EGLFS: Don’t compute logical DPI from physical size

Remove code which computes logical DPI from the screen’s
physical size.

Return a DPI of 100 instead (this value was previously
returned if the physical size was not available), and
add a matching logicalBaseDpi() implementation which
gives a device pixel ratio of 1.

Task-number: QTBUG-87035
Change-Id: Ib20afbbd24fd6b57c8ffb2fd697f1becba283cba
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>

src/plugins/platforms/eglfs/api/qeglfsdeviceintegration.cpp

@@ -224,14 +224,12 @@ QSize QEglFSDeviceIntegration::screenSize() const
 
 QDpi QEglFSDeviceIntegration::logicalDpi() const
 {
-    const QSizeF ps = physicalScreenSize();
+    return QDpi(100, 100);
-    const QSize s = screenSize();
+}
 
-    if (!ps.isEmpty() && !s.isEmpty())
+QDpi QEglFSDeviceIntegration::logicalBaseDpi() const
-        return QDpi(25.4 * s.width() / ps.width(),
+{
-                    25.4 * s.height() / ps.height());
+    return QDpi(100, 100);
-    else
-        return QDpi(100, 100);
 }
 
 Qt::ScreenOrientation QEglFSDeviceIntegration::nativeOrientation() const

src/plugins/platforms/eglfs/api/qeglfsdeviceintegration_p.h

@@ -80,6 +80,7 @@ public:
     virtual QSizeF physicalScreenSize() const;
     virtual QSize screenSize() const;
     virtual QDpi logicalDpi() const;
+    virtual QDpi logicalBaseDpi() const;
     virtual Qt::ScreenOrientation nativeOrientation() const;
     virtual Qt::ScreenOrientation orientation() const;
     virtual int screenDepth() const;

src/plugins/platforms/eglfs/api/qeglfsscreen.cpp

@@ -115,6 +115,11 @@ QDpi QEglFSScreen::logicalDpi() const
     return qt_egl_device_integration()->logicalDpi();
 }
 
+QDpi QEglFSScreen::logicalBaseDpi() const
+{
+    return qt_egl_device_integration()->logicalBaseDpi();
+}
+
 Qt::ScreenOrientation QEglFSScreen::nativeOrientation() const
 {
     return qt_egl_device_integration()->nativeOrientation();

src/plugins/platforms/eglfs/api/qeglfsscreen_p.h

@@ -74,6 +74,7 @@ public:
 
     QSizeF physicalSize() const override;
     QDpi logicalDpi() const override;
+    QDpi logicalBaseDpi() const override;
     Qt::ScreenOrientation nativeOrientation() const override;
     Qt::ScreenOrientation orientation() const override;
 

src/plugins/platforms/eglfs/deviceintegration/eglfs_emu/qeglfsemulatorscreen.cpp

@@ -75,14 +75,12 @@ QSizeF QEglFSEmulatorScreen::physicalSize() const
 
 QDpi QEglFSEmulatorScreen::logicalDpi() const
 {
-    const QSizeF ps = m_physicalSize;
+    return logicalBaseDpi();
-    const QSize s = m_geometry.size();
+}
 
-    if (!ps.isEmpty() && !s.isEmpty())
+QDpi QEglFSEmulatorScreen::logicalBaseDpi() const
-        return QDpi(25.4 * s.width() / ps.width(),
+{
-                    25.4 * s.height() / ps.height());
+    return QDpi(100, 100);
-    else
-        return QDpi(100, 100);
 }
 
 qreal QEglFSEmulatorScreen::refreshRate() const

src/plugins/platforms/eglfs/deviceintegration/eglfs_emu/qeglfsemulatorscreen.h

@@ -58,6 +58,7 @@ public:
     QImage::Format format() const override;
     QSizeF physicalSize() const override;
     QDpi logicalDpi() const override;
+    QDpi logicalBaseDpi() const override;
     qreal refreshRate() const override;
     Qt::ScreenOrientation nativeOrientation() const override;
     Qt::ScreenOrientation orientation() const override;

src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.cpp

@@ -160,14 +160,12 @@ QSizeF QEglFSKmsScreen::physicalSize() const
 
 QDpi QEglFSKmsScreen::logicalDpi() const
 {
-    const QSizeF ps = physicalSize();
+    return logicalBaseDpi();
-    const QSize s = geometry().size();
+}
 
-    if (!ps.isEmpty() && !s.isEmpty())
+QDpi QEglFSKmsScreen::logicalBaseDpi() const
-        return QDpi(25.4 * s.width() / ps.width(),
+{
-                    25.4 * s.height() / ps.height());
+    return QDpi(100, 100);
-    else
-        return QDpi(100, 100);
 }
 
 Qt::ScreenOrientation QEglFSKmsScreen::nativeOrientation() const

src/plugins/platforms/eglfs/deviceintegration/eglfs_kms_support/qeglfskmsscreen.h

@@ -69,6 +69,7 @@ public:
 
     QSizeF physicalSize() const override;
     QDpi logicalDpi() const override;
+    QDpi logicalBaseDpi() const override;
     Qt::ScreenOrientation nativeOrientation() const override;
     Qt::ScreenOrientation orientation() const override;