PerScreenDpi | QLabels incorrectly handle scale for icons (#4070)

* Fixes to icon generation. Generating a pixmap out of a size won't take the screen scaling factor into account, resulting in blurry results.
Note that this is not a catchall solution, every case needs to be addressed manually.

Signed-off-by: Danilo Aimini <82231674+AMZN-daimini@users.noreply.github.com>

* HighDpi fixes for startup splashscreen and About dialog

Signed-off-by: Danilo Aimini <82231674+AMZN-daimini@users.noreply.github.com>

* Add helper function to generate appropriate pixmaps for a screen based on its dpi settings.

Signed-off-by: Danilo Aimini <82231674+AMZN-daimini@users.noreply.github.com>

Code/Editor/AboutDialog.cpp

@@ -20,6 +20,7 @@
 // AzCore
 #include <AzCore/Casting/numeric_cast.h>    // for aznumeric_cast
 
+#include <AzQtComponents/Utilities/PixmapScaleUtilities.h>
 
 AZ_PUSH_DISABLE_DLL_EXPORT_MEMBER_WARNING
 #include <ui_AboutDialog.h>
@@ -46,8 +47,13 @@ CAboutDialog::CAboutDialog(QString versionText, QString richTextCopyrightNotice,
                     CAboutDialog > QLabel#link { text-decoration: underline; color: #94D2FF; }");
 
     // Prepare background image
-    QImage backgroundImage(QStringLiteral(":/StartupLogoDialog/splashscreen_background_developer_preview.jpg"));
-    m_backgroundImage = QPixmap::fromImage(backgroundImage.scaled(m_enforcedWidth, m_enforcedHeight, Qt::IgnoreAspectRatio, Qt::SmoothTransformation));
+    m_backgroundImage = AzQtComponents::ScalePixmapForScreenDpi(
+        QPixmap(QStringLiteral(":/StartupLogoDialog/splashscreen_background_developer_preview.jpg")),
+        screen(),
+        QSize(m_enforcedWidth, m_enforcedHeight),
+        Qt::IgnoreAspectRatio,
+        Qt::SmoothTransformation
+    );
 
     // Draw the Open 3D Engine logo from svg
     m_ui->m_logo->load(QStringLiteral(":/StartupLogoDialog/o3de_logo.svg"));

Code/Editor/StartupLogoDialog.cpp

@@ -9,11 +9,11 @@
 
 // Description : implementation file
 
-
 #include "EditorDefs.h"
-
 #include "StartupLogoDialog.h"
 
+#include <AzQtComponents/Utilities/PixmapScaleUtilities.h>
+
 // Qt
 #include <QPainter>
 #include <QThread>
@@ -22,8 +22,6 @@ AZ_PUSH_DISABLE_DLL_EXPORT_MEMBER_WARNING
 #include <ui_StartupLogoDialog.h>
 AZ_POP_DISABLE_DLL_EXPORT_MEMBER_WARNING
 
-
-
 /////////////////////////////////////////////////////////////////////////////
 // CStartupLogoDialog dialog
 
@@ -36,13 +34,16 @@ CStartupLogoDialog::CStartupLogoDialog(QString versionText, QString richTextCopy
     m_ui->setupUi(this);
 
     s_pLogoWindow = this;
-
-    m_backgroundImage = QPixmap(QStringLiteral(":/StartupLogoDialog/splashscreen_background_developer_preview.jpg"));
     setFixedSize(QSize(600, 300));
 
     // Prepare background image
-    QImage backgroundImage(QStringLiteral(":/StartupLogoDialog/splashscreen_background_developer_preview.jpg"));
-    m_backgroundImage = QPixmap::fromImage(backgroundImage.scaled(m_enforcedWidth, m_enforcedHeight, Qt::IgnoreAspectRatio, Qt::SmoothTransformation));
+    m_backgroundImage = AzQtComponents::ScalePixmapForScreenDpi(
+        QPixmap(QStringLiteral(":/StartupLogoDialog/splashscreen_background_developer_preview.jpg")),
+        screen(),
+        QSize(m_enforcedWidth, m_enforcedHeight),
+        Qt::IgnoreAspectRatio,
+        Qt::SmoothTransformation
+    );
 
     // Draw the Open 3D Engine logo from svg
     m_ui->m_logo->load(QStringLiteral(":/StartupLogoDialog/o3de_logo.svg"));

Code/Editor/WelcomeScreen/WelcomeScreenDialog.cpp

@@ -34,6 +34,7 @@
 // AzQtComponents
 #include <AzQtComponents/Components/Widgets/CheckBox.h>
 #include <AzQtComponents/Components/WindowDecorationWrapper.h>
+#include <AzQtComponents/Utilities/PixmapScaleUtilities.h>
 
 // Editor
 #include "Settings.h"
@@ -79,8 +80,11 @@ WelcomeScreenDialog::WelcomeScreenDialog(QWidget* pParent)
     {
         projectPreviewPath = ":/WelcomeScreenDialog/DefaultProjectImage.png";
     }
+    
     ui->activeProjectIcon->setPixmap(
-        QPixmap(projectPreviewPath).scaled(
+        AzQtComponents::ScalePixmapForScreenDpi(
+            QPixmap(projectPreviewPath),
+            screen(),
             ui->activeProjectIcon->size(),
             Qt::KeepAspectRatioByExpanding,
             Qt::SmoothTransformation

Code/Framework/AzQtComponents/AzQtComponents/Utilities/PixmapScaleUtilities.cpp

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project.
+ * For complete copyright and license terms please see the LICENSE at the root of this distribution.
+ *
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+
+#include <AzCore/Casting/numeric_cast.h>
+#include <AzQtComponents/Utilities/PixmapScaleUtilities.h>
+
+#include <QtGui/private/qhighdpiscaling_p.h>
+
+namespace AzQtComponents
+{
+    QPixmap ScalePixmapForScreenDpi(
+        QPixmap pixmap, QScreen* screen, QSize size, Qt::AspectRatioMode aspectRatioMode, Qt::TransformationMode transformationMode)
+    {
+        qreal screenDpiFactor = QHighDpiScaling::factor(screen);
+        pixmap.setDevicePixelRatio(screenDpiFactor);
+
+        QPixmap scaledPixmap;
+
+        size.setWidth(aznumeric_cast<int>(aznumeric_cast<qreal>(size.width()) * screenDpiFactor));
+        size.setHeight(aznumeric_cast<int>(aznumeric_cast<qreal>(size.height()) * screenDpiFactor));
+
+        scaledPixmap = pixmap.scaled(size, aspectRatioMode, transformationMode);
+
+        return scaledPixmap;
+    }
+}

Code/Framework/AzQtComponents/AzQtComponents/Utilities/PixmapScaleUtilities.h

@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project.
+ * For complete copyright and license terms please see the LICENSE at the root of this distribution.
+ *
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+
+#pragma once
+
+#include <AzQtComponents/AzQtComponentsAPI.h>
+
+#include <QPixmap>
+#include <QScreen>
+
+namespace AzQtComponents
+{
+    AZ_QT_COMPONENTS_API QPixmap ScalePixmapForScreenDpi(QPixmap pixmap, QScreen* screen, QSize size, Qt::AspectRatioMode aspectRatioMode, Qt::TransformationMode transformationMode);
+}; // namespace AzQtComponents

Code/Framework/AzQtComponents/AzQtComponents/azqtcomponents_files.cmake

@@ -276,6 +276,8 @@ set(FILES
     Utilities/HandleDpiAwareness.cpp
     Utilities/HandleDpiAwareness.h
     Utilities/MouseHider.h
+    Utilities/PixmapScaleUtilities.cpp
+    Utilities/PixmapScaleUtilities.h
     Utilities/QtPluginPaths.cpp
     Utilities/QtPluginPaths.h
     Utilities/QtWindowUtilities.cpp

Code/Framework/AzToolsFramework/AzToolsFramework/UI/EditorEntityUi/EditorEntityUiHandlerBase.cpp

@@ -47,9 +47,9 @@ namespace AzToolsFramework
         return QString();
     }
 
-    QPixmap EditorEntityUiHandlerBase::GenerateItemIcon(AZ::EntityId /*entityId*/) const
+    QIcon EditorEntityUiHandlerBase::GenerateItemIcon(AZ::EntityId /*entityId*/) const
     {
-        return QPixmap();
+        return QIcon();
     }
 
     bool EditorEntityUiHandlerBase::CanToggleLockVisibility(AZ::EntityId /*entityId*/) const

Code/Framework/AzToolsFramework/AzToolsFramework/UI/EditorEntityUi/EditorEntityUiHandlerBase.h

@@ -40,7 +40,7 @@ namespace AzToolsFramework
         //! Returns the item tooltip text to display in the Outliner.
         virtual QString GenerateItemTooltip(AZ::EntityId entityId) const;
         //! Returns the item icon pixmap to display in the Outliner.
-        virtual QPixmap GenerateItemIcon(AZ::EntityId entityId) const;
+        virtual QIcon GenerateItemIcon(AZ::EntityId entityId) const;
         //! Returns whether the element's lock and visibility state should be accessible in the Outliner
         virtual bool CanToggleLockVisibility(AZ::EntityId entityId) const;
         //! Returns whether the element's name should be editable

Code/Framework/AzToolsFramework/AzToolsFramework/UI/Layer/LayerUiHandler.cpp

@@ -66,9 +66,9 @@ namespace AzToolsFramework
         return result;
     }
 
-    QPixmap LayerUiHandler::GenerateItemIcon(AZ::EntityId /*entityId*/) const
+    QIcon LayerUiHandler::GenerateItemIcon(AZ::EntityId /*entityId*/) const
     {
-        return QPixmap(m_layerIconPath);
+        return QIcon(m_layerIconPath);
     }
 
     void LayerUiHandler::PaintItemBackground(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const

Code/Framework/AzToolsFramework/AzToolsFramework/UI/Layer/LayerUiHandler.h

@@ -24,7 +24,7 @@ namespace AzToolsFramework
 
         // EditorEntityUiHandler...
         QString GenerateItemInfoString(AZ::EntityId entityId) const override;
-        QPixmap GenerateItemIcon(AZ::EntityId entityId) const override;
+        QIcon GenerateItemIcon(AZ::EntityId entityId) const override;
         void PaintItemBackground(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const override;
         void PaintDescendantBackground(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index,
             const QModelIndex& descendantIndex) const override;

Code/Framework/AzToolsFramework/AzToolsFramework/UI/Outliner/EntityOutlinerListModel.cpp

@@ -280,17 +280,17 @@ namespace AzToolsFramework
     QVariant EntityOutlinerListModel::GetEntityIcon(const AZ::EntityId& id) const
     {
         auto entityUiHandler = m_editorEntityFrameworkInterface->GetHandler(id);
-        QPixmap pixmap;
+        QIcon icon;
 
         // Retrieve the icon from the handler
         if (entityUiHandler != nullptr)
         {
-            pixmap = entityUiHandler->GenerateItemIcon(id);
+            icon = entityUiHandler->GenerateItemIcon(id);
         }
 
-        if (!pixmap.isNull())
+        if (!icon.isNull())
         {
-            return QIcon(pixmap);
+            return icon;
         }
 
         // If no icon was returned by the handler, use the default one.
@@ -299,7 +299,7 @@ namespace AzToolsFramework
 
         if (isEditorOnly)
         {
-            return QIcon(QPixmap(QString(":/Icons/Entity_Editor_Only.svg")));
+            return QIcon(QString(":/Icons/Entity_Editor_Only.svg"));
         }
 
         AZ::Entity* entity = nullptr;
@@ -308,10 +308,10 @@ namespace AzToolsFramework
 
         if (!isInitiallyActive)
         {
-            return QIcon(QPixmap(QString(":/Icons/Entity_Not_Active.svg")));
+            return QIcon(QString(":/Icons/Entity_Not_Active.svg"));
         }
 
-        return QIcon(QPixmap(QString(":/Icons/Entity.svg")));
+        return QIcon(QString(":/Icons/Entity.svg"));
     }
 
     QVariant EntityOutlinerListModel::GetEntityTooltip(const AZ::EntityId& id) const

Code/Framework/AzToolsFramework/AzToolsFramework/UI/Prefab/LevelRootUiHandler.cpp

@@ -41,9 +41,9 @@ namespace AzToolsFramework
         }
     }
 
-    QPixmap LevelRootUiHandler::GenerateItemIcon(AZ::EntityId /*entityId*/) const
+    QIcon LevelRootUiHandler::GenerateItemIcon(AZ::EntityId /*entityId*/) const
     {
-        return QPixmap(m_levelRootIconPath);
+        return QIcon(m_levelRootIconPath);
     }
 
     QString LevelRootUiHandler::GenerateItemInfoString(AZ::EntityId entityId) const

Code/Framework/AzToolsFramework/AzToolsFramework/UI/Prefab/LevelRootUiHandler.h

@@ -29,7 +29,7 @@ namespace AzToolsFramework
         ~LevelRootUiHandler() override = default;
 
         // EditorEntityUiHandler...
-        QPixmap GenerateItemIcon(AZ::EntityId entityId) const override;
+        QIcon GenerateItemIcon(AZ::EntityId entityId) const override;
         QString GenerateItemInfoString(AZ::EntityId entityId) const override;
         bool CanToggleLockVisibility(AZ::EntityId entityId) const override;
         bool CanRename(AZ::EntityId entityId) const override;

Code/Framework/AzToolsFramework/AzToolsFramework/UI/Prefab/PrefabUiHandler.cpp

@@ -81,14 +81,14 @@ namespace AzToolsFramework
         return tooltip;
     }
 
-    QPixmap PrefabUiHandler::GenerateItemIcon(AZ::EntityId entityId) const
+    QIcon PrefabUiHandler::GenerateItemIcon(AZ::EntityId entityId) const
     {
         if (m_prefabEditInterface->IsOwningPrefabBeingEdited(entityId))
         {
-            return QPixmap(m_prefabEditIconPath);
+            return QIcon(m_prefabEditIconPath);
         }
 
-        return QPixmap(m_prefabIconPath);
+        return QIcon(m_prefabIconPath);
     }
 
     void PrefabUiHandler::PaintItemBackground(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const

Code/Framework/AzToolsFramework/AzToolsFramework/UI/Prefab/PrefabUiHandler.h

@@ -31,7 +31,7 @@ namespace AzToolsFramework
         // EditorEntityUiHandler...
         QString GenerateItemInfoString(AZ::EntityId entityId) const override;
         QString GenerateItemTooltip(AZ::EntityId entityId) const override;
-        QPixmap GenerateItemIcon(AZ::EntityId entityId) const override;
+        QIcon GenerateItemIcon(AZ::EntityId entityId) const override;
         void PaintItemBackground(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index) const override;
         void PaintDescendantBackground(QPainter* painter, const QStyleOptionViewItem& option, const QModelIndex& index,
             const QModelIndex& descendantIndex) const override;