| /* |
| * Copyright (C) 2007-2019 Apple 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: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. 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. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS 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 APPLE INC. OR ITS 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 "ComplexTextController.h" |
| |
| #include "CharacterProperties.h" |
| #include "FloatSize.h" |
| #include "FontCascade.h" |
| #include "RenderBlock.h" |
| #include "RenderText.h" |
| #include "TextRun.h" |
| #include <unicode/ubrk.h> |
| #include <wtf/StdLibExtras.h> |
| #include <wtf/text/TextBreakIterator.h> |
| #include <wtf/unicode/CharacterNames.h> |
| |
| #if PLATFORM(IOS_FAMILY) |
| #include <CoreText/CoreText.h> |
| #endif |
| |
| namespace WebCore { |
| |
| class TextLayout { |
| WTF_MAKE_FAST_ALLOCATED; |
| public: |
| static bool isNeeded(RenderText& text, const FontCascade& font) |
| { |
| TextRun run = RenderBlock::constructTextRun(text, text.style()); |
| return font.codePath(run) == FontCascade::CodePath::Complex; |
| } |
| |
| TextLayout(RenderText& text, const FontCascade& font, float xPos) |
| : m_font(font) |
| , m_run(constructTextRun(text, xPos)) |
| , m_controller(makeUnique<ComplexTextController>(m_font, m_run, true)) |
| { |
| } |
| |
| float width(unsigned from, unsigned len, HashSet<const Font*>* fallbackFonts) |
| { |
| m_controller->advance(from, 0, ByWholeGlyphs, fallbackFonts); |
| float beforeWidth = m_controller->runWidthSoFar(); |
| if (m_font.wordSpacing() && from && FontCascade::treatAsSpace(m_run[from])) |
| beforeWidth += m_font.wordSpacing(); |
| m_controller->advance(from + len, 0, ByWholeGlyphs, fallbackFonts); |
| float afterWidth = m_controller->runWidthSoFar(); |
| return afterWidth - beforeWidth; |
| } |
| |
| private: |
| static TextRun constructTextRun(RenderText& text, float xPos) |
| { |
| TextRun run = RenderBlock::constructTextRun(text, text.style()); |
| run.setXPos(xPos); |
| return run; |
| } |
| |
| // ComplexTextController has only references to its FontCascade and TextRun so they must be kept alive here. |
| FontCascade m_font; |
| TextRun m_run; |
| std::unique_ptr<ComplexTextController> m_controller; |
| }; |
| |
| void TextLayoutDeleter::operator()(TextLayout* layout) const |
| { |
| delete layout; |
| } |
| |
| std::unique_ptr<TextLayout, TextLayoutDeleter> FontCascade::createLayout(RenderText& text, float xPos, bool collapseWhiteSpace) const |
| { |
| if (!collapseWhiteSpace || !TextLayout::isNeeded(text, *this)) |
| return nullptr; |
| return std::unique_ptr<TextLayout, TextLayoutDeleter>(new TextLayout(text, *this, xPos)); |
| } |
| |
| float FontCascade::width(TextLayout& layout, unsigned from, unsigned len, HashSet<const Font*>* fallbackFonts) |
| { |
| return layout.width(from, len, fallbackFonts); |
| } |
| |
| void ComplexTextController::computeExpansionOpportunity() |
| { |
| if (!m_expansion) |
| m_expansionPerOpportunity = 0; |
| else { |
| unsigned expansionOpportunityCount = FontCascade::expansionOpportunityCount(m_run.text(), m_run.ltr() ? TextDirection::LTR : TextDirection::RTL, m_run.expansionBehavior()).first; |
| |
| if (!expansionOpportunityCount) |
| m_expansionPerOpportunity = 0; |
| else |
| m_expansionPerOpportunity = m_expansion / expansionOpportunityCount; |
| } |
| } |
| |
| ComplexTextController::ComplexTextController(const FontCascade& font, const TextRun& run, bool mayUseNaturalWritingDirection, HashSet<const Font*>* fallbackFonts, bool forTextEmphasis) |
| : m_fallbackFonts(fallbackFonts) |
| , m_font(font) |
| , m_run(run) |
| , m_end(run.length()) |
| , m_expansion(run.expansion()) |
| , m_mayUseNaturalWritingDirection(mayUseNaturalWritingDirection) |
| , m_forTextEmphasis(forTextEmphasis) |
| { |
| computeExpansionOpportunity(); |
| |
| collectComplexTextRuns(); |
| |
| finishConstruction(); |
| } |
| |
| ComplexTextController::ComplexTextController(const FontCascade& font, const TextRun& run, Vector<Ref<ComplexTextRun>>& runs) |
| : m_font(font) |
| , m_run(run) |
| , m_end(run.length()) |
| , m_expansion(run.expansion()) |
| { |
| computeExpansionOpportunity(); |
| |
| for (auto& run : runs) |
| m_complexTextRuns.append(run.ptr()); |
| |
| finishConstruction(); |
| } |
| |
| void ComplexTextController::finishConstruction() |
| { |
| adjustGlyphsAndAdvances(); |
| |
| if (!m_isLTROnly) { |
| unsigned length = m_complexTextRuns.size(); |
| m_runIndices.reserveInitialCapacity(length); |
| for (unsigned i = 0; i < length; ++i) |
| m_runIndices.uncheckedAppend(length - i - 1); |
| std::sort(m_runIndices.data(), m_runIndices.data() + length, |
| [this](auto a, auto b) { |
| return stringBegin(*m_complexTextRuns[a]) < stringBegin(*m_complexTextRuns[b]); |
| }); |
| |
| m_glyphCountFromStartToIndex.reserveInitialCapacity(length); |
| unsigned glyphCountSoFar = 0; |
| for (unsigned i = 0; i < length; ++i) { |
| m_glyphCountFromStartToIndex.uncheckedAppend(glyphCountSoFar); |
| glyphCountSoFar += m_complexTextRuns[i]->glyphCount(); |
| } |
| } |
| } |
| |
| unsigned ComplexTextController::offsetForPosition(float h, bool includePartialGlyphs) |
| { |
| if (h >= m_totalAdvance.width()) |
| return m_run.ltr() ? m_end : 0; |
| |
| if (h < 0) |
| return m_run.ltr() ? 0 : m_end; |
| |
| float x = h; |
| |
| size_t runCount = m_complexTextRuns.size(); |
| unsigned offsetIntoAdjustedGlyphs = 0; |
| |
| for (size_t r = 0; r < runCount; ++r) { |
| const ComplexTextRun& complexTextRun = *m_complexTextRuns[r]; |
| for (unsigned j = 0; j < complexTextRun.glyphCount(); ++j) { |
| unsigned index = offsetIntoAdjustedGlyphs + j; |
| float adjustedAdvance = m_adjustedBaseAdvances[index].width(); |
| bool hit = m_run.ltr() ? x < adjustedAdvance : (x <= adjustedAdvance && adjustedAdvance); |
| if (hit) { |
| unsigned hitGlyphStart = complexTextRun.indexAt(j); |
| unsigned hitGlyphEnd; |
| if (m_run.ltr()) |
| hitGlyphEnd = std::max(hitGlyphStart, j + 1 < complexTextRun.glyphCount() ? complexTextRun.indexAt(j + 1) : complexTextRun.indexEnd()); |
| else |
| hitGlyphEnd = std::max(hitGlyphStart, j > 0 ? complexTextRun.indexAt(j - 1) : complexTextRun.indexEnd()); |
| |
| // FIXME: Instead of dividing the glyph's advance equally between the characters, this |
| // could use the glyph's "ligature carets". This is available in CoreText via CTFontGetLigatureCaretPositions(). |
| unsigned hitIndex; |
| if (m_run.ltr()) |
| hitIndex = hitGlyphStart + (hitGlyphEnd - hitGlyphStart) * (x / adjustedAdvance); |
| else { |
| if (hitGlyphStart == hitGlyphEnd) |
| hitIndex = hitGlyphStart; |
| else if (x) |
| hitIndex = hitGlyphEnd - (hitGlyphEnd - hitGlyphStart) * (x / adjustedAdvance); |
| else |
| hitIndex = hitGlyphEnd - 1; |
| } |
| |
| unsigned stringLength = complexTextRun.stringLength(); |
| CachedTextBreakIterator cursorPositionIterator(StringView(complexTextRun.characters(), stringLength), TextBreakIterator::Mode::Caret, nullAtom()); |
| unsigned clusterStart; |
| if (cursorPositionIterator.isBoundary(hitIndex)) |
| clusterStart = hitIndex; |
| else |
| clusterStart = cursorPositionIterator.preceding(hitIndex).value_or(0); |
| |
| if (!includePartialGlyphs) |
| return complexTextRun.stringLocation() + clusterStart; |
| |
| unsigned clusterEnd = cursorPositionIterator.following(hitIndex).value_or(stringLength); |
| |
| float clusterWidth; |
| // FIXME: The search stops at the boundaries of complexTextRun. In theory, it should go on into neighboring ComplexTextRuns |
| // derived from the same CTLine. In practice, we do not expect there to be more than one CTRun in a CTLine, as no |
| // reordering and no font fallback should occur within a CTLine. |
| if (clusterEnd - clusterStart > 1) { |
| clusterWidth = adjustedAdvance; |
| if (j) { |
| unsigned firstGlyphBeforeCluster = j - 1; |
| while (complexTextRun.indexAt(firstGlyphBeforeCluster) >= clusterStart && complexTextRun.indexAt(firstGlyphBeforeCluster) < clusterEnd) { |
| float width = m_adjustedBaseAdvances[offsetIntoAdjustedGlyphs + firstGlyphBeforeCluster].width(); |
| clusterWidth += width; |
| x += width; |
| if (!firstGlyphBeforeCluster) |
| break; |
| firstGlyphBeforeCluster--; |
| } |
| } |
| unsigned firstGlyphAfterCluster = j + 1; |
| while (firstGlyphAfterCluster < complexTextRun.glyphCount() && complexTextRun.indexAt(firstGlyphAfterCluster) >= clusterStart && complexTextRun.indexAt(firstGlyphAfterCluster) < clusterEnd) { |
| clusterWidth += m_adjustedBaseAdvances[offsetIntoAdjustedGlyphs + firstGlyphAfterCluster].width(); |
| firstGlyphAfterCluster++; |
| } |
| } else { |
| clusterWidth = adjustedAdvance / (hitGlyphEnd - hitGlyphStart); |
| x -= clusterWidth * (m_run.ltr() ? hitIndex - hitGlyphStart : hitGlyphEnd - hitIndex - 1); |
| } |
| if (x <= clusterWidth / 2) |
| return complexTextRun.stringLocation() + (m_run.ltr() ? clusterStart : clusterEnd); |
| return complexTextRun.stringLocation() + (m_run.ltr() ? clusterEnd : clusterStart); |
| } |
| x -= adjustedAdvance; |
| } |
| offsetIntoAdjustedGlyphs += complexTextRun.glyphCount(); |
| } |
| |
| ASSERT_NOT_REACHED(); |
| return 0; |
| } |
| |
| // FIXME: We should consider reimplementing this function using ICU to advance by grapheme. |
| // The current implementation only considers explicitly emoji sequences and emoji variations. |
| static bool advanceByCombiningCharacterSequence(const UChar*& iterator, const UChar* end, UChar32& baseCharacter, unsigned& markCount) |
| { |
| ASSERT(iterator < end); |
| |
| markCount = 0; |
| |
| unsigned i = 0; |
| unsigned remainingCharacters = end - iterator; |
| U16_NEXT(iterator, i, remainingCharacters, baseCharacter); |
| iterator = iterator + i; |
| if (U_IS_SURROGATE(baseCharacter)) |
| return false; |
| |
| // Consume marks. |
| bool sawEmojiGroupCandidate = isEmojiGroupCandidate(baseCharacter); |
| bool sawJoiner = false; |
| bool sawRegionalIndicator = isEmojiRegionalIndicator(baseCharacter); |
| while (iterator < end) { |
| UChar32 nextCharacter; |
| unsigned markLength = 0; |
| bool shouldContinue = false; |
| ASSERT(end >= iterator); |
| U16_NEXT(iterator, markLength, static_cast<unsigned>(end - iterator), nextCharacter); |
| |
| if (isVariationSelector(nextCharacter) || isEmojiFitzpatrickModifier(nextCharacter)) |
| shouldContinue = true; |
| |
| if (sawRegionalIndicator && isEmojiRegionalIndicator(nextCharacter)) { |
| shouldContinue = true; |
| sawRegionalIndicator = false; |
| } |
| |
| if (sawJoiner && isEmojiGroupCandidate(nextCharacter)) |
| shouldContinue = true; |
| |
| sawJoiner = false; |
| if (sawEmojiGroupCandidate && nextCharacter == zeroWidthJoiner) { |
| sawJoiner = true; |
| shouldContinue = true; |
| } |
| |
| if (!shouldContinue && !(U_GET_GC_MASK(nextCharacter) & U_GC_M_MASK)) |
| break; |
| |
| markCount += markLength; |
| iterator += markLength; |
| } |
| |
| return true; |
| } |
| |
| // FIXME: Capitalization is language-dependent and context-dependent and should operate on grapheme clusters instead of codepoints. |
| static inline std::optional<UChar32> capitalized(UChar32 baseCharacter) |
| { |
| if (U_GET_GC_MASK(baseCharacter) & U_GC_M_MASK) |
| return std::nullopt; |
| |
| UChar32 uppercaseCharacter = u_toupper(baseCharacter); |
| ASSERT(uppercaseCharacter == baseCharacter || (U_IS_BMP(baseCharacter) == U_IS_BMP(uppercaseCharacter))); |
| if (uppercaseCharacter != baseCharacter) |
| return uppercaseCharacter; |
| return std::nullopt; |
| } |
| |
| static bool shouldSynthesize(bool dontSynthesizeSmallCaps, const Font* nextFont, UChar32 baseCharacter, std::optional<UChar32> capitalizedBase, FontVariantCaps fontVariantCaps, bool engageAllSmallCapsProcessing) |
| { |
| if (dontSynthesizeSmallCaps) |
| return false; |
| if (!nextFont || nextFont == Font::systemFallback()) |
| return false; |
| if (engageAllSmallCapsProcessing && isASCIISpace(baseCharacter)) |
| return false; |
| if (!engageAllSmallCapsProcessing && !capitalizedBase) |
| return false; |
| return !nextFont->variantCapsSupportsCharacterForSynthesis(fontVariantCaps, baseCharacter); |
| } |
| |
| void ComplexTextController::collectComplexTextRuns() |
| { |
| if (!m_end || !m_font.size()) |
| return; |
| |
| // We break up glyph run generation for the string by Font. |
| const UChar* cp; |
| |
| if (m_run.is8Bit()) { |
| String stringFor8BitRun = String::make16BitFrom8BitSource(m_run.characters8(), m_run.length()); |
| m_stringsFor8BitRuns.append(WTFMove(stringFor8BitRun)); |
| cp = m_stringsFor8BitRuns.last().characters16(); |
| } else |
| cp = m_run.characters16(); |
| |
| auto fontVariantCaps = m_font.fontDescription().variantCaps(); |
| bool dontSynthesizeSmallCaps = !static_cast<bool>(m_font.fontDescription().fontSynthesis() & FontSynthesisSmallCaps); |
| bool engageAllSmallCapsProcessing = fontVariantCaps == FontVariantCaps::AllSmall || fontVariantCaps == FontVariantCaps::AllPetite; |
| bool engageSmallCapsProcessing = engageAllSmallCapsProcessing || fontVariantCaps == FontVariantCaps::Small || fontVariantCaps == FontVariantCaps::Petite; |
| |
| if (engageAllSmallCapsProcessing || engageSmallCapsProcessing) |
| m_smallCapsBuffer.resize(m_end); |
| |
| unsigned indexOfFontTransition = 0; |
| const UChar* curr = cp; |
| const UChar* end = cp + m_end; |
| |
| const Font* font; |
| const Font* nextFont; |
| const Font* synthesizedFont = nullptr; |
| const Font* smallSynthesizedFont = nullptr; |
| |
| unsigned markCount; |
| UChar32 baseCharacter; |
| if (!advanceByCombiningCharacterSequence(curr, end, baseCharacter, markCount)) |
| return; |
| |
| nextFont = m_font.fontForCombiningCharacterSequence(cp, curr - cp); |
| |
| bool isSmallCaps = false; |
| bool nextIsSmallCaps = false; |
| |
| auto capitalizedBase = capitalized(baseCharacter); |
| if (shouldSynthesize(dontSynthesizeSmallCaps, nextFont, baseCharacter, capitalizedBase, fontVariantCaps, engageAllSmallCapsProcessing)) { |
| synthesizedFont = &nextFont->noSynthesizableFeaturesFont(); |
| smallSynthesizedFont = synthesizedFont->smallCapsFont(m_font.fontDescription()); |
| UChar32 characterToWrite = capitalizedBase ? capitalizedBase.value() : cp[0]; |
| unsigned characterIndex = 0; |
| U16_APPEND_UNSAFE(m_smallCapsBuffer, characterIndex, characterToWrite); |
| for (unsigned i = characterIndex; cp + i < curr; ++i) |
| m_smallCapsBuffer[i] = cp[i]; |
| nextIsSmallCaps = true; |
| } |
| |
| while (curr < end) { |
| font = nextFont; |
| isSmallCaps = nextIsSmallCaps; |
| unsigned index = curr - cp; |
| |
| if (!advanceByCombiningCharacterSequence(curr, end, baseCharacter, markCount)) |
| return; |
| |
| if (synthesizedFont) { |
| if (auto capitalizedBase = capitalized(baseCharacter)) { |
| unsigned characterIndex = index; |
| U16_APPEND_UNSAFE(m_smallCapsBuffer, characterIndex, capitalizedBase.value()); |
| for (unsigned i = 0; i < markCount; ++i) |
| m_smallCapsBuffer[i + characterIndex] = cp[i + characterIndex]; |
| nextIsSmallCaps = true; |
| } else { |
| if (engageAllSmallCapsProcessing) { |
| for (unsigned i = 0; i < curr - cp - index; ++i) |
| m_smallCapsBuffer[index + i] = cp[index + i]; |
| } |
| nextIsSmallCaps = engageAllSmallCapsProcessing; |
| } |
| } |
| |
| if (baseCharacter == zeroWidthJoiner) |
| nextFont = font; |
| else |
| nextFont = m_font.fontForCombiningCharacterSequence(cp + index, curr - cp - index); |
| |
| capitalizedBase = capitalized(baseCharacter); |
| if (!synthesizedFont && shouldSynthesize(dontSynthesizeSmallCaps, nextFont, baseCharacter, capitalizedBase, fontVariantCaps, engageAllSmallCapsProcessing)) { |
| // Rather than synthesize each character individually, we should synthesize the entire "run" if any character requires synthesis. |
| synthesizedFont = &nextFont->noSynthesizableFeaturesFont(); |
| smallSynthesizedFont = synthesizedFont->smallCapsFont(m_font.fontDescription()); |
| nextIsSmallCaps = true; |
| curr = cp + indexOfFontTransition; |
| continue; |
| } |
| |
| if (nextFont != font || nextIsSmallCaps != isSmallCaps) { |
| unsigned itemLength = index - indexOfFontTransition; |
| if (itemLength) { |
| unsigned itemStart = indexOfFontTransition; |
| if (synthesizedFont) { |
| if (isSmallCaps) |
| collectComplexTextRunsForCharacters(m_smallCapsBuffer.data() + itemStart, itemLength, itemStart, smallSynthesizedFont); |
| else |
| collectComplexTextRunsForCharacters(cp + itemStart, itemLength, itemStart, synthesizedFont); |
| } else |
| collectComplexTextRunsForCharacters(cp + itemStart, itemLength, itemStart, font); |
| if (nextFont != font) { |
| synthesizedFont = nullptr; |
| smallSynthesizedFont = nullptr; |
| nextIsSmallCaps = false; |
| } |
| } |
| indexOfFontTransition = index; |
| } |
| } |
| |
| ASSERT(m_end >= indexOfFontTransition); |
| unsigned itemLength = m_end - indexOfFontTransition; |
| if (itemLength) { |
| unsigned itemStart = indexOfFontTransition; |
| if (synthesizedFont) { |
| if (nextIsSmallCaps) |
| collectComplexTextRunsForCharacters(m_smallCapsBuffer.data() + itemStart, itemLength, itemStart, smallSynthesizedFont); |
| else |
| collectComplexTextRunsForCharacters(cp + itemStart, itemLength, itemStart, synthesizedFont); |
| } else |
| collectComplexTextRunsForCharacters(cp + itemStart, itemLength, itemStart, nextFont); |
| } |
| |
| if (!m_run.ltr()) |
| m_complexTextRuns.reverse(); |
| } |
| |
| unsigned ComplexTextController::ComplexTextRun::indexAt(unsigned i) const |
| { |
| ASSERT(i < m_glyphCount); |
| |
| return m_coreTextIndices[i]; |
| } |
| |
| void ComplexTextController::ComplexTextRun::setIsNonMonotonic() |
| { |
| ASSERT(m_isMonotonic); |
| m_isMonotonic = false; |
| |
| Vector<bool, 64> mappedIndices(m_stringLength, false); |
| for (unsigned i = 0; i < m_glyphCount; ++i) { |
| ASSERT(indexAt(i) < m_stringLength); |
| mappedIndices[indexAt(i)] = true; |
| } |
| |
| m_glyphEndOffsets.grow(m_glyphCount); |
| for (unsigned i = 0; i < m_glyphCount; ++i) { |
| unsigned nextMappedIndex = m_indexEnd; |
| for (unsigned j = indexAt(i) + 1; j < m_stringLength; ++j) { |
| if (mappedIndices[j]) { |
| nextMappedIndex = j; |
| break; |
| } |
| } |
| m_glyphEndOffsets[i] = nextMappedIndex; |
| } |
| } |
| |
| unsigned ComplexTextController::indexOfCurrentRun(unsigned& leftmostGlyph) |
| { |
| leftmostGlyph = 0; |
| |
| size_t runCount = m_complexTextRuns.size(); |
| if (m_currentRun >= runCount) |
| return runCount; |
| |
| if (m_isLTROnly) { |
| for (unsigned i = 0; i < m_currentRun; ++i) |
| leftmostGlyph += m_complexTextRuns[i]->glyphCount(); |
| return m_currentRun; |
| } |
| |
| unsigned currentRunIndex = m_runIndices[m_currentRun]; |
| leftmostGlyph = m_glyphCountFromStartToIndex[currentRunIndex]; |
| return currentRunIndex; |
| } |
| |
| unsigned ComplexTextController::incrementCurrentRun(unsigned& leftmostGlyph) |
| { |
| if (m_isLTROnly) { |
| leftmostGlyph += m_complexTextRuns[m_currentRun++]->glyphCount(); |
| return m_currentRun; |
| } |
| |
| m_currentRun++; |
| leftmostGlyph = 0; |
| return indexOfCurrentRun(leftmostGlyph); |
| } |
| |
| float ComplexTextController::runWidthSoFarFraction(unsigned glyphStartOffset, unsigned glyphEndOffset, unsigned oldCharacterInCurrentGlyph, GlyphIterationStyle iterationStyle) const |
| { |
| // FIXME: Instead of dividing the glyph's advance equally between the characters, this |
| // could use the glyph's "ligature carets". This is available in CoreText via CTFontGetLigatureCaretPositions(). |
| if (glyphStartOffset == glyphEndOffset) { |
| // When there are multiple glyphs per character we need to advance by the full width of the glyph. |
| ASSERT(m_characterInCurrentGlyph == oldCharacterInCurrentGlyph); |
| return 1; |
| } |
| |
| if (iterationStyle == ByWholeGlyphs) { |
| if (!oldCharacterInCurrentGlyph) |
| return 1; |
| return 0; |
| } |
| |
| return static_cast<float>(m_characterInCurrentGlyph - oldCharacterInCurrentGlyph) / (glyphEndOffset - glyphStartOffset); |
| } |
| |
| void ComplexTextController::advance(unsigned offset, GlyphBuffer* glyphBuffer, GlyphIterationStyle iterationStyle, HashSet<const Font*>* fallbackFonts) |
| { |
| if (offset > m_end) |
| offset = m_end; |
| |
| if (offset < m_currentCharacter) { |
| m_runWidthSoFar = 0; |
| m_numGlyphsSoFar = 0; |
| m_currentRun = 0; |
| m_glyphInCurrentRun = 0; |
| m_characterInCurrentGlyph = 0; |
| } |
| |
| m_currentCharacter = offset; |
| |
| size_t runCount = m_complexTextRuns.size(); |
| |
| unsigned indexOfLeftmostGlyphInCurrentRun = 0; // Relative to the beginning of ComplexTextController. |
| unsigned currentRunIndex = indexOfCurrentRun(indexOfLeftmostGlyphInCurrentRun); |
| while (m_currentRun < runCount) { |
| const ComplexTextRun& complexTextRun = *m_complexTextRuns[currentRunIndex]; |
| bool ltr = complexTextRun.isLTR(); |
| unsigned glyphCount = complexTextRun.glyphCount(); |
| unsigned glyphIndexIntoCurrentRun = ltr ? m_glyphInCurrentRun : glyphCount - 1 - m_glyphInCurrentRun; |
| unsigned glyphIndexIntoComplexTextController = indexOfLeftmostGlyphInCurrentRun + glyphIndexIntoCurrentRun; |
| if (fallbackFonts && &complexTextRun.font() != &m_font.primaryFont()) |
| fallbackFonts->add(&complexTextRun.font()); |
| |
| // We must store the initial advance for the first glyph we are going to draw. |
| // When leftmostGlyph is 0, it represents the first glyph to draw, taking into |
| // account the text direction. |
| if (!indexOfLeftmostGlyphInCurrentRun && glyphBuffer) |
| glyphBuffer->setInitialAdvance(makeGlyphBufferAdvance(complexTextRun.initialAdvance())); |
| |
| while (m_glyphInCurrentRun < glyphCount) { |
| unsigned glyphStartOffset = complexTextRun.indexAt(glyphIndexIntoCurrentRun); |
| unsigned glyphEndOffset; |
| if (complexTextRun.isMonotonic()) { |
| if (ltr) |
| glyphEndOffset = std::max(glyphStartOffset, glyphIndexIntoCurrentRun + 1 < glyphCount ? complexTextRun.indexAt(glyphIndexIntoCurrentRun + 1) : complexTextRun.indexEnd()); |
| else |
| glyphEndOffset = std::max(glyphStartOffset, glyphIndexIntoCurrentRun > 0 ? complexTextRun.indexAt(glyphIndexIntoCurrentRun - 1) : complexTextRun.indexEnd()); |
| } else |
| glyphEndOffset = complexTextRun.endOffsetAt(glyphIndexIntoCurrentRun); |
| |
| FloatSize adjustedBaseAdvance = m_adjustedBaseAdvances[glyphIndexIntoComplexTextController]; |
| |
| if (glyphStartOffset + complexTextRun.stringLocation() >= m_currentCharacter) |
| return; |
| |
| if (glyphBuffer && !m_characterInCurrentGlyph) { |
| auto currentGlyphOrigin = glyphOrigin(glyphIndexIntoComplexTextController); |
| GlyphBufferAdvance paintAdvance = makeGlyphBufferAdvance(adjustedBaseAdvance); |
| if (!glyphIndexIntoCurrentRun) { |
| // The first layout advance of every run includes the "initial layout advance." However, here, we need |
| // paint advances, so subtract it out before transforming the layout advance into a paint advance. |
| setWidth(paintAdvance, width(paintAdvance) - (complexTextRun.initialAdvance().width() - currentGlyphOrigin.x())); |
| setHeight(paintAdvance, height(paintAdvance) - (complexTextRun.initialAdvance().height() - currentGlyphOrigin.y())); |
| } |
| setWidth(paintAdvance, width(paintAdvance) + glyphOrigin(glyphIndexIntoComplexTextController + 1).x() - currentGlyphOrigin.x()); |
| setHeight(paintAdvance, height(paintAdvance) + glyphOrigin(glyphIndexIntoComplexTextController + 1).y() - currentGlyphOrigin.y()); |
| if (glyphIndexIntoCurrentRun == glyphCount - 1 && currentRunIndex + 1 < runCount) { |
| // Our paint advance points to the end of the run. However, the next run may have an |
| // initial advance, and our paint advance needs to point to the location of the next |
| // glyph. So, we need to add in the next run's initial advance. |
| setWidth(paintAdvance, width(paintAdvance) - glyphOrigin(glyphIndexIntoComplexTextController + 1).x() + m_complexTextRuns[currentRunIndex + 1]->initialAdvance().width()); |
| setHeight(paintAdvance, height(paintAdvance) - glyphOrigin(glyphIndexIntoComplexTextController + 1).y() + m_complexTextRuns[currentRunIndex + 1]->initialAdvance().height()); |
| } |
| setHeight(paintAdvance, -height(paintAdvance)); // Increasing y points down |
| glyphBuffer->add(m_adjustedGlyphs[glyphIndexIntoComplexTextController], complexTextRun.font(), paintAdvance, complexTextRun.indexAt(m_glyphInCurrentRun)); |
| } |
| |
| unsigned oldCharacterInCurrentGlyph = m_characterInCurrentGlyph; |
| m_characterInCurrentGlyph = std::min(m_currentCharacter - complexTextRun.stringLocation(), glyphEndOffset) - glyphStartOffset; |
| m_runWidthSoFar += adjustedBaseAdvance.width() * runWidthSoFarFraction(glyphStartOffset, glyphEndOffset, oldCharacterInCurrentGlyph, iterationStyle); |
| |
| if (glyphEndOffset + complexTextRun.stringLocation() > m_currentCharacter) |
| return; |
| |
| m_numGlyphsSoFar++; |
| m_glyphInCurrentRun++; |
| m_characterInCurrentGlyph = 0; |
| if (ltr) { |
| glyphIndexIntoCurrentRun++; |
| glyphIndexIntoComplexTextController++; |
| } else { |
| glyphIndexIntoCurrentRun--; |
| glyphIndexIntoComplexTextController--; |
| } |
| } |
| currentRunIndex = incrementCurrentRun(indexOfLeftmostGlyphInCurrentRun); |
| m_glyphInCurrentRun = 0; |
| } |
| } |
| |
| static inline std::pair<bool, bool> expansionLocation(bool ideograph, bool treatAsSpace, bool ltr, bool isAfterExpansion, bool forbidLeftExpansion, bool forbidRightExpansion, bool forceLeftExpansion, bool forceRightExpansion) |
| { |
| bool expandLeft = ideograph; |
| bool expandRight = ideograph; |
| if (treatAsSpace) { |
| if (ltr) |
| expandRight = true; |
| else |
| expandLeft = true; |
| } |
| if (isAfterExpansion) |
| expandLeft = false; |
| ASSERT(!forbidLeftExpansion || !forceLeftExpansion); |
| ASSERT(!forbidRightExpansion || !forceRightExpansion); |
| if (forbidLeftExpansion) |
| expandLeft = false; |
| if (forbidRightExpansion) |
| expandRight = false; |
| if (forceLeftExpansion) |
| expandLeft = true; |
| if (forceRightExpansion) |
| expandRight = true; |
| return std::make_pair(expandLeft, expandRight); |
| } |
| |
| void ComplexTextController::adjustGlyphsAndAdvances() |
| { |
| bool afterExpansion = m_run.expansionBehavior().left == ExpansionBehavior::Behavior::Forbid; |
| size_t runCount = m_complexTextRuns.size(); |
| bool hasExtraSpacing = (m_font.letterSpacing() || m_font.wordSpacing() || m_expansion) && !m_run.spacingDisabled(); |
| bool runForcesLeftExpansion = m_run.expansionBehavior().left == ExpansionBehavior::Behavior::Force; |
| bool runForcesRightExpansion = m_run.expansionBehavior().right == ExpansionBehavior::Behavior::Force; |
| bool runForbidsLeftExpansion = m_run.expansionBehavior().left == ExpansionBehavior::Behavior::Forbid; |
| bool runForbidsRightExpansion = m_run.expansionBehavior().right == ExpansionBehavior::Behavior::Forbid; |
| |
| // We are iterating in glyph order, not string order. Compare this to WidthIterator::advanceInternal() |
| for (size_t runIndex = 0; runIndex < runCount; ++runIndex) { |
| ComplexTextRun& complexTextRun = *m_complexTextRuns[runIndex]; |
| unsigned glyphCount = complexTextRun.glyphCount(); |
| const Font& font = complexTextRun.font(); |
| |
| if (!complexTextRun.isLTR()) |
| m_isLTROnly = false; |
| |
| const CGGlyph* glyphs = complexTextRun.glyphs(); |
| const FloatSize* advances = complexTextRun.baseAdvances(); |
| |
| // Lower in this function, synthetic bold is blanket-applied to everything, so no need to double-apply it here. |
| float spaceWidth = font.spaceWidth(Font::SyntheticBoldInclusion::Exclude); |
| const UChar* cp = complexTextRun.characters(); |
| FloatPoint glyphOrigin; |
| unsigned lastCharacterIndex = m_run.ltr() ? std::numeric_limits<unsigned>::min() : std::numeric_limits<unsigned>::max(); |
| bool isMonotonic = true; |
| |
| for (unsigned i = 0; i < glyphCount; i++) { |
| unsigned characterIndex = complexTextRun.indexAt(i); |
| if (m_run.ltr()) { |
| if (characterIndex < lastCharacterIndex) |
| isMonotonic = false; |
| } else { |
| if (characterIndex > lastCharacterIndex) |
| isMonotonic = false; |
| } |
| UChar ch = *(cp + characterIndex); |
| |
| bool treatAsSpace = FontCascade::treatAsSpace(ch); |
| CGGlyph glyph = glyphs[i]; |
| FloatSize advance = treatAsSpace ? FloatSize(spaceWidth, advances[i].height()) : advances[i]; |
| |
| if (ch == tabCharacter && m_run.allowTabs()) |
| advance.setWidth(m_font.tabWidth(font, m_run.tabSize(), m_run.xPos() + m_totalAdvance.width(), Font::SyntheticBoldInclusion::Exclude)); |
| else if (FontCascade::treatAsZeroWidthSpace(ch) && !treatAsSpace) { |
| advance.setWidth(0); |
| glyph = font.spaceGlyph(); |
| } |
| |
| if (!i) { |
| advance.expand(complexTextRun.initialAdvance().width(), complexTextRun.initialAdvance().height()); |
| if (auto* origins = complexTextRun.glyphOrigins()) |
| advance.expand(-origins[0].x(), -origins[0].y()); |
| } |
| |
| advance.expand(font.syntheticBoldOffset(), 0); |
| |
| if (hasExtraSpacing) { |
| // If we're a glyph with an advance, add in letter-spacing. |
| // That way we weed out zero width lurkers. This behavior matches the fast text code path. |
| if (advance.width()) |
| advance.expand(m_font.letterSpacing(), 0); |
| |
| unsigned characterIndexInRun = characterIndex + complexTextRun.stringLocation(); |
| bool isFirstCharacter = !(characterIndex + complexTextRun.stringLocation()); |
| bool isLastCharacter = characterIndexInRun + 1 == m_run.length() || (U16_IS_LEAD(ch) && characterIndexInRun + 2 == m_run.length() && U16_IS_TRAIL(*(cp + characterIndex + 1))); |
| |
| bool forceLeftExpansion = false; // On the left, regardless of m_run.ltr() |
| bool forceRightExpansion = false; // On the right, regardless of m_run.ltr() |
| bool forbidLeftExpansion = false; |
| bool forbidRightExpansion = false; |
| if (runForcesLeftExpansion) |
| forceLeftExpansion = m_run.ltr() ? isFirstCharacter : isLastCharacter; |
| if (runForcesRightExpansion) |
| forceRightExpansion = m_run.ltr() ? isLastCharacter : isFirstCharacter; |
| if (runForbidsLeftExpansion) |
| forbidLeftExpansion = m_run.ltr() ? isFirstCharacter : isLastCharacter; |
| if (runForbidsRightExpansion) |
| forbidRightExpansion = m_run.ltr() ? isLastCharacter : isFirstCharacter; |
| // Handle justification and word-spacing. |
| bool ideograph = FontCascade::canExpandAroundIdeographsInComplexText() && FontCascade::isCJKIdeographOrSymbol(ch); |
| if (treatAsSpace || ideograph || forceLeftExpansion || forceRightExpansion) { |
| // Distribute the run's total expansion evenly over all expansion opportunities in the run. |
| if (m_expansion) { |
| auto [expandLeft, expandRight] = expansionLocation(ideograph, treatAsSpace, m_run.ltr(), afterExpansion, forbidLeftExpansion, forbidRightExpansion, forceLeftExpansion, forceRightExpansion); |
| if (expandLeft) { |
| m_expansion -= m_expansionPerOpportunity; |
| // Increase previous width |
| if (m_adjustedBaseAdvances.isEmpty()) { |
| advance.expand(m_expansionPerOpportunity, 0); |
| complexTextRun.growInitialAdvanceHorizontally(m_expansionPerOpportunity); |
| } else { |
| m_adjustedBaseAdvances.last().expand(m_expansionPerOpportunity, 0); |
| m_totalAdvance.expand(m_expansionPerOpportunity, 0); |
| } |
| } |
| if (expandRight) { |
| m_expansion -= m_expansionPerOpportunity; |
| advance.expand(m_expansionPerOpportunity, 0); |
| afterExpansion = true; |
| } |
| } else |
| afterExpansion = false; |
| |
| // Account for word-spacing. |
| if (treatAsSpace && (ch != '\t' || !m_run.allowTabs()) && (characterIndex > 0 || runIndex > 0 || ch == noBreakSpace) && m_font.wordSpacing()) |
| advance.expand(m_font.wordSpacing(), 0); |
| } else |
| afterExpansion = false; |
| } |
| |
| m_totalAdvance += advance; |
| |
| // FIXME: Combining marks should receive a text emphasis mark if they are combine with a space. |
| if (m_forTextEmphasis && (!FontCascade::canReceiveTextEmphasis(ch) || (U_GET_GC_MASK(ch) & U_GC_M_MASK))) |
| glyph = 0; |
| |
| m_adjustedBaseAdvances.append(advance); |
| if (auto* origins = complexTextRun.glyphOrigins()) { |
| ASSERT(m_glyphOrigins.size() < m_adjustedBaseAdvances.size()); |
| m_glyphOrigins.grow(m_adjustedBaseAdvances.size()); |
| m_glyphOrigins[m_glyphOrigins.size() - 1] = origins[i]; |
| ASSERT(m_glyphOrigins.size() == m_adjustedBaseAdvances.size()); |
| } |
| m_adjustedGlyphs.append(glyph); |
| |
| FloatRect glyphBounds = font.boundsForGlyph(glyph); |
| glyphBounds.move(glyphOrigin.x(), glyphOrigin.y()); |
| m_minGlyphBoundingBoxX = std::min(m_minGlyphBoundingBoxX, glyphBounds.x()); |
| m_maxGlyphBoundingBoxX = std::max(m_maxGlyphBoundingBoxX, glyphBounds.maxX()); |
| m_minGlyphBoundingBoxY = std::min(m_minGlyphBoundingBoxY, glyphBounds.y()); |
| m_maxGlyphBoundingBoxY = std::max(m_maxGlyphBoundingBoxY, glyphBounds.maxY()); |
| glyphOrigin.move(advance); |
| |
| lastCharacterIndex = characterIndex; |
| } |
| if (!isMonotonic) |
| complexTextRun.setIsNonMonotonic(); |
| } |
| } |
| |
| // Missing glyphs run constructor. Core Text will not generate a run of missing glyphs, instead falling back on |
| // glyphs from LastResort. We want to use the primary font's missing glyph in order to match the fast text code path. |
| ComplexTextController::ComplexTextRun::ComplexTextRun(const Font& font, const UChar* characters, unsigned stringLocation, unsigned stringLength, unsigned indexBegin, unsigned indexEnd, bool ltr) |
| : m_font(font) |
| , m_characters(characters) |
| , m_stringLength(stringLength) |
| , m_indexBegin(indexBegin) |
| , m_indexEnd(indexEnd) |
| , m_stringLocation(stringLocation) |
| , m_isLTR(ltr) |
| { |
| auto runLengthInCodeUnits = m_indexEnd - m_indexBegin; |
| m_coreTextIndices.reserveInitialCapacity(runLengthInCodeUnits); |
| unsigned r = m_indexBegin; |
| while (r < m_indexEnd) { |
| auto currentIndex = r; |
| UChar32 character; |
| U16_NEXT(m_characters, r, m_stringLength, character); |
| // https://drafts.csswg.org/css-text-3/#white-space-processing |
| // "Unsupported Default_ignorable characters must be ignored for text rendering." |
| if (!FontCascade::isCharacterWhoseGlyphsShouldBeDeletedForTextRendering(character)) |
| m_coreTextIndices.uncheckedAppend(currentIndex); |
| } |
| m_glyphCount = m_coreTextIndices.size(); |
| if (!ltr) { |
| for (unsigned r = 0, end = m_glyphCount - 1; r < m_glyphCount / 2; ++r, --end) |
| std::swap(m_coreTextIndices[r], m_coreTextIndices[end]); |
| } |
| |
| // Synthesize a run of missing glyphs. |
| m_glyphs.fill(0, m_glyphCount); |
| // Synthetic bold will be handled later in adjustGlyphsAndAdvances(). |
| m_baseAdvances.fill(FloatSize(m_font.widthForGlyph(0, Font::SyntheticBoldInclusion::Exclude), 0), m_glyphCount); |
| } |
| |
| ComplexTextController::ComplexTextRun::ComplexTextRun(const Vector<FloatSize>& advances, const Vector<FloatPoint>& origins, const Vector<Glyph>& glyphs, const Vector<unsigned>& stringIndices, FloatSize initialAdvance, const Font& font, const UChar* characters, unsigned stringLocation, unsigned stringLength, unsigned indexBegin, unsigned indexEnd, bool ltr) |
| : m_baseAdvances(advances) |
| , m_glyphOrigins(origins) |
| , m_glyphs(glyphs) |
| , m_coreTextIndices(stringIndices) |
| , m_initialAdvance(initialAdvance) |
| , m_font(font) |
| , m_characters(characters) |
| , m_stringLength(stringLength) |
| , m_indexBegin(indexBegin) |
| , m_indexEnd(indexEnd) |
| , m_glyphCount(glyphs.size()) |
| , m_stringLocation(stringLocation) |
| , m_isLTR(ltr) |
| { |
| } |
| |
| } // namespace WebCore |
