From 6ba14c6d2a6b7eb325cd975393306c4fe6809acd Mon Sep 17 00:00:00 2001
From: Paolo Angelelli <paolo.angelelli@qt.io>
Date: Mon, 18 Sep 2017 11:43:29 +0200
Subject: Fix Map.fromCoordinate returning wrong values during tilting

Task-number: QTBUG-63251
Change-Id: I7ceeeebb30007c5d97d61e057c8ec6e827177b19
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>
---
 src/location/maps/qgeoprojection.cpp  | 20 +++++++++++++++-----
 tests/auto/declarative_ui/tst_map.qml | 22 ++++++++++++++++++++++
 2 files changed, 37 insertions(+), 5 deletions(-)

diff --git a/src/location/maps/qgeoprojection.cpp b/src/location/maps/qgeoprojection.cpp
index 013a8c33..fcf9a350 100644
--- a/src/location/maps/qgeoprojection.cpp
+++ b/src/location/maps/qgeoprojection.cpp
@@ -225,6 +225,9 @@ QDoubleVector2D QGeoProjectionWebMercator::itemPositionToWrappedMapProjection(co
 /* Default implementations */
 QGeoCoordinate QGeoProjectionWebMercator::itemPositionToCoordinate(const QDoubleVector2D &pos, bool clipToViewport) const
 {
+    if (qIsNaN(pos.x()) || qIsNaN(pos.y()))
+        return QGeoCoordinate();
+
     if (clipToViewport) {
         int w = m_viewportWidth;
         int h = m_viewportHeight;
@@ -242,7 +245,14 @@ QGeoCoordinate QGeoProjectionWebMercator::itemPositionToCoordinate(const QDouble
 
 QDoubleVector2D QGeoProjectionWebMercator::coordinateToItemPosition(const QGeoCoordinate &coordinate, bool clipToViewport) const
 {
-    QDoubleVector2D pos = wrappedMapProjectionToItemPosition(wrapMapProjection(geoToMapProjection(coordinate)));
+    if (!coordinate.isValid())
+        return QDoubleVector2D(qQNaN(), qQNaN());
+
+    QDoubleVector2D wrappedProjection = wrapMapProjection(geoToMapProjection(coordinate));
+    if (!isProjectable(wrappedProjection))
+        return QDoubleVector2D(qQNaN(), qQNaN());
+
+    QDoubleVector2D pos = wrappedMapProjectionToItemPosition(wrappedProjection);
 
     if (clipToViewport) {
         int w = m_viewportWidth;
@@ -339,10 +349,10 @@ QDoubleVector2D QGeoProjectionWebMercator::viewportToWrappedMapProjection(const
     pos *= QDoubleVector2D(m_halfWidth, m_halfHeight);
 
     QDoubleVector3D p = m_centerNearPlane;
-    p -= m_up * pos.y();
-    p -= m_side * pos.x();
+    p += m_up * pos.y();
+    p += m_side * pos.x();
 
-    QDoubleVector3D ray = p - m_eye;
+    QDoubleVector3D ray = m_eye - p;
     ray.normalize();
 
     return (xyPlane.lineIntersection(m_eye, ray, s) / m_sideLength).toVector2D();
@@ -461,7 +471,7 @@ void QGeoProjectionWebMercator::setupCamera()
     m_quickItemTransformation = m_transformation;
     m_transformation.scale(m_sideLength, m_sideLength, 1.0);
 
-    m_centerNearPlane = m_eye + m_viewNormalized;
+    m_centerNearPlane = m_eye - m_viewNormalized;
     m_centerNearPlaneMercator = m_eyeMercator - m_viewNormalized * m_nearPlaneMercator;
 
     // The method does not support tilting angles >= 90.0 or < 0.
diff --git a/tests/auto/declarative_ui/tst_map.qml b/tests/auto/declarative_ui/tst_map.qml
index c36ebc0e..8821f55e 100644
--- a/tests/auto/declarative_ui/tst_map.qml
+++ b/tests/auto/declarative_ui/tst_map.qml
@@ -72,6 +72,7 @@ Item {
                                 && coordinateMap.mapReady
                                 && mapTiltBearing.mapReady
                                 && mapTiltBearingHere.mapReady
+                                && mapTestProjection.mapReady
 
     Map { id: mapZoomOnCompleted; width: 200; height: 200;
         zoomLevel: 3; center: coordinate1; plugin: testPlugin;
@@ -113,6 +114,13 @@ Item {
         plugin: testPluginLazyParameter
     }
 
+    Map {
+        id: mapTestProjection
+        plugin: testPlugin
+        width: 200
+        height: 200
+    }
+
     MapParameter {
         id: testParameter
         type: "cameraCenter_test"
@@ -593,6 +601,20 @@ Item {
             coord = coordinateMap.toCoordinate(Qt.point(-5, -6))
             verify(isNaN(coord.latitude))
             verify(isNaN(coord.longitde))
+
+            // test with tilting
+            coord = QtPositioning.coordinate(45.6, 17.67)
+            var pos = mapTestProjection.fromCoordinate(coord, false)
+            compare(Math.floor(pos.x), 3339)
+            compare(Math.floor(pos.y), 1727)
+            mapTestProjection.tilt = 6
+            pos = mapTestProjection.fromCoordinate(coord, false)
+            compare(Math.floor(pos.x), 11066)
+            compare(Math.floor(pos.y), 5577)
+            mapTestProjection.tilt = 12
+            pos = mapTestProjection.fromCoordinate(coord, false)
+            verify(isNaN(pos.latitude))
+            verify(isNaN(pos.longitde))
         }
     }
 }
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