void HarfBuzzShaper::setGlyphPositionsForHarfBuzzRun(HarfBuzzRun* currentRun, hb_buffer_t* harfBuzzBuffer)
{
const SimpleFontData* currentFontData = currentRun->fontData();
hb_glyph_info_t* glyphInfos = hb_buffer_get_glyph_infos(harfBuzzBuffer, 0);
hb_glyph_position_t* glyphPositions = hb_buffer_get_glyph_positions(harfBuzzBuffer, 0);
unsigned numGlyphs = currentRun->numGlyphs();
uint16_t* glyphToCharacterIndexes = currentRun->glyphToCharacterIndexes();
float totalAdvance = 0;
// HarfBuzz returns the shaping result in visual order. We need not to flip for RTL.
for (size_t i = 0; i < numGlyphs; ++i) {
bool runEnd = i + 1 == numGlyphs;
uint16_t glyph = glyphInfos[i].codepoint;
float offsetX = harfBuzzPositionToFloat(glyphPositions[i].x_offset);
float offsetY = -harfBuzzPositionToFloat(glyphPositions[i].y_offset);
float advance = harfBuzzPositionToFloat(glyphPositions[i].x_advance);
unsigned currentCharacterIndex = currentRun->startIndex() + glyphInfos[i].cluster;
bool isClusterEnd = runEnd || glyphInfos[i].cluster != glyphInfos[i + 1].cluster;
float spacing = 0;
glyphToCharacterIndexes[i] = glyphInfos[i].cluster;
if (isClusterEnd && !Font::treatAsZeroWidthSpace(m_normalizedBuffer[currentCharacterIndex]))
spacing += m_letterSpacing;
if (isClusterEnd && isWordEnd(currentCharacterIndex))
spacing += determineWordBreakSpacing();
if (currentFontData->isZeroWidthSpaceGlyph(glyph)) {
currentRun->setGlyphAndPositions(i, glyph, 0, 0, 0);
continue;
}
advance += spacing;
if (m_run.rtl()) {
// In RTL, spacing should be added to left side of glyphs.
offsetX += spacing;
if (!isClusterEnd)
offsetX += m_letterSpacing;
}
currentRun->setGlyphAndPositions(i, glyph, advance, offsetX, offsetY);
totalAdvance += advance;
}
currentRun->setWidth(totalAdvance > 0.0 ? totalAdvance : 0.0);
m_totalWidth += currentRun->width();
}
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();
}
void ComplexTextController::setGlyphPositions(bool isRTL)
{
const double rtlFlip = isRTL ? -1 : 1;
double position = 0;
// logClustersIndex indexes logClusters for the first codepoint of the current glyph.
// Each time we advance a glyph, we skip over all the codepoints that contributed to the current glyph.
int logClustersIndex = 0;
// Iterate through the glyphs in logical order, flipping for RTL where necessary.
// Glyphs are positioned starting from m_offsetX; in RTL mode they go leftwards from there.
for (size_t i = 0; i < m_item.num_glyphs; ++i) {
while (static_cast<unsigned>(logClustersIndex) < m_item.item.length && m_item.log_clusters[logClustersIndex] < i)
logClustersIndex++;
// If the current glyph is just after a space, add in the word spacing.
position += determineWordBreakSpacing(logClustersIndex);
m_glyphs16[i] = m_item.glyphs[i];
double offsetX = truncateFixedPointToInteger(m_item.offsets[i].x);
double offsetY = truncateFixedPointToInteger(m_item.offsets[i].y);
double advance = truncateFixedPointToInteger(m_item.advances[i]);
if (isRTL)
offsetX -= advance;
m_positions[i].set(m_offsetX + (position * rtlFlip) + offsetX,
m_startingY + offsetY);
if (m_currentFontData->isZeroWidthSpaceGlyph(m_glyphs16[i]))
continue;
// At the end of each cluster, add in the letter spacing.
if (i + 1 == m_item.num_glyphs || m_item.attributes[i + 1].clusterStart)
position += m_letterSpacing;
position += advance;
}
m_pixelWidth = std::max(position, 0.0);
m_offsetX += m_pixelWidth * rtlFlip;
}
