bool FontPlatformData::hasSpaceInLigaturesOrKerning(
TypesettingFeatures features) const
{
const HarfBuzzFace* hbFace = harfBuzzFace();
if (!hbFace)
return false;
hb_face_t* face = hbFace->face();
ASSERT(face);
OwnPtr<hb_font_t> font = adoptPtr(hbFace->createFont());
ASSERT(font);
hb_codepoint_t space;
// If the space glyph isn't present in the font then each space character
// will be rendering using a fallback font, which grantees that it cannot
// affect the shape of the preceding word.
if (!hb_font_get_glyph(font.get(), spaceCharacter, 0, &space))
return false;
if (!hb_ot_layout_has_substitution(face)
&& !hb_ot_layout_has_positioning(face)) {
return false;
}
bool foundSpaceInTable = false;
hb_set_t* glyphs = hb_set_create();
if (features & Kerning)
foundSpaceInTable = tableHasSpace(face, glyphs, HB_OT_TAG_GPOS, space);
if (!foundSpaceInTable && (features & Ligatures))
foundSpaceInTable = tableHasSpace(face, glyphs, HB_OT_TAG_GSUB, space);
hb_set_destroy(glyphs);
return foundSpaceInTable;
}
bool OpenTypeCapsSupport::supportsOpenTypeFeature(
hb_script_t script,
uint32_t tag) const
{
hb_face_t* face = hb_font_get_face(m_harfBuzzFace->getScaledFont());
ASSERT(face);
ASSERT((tag == HB_TAG('s', 'm', 'c', 'p')
|| tag == HB_TAG('c', '2', 's', 'c')
|| tag == HB_TAG('p', 'c', 'a', 'p')
|| tag == HB_TAG('c', '2', 'p', 'c')
|| tag == HB_TAG('s', 'u', 'p', 's')
|| tag == HB_TAG('s', 'u', 'b', 's')
|| tag == HB_TAG('t', 'i', 't', 'l')
|| tag == HB_TAG('u', 'n', 'i', 'c')
|| tag == HB_TAG('v', 'e', 'r', 't')));
bool result = false;
if (!hb_ot_layout_has_substitution(face))
return false;
// Get the OpenType tag(s) that match this script code
const size_t kMaxScriptTags = 4;
hb_tag_t scriptTags[kMaxScriptTags] = {
HB_TAG_NONE,
HB_TAG_NONE,
HB_TAG_NONE,
HB_TAG_NONE
};
hb_ot_tags_from_script(static_cast<hb_script_t>(script),
&scriptTags[0],
&scriptTags[1]);
// Replace the first remaining NONE with DEFAULT
for (size_t i = 0; i < kMaxScriptTags; ++i) {
if (scriptTags[i] == HB_TAG_NONE) {
scriptTags[i] = HB_OT_TAG_DEFAULT_SCRIPT;
break;
}
}
// Now check for 'smcp' under the first of those scripts that is present
const hb_tag_t kGSUB = HB_TAG('G', 'S', 'U', 'B');
for (size_t j = 0; j < kMaxScriptTags; ++j) {
if (scriptTags[j] == HB_TAG_NONE)
break;
unsigned scriptIndex;
if (hb_ot_layout_table_find_script(face,
kGSUB,
scriptTags[j],
&scriptIndex)) {
if (hb_ot_layout_language_find_feature(face, kGSUB,
scriptIndex,
HB_OT_LAYOUT_DEFAULT_LANGUAGE_INDEX,
tag, nullptr)) {
result = true;
}
break;
}
}
return result;
}