Correct and improve the rendering of QuickMapItems

Various MapItems were not rendered correctly, especially in corner cases.
This change ensures that MapItems are rendered correctly in the vast
majority of cases.

All MapItems are shown correctly if they wrap around the globe and
appear twice on the map.

Circles that span around the globe or are located near poles are shown
correclty and filled all the way to the border of the map.

Polygons are shown correctly including their holes.

The code was simplified and some artefacts of previous implementations
were removed.

Fixes: QTBUG-110701
Fixes: QTBUG-110511
Pick-to: 6.5
Change-Id: I1110659989436cd5a93f6ec26f75caa06d5f2b71
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

1 files changed, 41 insertions, 0 deletions

diff --git a/src/location/quickmapitems/qdeclarativegeomapitemutils.cpp b/src/location/quickmapitems/qdeclarativegeomapitemutils.cpp
index 6a79b33b..a1501dd6 100644
--- a/src/location/quickmapitems/qdeclarativegeomapitemutils.cpp
+++ b/src/location/quickmapitems/qdeclarativegeomapitemutils.cpp
@@ -16,6 +16,31 @@ QT_BEGIN_NAMESPACE
 
 namespace QDeclarativeGeoMapItemUtils {
 
+double distanceSqrPointLine(double p0_x
+                          , double p0_y
+                          , double p1_x
+                          , double p1_y
+                          , double p2_x
+                          , double p2_y)
+{
+    const double t_x = p2_x - p1_x;
+    const double t_y = p2_y - p1_y;
+    const double p_x = p0_x - p1_x;
+    const double p_y = p0_y - p1_y;
+    const double tsqr = t_x * t_x + t_y * t_y;
+
+    if (tsqr == 0)
+        return qInf();
+
+    double alpha = (p_x * t_x + p_y * t_y) / tsqr;
+    alpha = qBound<double>(0, alpha, 1);
+
+    const double dx = p_x - t_x * alpha;
+    const double dy = p_y - t_y * alpha;
+
+    return dx * dx + dy * dy;
+}
+
 void wrapPath(const QList<QGeoCoordinate> &perimeter,
               const QGeoCoordinate &geoLeftBound,
               const QGeoProjectionWebMercator &p,
@@ -150,6 +175,22 @@ void projectBbox(const QList<QDoubleVector2D> &clippedBbox,
     projectedBbox.closeSubpath();
 }
 
+
+QRectF boundingRectangleFromList(const QList<QDoubleVector2D> &list)
+{
+    double xMin = qInf();
+    double xMax = -qInf();
+    double yMin = qInf();
+    double yMax = -qInf();
+    for (const auto &coord : list) {
+        xMin = qMin(xMin, coord.x());
+        xMax = qMax(xMax, coord.x());
+        yMin = qMin(yMin, coord.y());
+        yMax = qMax(yMax, coord.y());
+    }
+    return QRectF(xMin, yMin, xMax - xMin, yMax - yMin);
+}
+
 } // namespace QDeclarativeGeoMapItemUtils
 
 QT_END_NAMESPACE