bool HarfBuzzShaper::shapeHarfBuzzRuns(bool shouldSetDirection)
{
HarfBuzzScopedPtr<hb_buffer_t> harfBuzzBuffer(hb_buffer_create(), hb_buffer_destroy);
hb_buffer_set_unicode_funcs(harfBuzzBuffer.get(), hb_icu_get_unicode_funcs());
for (unsigned i = 0; i < m_harfBuzzRuns.size(); ++i) {
unsigned runIndex = m_run.rtl() ? m_harfBuzzRuns.size() - i - 1 : i;
HarfBuzzRun* currentRun = m_harfBuzzRuns[runIndex].get();
const SimpleFontData* currentFontData = currentRun->fontData();
if (currentFontData->isSVGFont())
return false;
hb_buffer_set_script(harfBuzzBuffer.get(), currentRun->script());
if (shouldSetDirection)
hb_buffer_set_direction(harfBuzzBuffer.get(), currentRun->rtl() ? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
else
// Leaving direction to HarfBuzz to guess is *really* bad, but will do for now.
hb_buffer_guess_segment_properties(harfBuzzBuffer.get());
// Add a space as pre-context to the buffer. This prevents showing dotted-circle
// for combining marks at the beginning of runs.
static const uint16_t preContext = ' ';
hb_buffer_add_utf16(harfBuzzBuffer.get(), &preContext, 1, 1, 0);
if (m_font->isSmallCaps() && u_islower(m_normalizedBuffer[currentRun->startIndex()])) {
String upperText = String(m_normalizedBuffer.get() + currentRun->startIndex(), currentRun->numCharacters());
upperText.makeUpper();
currentFontData = m_font->glyphDataForCharacter(upperText[0], false, SmallCapsVariant).fontData;
hb_buffer_add_utf16(harfBuzzBuffer.get(), upperText.characters(), currentRun->numCharacters(), 0, currentRun->numCharacters());
} else
hb_buffer_add_utf16(harfBuzzBuffer.get(), m_normalizedBuffer.get() + currentRun->startIndex(), currentRun->numCharacters(), 0, currentRun->numCharacters());
FontPlatformData* platformData = const_cast<FontPlatformData*>(¤tFontData->platformData());
HarfBuzzFace* face = platformData->harfBuzzFace();
if (!face)
return false;
if (m_font->fontDescription().orientation() == Vertical)
face->setScriptForVerticalGlyphSubstitution(harfBuzzBuffer.get());
HarfBuzzScopedPtr<hb_font_t> harfBuzzFont(face->createFont(), hb_font_destroy);
hb_shape(harfBuzzFont.get(), harfBuzzBuffer.get(), m_features.isEmpty() ? 0 : m_features.data(), m_features.size());
currentRun->applyShapeResult(harfBuzzBuffer.get());
setGlyphPositionsForHarfBuzzRun(currentRun, harfBuzzBuffer.get());
hb_buffer_reset(harfBuzzBuffer.get());
}
return true;
}
void HarfBuzzShaper::setGlyphPositionsForHarfBuzzRun(GlyphBuffer* glyphBuffer)
{
hb_glyph_info_t* glyphInfos = hb_buffer_get_glyph_infos(m_harfbuzzBuffer, 0);
hb_glyph_position_t* glyphPositions = hb_buffer_get_glyph_positions(m_harfbuzzBuffer, 0);
HarfBuzzRun* currentRun = m_harfbuzzRuns.last().get();
unsigned numGlyphs = currentRun->numGlyphs();
float totalAdvance = 0;
float nextOffsetX = harfbuzzPositionToFloat(glyphPositions[0].x_offset);
float nextOffsetY = -harfbuzzPositionToFloat(glyphPositions[0].y_offset);
// HarfBuzz returns the shaping result in visual order. We need not to flip them for RTL.
for (size_t i = 0; i < numGlyphs; ++i) {
bool runEnd = i + 1 == numGlyphs;
uint16_t glyph = glyphInfos[i].codepoint;
float offsetX = nextOffsetX;
float offsetY = nextOffsetY;
float advance = harfbuzzPositionToFloat(glyphPositions[i].x_advance);
nextOffsetX = runEnd ? 0 : harfbuzzPositionToFloat(glyphPositions[i + 1].x_offset);
nextOffsetY = runEnd ? 0 : -harfbuzzPositionToFloat(glyphPositions[i + 1].y_offset);
unsigned currentCharacterIndex = m_startIndexOfCurrentRun + glyphInfos[i].cluster;
bool isClusterEnd = runEnd || glyphInfos[i].cluster != glyphInfos[i + 1].cluster;
float spacing = isClusterEnd ? m_letterSpacing : 0;
if (isClusterEnd && isWordEnd(currentCharacterIndex))
spacing += determineWordBreakSpacing();
if (m_currentFontData->isZeroWidthSpaceGlyph(glyph)) {
currentRun->setGlyphAndPositions(i, glyph, 0, 0, 0);
if (glyphBuffer)
glyphBuffer->add(glyph, m_currentFontData, createGlyphBufferAdvance(0, 0));
continue;
}
advance += spacing;
currentRun->setGlyphAndPositions(i, glyph, totalAdvance + offsetX, offsetY, advance);
if (glyphBuffer) {
float glyphAdvanceX = advance + nextOffsetX - offsetX;
float glyphAdvanceY = nextOffsetY - offsetY;
glyphBuffer->add(glyph, m_currentFontData, createGlyphBufferAdvance(glyphAdvanceX, glyphAdvanceY));
}
totalAdvance += advance;
}
currentRun->setWidth(totalAdvance > 0.0 ? totalAdvance : 0.0);
m_totalWidth += currentRun->width();
}
bool HarfBuzzShaper::shapeHarfBuzzRuns()
{
HarfBuzzScopedPtr<hb_buffer_t> harfbuzzBuffer(hb_buffer_create(), hb_buffer_destroy);
hb_buffer_set_unicode_funcs(harfbuzzBuffer.get(), hb_icu_get_unicode_funcs());
if (m_run.rtl() || m_run.directionalOverride())
hb_buffer_set_direction(harfbuzzBuffer.get(), m_run.rtl() ? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
for (unsigned i = 0; i < m_harfbuzzRuns.size(); ++i) {
unsigned runIndex = m_run.rtl() ? m_harfbuzzRuns.size() - i - 1 : i;
HarfBuzzRun* currentRun = m_harfbuzzRuns[runIndex].get();
const SimpleFontData* currentFontData = currentRun->fontData();
if (m_font->isSmallCaps() && u_islower(m_normalizedBuffer[currentRun->startIndex()])) {
String upperText = String(m_normalizedBuffer.get() + currentRun->startIndex(), currentRun->numCharacters());
upperText.makeUpper();
currentFontData = m_font->glyphDataForCharacter(upperText[0], false, SmallCapsVariant).fontData;
hb_buffer_add_utf16(harfbuzzBuffer.get(), upperText.characters(), currentRun->numCharacters(), 0, currentRun->numCharacters());
} else
hb_buffer_add_utf16(harfbuzzBuffer.get(), m_normalizedBuffer.get() + currentRun->startIndex(), currentRun->numCharacters(), 0, currentRun->numCharacters());
FontPlatformData* platformData = const_cast<FontPlatformData*>(¤tFontData->platformData());
HarfBuzzNGFace* face = platformData->harfbuzzFace();
if (!face)
return false;
HarfBuzzScopedPtr<hb_font_t> harfbuzzFont(face->createFont(), hb_font_destroy);
hb_shape(harfbuzzFont.get(), harfbuzzBuffer.get(), m_features.isEmpty() ? 0 : m_features.data(), m_features.size());
currentRun->applyShapeResult(harfbuzzBuffer.get());
setGlyphPositionsForHarfBuzzRun(currentRun, harfbuzzBuffer.get());
hb_buffer_reset(harfbuzzBuffer.get());
if (m_run.rtl() || m_run.directionalOverride())
hb_buffer_set_direction(harfbuzzBuffer.get(), m_run.rtl() ? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
}
return true;
}
