Fix font axes/features settings UI (#17164)

Due to #16821 everything about #16104 broke. This PR rights the wrongs
by rewriting all the `Font`-based code to not use `Font` at all.
Instead we split the font spec once into font families, do a lot of
complex logic to split font axes/features into used and unused ones
and construct all the UI elements. So. much. boilerplate. code.

Closes #16943

## Validation Steps Performed
There are more edge cases than I can list here... Some ideas:
* Edit the settings.json with invalid axis/feature keys ✅
* ...out of range values ✅
* Settings UI reloads when the settings.json changes ✅
* Adding axes/features works ✅
* Removing axes/features works ✅
* Resetting axes/features works ✅
* Axes/features apply in the renderer when saving ✅

doc/cascadia/profiles.schema.json

@@ -349,7 +349,7 @@
  "description": "Sets the DWrite font features for the given font. For example, { \"ss01\": 1, \"liga\":0 } will enable ss01 and disable ligatures.",
  "type": "object",
  "patternProperties": {
- "^(([A-Za-z0-9]){4})$": {
+ "^[\\x20-\\x7E]{4}$": {
  "type": "integer"
  }
  },
@@ -359,7 +359,7 @@
  "description": "Sets the DWrite font axes for the given font. For example, { \"wght\": 200 } will set the font weight to 200.",
  "type": "object",
  "patternProperties": {
- "^([A-Za-z]{4})$": {
+ "^[\\x20-\\x7E]{4}$": {
  "type": "number"
  }
  },

src/cascadia/TerminalControl/ControlCore.cpp

@@ -959,26 +959,23 @@ namespace winrt::Microsoft::Terminal::Control::implementation
 
  if (_renderEngine)
  {
- std::unordered_map<std::wstring_view, uint32_t> featureMap;
- if (const auto fontFeatures = _settings->FontFeatures())
- {
- featureMap.reserve(fontFeatures.Size());
-
- for (const auto& [tag, param] : fontFeatures)
+ static constexpr auto cloneMap = [](const IFontFeatureMap& map) {
+ std::unordered_map<std::wstring_view, float> clone;
+ if (map)
  {
- featureMap.emplace(tag, param);
+ clone.reserve(map.Size());
+ for (const auto& [tag, param] : map)
+ {
+ clone.emplace(tag, param);
+ }
  }
- }
- std::unordered_map<std::wstring_view, float> axesMap;
- if (const auto fontAxes = _settings->FontAxes())
- {
- axesMap.reserve(fontAxes.Size());
+ return clone;
+ };
 
- for (const auto& [axis, value] : fontAxes)
- {
- axesMap.emplace(axis, value);
- }
- }
+ const auto fontFeatures = _settings->FontFeatures();
+ const auto fontAxes = _settings->FontAxes();
+ const auto featureMap = cloneMap(fontFeatures);
+ const auto axesMap = cloneMap(fontAxes);
 
  // TODO: MSFT:20895307 If the font doesn't exist, this doesn't
  // actually fail. We need a way to gracefully fallback.

src/cascadia/TerminalControl/ControlSettings.h

@@ -10,7 +10,7 @@ Licensed under the MIT license.
 #include <conattrs.hpp>
 #include "ControlAppearance.h"
 
-using IFontFeatureMap = winrt::Windows::Foundation::Collections::IMap<winrt::hstring, uint32_t>;
+using IFontFeatureMap = winrt::Windows::Foundation::Collections::IMap<winrt::hstring, float>;
 using IFontAxesMap = winrt::Windows::Foundation::Collections::IMap<winrt::hstring, float>;
 
 namespace winrt::Microsoft::Terminal::Control::implementation

src/cascadia/TerminalControl/IControlSettings.idl

@@ -40,7 +40,7 @@ namespace Microsoft.Terminal.Control
  Single FontSize { get; };
  Windows.UI.Text.FontWeight FontWeight { get; };
  String Padding { get; };
- Windows.Foundation.Collections.IMap<String, UInt32> FontFeatures { get; };
+ Windows.Foundation.Collections.IMap<String, Single> FontFeatures { get; };
  Windows.Foundation.Collections.IMap<String, Single> FontAxes { get; };
  Boolean EnableBuiltinGlyphs { get; };
  Boolean EnableColorGlyphs { get; };