Add support for the "faint" graphic rendition attribute

src/buffer/out/TextAttribute.cpp

@@ -97,6 +97,10 @@ std::pair<COLORREF, COLORREF> TextAttribute::CalculateRgbColors(const std::basic
 {
     auto fg = _foreground.GetColor(colorTable, defaultFgColor, IsBold());
     auto bg = _background.GetColor(colorTable, defaultBgColor);
+    if (IsFaint())
+    {
+        fg = (fg >> 1) & 0x7F7F7F; // Divide foreground color components by two.
+    }
     if (IsReverseVideo() ^ reverseScreenMode)
     {
         std::swap(fg, bg);
@@ -211,6 +215,11 @@ bool TextAttribute::IsBold() const noexcept
     return WI_IsFlagSet(_extendedAttrs, ExtendedAttributes::Bold);
 }
 
+bool TextAttribute::IsFaint() const noexcept
+{
+    return WI_IsFlagSet(_extendedAttrs, ExtendedAttributes::Faint);
+}
+
 bool TextAttribute::IsItalic() const noexcept
 {
     return WI_IsFlagSet(_extendedAttrs, ExtendedAttributes::Italics);
@@ -252,6 +261,11 @@ void TextAttribute::SetBold(bool isBold) noexcept
     WI_UpdateFlag(_extendedAttrs, ExtendedAttributes::Bold, isBold);
 }
 
+void TextAttribute::SetFaint(bool isFaint) noexcept
+{
+    WI_UpdateFlag(_extendedAttrs, ExtendedAttributes::Faint, isFaint);
+}
+
 void TextAttribute::SetItalics(bool isItalic) noexcept
 {
     WI_UpdateFlag(_extendedAttrs, ExtendedAttributes::Italics, isItalic);

src/buffer/out/TextAttribute.hpp

@@ -89,6 +89,7 @@ class TextAttribute final
 
     bool IsLegacy() const noexcept;
     bool IsBold() const noexcept;
+    bool IsFaint() const noexcept;
     bool IsItalic() const noexcept;
     bool IsBlinking() const noexcept;
     bool IsInvisible() const noexcept;
@@ -98,6 +99,7 @@ class TextAttribute final
     bool IsReverseVideo() const noexcept;
 
     void SetBold(bool isBold) noexcept;
+    void SetFaint(bool isFaint) noexcept;
     void SetItalics(bool isItalic) noexcept;
     void SetBlinking(bool isBlinking) noexcept;
     void SetInvisible(bool isInvisible) noexcept;

src/buffer/out/ut_textbuffer/TextAttributeTests.cpp

@@ -130,6 +130,7 @@ void TextAttributeTests::TestRoundtripExhaustive()
 void TextAttributeTests::TestTextAttributeColorGetters()
 {
     const COLORREF red = RGB(255, 0, 0);
+    const COLORREF faintRed = RGB(127, 0, 0);
     const COLORREF green = RGB(0, 255, 0);
     TextAttribute attr(red, green);
     auto view = _GetTableView();
@@ -149,6 +150,25 @@ void TextAttributeTests::TestTextAttributeColorGetters()
     VERIFY_ARE_EQUAL(red, attr.GetForeground().GetColor(view, _defaultFg));
     VERIFY_ARE_EQUAL(green, attr.GetBackground().GetColor(view, _defaultBg));
     VERIFY_ARE_EQUAL(std::make_pair(green, red), attr.CalculateRgbColors(view, _defaultFg, _defaultBg));
+
+    // reset the reverse video
+    attr.SetReverseVideo(false);
+
+    // with faint set, the calculated foreground value should be fainter
+    //      while the background and getters stay the same
+    attr.SetFaint(true);
+
+    VERIFY_ARE_EQUAL(red, attr.GetForeground().GetColor(view, _defaultFg));
+    VERIFY_ARE_EQUAL(green, attr.GetBackground().GetColor(view, _defaultBg));
+    VERIFY_ARE_EQUAL(std::make_pair(faintRed, green), attr.CalculateRgbColors(view, _defaultFg, _defaultBg));
+
+    // with reverse video set, calculated foreground/background values should be
+    //      switched, and the background fainter, while getters stay the same
+    attr.SetReverseVideo(true);
+
+    VERIFY_ARE_EQUAL(red, attr.GetForeground().GetColor(view, _defaultFg));
+    VERIFY_ARE_EQUAL(green, attr.GetBackground().GetColor(view, _defaultBg));
+    VERIFY_ARE_EQUAL(std::make_pair(green, faintRed), attr.CalculateRgbColors(view, _defaultFg, _defaultBg));
 }
 
 void TextAttributeTests::TestReverseDefaultColors()

src/cascadia/TerminalCore/TerminalDispatchGraphics.cpp

@@ -118,8 +118,12 @@ bool TerminalDispatch::SetGraphicsRendition(const std::basic_string_view<Dispatc
         case BoldBright:
             attr.SetBold(true);
             break;
-        case UnBold:
+        case RGBColorOrFaint:
+            attr.SetFaint(true);
+            break;
+        case NotBoldOrFaint:
             attr.SetBold(false);
+            attr.SetFaint(false);
             break;
         case Italics:
             attr.SetItalics(true);

src/host/ut_host/ScreenBufferTests.cpp

@@ -5014,14 +5014,16 @@ void ScreenBufferTests::TestExtendedTextAttributes()
     // Run this test for each and every possible combination of states.
     BEGIN_TEST_METHOD_PROPERTIES()
         TEST_METHOD_PROPERTY(L"Data:bold", L"{false, true}")
+        TEST_METHOD_PROPERTY(L"Data:faint", L"{false, true}")
         TEST_METHOD_PROPERTY(L"Data:italics", L"{false, true}")
         TEST_METHOD_PROPERTY(L"Data:blink", L"{false, true}")
         TEST_METHOD_PROPERTY(L"Data:invisible", L"{false, true}")
         TEST_METHOD_PROPERTY(L"Data:crossedOut", L"{false, true}")
     END_TEST_METHOD_PROPERTIES()
 
-    bool bold, italics, blink, invisible, crossedOut;
+    bool bold, faint, italics, blink, invisible, crossedOut;
     VERIFY_SUCCEEDED(TestData::TryGetValue(L"bold", bold));
+    VERIFY_SUCCEEDED(TestData::TryGetValue(L"faint", faint));
     VERIFY_SUCCEEDED(TestData::TryGetValue(L"italics", italics));
     VERIFY_SUCCEEDED(TestData::TryGetValue(L"blink", blink));
     VERIFY_SUCCEEDED(TestData::TryGetValue(L"invisible", invisible));
@@ -5043,6 +5045,11 @@ void ScreenBufferTests::TestExtendedTextAttributes()
         WI_SetFlag(expectedAttrs, ExtendedAttributes::Bold);
         vtSeq += L"\x1b[1m";
     }
+    if (faint)
+    {
+        WI_SetFlag(expectedAttrs, ExtendedAttributes::Faint);
+        vtSeq += L"\x1b[2m";
+    }
     if (italics)
     {
         WI_SetFlag(expectedAttrs, ExtendedAttributes::Italics);
@@ -5100,9 +5107,10 @@ void ScreenBufferTests::TestExtendedTextAttributes()
 
     // One-by-one, turn off each of these states with VT, then check that the
     // state matched.
-    if (bold)
+    if (bold || faint)
     {
-        WI_ClearFlag(expectedAttrs, ExtendedAttributes::Bold);
+        // The bold and faint attributes share the same reset sequence.
+        WI_ClearAllFlags(expectedAttrs, ExtendedAttributes::Bold | ExtendedAttributes::Faint);
         vtSeq = L"\x1b[22m";
         validate(expectedAttrs, vtSeq);
     }
@@ -5147,6 +5155,7 @@ void ScreenBufferTests::TestExtendedTextAttributesWithColors()
     // Run this test for each and every possible combination of states.
     BEGIN_TEST_METHOD_PROPERTIES()
         TEST_METHOD_PROPERTY(L"Data:bold", L"{false, true}")
+        TEST_METHOD_PROPERTY(L"Data:faint", L"{false, true}")
         TEST_METHOD_PROPERTY(L"Data:italics", L"{false, true}")
         TEST_METHOD_PROPERTY(L"Data:blink", L"{false, true}")
         TEST_METHOD_PROPERTY(L"Data:invisible", L"{false, true}")
@@ -5162,8 +5171,9 @@ void ScreenBufferTests::TestExtendedTextAttributesWithColors()
     const int Use256Color = 2;
     const int UseRGBColor = 3;
 
-    bool bold, italics, blink, invisible, crossedOut;
+    bool bold, faint, italics, blink, invisible, crossedOut;
     VERIFY_SUCCEEDED(TestData::TryGetValue(L"bold", bold));
+    VERIFY_SUCCEEDED(TestData::TryGetValue(L"faint", faint));
     VERIFY_SUCCEEDED(TestData::TryGetValue(L"italics", italics));
     VERIFY_SUCCEEDED(TestData::TryGetValue(L"blink", blink));
     VERIFY_SUCCEEDED(TestData::TryGetValue(L"invisible", invisible));
@@ -5189,6 +5199,11 @@ void ScreenBufferTests::TestExtendedTextAttributesWithColors()
         expectedAttr.SetBold(true);
         vtSeq += L"\x1b[1m";
     }
+    if (faint)
+    {
+        expectedAttr.SetFaint(true);
+        vtSeq += L"\x1b[2m";
+    }
     if (italics)
     {
         expectedAttr.SetItalics(true);
@@ -5290,9 +5305,11 @@ void ScreenBufferTests::TestExtendedTextAttributesWithColors()
 
     // One-by-one, turn off each of these states with VT, then check that the
     // state matched.
-    if (bold)
+    if (bold || faint)
     {
+        // The bold and faint attributes share the same reset sequence.
         expectedAttr.SetBold(false);
+        expectedAttr.SetFaint(false);
         vtSeq = L"\x1b[22m";
         validate(expectedAttr, vtSeq);
     }

src/host/ut_host/VtRendererTests.cpp

@@ -660,13 +660,15 @@ void VtRendererTest::Xterm256TestExtendedAttributes()
 {
     // Run this test for each and every possible combination of states.
     BEGIN_TEST_METHOD_PROPERTIES()
+        TEST_METHOD_PROPERTY(L"Data:faint", L"{false, true}")
         TEST_METHOD_PROPERTY(L"Data:italics", L"{false, true}")
         TEST_METHOD_PROPERTY(L"Data:blink", L"{false, true}")
         TEST_METHOD_PROPERTY(L"Data:invisible", L"{false, true}")
         TEST_METHOD_PROPERTY(L"Data:crossedOut", L"{false, true}")
     END_TEST_METHOD_PROPERTIES()
 
-    bool italics, blink, invisible, crossedOut;
+    bool faint, italics, blink, invisible, crossedOut;
+    VERIFY_SUCCEEDED(TestData::TryGetValue(L"faint", faint));
     VERIFY_SUCCEEDED(TestData::TryGetValue(L"italics", italics));
     VERIFY_SUCCEEDED(TestData::TryGetValue(L"blink", blink));
     VERIFY_SUCCEEDED(TestData::TryGetValue(L"invisible", invisible));
@@ -676,6 +678,12 @@ void VtRendererTest::Xterm256TestExtendedAttributes()
     std::vector<std::string> onSequences, offSequences;
 
     // Collect up a VT sequence to set the state given the method properties
+    if (faint)
+    {
+        desiredAttrs.SetFaint(true);
+        onSequences.push_back("\x1b[2m");
+        offSequences.push_back("\x1b[22m");
+    }
     if (italics)
     {
         desiredAttrs.SetItalics(true);
@@ -746,7 +754,7 @@ void VtRendererTest::Xterm256TestExtendedAttributes()
 void VtRendererTest::Xterm256TestAttributesAcrossReset()
 {
     BEGIN_TEST_METHOD_PROPERTIES()
-        TEST_METHOD_PROPERTY(L"Data:renditionAttribute", L"{1, 3, 4, 5, 7, 8, 9, 53}")
+        TEST_METHOD_PROPERTY(L"Data:renditionAttribute", L"{1, 2, 3, 4, 5, 7, 8, 9, 53}")
     END_TEST_METHOD_PROPERTIES()
 
     int renditionAttribute;
@@ -774,6 +782,10 @@ void VtRendererTest::Xterm256TestAttributesAcrossReset()
         Log::Comment(L"----Set Bold Attribute----");
         textAttributes.SetBold(true);
         break;
+    case GraphicsOptions::RGBColorOrFaint:
+        Log::Comment(L"----Set Faint Attribute----");
+        textAttributes.SetFaint(true);
+        break;
     case GraphicsOptions::Italics:
         Log::Comment(L"----Set Italics Attribute----");
         textAttributes.SetItalics(true);

src/inc/conattrs.hpp

@@ -19,7 +19,7 @@ enum class ExtendedAttributes : BYTE
     // TODO:GH#2916 add support for these to the parser as well.
     Underlined = 0x20, // _technically_ different from LVB_UNDERSCORE, see TODO:GH#2915
     DoublyUnderlined = 0x40, // Included for completeness, but not currently supported.
-    Faint = 0x80, // Included for completeness, but not currently supported.
+    Faint = 0x80,
 };
 DEFINE_ENUM_FLAG_OPERATORS(ExtendedAttributes);
 

src/renderer/vt/VtSequences.cpp

@@ -344,6 +344,17 @@ using namespace Microsoft::Console::Render;
     return _Write(isBold ? "\x1b[1m" : "\x1b[22m");
 }
 
+// Method Description:
+// - Formats and writes a sequence to change the faintness of the following text.
+// Arguments:
+// - isFaint: If true, we'll make the text faint. Otherwise we'll remove the faintness.
+// Return Value:
+// - S_OK if we succeeded, else an appropriate HRESULT for failing to allocate or write.
+[[nodiscard]] HRESULT VtEngine::_SetFaint(const bool isFaint) noexcept
+{
+    return _Write(isFaint ? "\x1b[2m" : "\x1b[22m");
+}
+
 // Method Description:
 // - Formats and writes a sequence to change the underline of the following text.
 // Arguments:

src/renderer/vt/Xterm256Engine.cpp

@@ -41,10 +41,28 @@ Xterm256Engine::Xterm256Engine(_In_ wil::unique_hfile hPipe,
 // - S_OK if we succeeded, else an appropriate HRESULT for failing to allocate or write.
 [[nodiscard]] HRESULT Xterm256Engine::_UpdateExtendedAttrs(const TextAttribute& textAttributes) noexcept
 {
-    if (textAttributes.IsBold() != _lastTextAttributes.IsBold())
+    // Turning off Bold and Faint must be handled at the same time,
+    // since there is only one sequence that resets both of them.
+    const auto boldTurnedOff = !textAttributes.IsBold() && _lastTextAttributes.IsBold();
+    const auto faintTurnedOff = !textAttributes.IsFaint() && _lastTextAttributes.IsFaint();
+    if (boldTurnedOff || faintTurnedOff)
     {
-        RETURN_IF_FAILED(_SetBold(textAttributes.IsBold()));
-        _lastTextAttributes.SetBold(textAttributes.IsBold());
+        RETURN_IF_FAILED(_SetBold(false));
+        _lastTextAttributes.SetBold(false);
+        _lastTextAttributes.SetFaint(false);
+    }
+
+    // Once we've handled the cases where they need to be turned off,
+    // we can then check if either should be turned back on again.
+    if (textAttributes.IsBold() && !_lastTextAttributes.IsBold())
+    {
+        RETURN_IF_FAILED(_SetBold(true));
+        _lastTextAttributes.SetBold(true);
+    }
+    if (textAttributes.IsFaint() && !_lastTextAttributes.IsFaint())
+    {
+        RETURN_IF_FAILED(_SetFaint(true));
+        _lastTextAttributes.SetFaint(true);
     }
 
     if (textAttributes.IsUnderlined() != _lastTextAttributes.IsUnderlined())

src/renderer/vt/vtrenderer.hpp

@@ -186,6 +186,7 @@ namespace Microsoft::Console::Render
         [[nodiscard]] HRESULT _ResizeWindow(const short sWidth, const short sHeight) noexcept;
 
         [[nodiscard]] HRESULT _SetBold(const bool isBold) noexcept;
+        [[nodiscard]] HRESULT _SetFaint(const bool isFaint) noexcept;
         [[nodiscard]] HRESULT _SetUnderline(const bool isUnderlined) noexcept;
         [[nodiscard]] HRESULT _SetOverline(const bool isUnderlined) noexcept;
         [[nodiscard]] HRESULT _SetItalics(const bool isItalic) noexcept;

src/terminal/adapter/DispatchTypes.hpp

@@ -28,7 +28,7 @@ namespace Microsoft::Console::VirtualTerminal::DispatchTypes
         Invisible = 8,
         CrossedOut = 9,
         DoublyUnderlined = 21,
-        UnBold = 22,
+        NotBoldOrFaint = 22,
         NotItalics = 23,
         NoUnderline = 24,
         Steady = 25, // _not_ blink

src/terminal/adapter/adaptDispatchGraphics.cpp

@@ -127,8 +127,12 @@ bool AdaptDispatch::SetGraphicsRendition(const std::basic_string_view<DispatchTy
             case BoldBright:
                 attr.SetBold(true);
                 break;
-            case UnBold:
+            case RGBColorOrFaint:
+                attr.SetFaint(true);
+                break;
+            case NotBoldOrFaint:
                 attr.SetBold(false);
+                attr.SetFaint(false);
                 break;
             case Italics:
                 attr.SetItalics(true);

src/terminal/adapter/ut_adapter/adapterTest.cpp

@@ -1261,7 +1261,7 @@ class AdapterTest
     TEST_METHOD(GraphicsSingleTests)
     {
         BEGIN_TEST_METHOD_PROPERTIES()
-            TEST_METHOD_PROPERTY(L"Data:uiGraphicsOptions", L"{0, 1, 4, 7, 24, 27, 30, 31, 32, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 53, 55, 90, 91, 92, 93, 94, 95, 96, 97, 100, 101, 102, 103, 104, 105, 106, 107}") // corresponds to options in DispatchTypes::GraphicsOptions
+            TEST_METHOD_PROPERTY(L"Data:uiGraphicsOptions", L"{0, 1, 2, 4, 7, 22, 24, 27, 30, 31, 32, 33, 34, 35, 36, 37, 39, 40, 41, 42, 43, 44, 45, 46, 47, 49, 53, 55, 90, 91, 92, 93, 94, 95, 96, 97, 100, 101, 102, 103, 104, 105, 106, 107}") // corresponds to options in DispatchTypes::GraphicsOptions
         END_TEST_METHOD_PROPERTIES()
 
         Log::Comment(L"Starting test...");
@@ -1290,6 +1290,12 @@ class AdapterTest
             _testGetSet->_expectedAttribute = TextAttribute{ 0 };
             _testGetSet->_expectedAttribute.SetBold(true);
             break;
+        case DispatchTypes::GraphicsOptions::RGBColorOrFaint:
+            Log::Comment(L"Testing graphics 'Faint'");
+            _testGetSet->_attribute = TextAttribute{ 0 };
+            _testGetSet->_expectedAttribute = TextAttribute{ 0 };
+            _testGetSet->_expectedAttribute.SetFaint(true);
+            break;
         case DispatchTypes::GraphicsOptions::Underline:
             Log::Comment(L"Testing graphics 'Underline'");
             _testGetSet->_attribute = TextAttribute{ 0 };
@@ -1305,6 +1311,13 @@ class AdapterTest
             _testGetSet->_attribute = TextAttribute{ 0 };
             _testGetSet->_expectedAttribute = TextAttribute{ COMMON_LVB_REVERSE_VIDEO };
             break;
+        case DispatchTypes::GraphicsOptions::NotBoldOrFaint:
+            Log::Comment(L"Testing graphics 'No Bold or Faint'");
+            _testGetSet->_attribute = TextAttribute{ 0 };
+            _testGetSet->_attribute.SetBold(true);
+            _testGetSet->_attribute.SetFaint(true);
+            _testGetSet->_expectedAttribute = TextAttribute{ 0 };
+            break;
         case DispatchTypes::GraphicsOptions::NoUnderline:
             Log::Comment(L"Testing graphics 'No Underline'");
             _testGetSet->_attribute = TextAttribute{ COMMON_LVB_UNDERSCORE };