Enable vintage opacity on Windows 10 (#14481)

This reverts #11372 and #11285, and brings #11180 to everyone, now that MSFT:37879806 has been serviced to everyone in [KB5011831](https://support.microsoft.com/en-gb/topic/april-25-2022-kb5011831-os-builds-19042-1682-19043-1682-and-19044-1682-preview-fe4ff411-d25a-4185-aabb-8bc66e9dbb6c)[1].

I tested this on my home Win10 laptop that's super old and doesn't have a functioning clock, but it does have that update at the very least.

I don't think we had an issue tracking this?

[1]: I'm pretty sure about this at least

(cherry picked from commit a5c5b8a)
Service-Card-Id: 87176746
Service-Version: 1.16

src/cascadia/TerminalControl/ControlCore.cpp

@@ -604,13 +604,8 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         // Update our runtime opacity value
         _runtimeOpacity = newOpacity;
 
-        // GH#11285 - If the user is on Windows 10, and they changed the
-        // transparency of the control s.t. it should be partially opaque, then
-        // opt them in to acrylic. It's the only way to have transparency on
-        // Windows 10.
-        // We'll also turn the acrylic back off when they're fully opaque, which
-        // is what the Terminal did prior to 1.12.
-        _runtimeUseAcrylic = newOpacity < 1.0 && (!IsVintageOpacityAvailable() || _settings->UseAcrylic());
+        // Manually turn off acrylic if they turn off transparency.
+        _runtimeUseAcrylic = newOpacity < 1.0 && _settings->UseAcrylic();
 
         // Update the renderer as well. It might need to fall back from
         // cleartype -> grayscale if the BG is transparent / acrylic.
@@ -736,13 +731,11 @@ namespace winrt::Microsoft::Terminal::Control::implementation
 
         auto lock = _terminal->LockForWriting();
 
-        // GH#11285 - If the user is on Windows 10, and they wanted opacity, but
-        // didn't explicitly request acrylic, then opt them in to acrylic.
-        // On Windows 11+, this isn't needed, because we can have vintage opacity.
-        // Instead, disable acrylic while the opacity is 100%
-        _runtimeUseAcrylic = _settings->Opacity() < 1.0 && (!IsVintageOpacityAvailable() || _settings->UseAcrylic());
         _runtimeOpacity = std::nullopt;
 
+        // Manually turn off acrylic if they turn off transparency.
+        _runtimeUseAcrylic = _settings->Opacity() < 1.0 && _settings->UseAcrylic();
+
         const auto sizeChanged = _setFontSizeUnderLock(_settings->FontSize());
 
         // Update the terminal core with its new Core settings
@@ -1759,22 +1752,6 @@ namespace winrt::Microsoft::Terminal::Control::implementation
         return hstring(ss.str());
     }
 
-    // Helper to check if we're on Windows 11 or not. This is used to check if
-    // we need to use acrylic to achieve transparency, because vintage opacity
-    // doesn't work in islands on win10.
-    // Remove when we can remove the rest of GH#11285
-    bool ControlCore::IsVintageOpacityAvailable() noexcept
-    {
-        OSVERSIONINFOEXW osver{};
-        osver.dwOSVersionInfoSize = sizeof(osver);
-        osver.dwBuildNumber = 22000;
-
-        DWORDLONG dwlConditionMask = 0;
-        VER_SET_CONDITION(dwlConditionMask, VER_BUILDNUMBER, VER_GREATER_EQUAL);
-
-        return VerifyVersionInfoW(&osver, VER_BUILDNUMBER, dwlConditionMask) != FALSE;
-    }
-
     Core::Scheme ControlCore::ColorScheme() const noexcept
     {
         Core::Scheme s;

src/cascadia/TerminalSettingsEditor/ProfileViewModel.cpp

@@ -51,22 +51,6 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
                 // NOTE: this is similar to what is done with BackgroundImagePath above
                 _NotifyChanges(L"UseParentProcessDirectory", L"UseCustomStartingDirectory");
             }
-            else if (viewModelProperty == L"UseAcrylic")
-            {
-                // GH#11372: If we're on Windows 10, and someone turns off
-                // acrylic, we're going to disable opacity for them. Opacity
-                // doesn't work without acrylic on Windows 10.
-                //
-                // BODGY: CascadiaSettings's function IsDefaultTerminalAvailable
-                // is basically a "are we on Windows 11" check, because defterm
-                // only works on Win11. So we'll use that.
-                //
-                // Remove when we can remove the rest of GH#11285
-                if (!UseAcrylic() && !CascadiaSettings::IsDefaultTerminalAvailable())
-                {
-                    Opacity(1.0);
-                }
-            }
             else if (viewModelProperty == L"AntialiasingMode")
             {
                 _NotifyChanges(L"CurrentAntiAliasingMode");

src/cascadia/TerminalSettingsEditor/ProfileViewModel.h

@@ -35,21 +35,6 @@ namespace winrt::Microsoft::Terminal::Settings::Editor::implementation
         void SetAcrylicOpacityPercentageValue(double value)
         {
             Opacity(winrt::Microsoft::Terminal::Settings::Editor::Converters::PercentageValueToPercentage(value));
-
-            // GH#11372: If we're on Windows 10, and someone wants opacity, then
-            // we'll turn acrylic on for them. Opacity doesn't work without
-            // acrylic on Windows 10.
-            //
-            // BODGY: CascadiaSettings's function IsDefaultTerminalAvailable
-            // is basically a "are we on Windows 11" check, because defterm
-            // only works on Win11. So we'll use that.
-            //
-            // Remove when we can remove the rest of GH#11285
-            if (value < 100.0 &&
-                !winrt::Microsoft::Terminal::Settings::Model::CascadiaSettings::IsDefaultTerminalAvailable())
-            {
-                UseAcrylic(true);
-            }
         };
 
         void SetPadding(double value)

src/cascadia/UnitTests_Control/ControlCoreTests.cpp

@@ -142,8 +142,8 @@ namespace ControlUnitTests
             // requested acrylic.
 
             auto expectedUseAcrylic = expectedOpacity < 1.0;
+            VERIFY_IS_TRUE(core->_settings->UseAcrylic());
             VERIFY_ARE_EQUAL(expectedUseAcrylic, core->UseAcrylic());
-            VERIFY_ARE_EQUAL(true, core->_settings->UseAcrylic());
         };
         core->TransparencyChanged(opacityCallback);
 

src/cascadia/UnitTests_Control/ControlInteractivityTests.cpp

@@ -145,7 +145,7 @@ namespace ControlUnitTests
             VERIFY_ARE_EQUAL(0.5, settings->Opacity());
 
             auto expectedUseAcrylic = expectedOpacity < 1.0 &&
-                                      (!winrt::Microsoft::Terminal::Control::implementation::ControlCore::IsVintageOpacityAvailable() || useAcrylic);
+                                      (useAcrylic);
             VERIFY_ARE_EQUAL(useAcrylic, settings->UseAcrylic());
             VERIFY_ARE_EQUAL(expectedUseAcrylic, core->UseAcrylic());
         };