Use float instead of double by default (#17100)

While `double` is probably generally preferable for UI code,
our application is essentially a complex wrapper wrapper around
DWrite, D2D and D3D, all of which use `float` exclusively.

Of course it also uses XAML, but that one uses `float` for roughly
1/3rd of its API functions, so I'm not sure what it prefers.
Additionally, it's mostly a coincidence that we use WinUI/XAML for
Windows Terminal whereas DWrite/D2D/D3D are effectively essential.
This is demonstrated by the fact that we have a `HwndTerminal`,
while there's no alternative to e.g. D3D on Windows.

The goal of this PR is that DIP based calculations never end up
mixing `float` and `double`. This PR also changes opacity-related
values to `float` because I felt like that fits the theme.

src/cascadia/TerminalApp/ActionPreviewHandlers.cpp

@@ -127,7 +127,7 @@ namespace winrt::TerminalApp::implementation
             auto originalOpacity{ control.BackgroundOpacity() };
 
             // Apply the new opacity
-            control.AdjustOpacity(args.Opacity() / 100.0, args.Relative());
+            control.AdjustOpacity(args.Opacity() / 100.0f, args.Relative());
 
             if (backup)
             {

src/cascadia/TerminalApp/AppActionHandlers.cpp

@@ -286,7 +286,7 @@ namespace winrt::TerminalApp::implementation
             _SplitPane(terminalTab,
                        realArgs.SplitDirection(),
                        // This is safe, we're already filtering so the value is (0, 1)
-                       ::base::saturated_cast<float>(realArgs.SplitSize()),
+                       realArgs.SplitSize(),
                        _MakePane(realArgs.ContentArgs(), duplicateFromTab));
             args.Handled(true);
         }
@@ -1247,7 +1247,7 @@ namespace winrt::TerminalApp::implementation
             if (const auto& realArgs = args.ActionArgs().try_as<AdjustOpacityArgs>())
             {
                 const auto res = _ApplyToActiveControls([&](auto& control) {
-                    control.AdjustOpacity(realArgs.Opacity() / 100.0, realArgs.Relative());
+                    control.AdjustOpacity(realArgs.Opacity() / 100.0f, realArgs.Relative());
                 });
                 args.Handled(res);
             }

src/cascadia/TerminalApp/Pane.cpp

@@ -151,7 +151,7 @@ Pane::BuildStartupState Pane::BuildStartupActions(uint32_t currentId, uint32_t n
         // When creating a pane the split size is the size of the new pane
         // and not position.
         const auto splitDirection = _splitState == SplitState::Horizontal ? SplitDirection::Down : SplitDirection::Right;
-        const auto splitSize = (kind != BuildStartupKind::None && _IsLeaf() ? .5 : 1. - _desiredSplitPosition);
+        const auto splitSize = (kind != BuildStartupKind::None && _IsLeaf() ? 0.5f : 1.0f - _desiredSplitPosition);
         SplitPaneArgs args{ SplitType::Manual, splitDirection, splitSize, terminalArgs };
         actionAndArgs.Args(args);
 
@@ -1595,12 +1595,12 @@ void Pane::_CloseChildRoutine(const bool closeFirst)
     const auto splitWidth = _splitState == SplitState::Vertical;
 
     Size removedOriginalSize{
-        ::base::saturated_cast<float>(removedChild->_root.ActualWidth()),
-        ::base::saturated_cast<float>(removedChild->_root.ActualHeight())
+        static_cast<float>(removedChild->_root.ActualWidth()),
+        static_cast<float>(removedChild->_root.ActualHeight())
     };
     Size remainingOriginalSize{
-        ::base::saturated_cast<float>(remainingChild->_root.ActualWidth()),
-        ::base::saturated_cast<float>(remainingChild->_root.ActualHeight())
+        static_cast<float>(remainingChild->_root.ActualWidth()),
+        static_cast<float>(remainingChild->_root.ActualHeight())
     };
 
     // Remove both children from the grid
@@ -1902,7 +1902,7 @@ void Pane::_SetupEntranceAnimation()
     //   looks bad.
     _secondChild->_root.Background(_themeResources.unfocusedBorderBrush);
 
-    const auto [firstSize, secondSize] = _CalcChildrenSizes(::base::saturated_cast<float>(totalSize));
+    const auto [firstSize, secondSize] = _CalcChildrenSizes(static_cast<float>(totalSize));
 
     // This is safe to capture this, because it's only being called in the
     // context of this method (not on another thread)

src/cascadia/TerminalApp/TerminalPage.cpp

@@ -1947,8 +1947,8 @@ namespace winrt::TerminalApp::implementation
         layout.LaunchMode({ mode });
 
         // Only save the content size because the tab size will be added on load.
-        const auto contentWidth = ::base::saturated_cast<float>(_tabContent.ActualWidth());
-        const auto contentHeight = ::base::saturated_cast<float>(_tabContent.ActualHeight());
+        const auto contentWidth = static_cast<float>(_tabContent.ActualWidth());
+        const auto contentHeight = static_cast<float>(_tabContent.ActualHeight());
         const winrt::Windows::Foundation::Size windowSize{ contentWidth, contentHeight };
 
         layout.InitialSize(windowSize);
@@ -2358,8 +2358,8 @@ namespace winrt::TerminalApp::implementation
         {
             return;
         }
-        const auto contentWidth = ::base::saturated_cast<float>(_tabContent.ActualWidth());
-        const auto contentHeight = ::base::saturated_cast<float>(_tabContent.ActualHeight());
+        const auto contentWidth = static_cast<float>(_tabContent.ActualWidth());
+        const auto contentHeight = static_cast<float>(_tabContent.ActualHeight());
         const winrt::Windows::Foundation::Size availableSpace{ contentWidth, contentHeight };
 
         const auto realSplitType = activeTab->PreCalculateCanSplit(splitDirection, splitSize, availableSpace);

src/cascadia/TerminalApp/TitlebarControl.cpp

@@ -44,12 +44,12 @@ namespace winrt::TerminalApp::implementation
         });
     }
 
-    double TitlebarControl::CaptionButtonWidth()
+    float TitlebarControl::CaptionButtonWidth()
     {
         // Divide by three, since we know there are only three buttons. When
         // Windows 12 comes along and adds another, we can update this /s
-        static auto width{ MinMaxCloseControl().ActualWidth() / 3.0 };
-        return width;
+        const auto minMaxCloseWidth = MinMaxCloseControl().ActualWidth();
+        return static_cast<float>(minMaxCloseWidth) / 3.0f;
     }
 
     IInspectable TitlebarControl::Content()

src/cascadia/TerminalApp/TitlebarControl.h

@@ -15,7 +15,7 @@ namespace winrt::TerminalApp::implementation
         void PressButton(CaptionButton button);
         winrt::fire_and_forget ClickButton(CaptionButton button);
         void ReleaseButtons();
-        double CaptionButtonWidth();
+        float CaptionButtonWidth();
 
         IInspectable Content();
         void Content(IInspectable content);

src/cascadia/TerminalApp/TitlebarControl.idl

@@ -27,7 +27,7 @@ namespace TerminalApp
         void PressButton(CaptionButton button);
         void ClickButton(CaptionButton button);
         void ReleaseButtons();
-        Double CaptionButtonWidth { get; };
+        Single CaptionButtonWidth { get; };
 
         IInspectable Content;
         Windows.UI.Xaml.Controls.Border DragBar { get; };

src/cascadia/TerminalControl/ControlCore.cpp

@@ -677,7 +677,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         }
     }
 
-    void ControlCore::AdjustOpacity(const double adjustment)
+    void ControlCore::AdjustOpacity(const float adjustment)
     {
         if (adjustment == 0)
         {
@@ -694,11 +694,9 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     // - focused (default == true): Whether the window is focused or unfocused.
     // Return Value:
     // - <none>
-    void ControlCore::_setOpacity(const double opacity, bool focused)
+    void ControlCore::_setOpacity(const float opacity, bool focused)
     {
-        const auto newOpacity = std::clamp(opacity,
-                                           0.0,
-                                           1.0);
+        const auto newOpacity = std::clamp(opacity, 0.0f, 1.0f);
 
         if (newOpacity == Opacity())
         {
@@ -713,7 +711,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         _runtimeFocusedOpacity = focused ? newOpacity : _runtimeFocusedOpacity;
 
         // Manually turn off acrylic if they turn off transparency.
-        _runtimeUseAcrylic = newOpacity < 1.0 && _settings->UseAcrylic();
+        _runtimeUseAcrylic = newOpacity < 1.0f && _settings->UseAcrylic();
 
         // Update the renderer as well. It might need to fall back from
         // cleartype -> grayscale if the BG is transparent / acrylic.
@@ -881,7 +879,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     // Method Description:
     // - Updates the appearance of the current terminal.
     // - INVARIANT: This method can only be called if the caller DOES NOT HAVE writing lock on the terminal.
-    void ControlCore::ApplyAppearance(const bool& focused)
+    void ControlCore::ApplyAppearance(const bool focused)
     {
         const auto lock = _terminal->LockForWriting();
         const auto& newAppearance{ focused ? _settings->FocusedAppearance() : _settings->UnfocusedAppearance() };
@@ -900,10 +898,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
             // Incase EnableUnfocusedAcrylic is disabled and Focused Acrylic is set to true,
             // the terminal should ignore the unfocused opacity from settings.
             // The Focused Opacity from settings should be ignored if overridden at runtime.
-            bool useFocusedRuntimeOpacity = focused || (!_settings->EnableUnfocusedAcrylic() && UseAcrylic());
-            double newOpacity = useFocusedRuntimeOpacity ?
-                                    FocusedOpacity() :
-                                    newAppearance->Opacity();
+            const auto useFocusedRuntimeOpacity = focused || (!_settings->EnableUnfocusedAcrylic() && UseAcrylic());
+            const auto newOpacity = useFocusedRuntimeOpacity ? FocusedOpacity() : newAppearance->Opacity();
             _setOpacity(newOpacity, focused);
 
             // No need to update Acrylic if UnfocusedAcrylic is disabled
@@ -1422,8 +1418,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     {
         const auto fontSize = _actualFont.GetSize();
         return {
-            ::base::saturated_cast<float>(fontSize.width),
-            ::base::saturated_cast<float>(fontSize.height)
+            static_cast<float>(fontSize.width),
+            static_cast<float>(fontSize.height)
         };
     }
 
@@ -2350,7 +2346,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         return _settings->HasUnfocusedAppearance();
     }
 
-    void ControlCore::AdjustOpacity(const double opacityAdjust, const bool relative)
+    void ControlCore::AdjustOpacity(const float opacityAdjust, const bool relative)
     {
         if (relative)
         {

src/cascadia/TerminalControl/ControlCore.h

@@ -91,7 +91,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         void Detach();
 
         void UpdateSettings(const Control::IControlSettings& settings, const IControlAppearance& newAppearance);
-        void ApplyAppearance(const bool& focused);
+        void ApplyAppearance(const bool focused);
         Control::IControlSettings Settings();
         Control::IControlAppearance FocusedAppearance() const;
         Control::IControlAppearance UnfocusedAppearance() const;
@@ -136,7 +136,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         void LostFocus();
 
         void ToggleShaderEffects();
-        void AdjustOpacity(const double adjustment);
+        void AdjustOpacity(const float adjustment);
         void ResumeRendering();
 
         void SetHoveredCell(Core::Point terminalPosition);
@@ -243,7 +243,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         hstring ReadEntireBuffer() const;
         Control::CommandHistoryContext CommandHistory() const;
 
-        void AdjustOpacity(const double opacity, const bool relative);
+        void AdjustOpacity(const float opacity, const bool relative);
 
         void WindowVisibilityChanged(const bool showOrHide);
 
@@ -258,8 +258,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         bool ShouldShowSelectCommand();
         bool ShouldShowSelectOutput();
 
-        RUNTIME_SETTING(double, Opacity, _settings->Opacity());
-        RUNTIME_SETTING(double, FocusedOpacity, FocusedAppearance().Opacity());
+        RUNTIME_SETTING(float, Opacity, _settings->Opacity());
+        RUNTIME_SETTING(float, FocusedOpacity, FocusedAppearance().Opacity());
         RUNTIME_SETTING(bool, UseAcrylic, _settings->UseAcrylic());
 
         // -------------------------------- WinRT Events ---------------------------------
@@ -399,7 +399,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         void _updateAntiAliasingMode();
         void _connectionOutputHandler(const hstring& hstr);
         void _updateHoveredCell(const std::optional<til::point> terminalPosition);
-        void _setOpacity(const double opacity, const bool focused = true);
+        void _setOpacity(const float opacity, const bool focused = true);
 
         bool _isBackgroundTransparent();
         void _focusChanged(bool focused);

src/cascadia/TerminalControl/ControlCore.idl

@@ -88,7 +88,7 @@ namespace Microsoft.Terminal.Control
 
         Windows.Foundation.Size FontSize { get; };
         UInt16 FontWeight { get; };
-        Double Opacity { get; };
+        Single Opacity { get; };
         Boolean UseAcrylic { get; };
 
         Boolean TryMarkModeKeybinding(Int16 vkey,
@@ -149,7 +149,7 @@ namespace Microsoft.Terminal.Control
         String ReadEntireBuffer();
         CommandHistoryContext CommandHistory();
 
-        void AdjustOpacity(Double Opacity, Boolean relative);
+        void AdjustOpacity(Single Opacity, Boolean relative);
         void WindowVisibilityChanged(Boolean showOrHide);
 
         void ColorSelection(SelectionColor fg, SelectionColor bg, Microsoft.Terminal.Core.MatchMode matchMode);

src/cascadia/TerminalControl/ControlInteractivity.cpp

@@ -518,7 +518,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     void ControlInteractivity::_mouseTransparencyHandler(const int32_t mouseDelta) const
     {
         // Transparency is on a scale of [0.0,1.0], so only increment by .01.
-        const auto effectiveDelta = mouseDelta < 0 ? -.01 : .01;
+        const auto effectiveDelta = mouseDelta < 0 ? -.01f : .01f;
         _core->AdjustOpacity(effectiveDelta);
     }
 
@@ -554,7 +554,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         // underneath us. We wouldn't know - we don't want the overhead of
         // another ScrollPositionChanged handler. If the scrollbar should be
         // somewhere other than where it is currently, then start from that row.
-        const auto currentInternalRow = ::base::saturated_cast<int>(::std::round(_internalScrollbarPosition));
+        const auto currentInternalRow = std::lround(_internalScrollbarPosition);
         const auto currentCoreRow = _core->ScrollOffset();
         const auto currentOffset = currentInternalRow == currentCoreRow ?
                                        _internalScrollbarPosition :
@@ -564,13 +564,13 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         // However, for us, the signs are flipped.
         // With one of the precision mice, one click is always a multiple of 120 (WHEEL_DELTA),
         // but the "smooth scrolling" mode results in non-int values
-        const auto rowDelta = mouseDelta / (-1.0 * WHEEL_DELTA);
+        const auto rowDelta = mouseDelta / (-1.0f * WHEEL_DELTA);
 
         // WHEEL_PAGESCROLL is a Win32 constant that represents the "scroll one page
         // at a time" setting. If we ignore it, we will scroll a truly absurd number
         // of rows.
-        const auto rowsToScroll{ _rowsToScroll == WHEEL_PAGESCROLL ? ::base::saturated_cast<double>(_core->ViewHeight()) : _rowsToScroll };
-        auto newValue = (rowsToScroll * rowDelta) + (currentOffset);
+        const auto rowsToScroll{ _rowsToScroll == WHEEL_PAGESCROLL ? _core->ViewHeight() : _rowsToScroll };
+        const auto newValue = rowsToScroll * rowDelta + currentOffset;
 
         // Update the Core's viewport position, and raise a
         // ScrollPositionChanged event to update the scrollbar
@@ -600,17 +600,17 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     // - newValue: The new top of the viewport
     // Return Value:
     // - <none>
-    void ControlInteractivity::UpdateScrollbar(const double newValue)
+    void ControlInteractivity::UpdateScrollbar(const float newValue)
     {
         // Set this as the new value of our internal scrollbar representation.
         // We're doing this so we can accumulate fractional amounts of a row to
         // scroll each time the mouse scrolls.
-        _internalScrollbarPosition = std::clamp<double>(newValue, 0.0, _core->BufferHeight());
+        _internalScrollbarPosition = std::clamp(newValue, 0.0f, static_cast<float>(_core->BufferHeight()));
 
         // If the new scrollbar position, rounded to an int, is at a different
         // row, then actually update the scroll position in the core, and raise
         // a ScrollPositionChanged to inform the control.
-        auto viewTop = ::base::saturated_cast<int>(::std::round(_internalScrollbarPosition));
+        const auto viewTop = std::lround(_internalScrollbarPosition);
         if (viewTop != _core->ScrollOffset())
         {
             _core->UserScrollViewport(viewTop);

src/cascadia/TerminalControl/ControlInteractivity.h

@@ -78,7 +78,7 @@ namespace winrt::Microsoft::Terminal::Control::implementation
                         const Core::Point pixelPosition,
                         const Control::MouseButtonState state);
 
-        void UpdateScrollbar(const double newValue);
+        void UpdateScrollbar(const float newValue);
 
 #pragma endregion
 
@@ -110,8 +110,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         std::unique_ptr<::Microsoft::Console::Render::UiaEngine> _uiaEngine;
 
         winrt::com_ptr<ControlCore> _core{ nullptr };
-        unsigned int _rowsToScroll;
-        double _internalScrollbarPosition{ 0.0 };
+        UINT _rowsToScroll = 3;
+        float _internalScrollbarPosition = 0;
 
         // If this is set, then we assume we are in the middle of panning the
         //      viewport via touch input.

src/cascadia/TerminalControl/ControlInteractivity.idl

@@ -64,7 +64,7 @@ namespace Microsoft.Terminal.Control
                            Microsoft.Terminal.Core.Point pixelPosition,
                            MouseButtonState state);
 
-        void UpdateScrollbar(Double newValue);
+        void UpdateScrollbar(Single newValue);
 
         Boolean ManglePathsForWsl { get; };
 

src/cascadia/TerminalControl/EventArgs.h

@@ -133,12 +133,12 @@ namespace winrt::Microsoft::Terminal::Control::implementation
     struct TransparencyChangedEventArgs : public TransparencyChangedEventArgsT<TransparencyChangedEventArgs>
     {
     public:
-        TransparencyChangedEventArgs(const double opacity) :
+        TransparencyChangedEventArgs(const float opacity) :
             _Opacity(opacity)
         {
         }
 
-        WINRT_PROPERTY(double, Opacity);
+        WINRT_PROPERTY(float, Opacity);
     };
 
     struct UpdateSearchResultsEventArgs : public UpdateSearchResultsEventArgsT<UpdateSearchResultsEventArgs>

src/cascadia/TerminalControl/EventArgs.idl

@@ -75,7 +75,7 @@ namespace Microsoft.Terminal.Control
 
     runtimeclass TransparencyChangedEventArgs
     {
-        Double Opacity { get; };
+        Single Opacity { get; };
     }
 
     enum SearchState

src/cascadia/TerminalControl/HwndTerminal.cpp

@@ -1090,9 +1090,9 @@ til::rect HwndTerminal::GetPadding() const noexcept
     return {};
 }
 
-double HwndTerminal::GetScaleFactor() const noexcept
+float HwndTerminal::GetScaleFactor() const noexcept
 {
-    return static_cast<double>(_currentDpi) / static_cast<double>(USER_DEFAULT_SCREEN_DPI);
+    return static_cast<float>(_currentDpi) / static_cast<float>(USER_DEFAULT_SCREEN_DPI);
 }
 
 void HwndTerminal::ChangeViewport(const til::inclusive_rect& NewWindow)

src/cascadia/TerminalControl/HwndTerminal.hpp

@@ -146,7 +146,7 @@ struct HwndTerminal : ::Microsoft::Console::Types::IControlAccessibilityInfo
     // Inherited via IControlAccessibilityInfo
     til::size GetFontSize() const noexcept override;
     til::rect GetBounds() const noexcept override;
-    double GetScaleFactor() const noexcept override;
+    float GetScaleFactor() const noexcept override;
     void ChangeViewport(const til::inclusive_rect& NewWindow) override;
     HRESULT GetHostUiaProvider(IRawElementProviderSimple** provider) noexcept override;
     til::rect GetPadding() const noexcept override;