Read the weight from the OS/2 table rather than asking CoreText

The weights reported by CT are only occasionally correlated with the
OS/2 weights, and GDI uses the latter.
This commit is contained in:
Thomas Goyne 2015-12-11 11:45:14 -08:00
parent 8e6c4ff3ba
commit f2b3b69b3f

View file

@ -23,8 +23,8 @@ namespace {
struct FontMatch {
NSURL *url;
NSCharacterSet *codepoints;
double weight;
double width;
int weight;
int width;
bool italic;
};
@ -34,84 +34,57 @@ void process_descriptor(NSFontDescriptor *font, std::vector<FontMatch>& out) {
if (!url)
return;
NSDictionary *attributes = [font objectForKey:NSFontTraitsAttribute];
double weight = [attributes[NSFontWeightTrait] doubleValue];
double width = [attributes[NSFontWidthTrait] doubleValue];
bool italic = [attributes[NSFontSlantTrait] doubleValue] > 0.03;
NSFont *nsfont = [NSFont fontWithDescriptor:font size:10];
auto traits = CTFontGetSymbolicTraits((__bridge CTFontRef)nsfont);
bool italic = !!(traits & kCTFontItalicTrait);
// CoreText sometimes reports a slant of zero (or a very small slant)
// despite the macStyle field indicating that the font is italic, so
// double check by reading that field from the ttf
if (!italic) @autoreleasepool {
NSFont *nsfont = [NSFont fontWithDescriptor:font size:10];
if (!italic) {
auto data = (__bridge_transfer NSData *)CTFontCopyTable((__bridge CTFontRef)nsfont, kCTFontTableHead, 0);
if (data.length > 45) {
italic = static_cast<const char *>(data.bytes)[45] & 2;
}
}
auto data = (__bridge_transfer NSData *)CTFontCopyTable((__bridge CTFontRef)nsfont, kCTFontTableOS2, 0);
if (data.length < 6)
return;
auto bytes = static_cast<const uint8_t *>(data.bytes);
int weight = (bytes[4] << 8) + bytes[5];
int width = (bytes[6] << 8) + bytes[7];
out.push_back({url, [font objectForKey:NSFontCharacterSetAttribute], weight, width, italic});
}
void select_best(CollectionResult& ret, std::vector<FontMatch>& options, double bold,
void select_best(CollectionResult& ret, std::vector<FontMatch>& options, int bold,
bool italic, std::vector<int> const& characters) {
if (options.empty())
return;
// Prioritize fonts with the width closest to normal
sort(begin(options), end(options), [](FontMatch const& lft, FontMatch const& rgt) {
return std::abs(lft.width) < std::abs(rgt.width);
return std::abs(lft.width - 100) < std::abs(rgt.width - 100);
});
const FontMatch *match = nullptr;
auto check_weight = [&](FontMatch const& m) {
if (m.weight < bold)
return false;
if (match && m.weight >= match->weight)
return false;
return true;
};
auto check_slant = [&](FontMatch const& m) {
return (italic && m.italic) || (!italic && !m.italic);
};
// First look for the best valid match
for (auto const& m : options) {
if (check_slant(m) && check_weight(m))
if (italic == m.italic && (!match || std::abs(match->weight - bold + 1) > std::abs(m.weight - bold + 1)))
match = &m;
}
if (!match) {
// Either none are italic, or none are heavy enough
// Just pick the heaviest one (italic if applicable)
for (auto const& m : options) {
if (!check_slant(m) || (match && m.weight >= match->weight))
continue;
match = &m;
ret.fake_bold = bold > 0;
}
}
if (!match) {
// We want italic but there is none, or we want regular and there is
// only italic. Don't complain about fake italic in the latter case.
ret.fake_italic = italic;
for (auto const& m : options) {
if (check_weight(m))
if (!match || std::abs(match->weight - bold + 1) > std::abs(m.weight - bold + 1))
match = &m;
}
}
if (!match) {
// No correct weight match even in non-italic, so just pick the heaviest
ret.fake_bold = bold > 0;
for (auto const& m : options) {
if (match && m.weight >= match->weight)
continue;
match = &m;
}
}
ret.fake_bold = bold > 400 && match->weight < bold;
auto& best = *match;
ret.paths.push_back(best.url.fileSystemRepresentation);
@ -128,23 +101,10 @@ CollectionResult CoreTextFontFileLister::GetFontPaths(std::string const& facenam
std::vector<int> const& characters) {
CollectionResult ret;
double desired_weight;
if (bold == 0)
desired_weight = 0;
bold = 400;
else if (bold == 1)
desired_weight = 0.4;
else if (bold < 400)
desired_weight = -0.4;
else if (bold < 500)
desired_weight = 0;
else if (bold < 600)
desired_weight = 0.23;
else if (bold < 700)
desired_weight = 0.3;
else if (bold < 800)
desired_weight = 0.4;
else
desired_weight = 0.62;
bold = 700;
std::vector<FontMatch> fonts;
@autoreleasepool {
@ -160,7 +120,7 @@ CollectionResult CoreTextFontFileLister::GetFontPaths(std::string const& facenam
for (NSFontDescriptor *desc in font_collection.matchingDescriptors) {
process_descriptor(desc, fonts);
}
select_best(ret, fonts, desired_weight, italic, characters);
select_best(ret, fonts, bold, italic, characters);
}
return ret;