Refactoring QGeoTiledMapScene::mercatorToItemPosition

This patch reimplements the method mercatorToItemPosition using
values relevant for this type of conversion, instead of re-using
values initially computed for the tile generation.

This allows to greatly optimize the method, reducing branches and
the total number of operations, as well as making it easier to
understand.

This patch also removes the support for letterboxing the map
viewport inside the DeclarativeGeoMap, as there now is the
constraint that the map can never be smaller than the containing
element.

Change-Id: Ida98e97ad0a6b65233c80ae3c4abd3ec7664c555
Reviewed-by: Michal Klocek <michal.klocek@qt.io>
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

1 files changed, 71 insertions, 76 deletions

diff --git a/tests/auto/qgeotiledmapscene/tst_qgeotiledmapscene.cpp b/tests/auto/qgeotiledmapscene/tst_qgeotiledmapscene.cpp
index 3d43ebd8..b619b6ce 100644
--- a/tests/auto/qgeotiledmapscene/tst_qgeotiledmapscene.cpp
+++ b/tests/auto/qgeotiledmapscene/tst_qgeotiledmapscene.cpp
@@ -52,7 +52,7 @@ class tst_QGeoTiledMapScene : public QObject
     Q_OBJECT
 
     private:
-    void row(QString name, double screenX, double screenY, double cameraCenterX, double cameraCenterY,
+    void row(QString name, double screenX, double screenX2, double screenY, double cameraCenterX, double cameraCenterY,
              double zoom, int tileSize, int screenWidth, int screenHeight, double mercatorX, double mercatorY){
 
         // expected behaviour of wrapping
@@ -62,7 +62,7 @@ class tst_QGeoTiledMapScene : public QObject
             mercatorX -= 1.0;
 
         QTest::newRow(qPrintable(name))
-                << screenX << screenY
+                << screenX << screenX2 << screenY
                 << cameraCenterX << cameraCenterY
                 << zoom << tileSize
                 << screenWidth << screenHeight
@@ -74,6 +74,7 @@ class tst_QGeoTiledMapScene : public QObject
                          int tileSize, int screenWidth, int screenHeight)
     {
         double screenX;
+        double screenX2;
         double screenY;
         double mercatorX;
         double mercatorY;
@@ -84,76 +85,92 @@ class tst_QGeoTiledMapScene : public QObject
         double scaledHalfLengthX = halfLength * scaleX;
         double scaledHalfLengthY = halfLength * scaleY;
 
-        // top left
-        screenX = 0.0;
+        bool matchingMapEnds = false;
+        if (screenWidth == std::pow(2.0, zoom) * tileSize)
+            matchingMapEnds = true;
+
+        // bottom left
+        screenX = screenX2 = 0.0;
+        if (matchingMapEnds)
+            screenX2 = abs(screenX - 1.0) * screenWidth;
         screenY = 1.0 * screenHeight;
         mercatorX = cameraCenterX - scaledHalfLengthX;
         mercatorY = cameraCenterY + scaledHalfLengthY;
-        row (name + QString("_topLeftScreen"), screenX, screenY, cameraCenterX, cameraCenterY,
+        row (name + QString("_bottomLeftScreen"), screenX, screenX2, screenY, cameraCenterX, cameraCenterY,
                      zoom, tileSize, screenWidth, screenHeight, mercatorX, mercatorY);
 
-        // top
-        screenX = 0.5 * screenWidth;
+        // bottom
+        screenX = screenX2 = 0.5 * screenWidth;
         screenY = 1.0 * screenHeight;
         mercatorX = cameraCenterX;
         mercatorY = cameraCenterY + scaledHalfLengthY;
-        row (name + QString("_topScreen"), screenX, screenY, cameraCenterX, cameraCenterY,
+        row (name + QString("_bottomScreen"), screenX, screenX2, screenY, cameraCenterX, cameraCenterY,
                      zoom, tileSize, screenWidth, screenHeight, mercatorX, mercatorY);
 
-        // top right
-        screenX = 1.0 * screenWidth;
+        // bottom right
+        screenX = screenX2 = 1.0 * screenWidth;
+        if (matchingMapEnds)
+            screenX2 = abs(screenX - 1.0) * screenWidth;
         screenY = 1.0 * screenHeight;
         mercatorX = cameraCenterX + scaledHalfLengthX;
         mercatorY = cameraCenterY + scaledHalfLengthY;
-        row (name + QString("_topRightScreen"), screenX, screenY, cameraCenterX, cameraCenterY,
+        row (name + QString("_bottomRightScreen"), screenX, screenX2, screenY, cameraCenterX, cameraCenterY,
                      zoom, tileSize, screenWidth, screenHeight, mercatorX, mercatorY);
 
         // left
-        screenX = 0.0 * screenWidth;
+        screenX = screenX2 = 0.0 * screenWidth;
+        if (matchingMapEnds)
+            screenX2 = abs(screenX - 1.0) * screenWidth;
         screenY = 0.5 * screenHeight;
         mercatorX = cameraCenterX - scaledHalfLengthX;
         mercatorY = cameraCenterY;
-        row (name + QString("_leftScreen"), screenX, screenY, cameraCenterX, cameraCenterY,
+        row (name + QString("_leftScreen"), screenX, screenX2, screenY, cameraCenterX, cameraCenterY,
                      zoom, tileSize, screenWidth, screenHeight, mercatorX, mercatorY);
 
         // center
-        screenX = 0.5 * screenWidth;
+        screenX = screenX2 = 0.5 * screenWidth;
         screenY = 0.5 * screenHeight;
         mercatorX = cameraCenterX;
         mercatorY = cameraCenterY;
-        row (name + QString("_centerScreen"), screenX, screenY, cameraCenterX, cameraCenterY,
+        row (name + QString("_centerScreen"), screenX, screenX2, screenY, cameraCenterX, cameraCenterY,
                      zoom, tileSize, screenWidth, screenHeight, mercatorX, mercatorY);
 
         // right
-        screenX = 1.0 * screenWidth;
+        screenX = screenX2 = 1.0 * screenWidth;
+        if (matchingMapEnds)
+            screenX2 = abs(screenX - 1.0) * screenWidth;
         screenY = 0.5 * screenHeight;
         mercatorX = cameraCenterX + scaledHalfLengthX;
         mercatorY = cameraCenterY;
-        row (name + QString("_rightScreen"), screenX, screenY, cameraCenterX, cameraCenterY,
+        row (name + QString("_rightScreen"), screenX, screenX2, screenY, cameraCenterX, cameraCenterY,
                      zoom, tileSize, screenWidth, screenHeight, mercatorX, mercatorY);
 
-        // bottom left
-        screenX = 0.0;
+        // top left
+        screenX = screenX2 = 0.0;
+        if (matchingMapEnds)
+            screenX2 = abs(screenX - 1.0) * screenWidth;
         screenY = 0.0;
         mercatorX = cameraCenterX - scaledHalfLengthX;
         mercatorY = cameraCenterY - scaledHalfLengthY;
-        row (name + QString("_bottomLeftrScreen"), screenX, screenY, cameraCenterX, cameraCenterY,
+        row (name + QString("_topLeftrScreen"), screenX, screenX2, screenY, cameraCenterX, cameraCenterY,
                      zoom, tileSize, screenWidth, screenHeight, mercatorX, mercatorY);
 
-        // bottom
-        screenX = 0.5 * screenWidth;
+        // top
+        screenX = screenX2 = 0.5 * screenWidth;
         screenY = 0.0;
         mercatorX = cameraCenterX;
         mercatorY = cameraCenterY - scaledHalfLengthY;
-        row (name + QString("_bottomScreen"), screenX, screenY, cameraCenterX, cameraCenterY,
+        row (name + QString("_topScreen"), screenX, screenX2, screenY, cameraCenterX, cameraCenterY,
                      zoom, tileSize, screenWidth, screenHeight, mercatorX, mercatorY);
 
-        // bottom right
-        screenX = 1.0 * screenWidth;
+        // top right
+        screenX = screenX2 = 1.0 * screenWidth;
+        if (matchingMapEnds)
+            screenX2 = abs(screenX - 1.0) * screenWidth;
         screenY = 0.0;
         mercatorX = cameraCenterX + scaledHalfLengthX;
         mercatorY = cameraCenterY - scaledHalfLengthY;
-        row (name + QString("_bottomRightScreen"), screenX, screenY, cameraCenterX, cameraCenterY,
+        row (name + QString("_topRightScreen"), screenX, screenX2, screenY, cameraCenterX, cameraCenterY,
                      zoom, tileSize, screenWidth, screenHeight, mercatorX, mercatorY);
 
     }
@@ -164,21 +181,21 @@ class tst_QGeoTiledMapScene : public QObject
         double cameraCenterX;
         double cameraCenterY;
 
-        // top left
+        // bottom left
         cameraCenterX = 0;
         cameraCenterY = 1.0;
-        screenPositions(name + QString("_topLeftCamera"), cameraCenterX, cameraCenterY,
+        screenPositions(name + QString("_bottomLeftCamera"), cameraCenterX, cameraCenterY,
                         zoom, tileSize, screenWidth, screenHeight);
 
-        // top
+        // bottom
         cameraCenterX = 0.5;
         cameraCenterY = 1.0;
-        screenPositions(name + QString("_topCamera"), cameraCenterX, cameraCenterY,
+        screenPositions(name + QString("_bottomCamera"), cameraCenterX, cameraCenterY,
                         zoom, tileSize, screenWidth, screenHeight);
-        // top right
+        // bottom right
         cameraCenterX = 1.0;
         cameraCenterY = 1.0;
-        screenPositions(name + QString("_topRightCamera"), cameraCenterX, cameraCenterY,
+        screenPositions(name + QString("_bottomRightCamera"), cameraCenterX, cameraCenterY,
                         zoom, tileSize, screenWidth, screenHeight);
         // left
         cameraCenterX = 0.0;
@@ -195,25 +212,26 @@ class tst_QGeoTiledMapScene : public QObject
         cameraCenterY = 0.5;
         screenPositions(name + QString("_rightCamera"), cameraCenterX, cameraCenterY,
                         zoom, tileSize, screenWidth, screenHeight);
-        // bottom left
+        // top left
         cameraCenterX = 0.0;
         cameraCenterY = 0.0;
-        screenPositions(name + QString("_bottomLeftCamera"), cameraCenterX, cameraCenterY,
+        screenPositions(name + QString("_topLeftCamera"), cameraCenterX, cameraCenterY,
                         zoom, tileSize, screenWidth, screenHeight);
-        // bottom
+        // top
         cameraCenterX = 0.5;
         cameraCenterY = 0.0;
-        screenPositions(name + QString("_bottomCamera"), cameraCenterX, cameraCenterY,
+        screenPositions(name + QString("_topCamera"), cameraCenterX, cameraCenterY,
                         zoom, tileSize, screenWidth, screenHeight);
-        // bottom right
+        // top right
         cameraCenterX = 1.0;
         cameraCenterY = 0.0;
-        screenPositions(name + QString("_bottomRightCamera"), cameraCenterX, cameraCenterY,
+        screenPositions(name + QString("_topRightCamera"), cameraCenterX, cameraCenterY,
                         zoom, tileSize, screenWidth, screenHeight);
     }
 
     void populateScreenMercatorData(){
         QTest::addColumn<double>("screenX");
+        QTest::addColumn<double>("screenX2");
         QTest::addColumn<double>("screenY");
         QTest::addColumn<double>("cameraCenterX");
         QTest::addColumn<double>("cameraCenterY");
@@ -230,7 +248,7 @@ class tst_QGeoTiledMapScene : public QObject
         int screenHeight;
         QString name;
         tileSize = 16;
-        zoom = 4.0;
+        zoom = 1.0; // 4 tiles in the map. map size =  32x32
 
         /*
             ScreenWidth = t
@@ -259,6 +277,7 @@ class tst_QGeoTiledMapScene : public QObject
         name = QString("_(2t x t)");
         screenCameraPositions(name, zoom, tileSize, screenWidth, screenHeight);
 
+
         /*
             Screen Width = t * 2
             Screen Height = t * 2
@@ -270,37 +289,6 @@ class tst_QGeoTiledMapScene : public QObject
     }
 
     private slots:
-
-       void useVerticalLock(){
-            QGeoCameraData camera;
-            camera.setZoomLevel(4.0);
-            camera.setCenter(QGeoProjection::mercatorToCoord(QDoubleVector2D(0.0, 0.0)));
-
-            QGeoCameraTiles ct;
-            ct.setTileSize(16);
-            ct.setCameraData(camera);
-            ct.setScreenSize(QSize(16,16));
-
-            QGeoTiledMapScene mapScene;
-            mapScene.setTileSize(16);
-            mapScene.setScreenSize(QSize(16,16*32));
-            mapScene.setCameraData(camera);
-            QVERIFY(!mapScene.verticalLock());
-            mapScene.setUseVerticalLock(true);
-            mapScene.setVisibleTiles(ct.createTiles());
-            QVERIFY(mapScene.verticalLock());
-
-            // Test the case when setting vertical lock has no effect
-            QGeoTiledMapScene mapScene2;
-            mapScene2.setTileSize(16);
-            mapScene2.setScreenSize(QSize(16,16));
-            mapScene2.setCameraData(camera);
-            QVERIFY(!mapScene2.verticalLock());
-            mapScene2.setUseVerticalLock(true);
-            mapScene2.setVisibleTiles(ct.createTiles());
-            QVERIFY(!mapScene2.verticalLock());
-        }
-
         void screenToMercatorPositions(){
             QFETCH(double, screenX);
             QFETCH(double, screenY);
@@ -315,7 +303,8 @@ class tst_QGeoTiledMapScene : public QObject
 
             QGeoCameraData camera;
             camera.setZoomLevel(zoom);
-            camera.setCenter(QGeoProjection::mercatorToCoord(QDoubleVector2D(cameraCenterX, cameraCenterY)));
+            QGeoCoordinate centerCoordinate = QGeoProjection::mercatorToCoord(QDoubleVector2D(cameraCenterX, cameraCenterY));
+            camera.setCenter(centerCoordinate);
 
             QGeoCameraTiles ct;
             ct.setTileSize(tileSize);
@@ -329,10 +318,10 @@ class tst_QGeoTiledMapScene : public QObject
             mapGeometry.setVisibleTiles(ct.createTiles());
 
             QDoubleVector2D point(screenX,screenY);
-            QDoubleVector2D mecartorPos = mapGeometry.itemPositionToMercator(point);
+            QDoubleVector2D mercartorPos = mapGeometry.itemPositionToMercator(point);
 
-            QCOMPARE(mecartorPos.x(),mercatorX);
-            QCOMPARE(mecartorPos.y(),mercatorY);
+            QCOMPARE(mercartorPos.x(), mercatorX);
+            QCOMPARE(mercartorPos.y(), mercatorY);
         }
 
         void screenToMercatorPositions_data()
@@ -342,6 +331,7 @@ class tst_QGeoTiledMapScene : public QObject
 
         void mercatorToScreenPositions(){
             QFETCH(double, screenX);
+            QFETCH(double, screenX2);
             QFETCH(double, screenY);
             QFETCH(double, cameraCenterX);
             QFETCH(double, cameraCenterY);
@@ -354,7 +344,8 @@ class tst_QGeoTiledMapScene : public QObject
 
             QGeoCameraData camera;
             camera.setZoomLevel(zoom);
-            camera.setCenter(QGeoProjection::mercatorToCoord(QDoubleVector2D(cameraCenterX, cameraCenterY)));
+            QGeoCoordinate coord = QGeoProjection::mercatorToCoord(QDoubleVector2D(cameraCenterX, cameraCenterY));
+            camera.setCenter(coord);
 
             QGeoCameraTiles ct;
             ct.setTileSize(tileSize);
@@ -370,7 +361,11 @@ class tst_QGeoTiledMapScene : public QObject
             QDoubleVector2D mercatorPos(mercatorX, mercatorY);
             QPointF point = mapGeometry.mercatorToItemPosition(mercatorPos).toPointF();
 
-            QCOMPARE(point.x(), screenX);
+            QVERIFY2((point.x() == screenX) || (point.x() == screenX2),
+                                 qPrintable(QString("Accepted: { %1 , %2 } Actual: %3")
+                                            .arg(QString::number(screenX))
+                                            .arg(QString::number(screenX2))
+                                            .arg(QString::number(point.x()))));
             QCOMPARE(point.y(), screenY);
         }