fix Font and FontAsset cache not completely refreshed when options change

Source/Editor/Windows/Assets/FontWindow.cs

@@ -141,7 +141,6 @@ namespace FlaxEditor.Windows.Assets
             if (assetOptions != options)
             {
                 Asset.Options = options;
-                Asset.Invalidate();
             }
         }
 

Source/Engine/Render2D/Font.cpp

@@ -112,6 +112,21 @@ void Font::CacheText(const StringView& text)
     }
 }
 
+void Font::Invalidate()
+{
+    ScopeLock lock(_asset->Locker);
+
+    FlushFaceSize();
+    const FT_Face face = _asset->GetFTFace();
+    ASSERT(face != nullptr);
+    _height = Convert26Dot6ToRoundedPixel<int32>(FT_MulFix(face->height, face->size->metrics.y_scale));
+    _hasKerning = FT_HAS_KERNING(face) != 0;
+    _ascender = Convert26Dot6ToRoundedPixel<int16>(face->size->metrics.ascender);
+    _descender = Convert26Dot6ToRoundedPixel<int16>(face->size->metrics.descender);
+    _lineGap = _height - _ascender + _descender;
+    _kerningTable.Clear();
+}
+
 void Font::ProcessText(const StringView& text, Array<FontLineCache, InlinedAllocation<8>>& outputLines, const TextLayoutOptions& layout)
 {
     int32 textLength = text.Length();
@@ -463,8 +478,7 @@ void Font::FlushFaceSize() const
 {
     // Set the character size
     const FT_Face face = _asset->GetFTFace();
-    FontOptions options = _asset->GetOptions();
-    float size = options.RasterMode == FontRasterMode::MSDF ? options.MSDFSize : _size;
+    float size = _asset->GetOptions().RasterMode == FontRasterMode::MSDF ? _asset->GetOptions().MSDFSize : _size;
     const FT_Error error = FT_Set_Char_Size(face, 0, ConvertPixelTo26Dot6<FT_F26Dot6>(size * FontManager::FontScale), DefaultDPI, DefaultDPI);
     if (error)
     {

Source/Engine/Render2D/Font.h

@@ -228,6 +228,11 @@ public:
     /// <param name="text">The text witch characters to cache.</param>
     API_FUNCTION() void CacheText(const StringView& text);
 
+    /// <summary>
+    /// Refresh cached metrics. Can be used after changing font asset options.
+    /// </summary>
+    API_FUNCTION() void Invalidate();
+
 public:
     /// <summary>
     /// Processes text to get cached lines for rendering.

Source/Engine/Render2D/FontAsset.cpp

@@ -101,6 +101,26 @@ FontFlags FontAsset::GetStyle() const
 void FontAsset::SetOptions(const FontOptions& value)
 {
     _options = value;
+    Invalidate();
+
+    if (_virtualBold)
+    {
+        auto options = _options;
+        options.Flags |= FontFlags::Bold;
+        _virtualBold->SetOptions(options);
+    }
+    if (_virtualItalic)
+    {
+        auto options = _options;
+        options.Flags |= FontFlags::Italic;
+        _virtualItalic->SetOptions(options);
+    }
+    if (_virtualMSDF)
+    {
+        auto options = _options;
+        options.RasterMode = FontRasterMode::MSDF;
+        _virtualMSDF->SetOptions(options);
+    }
 }
 
 Font* FontAsset::CreateFont(float size)
@@ -218,6 +238,10 @@ void FontAsset::Invalidate()
         FontManager::Invalidate(entry.Value);
 
     _characterCache.Clear();
+
+    // Refresh cached metrics of all fonts created from this asset
+    for (auto font : _fonts)
+        font->Invalidate();
 }
 
 uint64 FontAsset::GetMemoryUsage() const