Fix shaping for text that uses a single CR for line breaking

sysfce2 · Jun 10, 2024 · c2b4610 · c2b4610
1 parent c4d5ffa
commit c2b4610
Showing 1 changed file with 9 additions and 6 deletions.
diff --git a/modules/juce_graphics/fonts/juce_SimpleShapedText.cpp b/modules/juce_graphics/fonts/juce_SimpleShapedText.cpp
@@ -381,7 +381,8 @@ static std::vector<ShapedGlyph> lowLevelShape (const String& string,
  // Adding the converted portion of the text with hb_buffer_add_utf32() or especially with
  // hb_buffer_add() gives us control over cluster numbers. hb_buffer_add_utf32() will increment
  // cluster numbers by unicode codepoints (as opposed to UTF8 bytes) starting from 0.
- auto utf32Ptr = string.toUTF32() + (int) range.getStart();
+ auto utf32Span = Span { string.toUTF32().getAddress() + (size_t) range.getStart(),
+ (size_t) range.getLength() };
 
  // TODO(ati) This should be configurable in case someone wants to implement a "display whitespace" functionality
  // We're using a word joiner (zero width non-breaking space) followed by a non-breaking space
@@ -391,11 +392,12 @@ static std::vector<ShapedGlyph> lowLevelShape (const String& string,
 
  const auto numLineEndsToReplace = [&]
  {
- const auto chunkLength = (int) range.getLength();
+ constexpr auto lf = 0x0a;
+ constexpr auto cr = 0x0d;
 
- if (chunkLength >= 1 && utf32Ptr[chunkLength - 1] == 0xa)
+ if (! utf32Span.empty() && (utf32Span.back() == lf || utf32Span.back() == cr))
  {
- if (chunkLength >= 2 && utf32Ptr[chunkLength - 2] == 0xd)
+ if (utf32Span.size() >= 2 && utf32Span[utf32Span.size() - 2] == cr)
  return 2;
 
  return 1;
@@ -405,7 +407,7 @@ static std::vector<ShapedGlyph> lowLevelShape (const String& string,
  }();
 
  hb_buffer_add_utf32 (buffer.get(),
- (uint32_t*) utf32Ptr.getAddress(),
+ (uint32_t*) utf32Span.data(),
  (int) range.getLength() - numLineEndsToReplace,
  (unsigned int) 0,
  (int) range.getLength() - numLineEndsToReplace);
@@ -467,7 +469,8 @@ static std::vector<ShapedGlyph> lowLevelShape (const String& string,
  });
 
  // It this is hit, the typeface can't display one or more characters.
- // This normally shouldn't happen if font fallback is enabled.
+ // This normally shouldn't happen if font fallback is enabled, unless the String contains
+ // control characters that JUCE doesn't know how to handle appropriately.
  jassert (unknownGlyph == infos.end());
 
  [[maybe_unused]] const auto trackingAmount = (! HB_DIRECTION_IS_VERTICAL (direction) && ! trackingIsDefault)