Add support for passing through extended text attributes, like… (#2917)

## Summary of the Pull Request
Adds support for Italics, Blinking, Invisible, CrossedOut text, THROUGH CONPTY. This does **NOT** add support for those styles to conhost or the terminal.

We will store these "Extended Text Attributes" in a `TextAttribute`. When we go to render a line, we'll see if the state has changed from our previous state, and if so, we'll appropriately toggle that state with VT. Boldness has been moved from a `bool` to a single bit in these flags.

Technically, now that these are stored in the buffer, we only need to make changes to the renderers to be able to support them. That's not being done as a part of this PR however.

## References
See also #2915 and #2916, which are some follow-up tasks from this fix. I thought them too risky for 20H1.

## PR Checklist
* [x] Closes #2554
* [x] I work here
* [x] Tests added/passed
* [n/a] Requires documentation to be updated


<hr>

* store text with extended attributes too

* Plumb attributes through all the renderers

* parse extended attrs, though we're not renderering them right

* Render these states correctly

* Add a very extensive test

* Cleanup for PR

* a block of PR feedback

* add 512 test cases

* Fix the build

* Fix @carlos-zamora's suggestions

* @miniksa's PR feedback

src/buffer/out/TextAttribute.cpp

@@ -44,7 +44,7 @@ COLORREF TextAttribute::CalculateRgbBackground(std::basic_string_view<COLORREF>
 COLORREF TextAttribute::_GetRgbForeground(std::basic_string_view<COLORREF> colorTable,
                                           COLORREF defaultColor) const noexcept
 {
-    return _foreground.GetColor(colorTable, defaultColor, _isBold);
+    return _foreground.GetColor(colorTable, defaultColor, IsBold());
 }
 
 // Routine Description:
@@ -155,11 +155,6 @@ void TextAttribute::SetColor(const COLORREF rgbColor, const bool fIsForeground)
     }
 }
 
-bool TextAttribute::IsBold() const noexcept
-{
-    return _isBold;
-}
-
 bool TextAttribute::_IsReverseVideo() const noexcept
 {
     return WI_IsFlagSet(_wAttrLegacy, COMMON_LVB_REVERSE_VIDEO);
@@ -215,6 +210,11 @@ void TextAttribute::Debolden() noexcept
     _SetBoldness(false);
 }
 
+void TextAttribute::SetExtendedAttributes(const ExtendedAttributes attrs) noexcept
+{
+    _extendedAttrs = attrs;
+}
+
 // Routine Description:
 // - swaps foreground and background color
 void TextAttribute::Invert() noexcept
@@ -224,7 +224,7 @@ void TextAttribute::Invert() noexcept
 
 void TextAttribute::_SetBoldness(const bool isBold) noexcept
 {
-    _isBold = isBold;
+    WI_UpdateFlag(_extendedAttrs, ExtendedAttributes::Bold, isBold);
 }
 
 void TextAttribute::SetDefaultForeground() noexcept

src/buffer/out/TextAttribute.hpp

@@ -27,22 +27,24 @@ Revision History:
 #include "WexTestClass.h"
 #endif
 
+#pragma pack(push, 1)
+
 class TextAttribute final
 {
 public:
     constexpr TextAttribute() noexcept :
         _wAttrLegacy{ 0 },
         _foreground{},
         _background{},
-        _isBold{ false }
+        _extendedAttrs{ ExtendedAttributes::Normal }
     {
     }
 
     constexpr TextAttribute(const WORD wLegacyAttr) noexcept :
         _wAttrLegacy{ gsl::narrow_cast<WORD>(wLegacyAttr & META_ATTRS) },
         _foreground{ gsl::narrow_cast<BYTE>(wLegacyAttr & FG_ATTRS) },
         _background{ gsl::narrow_cast<BYTE>((wLegacyAttr & BG_ATTRS) >> 4) },
-        _isBold{ false }
+        _extendedAttrs{ ExtendedAttributes::Normal }
     {
         // If we're given lead/trailing byte information with the legacy color, strip it.
         WI_ClearAllFlags(_wAttrLegacy, COMMON_LVB_SBCSDBCS);
@@ -53,7 +55,7 @@ class TextAttribute final
         _wAttrLegacy{ 0 },
         _foreground{ rgbForeground },
         _background{ rgbBackground },
-        _isBold{ false }
+        _extendedAttrs{ ExtendedAttributes::Normal }
     {
     }
 
@@ -62,7 +64,7 @@ class TextAttribute final
         const BYTE fg = (_foreground.GetIndex() & FG_ATTRS);
         const BYTE bg = (_background.GetIndex() << 4) & BG_ATTRS;
         const WORD meta = (_wAttrLegacy & META_ATTRS);
-        return (fg | bg | meta) | (_isBold ? FOREGROUND_INTENSITY : 0);
+        return (fg | bg | meta) | (IsBold() ? FOREGROUND_INTENSITY : 0);
     }
 
     // Method Description:
@@ -85,7 +87,7 @@ class TextAttribute final
         const BYTE fg = (fgIndex & FG_ATTRS);
         const BYTE bg = (bgIndex << 4) & BG_ATTRS;
         const WORD meta = (_wAttrLegacy & META_ATTRS);
-        return (fg | bg | meta) | (_isBold ? FOREGROUND_INTENSITY : 0);
+        return (fg | bg | meta) | (IsBold() ? FOREGROUND_INTENSITY : 0);
     }
 
     COLORREF CalculateRgbForeground(std::basic_string_view<COLORREF> colorTable,
@@ -131,7 +133,18 @@ class TextAttribute final
     friend constexpr bool operator!=(const WORD& legacyAttr, const TextAttribute& attr) noexcept;
 
     bool IsLegacy() const noexcept;
-    bool IsBold() const noexcept;
+
+    constexpr bool IsBold() const noexcept
+    {
+        return WI_IsFlagSet(_extendedAttrs, ExtendedAttributes::Bold);
+    }
+
+    constexpr ExtendedAttributes GetExtendedAttributes() const noexcept
+    {
+        return _extendedAttrs;
+    }
+
+    void SetExtendedAttributes(const ExtendedAttributes attrs) noexcept;
 
     void SetForeground(const COLORREF rgbForeground) noexcept;
     void SetBackground(const COLORREF rgbBackground) noexcept;
@@ -159,7 +172,7 @@ class TextAttribute final
     WORD _wAttrLegacy;
     TextColor _foreground;
     TextColor _background;
-    bool _isBold;
+    ExtendedAttributes _extendedAttrs;
 
 #ifdef UNIT_TESTING
     friend class TextBufferTests;
@@ -169,6 +182,13 @@ class TextAttribute final
 #endif
 };
 
+#pragma pack(pop)
+// 2 for _wAttrLegacy
+// 4 for _foreground
+// 4 for _background
+// 1 for _extendedAttrs
+static_assert(sizeof(TextAttribute) <= 11 * sizeof(BYTE), "We should only need 11B for an entire TextColor. Any more than that is just waste");
+
 enum class TextAttributeBehavior
 {
     Stored, // use contained text attribute
@@ -181,7 +201,7 @@ constexpr bool operator==(const TextAttribute& a, const TextAttribute& b) noexce
     return a._wAttrLegacy == b._wAttrLegacy &&
            a._foreground == b._foreground &&
            a._background == b._background &&
-           a._isBold == b._isBold;
+           a._extendedAttrs == b._extendedAttrs;
 }
 
 constexpr bool operator!=(const TextAttribute& a, const TextAttribute& b) noexcept

src/cascadia/TerminalCore/TerminalDispatchGraphics.cpp

@@ -103,7 +103,7 @@ bool TerminalDispatch::_SetRgbColorsHelper(_In_reads_(cOptions) const DispatchTy
             isForeground = false;
         }
 
-        if (typeOpt == DispatchTypes::GraphicsOptions::RGBColor && cOptions >= 5)
+        if (typeOpt == DispatchTypes::GraphicsOptions::RGBColorOrFaint && cOptions >= 5)
         {
             *pcOptionsConsumed = 5;
             // ensure that each value fits in a byte
@@ -115,7 +115,7 @@ bool TerminalDispatch::_SetRgbColorsHelper(_In_reads_(cOptions) const DispatchTy
 
             fSuccess = _terminalApi.SetTextRgbColor(color, isForeground);
         }
-        else if (typeOpt == DispatchTypes::GraphicsOptions::Xterm256Index && cOptions >= 3)
+        else if (typeOpt == DispatchTypes::GraphicsOptions::BlinkOrXterm256Index && cOptions >= 3)
         {
             *pcOptionsConsumed = 3;
             if (rgOptions[2] <= 255) // ensure that the provided index is on the table

src/host/getset.cpp

@@ -981,6 +981,39 @@ void DoSrvPrivateBoldText(SCREEN_INFORMATION& screenInfo, const bool bolded)
     buffer.SetAttributes(attrs);
 }
 
+// Method Description:
+// - Retrieves the active ExtendedAttributes (italic, underline, etc.) of the
+//   given screen buffer. Text written to this buffer will be written with these
+//   attributes.
+// Arguments:
+// - screenInfo: The buffer to get the extended attrs from.
+// Return Value:
+// - the currently active ExtendedAttributes.
+ExtendedAttributes DoSrvPrivateGetExtendedTextAttributes(SCREEN_INFORMATION& screenInfo)
+{
+    auto& buffer = screenInfo.GetActiveBuffer();
+    auto attrs = buffer.GetAttributes();
+    return attrs.GetExtendedAttributes();
+}
+
+// Method Description:
+// - Sets the active ExtendedAttributes (italic, underline, etc.) of the given
+//   screen buffer. Text written to this buffer will be written with these
+//   attributes.
+// Arguments:
+// - screenInfo: The buffer to set the extended attrs for.
+// - extendedAttrs: The new ExtendedAttributes to use
+// Return Value:
+// - <none>
+void DoSrvPrivateSetExtendedTextAttributes(SCREEN_INFORMATION& screenInfo,
+                                           const ExtendedAttributes extendedAttrs)
+{
+    auto& buffer = screenInfo.GetActiveBuffer();
+    auto attrs = buffer.GetAttributes();
+    attrs.SetExtendedAttributes(extendedAttrs);
+    buffer.SetAttributes(attrs);
+}
+
 // Routine Description:
 // - Sets the codepage used for translating text when calling A versions of functions affecting the output buffer.
 // Arguments:

src/host/getset.h

@@ -60,6 +60,9 @@ void DoSrvPrivateSetConsoleRGBTextAttribute(SCREEN_INFORMATION& screenInfo,
 
 void DoSrvPrivateBoldText(SCREEN_INFORMATION& screenInfo, const bool bolded);
 
+ExtendedAttributes DoSrvPrivateGetExtendedTextAttributes(SCREEN_INFORMATION& screenInfo);
+void DoSrvPrivateSetExtendedTextAttributes(SCREEN_INFORMATION& screenInfo, const ExtendedAttributes attrs);
+
 [[nodiscard]] NTSTATUS DoSrvPrivateEraseAll(SCREEN_INFORMATION& screenInfo);
 
 void DoSrvSetCursorStyle(SCREEN_INFORMATION& screenInfo,

src/host/outputStream.cpp

@@ -273,6 +273,32 @@ BOOL ConhostInternalGetSet::PrivateBoldText(const bool bolded)
     return TRUE;
 }
 
+// Method Description:
+// - Retrieves the currently active ExtendedAttributes. See also
+//   DoSrvPrivateGetExtendedTextAttributes
+// Arguments:
+// - pAttrs: Recieves the ExtendedAttributes value.
+// Return Value:
+// - TRUE if successful (see DoSrvPrivateGetExtendedTextAttributes). FALSE otherwise.
+BOOL ConhostInternalGetSet::PrivateGetExtendedTextAttributes(ExtendedAttributes* const pAttrs)
+{
+    *pAttrs = DoSrvPrivateGetExtendedTextAttributes(_io.GetActiveOutputBuffer());
+    return TRUE;
+}
+
+// Method Description:
+// - Sets the active ExtendedAttributes of the active screen buffer. Text
+//   written to this buffer will be written with these attributes.
+// Arguments:
+// - extendedAttrs: The new ExtendedAttributes to use
+// Return Value:
+// - TRUE if successful (see DoSrvPrivateSetExtendedTextAttributes). FALSE otherwise.
+BOOL ConhostInternalGetSet::PrivateSetExtendedTextAttributes(const ExtendedAttributes attrs)
+{
+    DoSrvPrivateSetExtendedTextAttributes(_io.GetActiveOutputBuffer(), attrs);
+    return TRUE;
+}
+
 // Routine Description:
 // - Connects the WriteConsoleInput API call directly into our Driver Message servicing call inside Conhost.exe
 // Arguments:

src/host/outputStream.hpp

@@ -88,6 +88,8 @@ class ConhostInternalGetSet final : public Microsoft::Console::VirtualTerminal::
                                     const bool fIsForeground) override;
 
     BOOL PrivateBoldText(const bool bolded) override;
+    BOOL PrivateGetExtendedTextAttributes(ExtendedAttributes* const pAttrs) override;
+    BOOL PrivateSetExtendedTextAttributes(const ExtendedAttributes attrs) override;
 
     BOOL PrivateWriteConsoleInputW(_Inout_ std::deque<std::unique_ptr<IInputEvent>>& events,
                                    _Out_ size_t& eventsWritten) override;