winrt: Use physical window resolution

This partially reverts eea02ff1 in that devicePixelRatio() will now
always return 1. This is because non-integer ratios are bound to cause
problems with pixel alignments, and their use prevents users from
accessing the complete pixel grid in Qt Quick. Now, the full physical
resolution of the screen/window is reported instead.

The EGL initialization is adjusted to match requirements for ANGLE 2.1.

Change-Id: I24c6dcf4419f30e5e4c73c592beb446a418a0b8b
Reviewed-by: Jochen Seemann <seemann.jochen@gmail.com>
Reviewed-by: Andrew Knight <andrew.knight@digia.com>

2 files changed, 36 insertions, 42 deletions

diff --git a/src/plugins/platforms/winrt/qwinrtscreen.cpp b/src/plugins/platforms/winrt/qwinrtscreen.cpp
index cbc7449591..1a263719b5 100644
--- a/src/plugins/platforms/winrt/qwinrtscreen.cpp
+++ b/src/plugins/platforms/winrt/qwinrtscreen.cpp
@@ -445,10 +445,10 @@ public:
     ComPtr<QWinRTInputContext> inputContext;
 #endif
 
-    QRectF geometry;
+    QSizeF logicalSize;
     QSurfaceFormat surfaceFormat;
-    qreal dpi;
-    qreal devicePixelRatio;
+    qreal logicalDpi;
+    qreal scaleFactor;
     Qt::ScreenOrientation nativeOrientation;
     Qt::ScreenOrientation orientation;
     QList<QWindow *> visibleWindows;
@@ -501,8 +501,9 @@ QWinRTScreen::QWinRTScreen()
 #endif
 
     Rect rect;
-    d->coreWindow->get_Bounds(&rect);
-    d->geometry = QRectF(0, 0, rect.Width, rect.Height);
+    hr = d->coreWindow->get_Bounds(&rect);
+    Q_ASSERT_SUCCEEDED(hr);
+    d->logicalSize = QSizeF(rect.Width, rect.Height);
 
     d->surfaceFormat.setAlphaBufferSize(0);
     d->surfaceFormat.setRedBufferSize(8);
@@ -514,18 +515,6 @@ QWinRTScreen::QWinRTScreen()
     d->surfaceFormat.setDepthBufferSize(24);
     d->surfaceFormat.setStencilBufferSize(8);
 
-    d->eglDisplay = eglGetDisplay(EGL_DEFAULT_DISPLAY);
-    if (d->eglDisplay == EGL_NO_DISPLAY)
-        qFatal("Qt WinRT platform plugin: failed to initialize EGL display.");
-
-    if (!eglInitialize(d->eglDisplay, NULL, NULL))
-        qFatal("Qt WinRT platform plugin: failed to initialize EGL. This can happen if you haven't included the D3D compiler DLL in your application package.");
-
-    // TODO: move this to Window
-    d->eglSurface = eglCreateWindowSurface(d->eglDisplay, q_configFromGLFormat(d->eglDisplay, d->surfaceFormat), d->coreWindow.Get(), NULL);
-    if (d->eglSurface == EGL_NO_SURFACE)
-        qFatal("Could not create EGL surface, error 0x%X", eglGetError());
-
     hr = d->coreWindow->add_KeyDown(Callback<KeyHandler>(this, &QWinRTScreen::onKeyDown).Get(), &d->windowTokens[&ICoreWindow::remove_KeyDown]);
     Q_ASSERT_SUCCEEDED(hr);
     hr = d->coreWindow->add_KeyUp(Callback<KeyHandler>(this, &QWinRTScreen::onKeyUp).Get(), &d->windowTokens[&ICoreWindow::remove_KeyUp]);
@@ -585,6 +574,17 @@ QWinRTScreen::QWinRTScreen()
     onOrientationChanged(Q_NULLPTR, Q_NULLPTR);
     onDpiChanged(Q_NULLPTR, Q_NULLPTR);
     setOrientationUpdateMask(d->nativeOrientation);
+
+    d->eglDisplay = eglGetDisplay(d->displayInformation.Get());
+    if (d->eglDisplay == EGL_NO_DISPLAY)
+        qCritical("Failed to initialize EGL display: 0x%x", eglGetError());
+
+    if (!eglInitialize(d->eglDisplay, NULL, NULL))
+        qCritical("Failed to initialize EGL: 0x%x", eglGetError());
+
+    d->eglSurface = eglCreateWindowSurface(d->eglDisplay, q_configFromGLFormat(d->eglDisplay, d->surfaceFormat), d->coreWindow.Get(), NULL);
+    if (d->eglSurface == EGL_NO_SURFACE)
+        qCritical("Failed to create EGL window surface: 0x%x", eglGetError());
 }
 
 QWinRTScreen::~QWinRTScreen()
@@ -607,7 +607,7 @@ QWinRTScreen::~QWinRTScreen()
 QRect QWinRTScreen::geometry() const
 {
     Q_D(const QWinRTScreen);
-    return d->geometry.toRect();
+    return QRect(QPoint(), (d->logicalSize * d->scaleFactor).toSize());
 }
 
 int QWinRTScreen::depth() const
@@ -629,19 +629,13 @@ QSurfaceFormat QWinRTScreen::surfaceFormat() const
 QSizeF QWinRTScreen::physicalSize() const
 {
     Q_D(const QWinRTScreen);
-    return d->geometry.size() / d->dpi * qreal(25.4);
+    return d->logicalSize / d->logicalDpi * qreal(25.4);
 }
 
 QDpi QWinRTScreen::logicalDpi() const
 {
     Q_D(const QWinRTScreen);
-    return QDpi(d->dpi, d->dpi);
-}
-
-qreal QWinRTScreen::devicePixelRatio() const
-{
-    Q_D(const QWinRTScreen);
-    return d->devicePixelRatio;
+    return QDpi(d->logicalDpi, d->logicalDpi);
 }
 
 QWinRTInputContext *QWinRTScreen::inputContext() const
@@ -779,10 +773,9 @@ void QWinRTScreen::handleExpose()
     if (d->visibleWindows.isEmpty())
         return;
     QList<QWindow *>::const_iterator it = d->visibleWindows.constBegin();
-    QWindowSystemInterface::handleExposeEvent(*it, d->geometry.toRect());
+    QWindowSystemInterface::handleExposeEvent(*it, geometry());
     while (++it != d->visibleWindows.constEnd())
         QWindowSystemInterface::handleExposeEvent(*it, QRegion());
-    QWindowSystemInterface::flushWindowSystemEvents();
 }
 
 HRESULT QWinRTScreen::onKeyDown(ABI::Windows::UI::Core::ICoreWindow *, ABI::Windows::UI::Core::IKeyEventArgs *args)
@@ -967,8 +960,9 @@ HRESULT QWinRTScreen::onPointerUpdated(ICoreWindow *, IPointerEventArgs *args)
             it.value().state = Qt::TouchPointPressed;
             it.value().id = id;
         }
-        it.value().area = QRectF(area.X, area.Y, area.Width, area.Height);
-        it.value().normalPosition = QPointF(pos.x()/d->geometry.width(), pos.y()/d->geometry.height());
+        it.value().area = QRectF(area.X * d->scaleFactor, area.Y * d->scaleFactor,
+                                 area.Width * d->scaleFactor, area.Height * d->scaleFactor);
+        it.value().normalPosition = QPointF(pos.x()/d->logicalSize.width(), pos.y()/d->logicalSize.height());
         it.value().pressure = pressure;
 
         QWindowSystemInterface::handleTouchEvent(topWindow(), d->touchDevice, d->touchPoints.values(), mods);
@@ -1036,11 +1030,16 @@ HRESULT QWinRTScreen::onSizeChanged(ICoreWindow *, IWindowSizeChangedEventArgs *
     HRESULT hr = args->get_Size(&size);
     RETURN_OK_IF_FAILED("Failed to get window size.");
 
+    QSizeF logicalSize = QSizeF(size.Width, size.Height);
+    if (d->logicalSize == logicalSize)
+        return S_OK;
+
     // Regardless of state, all top-level windows are viewport-sized - this might change if
     // a more advanced compositor is written.
-    d->geometry.setSize(QSizeF(size.Width, size.Height));
-    QWindowSystemInterface::handleScreenGeometryChange(screen(), d->geometry.toRect());
-    QWindowSystemInterface::handleScreenAvailableGeometryChange(screen(), d->geometry.toRect());
+    d->logicalSize = logicalSize;
+    const QRect newGeometry = geometry();
+    QWindowSystemInterface::handleScreenGeometryChange(screen(), newGeometry);
+    QWindowSystemInterface::handleScreenAvailableGeometryChange(screen(), newGeometry);
     QPlatformScreen::resizeMaximizedWindows();
     handleExpose();
 
@@ -1125,22 +1124,18 @@ HRESULT QWinRTScreen::onDpiChanged(IDisplayInformation *, IInspectable *)
     ComPtr<IDisplayInformation2> displayInformation;
     hr = d->displayInformation.As(&displayInformation);
     RETURN_OK_IF_FAILED("Failed to cast display information.");
-    hr = displayInformation->get_RawPixelsPerViewPixel(&d->devicePixelRatio);
+    hr = displayInformation->get_RawPixelsPerViewPixel(&d->scaleFactor);
 #else
     ResolutionScale resolutionScale;
     hr = d->displayInformation->get_ResolutionScale(&resolutionScale);
-    d->devicePixelRatio = qreal(resolutionScale) / 100;
+    d->scaleFactor = qreal(resolutionScale) / 100;
 #endif
-    RETURN_OK_IF_FAILED("Failed to get resolution scale");
-
-    // Correct the scale factor for integer window size
-    d->devicePixelRatio = d->devicePixelRatio * ((d->geometry.width()/qRound(d->geometry.width()) +
-                                                  d->geometry.height()/qRound(d->geometry.height())) / 2.0);
+    RETURN_OK_IF_FAILED("Failed to get scale factor");
 
     FLOAT dpi;
     hr = d->displayInformation->get_LogicalDpi(&dpi);
     RETURN_OK_IF_FAILED("Failed to get logical DPI.");
-    d->dpi = dpi;
+    d->logicalDpi = dpi;
 
     return S_OK;
 }
diff --git a/src/plugins/platforms/winrt/qwinrtscreen.h b/src/plugins/platforms/winrt/qwinrtscreen.h
index 18745f1017..21673c9f06 100644
--- a/src/plugins/platforms/winrt/qwinrtscreen.h
+++ b/src/plugins/platforms/winrt/qwinrtscreen.h
@@ -101,7 +101,6 @@ public:
     QSurfaceFormat surfaceFormat() const;
     QSizeF physicalSize() const Q_DECL_OVERRIDE;
     QDpi logicalDpi() const Q_DECL_OVERRIDE;
-    qreal devicePixelRatio() const Q_DECL_OVERRIDE;
     QWinRTInputContext *inputContext() const;
     QPlatformCursor *cursor() const;
     Qt::KeyboardModifiers keyboardModifiers() const;