// TODO crbug.com/542701: This should be a method on ShapeResult.
void HarfBuzzShaper::insertRunIntoShapeResult(ShapeResult* result,
PassOwnPtr<ShapeResult::RunInfo> runToInsert, unsigned startGlyph, unsigned numGlyphs,
hb_buffer_t* harfBuzzBuffer)
{
ASSERT(numGlyphs > 0);
OwnPtr<ShapeResult::RunInfo> run(std::move(runToInsert));
ASSERT(numGlyphs == run->m_glyphData.size());
const SimpleFontData* currentFontData = run->m_fontData.get();
const hb_glyph_info_t* glyphInfos = hb_buffer_get_glyph_infos(harfBuzzBuffer, 0);
const hb_glyph_position_t* glyphPositions = hb_buffer_get_glyph_positions(harfBuzzBuffer, 0);
const unsigned startCluster = HB_DIRECTION_IS_FORWARD(hb_buffer_get_direction(harfBuzzBuffer))
? glyphInfos[startGlyph].cluster : glyphInfos[startGlyph + numGlyphs - 1].cluster;
float totalAdvance = 0.0f;
FloatPoint glyphOrigin;
bool hasVerticalOffsets = !HB_DIRECTION_IS_HORIZONTAL(run->m_direction);
// HarfBuzz returns result in visual order, no need to flip for RTL.
for (unsigned i = 0; i < numGlyphs; ++i) {
uint16_t glyph = glyphInfos[startGlyph + i].codepoint;
float offsetX = harfBuzzPositionToFloat(glyphPositions[startGlyph + i].x_offset);
float offsetY = -harfBuzzPositionToFloat(glyphPositions[startGlyph + i].y_offset);
// One out of x_advance and y_advance is zero, depending on
// whether the buffer direction is horizontal or vertical.
float advance = harfBuzzPositionToFloat(glyphPositions[startGlyph + i].x_advance - glyphPositions[startGlyph + i].y_advance);
RELEASE_ASSERT(m_normalizedBufferLength > glyphInfos[startGlyph + i].cluster);
// The characterIndex of one ShapeResult run is normalized to the run's
// startIndex and length. TODO crbug.com/542703: Consider changing that
// and instead pass the whole run to hb_buffer_t each time.
run->m_glyphData[i].characterIndex = glyphInfos[startGlyph + i].cluster - startCluster;
run->setGlyphAndPositions(i, glyph, advance, offsetX, offsetY);
totalAdvance += advance;
hasVerticalOffsets |= (offsetY != 0);
FloatRect glyphBounds = currentFontData->boundsForGlyph(glyph);
glyphBounds.move(glyphOrigin.x(), glyphOrigin.y());
result->m_glyphBoundingBox.unite(glyphBounds);
glyphOrigin += FloatSize(advance + offsetX, offsetY);
}
run->m_width = std::max(0.0f, totalAdvance);
result->m_width += run->m_width;
result->m_numGlyphs += numGlyphs;
ASSERT(result->m_numGlyphs >= numGlyphs); // no overflow
result->m_hasVerticalOffsets |= hasVerticalOffsets;
// The runs are stored in result->m_runs in visual order. For LTR, we place
// the run to be inserted before the next run with a bigger character
// start index. For RTL, we place the run before the next run with a lower
// character index. Otherwise, for both directions, at the end.
if (HB_DIRECTION_IS_FORWARD(run->m_direction)) {
for (size_t pos = 0; pos < result->m_runs.size(); ++pos) {
if (result->m_runs.at(pos)->m_startIndex > run->m_startIndex) {
result->m_runs.insert(pos, run.release());
break;
}
}
} else {
for (size_t pos = 0; pos < result->m_runs.size(); ++pos) {
if (result->m_runs.at(pos)->m_startIndex < run->m_startIndex) {
result->m_runs.insert(pos, run.release());
break;
}
}
}
// If we didn't find an existing slot to place it, append.
if (run) {
result->m_runs.append(run.release());
}
}
bool HarfBuzzShaper::extractShapeResults(hb_buffer_t* harfBuzzBuffer,
ShapeResult* shapeResult,
bool& fontCycleQueued, const HolesQueueItem& currentQueueItem,
const SimpleFontData* currentFont,
UScriptCode currentRunScript,
bool isLastResort)
{
enum ClusterResult {
Shaped,
NotDef,
Unknown
};
ClusterResult currentClusterResult = Unknown;
ClusterResult previousClusterResult = Unknown;
unsigned previousCluster = 0;
unsigned currentCluster = 0;
// Find first notdef glyph in harfBuzzBuffer.
unsigned numGlyphs = hb_buffer_get_length(harfBuzzBuffer);
hb_glyph_info_t* glyphInfo = hb_buffer_get_glyph_infos(harfBuzzBuffer, 0);
unsigned lastChangePosition = 0;
if (!numGlyphs) {
DLOG(ERROR) << "HarfBuzz returned empty glyph buffer after shaping.";
return false;
}
for (unsigned glyphIndex = 0; glyphIndex <= numGlyphs; ++glyphIndex) {
// Iterating by clusters, check for when the state switches from shaped
// to non-shaped and vice versa. Taking into account the edge cases of
// beginning of the run and end of the run.
previousCluster = currentCluster;
currentCluster = glyphInfo[glyphIndex].cluster;
if (glyphIndex < numGlyphs) {
// Still the same cluster, merge shaping status.
if (previousCluster == currentCluster && glyphIndex != 0) {
if (glyphInfo[glyphIndex].codepoint == 0) {
currentClusterResult = NotDef;
} else {
// We can only call the current cluster fully shapped, if
// all characters that are part of it are shaped, so update
// currentClusterResult to Shaped only if the previous
// characters have been shaped, too.
currentClusterResult = currentClusterResult == Shaped ? Shaped : NotDef;
}
continue;
}
// We've moved to a new cluster.
previousClusterResult = currentClusterResult;
currentClusterResult = glyphInfo[glyphIndex].codepoint == 0 ? NotDef : Shaped;
} else {
// The code below operates on the "flanks"/changes between NotDef
// and Shaped. In order to keep the code below from explictly
// dealing with character indices and run end, we explicitly
// terminate the cluster/run here by setting the result value to the
// opposite of what it was, leading to atChange turning true.
previousClusterResult = currentClusterResult;
currentClusterResult = currentClusterResult == NotDef ? Shaped : NotDef;
}
bool atChange = (previousClusterResult != currentClusterResult) && previousClusterResult != Unknown;
if (!atChange)
continue;
// Compute the range indices of consecutive shaped or .notdef glyphs.
// Cluster information for RTL runs becomes reversed, e.g. character 0
// has cluster index 5 in a run of 6 characters.
unsigned numCharacters = 0;
unsigned numGlyphsToInsert = 0;
unsigned startIndex = 0;
if (HB_DIRECTION_IS_FORWARD(hb_buffer_get_direction(harfBuzzBuffer))) {
startIndex = glyphInfo[lastChangePosition].cluster;
if (glyphIndex == numGlyphs) {
numCharacters = currentQueueItem.m_startIndex + currentQueueItem.m_numCharacters - glyphInfo[lastChangePosition].cluster;
numGlyphsToInsert = numGlyphs - lastChangePosition;
} else {
numCharacters = glyphInfo[glyphIndex].cluster - glyphInfo[lastChangePosition].cluster;
numGlyphsToInsert = glyphIndex - lastChangePosition;
}
} else {
// Direction Backwards
startIndex = glyphInfo[glyphIndex - 1].cluster;
if (lastChangePosition == 0) {
numCharacters = currentQueueItem.m_startIndex + currentQueueItem.m_numCharacters - glyphInfo[glyphIndex - 1].cluster;
} else {
numCharacters = glyphInfo[lastChangePosition - 1].cluster - glyphInfo[glyphIndex - 1].cluster;
}
numGlyphsToInsert = glyphIndex - lastChangePosition;
}
if (currentClusterResult == Shaped && !isLastResort) {
// Now it's clear that we need to continue processing.
if (!fontCycleQueued) {
appendToHolesQueue(HolesQueueNextFont, 0, 0);
fontCycleQueued = true;
}
// Here we need to put character positions.
ASSERT(numCharacters);
appendToHolesQueue(HolesQueueRange, startIndex, numCharacters);
}
// If numCharacters is 0, that means we hit a NotDef before shaping the
// whole grapheme. We do not append it here. For the next glyph we
// encounter, atChange will be true, and the characters corresponding to
// the grapheme will be added to the TODO queue again, attempting to
// shape the whole grapheme with the next font.
// When we're getting here with the last resort font, we have no other
// choice than adding boxes to the ShapeResult.
if ((currentClusterResult == NotDef && numCharacters) || isLastResort) {
hb_direction_t direction = TextDirectionToHBDirection(
m_textRun.direction(),
m_font->getFontDescription().orientation(), currentFont);
// Here we need to specify glyph positions.
ShapeResult::RunInfo* run = new ShapeResult::RunInfo(currentFont,
direction, ICUScriptToHBScript(currentRunScript),
startIndex, numGlyphsToInsert, numCharacters);
shapeResult->insertRun(adoptPtr(run), lastChangePosition,
numGlyphsToInsert,
harfBuzzBuffer);
}
lastChangePosition = glyphIndex;
}
return true;
}
void ShapeResult::insertRun(std::unique_ptr<ShapeResult::RunInfo> runToInsert,
unsigned startGlyph,
unsigned numGlyphs,
hb_buffer_t* harfBuzzBuffer) {
ASSERT(numGlyphs > 0);
std::unique_ptr<ShapeResult::RunInfo> run(std::move(runToInsert));
ASSERT(numGlyphs == run->m_glyphData.size());
const SimpleFontData* currentFontData = run->m_fontData.get();
const hb_glyph_info_t* glyphInfos =
hb_buffer_get_glyph_infos(harfBuzzBuffer, 0);
const hb_glyph_position_t* glyphPositions =
hb_buffer_get_glyph_positions(harfBuzzBuffer, 0);
const unsigned startCluster =
HB_DIRECTION_IS_FORWARD(hb_buffer_get_direction(harfBuzzBuffer))
? glyphInfos[startGlyph].cluster
: glyphInfos[startGlyph + numGlyphs - 1].cluster;
float totalAdvance = 0.0f;
FloatPoint glyphOrigin;
bool hasVerticalOffsets = !HB_DIRECTION_IS_HORIZONTAL(run->m_direction);
// HarfBuzz returns result in visual order, no need to flip for RTL.
for (unsigned i = 0; i < numGlyphs; ++i) {
uint16_t glyph = glyphInfos[startGlyph + i].codepoint;
hb_glyph_position_t pos = glyphPositions[startGlyph + i];
float offsetX = harfBuzzPositionToFloat(pos.x_offset);
float offsetY = -harfBuzzPositionToFloat(pos.y_offset);
// One out of x_advance and y_advance is zero, depending on
// whether the buffer direction is horizontal or vertical.
// Convert to float and negate to avoid integer-overflow for ULONG_MAX.
float advance;
if (LIKELY(pos.x_advance))
advance = harfBuzzPositionToFloat(pos.x_advance);
else
advance = -harfBuzzPositionToFloat(pos.y_advance);
run->m_glyphData[i].characterIndex =
glyphInfos[startGlyph + i].cluster - startCluster;
run->setGlyphAndPositions(i, glyph, advance, offsetX, offsetY);
totalAdvance += advance;
hasVerticalOffsets |= (offsetY != 0);
FloatRect glyphBounds = currentFontData->boundsForGlyph(glyph);
glyphBounds.move(glyphOrigin.x(), glyphOrigin.y());
m_glyphBoundingBox.unite(glyphBounds);
glyphOrigin += FloatSize(advance + offsetX, offsetY);
}
run->m_width = std::max(0.0f, totalAdvance);
m_width += run->m_width;
m_numGlyphs += numGlyphs;
ASSERT(m_numGlyphs >= numGlyphs);
m_hasVerticalOffsets |= hasVerticalOffsets;
// The runs are stored in result->m_runs in visual order. For LTR, we place
// the run to be inserted before the next run with a bigger character
// start index. For RTL, we place the run before the next run with a lower
// character index. Otherwise, for both directions, at the end.
if (HB_DIRECTION_IS_FORWARD(run->m_direction)) {
for (size_t pos = 0; pos < m_runs.size(); ++pos) {
if (m_runs.at(pos)->m_startIndex > run->m_startIndex) {
m_runs.insert(pos, std::move(run));
break;
}
}
} else {
for (size_t pos = 0; pos < m_runs.size(); ++pos) {
if (m_runs.at(pos)->m_startIndex < run->m_startIndex) {
m_runs.insert(pos, std::move(run));
break;
}
}
}
// If we didn't find an existing slot to place it, append.
if (run)
m_runs.append(std::move(run));
}
