p1) / (p2 - p1)));
// Great circle point
double f = (x - p1) / (p2 - p1);
QPointF p(_map->ll2xy(gc.pointAt(f)));
// Segment line of the great circle path
double f1 = floor(n * f) / n;
double f2 = ceil(n * f) / n;
QLineF l(_map->ll2xy(gc.pointAt(f1)), _map->ll2xy(gc.pointAt(f2)));
// Project the great circle point to the segment line
QLineF u = l.unitVector();
double lambda = (u.dx() * (p.x() - l.p1().x())) + (u.dy() * (p.y()
- l.p1().y()));
return QPointF((u.dx() * lambda) + l.p1().x(), (u.dy() * lambda)
+ l.p1().y());
} else {
QLineF l(_map->ll2xy(c1), _map->ll2xy(c2));
return l.pointAt((x - p1) / (p2 - p1));