Move the coordinate <-> item position conversion to QGeoProjection

This patch simplifies the QGeoMap API removing all the API
necessary to convert to and from screen.
This is now demanded to a specific QGeoProjection class, that will
be independent of the map, except for using the same Geo projection
(currently only WebMercator, or EPSG:3857, although we use a sphere
instead of an ellipsoid, i believe)

The benefits are
- This relieves subclasses of QGeoMap from implementing a
GeoProjection API, especially since QtLocation currently supports
only WebMercator, and reimplementations would have to anyway
produce the same results as the inbuilt one.

- This avoids the several indirection steps previously necessary
to perform a map projection (qgeotiledmap -> private->mapscene->
private). Since these operation are quite frequent one per
map item coordinate at every redraw, shortening the indirection
chain is beneficial

- It simplifies the highly complex QGeoTiledMapScene, separating
all the logic that is not needed to draw the scene, but only
to perform geo coordinate <-> screen coordinate conversion

Change-Id: I9e3ca5280166f2d6430a32deb44c030d02d9d4e1
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

1 files changed, 0 insertions, 3 deletions

diff --git a/src/location/maps/qgeotiledmap_p_p.h b/src/location/maps/qgeotiledmap_p_p.h
index 72873d77..7106adf3 100644
--- a/src/location/maps/qgeotiledmap_p_p.h
+++ b/src/location/maps/qgeotiledmap_p_p.h
@@ -76,9 +76,6 @@ public:
 
     QSGNode *updateSceneGraph(QSGNode *node, QQuickWindow *window);
 
-    QGeoCoordinate itemPositionToCoordinate(const QDoubleVector2D &pos) const;
-    QDoubleVector2D coordinateToItemPosition(const QGeoCoordinate &coordinate) const;
-
     void updateTile(const QGeoTileSpec &spec);
     void prefetchTiles();
     QGeoMapType activeMapType();