[coretext] Use kCTFontOpenTypeFeatureTag

Instead of trying to map OpenType features to AAT feature selectors
which only works for a small subset of OpenType features, use the
simpler kCTFontOpenTypeFeatureTag with OpenType feature tags directly.

With this change, features like cvXX can be enabled in coretext shaper,
while they were previously ignored due to missing mapping.

This seems to work even with AAT fonts that don’t have OpenType layout
tables, which suggests that CoreText is doing the mapping itself in this
case.

kCTFontOpenTypeFeatureTag seems to have been introduced in macOS 10.10
and iOS 8.0, though, so its use is conditional on version check for now.
Not sure how to check iOS version, so I left this out.
This commit is contained in:
Khaled Hosny 2019-12-18 15:57:14 +02:00 committed by Behdad Esfahbod
parent b28c282585
commit 68c1798a67
1 changed files with 19 additions and 1 deletions

View File

@ -475,13 +475,19 @@ _hb_coretext_shape (hb_shape_plan_t *shape_plan,
hb_vector_t<feature_event_t> feature_events;
for (unsigned int i = 0; i < num_features; i++)
{
active_feature_t feature;
#if MAC_OS_X_VERSION_MIN_REQUIRED < 1010
const hb_aat_feature_mapping_t * mapping = hb_aat_layout_find_feature_mapping (features[i].tag);
if (!mapping)
continue;
active_feature_t feature;
feature.rec.feature = mapping->aatFeatureType;
feature.rec.setting = features[i].value ? mapping->selectorToEnable : mapping->selectorToDisable;
#else
feature.rec.feature = features[i].tag;
feature.rec.setting = features[i].value;
#endif
feature.order = i;
feature_event_t *event;
@ -530,6 +536,7 @@ _hb_coretext_shape (hb_shape_plan_t *shape_plan,
/* active_features.qsort (); */
for (unsigned int j = 0; j < active_features.length; j++)
{
#if MAC_OS_X_VERSION_MIN_REQUIRED < 1010
CFStringRef keys[] = {
kCTFontFeatureTypeIdentifierKey,
kCTFontFeatureSelectorIdentifierKey
@ -538,6 +545,17 @@ _hb_coretext_shape (hb_shape_plan_t *shape_plan,
CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &active_features[j].rec.feature),
CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &active_features[j].rec.setting)
};
#else
char tag[5] = {HB_UNTAG (active_features[j].rec.feature)};
CFTypeRef keys[] = {
kCTFontOpenTypeFeatureTag,
kCTFontOpenTypeFeatureValue
};
CFTypeRef values[] = {
CFStringCreateWithCString (kCFAllocatorDefault, tag, kCFStringEncodingASCII),
CFNumberCreate (kCFAllocatorDefault, kCFNumberIntType, &active_features[j].rec.setting)
};
#endif
static_assert ((ARRAY_LENGTH_CONST (keys) == ARRAY_LENGTH_CONST (values)), "");
CFDictionaryRef dict = CFDictionaryCreate (kCFAllocatorDefault,
(const void **) keys,