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HarfBuzzShaper.cpp
697 lines (606 loc) · 27.2 KB
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HarfBuzzShaper.cpp
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/*
* Copyright (c) 2012 Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "HarfBuzzShaper.h"
#include "FontCascade.h"
#include "HarfBuzzFace.h"
#include "SurrogatePairAwareTextIterator.h"
#include <hb-icu.h>
#include <unicode/normlzr.h>
#include <unicode/uchar.h>
#include <wtf/MathExtras.h>
#include <wtf/StdLibExtras.h>
#include <wtf/text/StringView.h>
namespace WebCore {
template<typename T>
class HarfBuzzScopedPtr {
public:
typedef void (*DestroyFunction)(T*);
HarfBuzzScopedPtr(T* ptr, DestroyFunction destroy)
: m_ptr(ptr)
, m_destroy(destroy)
{
ASSERT(m_destroy);
}
~HarfBuzzScopedPtr()
{
if (m_ptr)
(*m_destroy)(m_ptr);
}
T* get() { return m_ptr; }
private:
T* m_ptr;
DestroyFunction m_destroy;
};
static inline float harfBuzzPositionToFloat(hb_position_t value)
{
return static_cast<float>(value) / (1 << 16);
}
HarfBuzzShaper::HarfBuzzRun::HarfBuzzRun(const Font* fontData, unsigned startIndex, unsigned numCharacters, TextDirection direction, hb_script_t script)
: m_fontData(fontData)
, m_startIndex(startIndex)
, m_numCharacters(numCharacters)
, m_direction(direction)
, m_script(script)
{
}
void HarfBuzzShaper::HarfBuzzRun::applyShapeResult(hb_buffer_t* harfBuzzBuffer)
{
m_numGlyphs = hb_buffer_get_length(harfBuzzBuffer);
if (!m_numGlyphs) {
// HarfBuzzShaper::fillGlyphBuffer gets offsets()[0]
m_offsets.resize(1);
return;
}
m_glyphs.resize(m_numGlyphs);
m_advances.resize(m_numGlyphs);
m_glyphToCharacterIndexes.resize(m_numGlyphs);
m_offsets.resize(m_numGlyphs);
}
void HarfBuzzShaper::HarfBuzzRun::setGlyphAndPositions(unsigned index, uint16_t glyphId, float advance, float offsetX, float offsetY)
{
m_glyphs[index] = glyphId;
m_advances[index] = advance;
m_offsets[index] = FloatPoint(offsetX, offsetY);
}
unsigned HarfBuzzShaper::HarfBuzzRun::characterIndexForXPosition(float targetX)
{
ASSERT(targetX <= m_width);
float currentX = 0;
float currentAdvance = m_advances[0];
unsigned glyphIndex = 0;
// Sum up advances that belong to a character.
while (glyphIndex < m_numGlyphs - 1 && m_glyphToCharacterIndexes[glyphIndex] == m_glyphToCharacterIndexes[glyphIndex + 1])
currentAdvance += m_advances[++glyphIndex];
currentAdvance = currentAdvance / 2.0;
if (targetX <= currentAdvance)
return rtl() ? m_numCharacters : 0;
++glyphIndex;
while (glyphIndex < m_numGlyphs) {
unsigned prevCharacterIndex = m_glyphToCharacterIndexes[glyphIndex - 1];
float prevAdvance = currentAdvance;
currentAdvance = m_advances[glyphIndex];
while (glyphIndex < m_numGlyphs - 1 && m_glyphToCharacterIndexes[glyphIndex] == m_glyphToCharacterIndexes[glyphIndex + 1])
currentAdvance += m_advances[++glyphIndex];
currentAdvance = currentAdvance / 2.0;
float nextX = currentX + prevAdvance + currentAdvance;
if (currentX <= targetX && targetX <= nextX)
return rtl() ? prevCharacterIndex : m_glyphToCharacterIndexes[glyphIndex];
currentX = nextX;
prevAdvance = currentAdvance;
++glyphIndex;
}
return rtl() ? 0 : m_numCharacters;
}
float HarfBuzzShaper::HarfBuzzRun::xPositionForOffset(unsigned offset)
{
ASSERT(offset < m_numCharacters);
unsigned glyphIndex = 0;
float position = 0;
if (rtl()) {
while (glyphIndex < m_numGlyphs && m_glyphToCharacterIndexes[glyphIndex] > offset) {
position += m_advances[glyphIndex];
++glyphIndex;
}
// For RTL, we need to return the right side boundary of the character.
// Add advance of glyphs which are part of the character.
while (glyphIndex < m_numGlyphs - 1 && m_glyphToCharacterIndexes[glyphIndex] == m_glyphToCharacterIndexes[glyphIndex + 1]) {
position += m_advances[glyphIndex];
++glyphIndex;
}
position += m_advances[glyphIndex];
} else {
while (glyphIndex < m_numGlyphs && m_glyphToCharacterIndexes[glyphIndex] < offset) {
position += m_advances[glyphIndex];
++glyphIndex;
}
}
return position;
}
HarfBuzzShaper::HarfBuzzShaper(const FontCascade* font, const TextRun& run)
: m_font(font)
, m_normalizedBufferLength(0)
, m_run(run)
, m_wordSpacingAdjustment(font->wordSpacing())
, m_padding(0)
, m_padPerWordBreak(0)
, m_padError(0)
, m_letterSpacing(font->letterSpacing())
{
setNormalizedBuffer();
setPadding(m_run.expansion());
setFontFeatures();
}
HarfBuzzShaper::~HarfBuzzShaper()
{
}
static void normalizeSpacesAndMirrorChars(const UChar* source, UChar* destination, unsigned length, HarfBuzzShaper::NormalizeMode normalizeMode)
{
unsigned position = 0;
bool error = false;
// Iterate characters in source and mirror character if needed.
while (position < length) {
UChar32 character;
unsigned nextPosition = position;
U16_NEXT(source, nextPosition, length, character);
// Don't normalize tabs as they are not treated as spaces for word-end
if (FontCascade::treatAsSpace(character) && character != '\t')
character = ' ';
else if (FontCascade::treatAsZeroWidthSpaceInComplexScript(character))
character = zeroWidthSpace;
else if (normalizeMode == HarfBuzzShaper::NormalizeMirrorChars)
character = u_charMirror(character);
U16_APPEND(destination, position, length, character, error);
ASSERT_UNUSED(error, !error);
position = nextPosition;
}
}
void HarfBuzzShaper::setNormalizedBuffer(NormalizeMode normalizeMode)
{
// Normalize the text run in three ways:
// 1) Convert the |originalRun| to NFC normalized form if combining diacritical marks
// (U+0300..) are used in the run. This conversion is necessary since most OpenType
// fonts (e.g., Arial) don't have substitution rules for the diacritical marks in
// their GSUB tables.
//
// Note that we don't use the icu::Normalizer::isNormalized(UNORM_NFC) API here since
// the API returns FALSE (= not normalized) for complex runs that don't require NFC
// normalization (e.g., Arabic text). Unless the run contains the diacritical marks,
// HarfBuzz will do the same thing for us using the GSUB table.
// 2) Convert spacing characters into plain spaces, as some fonts will provide glyphs
// for characters like '\n' otherwise.
// 3) Convert mirrored characters such as parenthesis for rtl text.
// Convert to NFC form if the text has diacritical marks.
icu::UnicodeString normalizedString;
UErrorCode error = U_ZERO_ERROR;
const UChar* runCharacters;
String stringFor8BitRun;
if (m_run.is8Bit()) {
stringFor8BitRun = String::make16BitFrom8BitSource(m_run.characters8(), m_run.length());
runCharacters = stringFor8BitRun.characters16();
} else
runCharacters = m_run.characters16();
for (unsigned i = 0; i < m_run.length(); ++i) {
UChar ch = runCharacters[i];
if (::ublock_getCode(ch) == UBLOCK_COMBINING_DIACRITICAL_MARKS) {
icu::Normalizer::normalize(icu::UnicodeString(runCharacters,
m_run.length()), UNORM_NFC, 0 /* no options */,
normalizedString, error);
if (U_FAILURE(error))
normalizedString.remove();
break;
}
}
const UChar* sourceText;
if (normalizedString.isEmpty()) {
m_normalizedBufferLength = m_run.length();
sourceText = runCharacters;
} else {
m_normalizedBufferLength = normalizedString.length();
sourceText = normalizedString.getBuffer();
}
m_normalizedBuffer = std::make_unique<UChar[]>(m_normalizedBufferLength + 1);
normalizeSpacesAndMirrorChars(sourceText, m_normalizedBuffer.get(), m_normalizedBufferLength, normalizeMode);
}
bool HarfBuzzShaper::isWordEnd(unsigned index)
{
// This could refer a high-surrogate, but should work.
return index && isCodepointSpace(m_normalizedBuffer[index]);
}
int HarfBuzzShaper::determineWordBreakSpacing()
{
int wordBreakSpacing = m_wordSpacingAdjustment;
if (m_padding > 0) {
int toPad = roundf(m_padPerWordBreak + m_padError);
m_padError += m_padPerWordBreak - toPad;
if (m_padding < toPad)
toPad = m_padding;
m_padding -= toPad;
wordBreakSpacing += toPad;
}
return wordBreakSpacing;
}
// setPadding sets a number of pixels to be distributed across the TextRun.
// WebKit uses this to justify text.
void HarfBuzzShaper::setPadding(int padding)
{
m_padding = padding;
m_padError = 0;
if (!m_padding)
return;
// If we have padding to distribute, then we try to give an equal
// amount to each space. The last space gets the smaller amount, if
// any.
unsigned numWordEnds = 0;
for (unsigned i = 0; i < m_normalizedBufferLength; i++) {
if (isWordEnd(i))
numWordEnds++;
}
if (numWordEnds)
m_padPerWordBreak = m_padding / numWordEnds;
else
m_padPerWordBreak = 0;
}
void HarfBuzzShaper::setFontFeatures()
{
const auto& description = m_font->fontDescription();
if (description.orientation() == Vertical) {
static hb_feature_t vert = { HarfBuzzFace::vertTag, 1, 0, static_cast<unsigned>(-1) };
static hb_feature_t vrt2 = { HarfBuzzFace::vrt2Tag, 1, 0, static_cast<unsigned>(-1) };
m_features.append(vert);
m_features.append(vrt2);
}
hb_feature_t kerning = { HarfBuzzFace::kernTag, 0, 0, static_cast<unsigned>(-1) };
switch (description.kerning()) {
case Kerning::Normal:
kerning.value = 1;
m_features.append(kerning);
break;
case Kerning::NoShift:
kerning.value = 0;
m_features.append(kerning);
break;
case Kerning::Auto:
break;
default:
ASSERT_NOT_REACHED();
}
const FontFeatureSettings& settings = description.featureSettings();
unsigned numFeatures = settings.size();
for (unsigned i = 0; i < numFeatures; ++i) {
hb_feature_t feature;
auto& tag = settings[i].tag();
feature.tag = HB_TAG(tag[0], tag[1], tag[2], tag[3]);
feature.value = settings[i].value();
feature.start = 0;
feature.end = static_cast<unsigned>(-1);
m_features.append(feature);
}
}
bool HarfBuzzShaper::shape(GlyphBuffer* glyphBuffer)
{
if (!collectHarfBuzzRuns())
return false;
m_totalWidth = 0;
// WebKit doesn't set direction when calulating widths. Leave the direction setting to
// HarfBuzz when we are calculating widths (except when directionalOverride() is set).
if (!shapeHarfBuzzRuns(glyphBuffer || m_run.directionalOverride()))
return false;
m_totalWidth = roundf(m_totalWidth);
if (glyphBuffer && !fillGlyphBuffer(glyphBuffer))
return false;
return true;
}
FloatPoint HarfBuzzShaper::adjustStartPoint(const FloatPoint& point)
{
return point + m_startOffset;
}
bool HarfBuzzShaper::collectHarfBuzzRuns()
{
const UChar* normalizedBufferEnd = m_normalizedBuffer.get() + m_normalizedBufferLength;
SurrogatePairAwareTextIterator iterator(m_normalizedBuffer.get(), 0, m_normalizedBufferLength, m_normalizedBufferLength);
UChar32 character;
unsigned clusterLength = 0;
unsigned startIndexOfCurrentRun = 0;
if (!iterator.consume(character, clusterLength))
return false;
const Font* nextFontData = m_font->glyphDataForCharacter(character, false).font;
UErrorCode errorCode = U_ZERO_ERROR;
UScriptCode nextScript = uscript_getScript(character, &errorCode);
if (U_FAILURE(errorCode))
return false;
do {
const UChar* currentCharacterPosition = iterator.characters();
const Font* currentFontData = nextFontData;
if (!currentFontData)
currentFontData = &m_font->primaryFont();
UScriptCode currentScript = nextScript;
for (iterator.advance(clusterLength); iterator.consume(character, clusterLength); iterator.advance(clusterLength)) {
if (FontCascade::treatAsZeroWidthSpace(character))
continue;
if (U_GET_GC_MASK(character) & U_GC_M_MASK) {
unsigned markLength = clusterLength;
const UChar* markCharactersEnd = iterator.characters() + clusterLength;
while (markCharactersEnd < normalizedBufferEnd) {
UChar32 nextCharacter;
unsigned nextCharacterLength = 0;
U16_NEXT(markCharactersEnd, nextCharacterLength, normalizedBufferEnd - markCharactersEnd, nextCharacter);
if (!(U_GET_GC_MASK(nextCharacter) & U_GC_M_MASK))
break;
markLength += nextCharacterLength;
markCharactersEnd += nextCharacterLength;
}
if (currentFontData->canRenderCombiningCharacterSequence(currentCharacterPosition, markCharactersEnd - currentCharacterPosition)) {
clusterLength = markLength;
continue;
}
nextFontData = m_font->glyphDataForCharacter(character, false).font;
} else
nextFontData = m_font->glyphDataForCharacter(character, false).font;
nextScript = uscript_getScript(character, &errorCode);
if (U_FAILURE(errorCode))
return false;
if (nextFontData != currentFontData)
break;
// §5.1 Handling Characters with the Common Script Property.
// Programs must resolve any of the special Script property values, such as Common,
// based on the context of the surrounding characters. A simple heuristic uses the
// script of the preceding character, which works well in many cases.
// http://www.unicode.org/reports/tr24/#Common.
//
// FIXME: cover all other cases mentioned in the spec (ie. brackets or quotation marks).
// https://bugs.webkit.org/show_bug.cgi?id=177003.
//
// If next script is inherited or common, keep using the current script.
if (nextScript == USCRIPT_INHERITED || nextScript == USCRIPT_COMMON) {
currentCharacterPosition = iterator.characters();
continue;
}
// If current script is inherited or common, set the next script as current.
if (currentScript == USCRIPT_INHERITED || currentScript == USCRIPT_COMMON) {
currentScript = nextScript;
currentCharacterPosition = iterator.characters();
continue;
}
if (currentScript != nextScript && !uscript_hasScript(character, currentScript))
break;
currentCharacterPosition = iterator.characters();
}
unsigned numCharactersOfCurrentRun = iterator.currentIndex() - startIndexOfCurrentRun;
hb_script_t script = hb_icu_script_to_script(currentScript);
m_harfBuzzRuns.append(std::make_unique<HarfBuzzRun>(currentFontData, startIndexOfCurrentRun, numCharactersOfCurrentRun, m_run.direction(), script));
currentFontData = nextFontData;
startIndexOfCurrentRun = iterator.currentIndex();
} while (iterator.consume(character, clusterLength));
return !m_harfBuzzRuns.isEmpty();
}
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 Font* currentFontData = currentRun->fontData();
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()).convertToUppercaseWithoutLocale();
currentFontData = m_font->glyphDataForCharacter(upperText[0], false, SmallCapsVariant).font;
const UChar* characters = StringView(upperText).upconvertedCharacters();
hb_buffer_add_utf16(harfBuzzBuffer.get(), reinterpret_cast<const uint16_t*>(characters), currentRun->numCharacters(), 0, currentRun->numCharacters());
} else
hb_buffer_add_utf16(harfBuzzBuffer.get(), reinterpret_cast<const uint16_t*>(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(HarfBuzzRun* currentRun, hb_buffer_t* harfBuzzBuffer)
{
const Font* 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 && !FontCascade::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::fillGlyphBufferFromHarfBuzzRun(GlyphBuffer* glyphBuffer, HarfBuzzRun* currentRun, FloatPoint& firstOffsetOfNextRun)
{
FloatPoint* offsets = currentRun->offsets();
uint16_t* glyphs = currentRun->glyphs();
float* advances = currentRun->advances();
unsigned numGlyphs = currentRun->numGlyphs();
uint16_t* glyphToCharacterIndexes = currentRun->glyphToCharacterIndexes();
for (unsigned i = 0; i < numGlyphs; ++i) {
uint16_t currentCharacterIndex = currentRun->startIndex() + glyphToCharacterIndexes[i];
FloatPoint& currentOffset = offsets[i];
FloatPoint& nextOffset = (i == numGlyphs - 1) ? firstOffsetOfNextRun : offsets[i + 1];
float glyphAdvanceX = advances[i] + nextOffset.x() - currentOffset.x();
float glyphAdvanceY = nextOffset.y() - currentOffset.y();
if (m_run.rtl()) {
if (currentCharacterIndex > m_run.length())
m_startOffset.move(glyphAdvanceX, glyphAdvanceY);
else
glyphBuffer->add(glyphs[i], currentRun->fontData(), createGlyphBufferAdvance(glyphAdvanceX, glyphAdvanceY), currentCharacterIndex);
} else {
if (currentCharacterIndex < m_run.length())
glyphBuffer->add(glyphs[i], currentRun->fontData(), createGlyphBufferAdvance(glyphAdvanceX, glyphAdvanceY), currentCharacterIndex);
}
}
}
bool HarfBuzzShaper::fillGlyphBuffer(GlyphBuffer* glyphBuffer)
{
unsigned numRuns = m_harfBuzzRuns.size();
if (m_run.rtl()) {
m_startOffset = m_harfBuzzRuns.last()->offsets()[0];
for (int runIndex = numRuns - 1; runIndex >= 0; --runIndex) {
HarfBuzzRun* currentRun = m_harfBuzzRuns[runIndex].get();
FloatPoint firstOffsetOfNextRun = !runIndex ? FloatPoint() : m_harfBuzzRuns[runIndex - 1]->offsets()[0];
fillGlyphBufferFromHarfBuzzRun(glyphBuffer, currentRun, firstOffsetOfNextRun);
}
} else {
m_startOffset = m_harfBuzzRuns.first()->offsets()[0];
for (unsigned runIndex = 0; runIndex < numRuns; ++runIndex) {
HarfBuzzRun* currentRun = m_harfBuzzRuns[runIndex].get();
FloatPoint firstOffsetOfNextRun = runIndex == numRuns - 1 ? FloatPoint() : m_harfBuzzRuns[runIndex + 1]->offsets()[0];
fillGlyphBufferFromHarfBuzzRun(glyphBuffer, currentRun, firstOffsetOfNextRun);
}
}
return glyphBuffer->size();
}
int HarfBuzzShaper::offsetForPosition(float targetX)
{
int charactersSoFar = 0;
float currentX = 0;
if (m_run.rtl()) {
charactersSoFar = m_normalizedBufferLength;
for (int i = m_harfBuzzRuns.size() - 1; i >= 0; --i) {
charactersSoFar -= m_harfBuzzRuns[i]->numCharacters();
float nextX = currentX + m_harfBuzzRuns[i]->width();
float offsetForRun = targetX - currentX;
if (offsetForRun >= 0 && offsetForRun <= m_harfBuzzRuns[i]->width()) {
// The x value in question is within this script run.
const unsigned index = m_harfBuzzRuns[i]->characterIndexForXPosition(offsetForRun);
return charactersSoFar + index;
}
currentX = nextX;
}
} else {
for (unsigned i = 0; i < m_harfBuzzRuns.size(); ++i) {
float nextX = currentX + m_harfBuzzRuns[i]->width();
float offsetForRun = targetX - currentX;
if (offsetForRun >= 0 && offsetForRun <= m_harfBuzzRuns[i]->width()) {
const unsigned index = m_harfBuzzRuns[i]->characterIndexForXPosition(offsetForRun);
return charactersSoFar + index;
}
charactersSoFar += m_harfBuzzRuns[i]->numCharacters();
currentX = nextX;
}
}
return charactersSoFar;
}
FloatRect HarfBuzzShaper::selectionRect(const FloatPoint& point, int height, unsigned from, unsigned to)
{
float currentX = 0;
float fromX = 0;
float toX = 0;
bool foundFromX = false;
bool foundToX = false;
std::optional<unsigned> fromIndex = from;
std::optional<unsigned> toIndex = to;
if (m_run.rtl())
currentX = m_totalWidth;
for (unsigned i = 0; i < m_harfBuzzRuns.size(); ++i) {
if (m_run.rtl())
currentX -= m_harfBuzzRuns[i]->width();
unsigned numCharacters = m_harfBuzzRuns[i]->numCharacters();
if (!foundFromX && fromIndex.value() < numCharacters) {
fromX = m_harfBuzzRuns[i]->xPositionForOffset(fromIndex.value()) + currentX;
foundFromX = true;
} else {
if (fromIndex && fromIndex.value() >= numCharacters)
fromIndex.value() -= numCharacters;
else
fromIndex = std::nullopt;
}
if (!foundToX && toIndex.value() < numCharacters) {
toX = m_harfBuzzRuns[i]->xPositionForOffset(toIndex.value()) + currentX;
foundToX = true;
} else {
if (toIndex && toIndex.value() >= numCharacters)
toIndex.value() -= numCharacters;
else
toIndex = std::nullopt;
}
if (foundFromX && foundToX)
break;
if (!m_run.rtl())
currentX += m_harfBuzzRuns[i]->width();
}
// The position in question might be just after the text.
if (!foundFromX)
fromX = 0;
if (!foundToX)
toX = m_run.rtl() ? 0 : m_totalWidth;
// Using floorf() and roundf() as the same as mac port.
if (fromX < toX)
return FloatRect(floorf(point.x() + fromX), point.y(), roundf(toX - fromX), height);
return FloatRect(floorf(point.x() + toX), point.y(), roundf(fromX - toX), height);
}
} // namespace WebCore