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1 // Copyright 2019 Google LLC.
2 
3 #include "modules/skparagraph/src/Iterators.h"
4 #include "modules/skparagraph/src/OneLineShaper.h"
5 #include "src/Run.h"
6 #include "src/utils/SkUTF.h"
7 
8 #include <algorithm>
9 #include <cstdint>
10 #include <unordered_set>
11 
12 
nextUtf8Unit(const char ** ptr,const char * end)13 static inline SkUnichar nextUtf8Unit(const char** ptr, const char* end) {
14     SkUnichar val = SkUTF::NextUTF8(ptr, end);
15     return val < 0 ? 0xFFFD : val;
16 }
17 
18 namespace skia {
19 namespace textlayout {
20 
commitRunBuffer(const RunInfo &)21 void OneLineShaper::commitRunBuffer(const RunInfo&) {
22 
23     fCurrentRun->commit();
24 
25     auto oldUnresolvedCount = fUnresolvedBlocks.size();
26 /*
27     SkDebugf("Run [%zu:%zu)\n", fCurrentRun->fTextRange.start, fCurrentRun->fTextRange.end);
28     for (size_t i = 0; i < fCurrentRun->size(); ++i) {
29         SkDebugf("[%zu] %hu %u %f\n", i, fCurrentRun->fGlyphs[i], fCurrentRun->fClusterIndexes[i], fCurrentRun->fPositions[i].fX);
30     }
31 */
32     // Find all unresolved blocks
33     sortOutGlyphs([&](GlyphRange block){
34         if (block.width() == 0) {
35             return;
36         }
37         addUnresolvedWithRun(block);
38     });
39 
40     // Fill all the gaps between unresolved blocks with resolved ones
41     if (oldUnresolvedCount == fUnresolvedBlocks.size()) {
42         // No unresolved blocks added - we resolved the block with one run entirely
43         addFullyResolved();
44         return;
45     } else if (oldUnresolvedCount == fUnresolvedBlocks.size() - 1) {
46         auto& unresolved = fUnresolvedBlocks.back();
47         if (fCurrentRun->textRange() == unresolved.fText) {
48             // Nothing was resolved; preserve the initial run if it makes sense
49             auto& front = fUnresolvedBlocks.front();
50             if (front.fRun != nullptr) {
51                unresolved.fRun = front.fRun;
52                unresolved.fGlyphs = front.fGlyphs;
53             }
54             return;
55         }
56     }
57 
58     fillGaps(oldUnresolvedCount);
59 }
60 
61 #ifdef SK_DEBUG
printState()62 void OneLineShaper::printState() {
63     SkDebugf("Resolved: %zu\n", fResolvedBlocks.size());
64     for (auto& resolved : fResolvedBlocks) {
65         if (resolved.fRun ==  nullptr) {
66             SkDebugf("[%zu:%zu) unresolved\n",
67                     resolved.fText.start, resolved.fText.end);
68             continue;
69         }
70         SkString name("???");
71         if (resolved.fRun->fFont.getTypeface() != nullptr) {
72             resolved.fRun->fFont.getTypeface()->getFamilyName(&name);
73         }
74         SkDebugf("[%zu:%zu) ", resolved.fGlyphs.start, resolved.fGlyphs.end);
75         SkDebugf("[%zu:%zu) with %s\n",
76                 resolved.fText.start, resolved.fText.end,
77                 name.c_str());
78     }
79 
80     auto size = fUnresolvedBlocks.size();
81     SkDebugf("Unresolved: %zu\n", size);
82     for (const auto& unresolved : fUnresolvedBlocks) {
83         SkDebugf("[%zu:%zu)\n", unresolved.fText.start, unresolved.fText.end);
84     }
85 }
86 #endif
87 
fillGaps(size_t startingCount)88 void OneLineShaper::fillGaps(size_t startingCount) {
89     // Fill out gaps between all unresolved blocks
90     TextRange resolvedTextLimits = fCurrentRun->fTextRange;
91     if (!fCurrentRun->leftToRight()) {
92         std::swap(resolvedTextLimits.start, resolvedTextLimits.end);
93     }
94     TextIndex resolvedTextStart = resolvedTextLimits.start;
95     GlyphIndex resolvedGlyphsStart = 0;
96 
97     auto begin = fUnresolvedBlocks.begin();
98     auto end = fUnresolvedBlocks.end();
99     begin += startingCount; // Skip the old ones, do the new ones
100     TextRange prevText = EMPTY_TEXT;
101     for (; begin != end; ++begin) {
102         auto& unresolved = *begin;
103 
104         if (unresolved.fText == prevText) {
105             // Clean up repetitive blocks that appear inside the same grapheme block
106             unresolved.fText = EMPTY_TEXT;
107             continue;
108         } else {
109             prevText = unresolved.fText;
110         }
111 
112         TextRange resolvedText(resolvedTextStart, fCurrentRun->leftToRight() ? unresolved.fText.start : unresolved.fText.end);
113         if (resolvedText.width() > 0) {
114             if (!fCurrentRun->leftToRight()) {
115                 std::swap(resolvedText.start, resolvedText.end);
116             }
117 
118             GlyphRange resolvedGlyphs(resolvedGlyphsStart, unresolved.fGlyphs.start);
119             RunBlock resolved(fCurrentRun, resolvedText, resolvedGlyphs, resolvedGlyphs.width());
120 
121             if (resolvedGlyphs.width() == 0) {
122                 // Extend the unresolved block with an empty resolved
123                 if (unresolved.fText.end <= resolved.fText.start) {
124                     unresolved.fText.end = resolved.fText.end;
125                 }
126                 if (unresolved.fText.start >= resolved.fText.end) {
127                     unresolved.fText.start = resolved.fText.start;
128                 }
129             } else {
130                 fResolvedBlocks.emplace_back(resolved);
131             }
132         }
133         resolvedGlyphsStart = unresolved.fGlyphs.end;
134         resolvedTextStart =  fCurrentRun->leftToRight()
135                                 ? unresolved.fText.end
136                                 : unresolved.fText.start;
137     }
138 
139     TextRange resolvedText(resolvedTextStart,resolvedTextLimits.end);
140     if (resolvedText.width() > 0) {
141         if (!fCurrentRun->leftToRight()) {
142             std::swap(resolvedText.start, resolvedText.end);
143         }
144 
145         GlyphRange resolvedGlyphs(resolvedGlyphsStart, fCurrentRun->size());
146         RunBlock resolved(fCurrentRun, resolvedText, resolvedGlyphs, resolvedGlyphs.width());
147         fResolvedBlocks.emplace_back(resolved);
148     }
149 }
150 
151 #ifdef OHOS_SUPPORT
152 // 1. glyphs in run between [glyphStart, glyphEnd) are all equal to zero.
153 // 2. run is nullptr.
154 // 3. charStart flag has kCombine.
155 // one of the above conditions is met, will return true.
156 // anything else, return false.
isUnresolvedCombineGlyphRange(std::shared_ptr<Run> run,size_t glyphStart,size_t glyphEnd,size_t charStart) const157 bool OneLineShaper::isUnresolvedCombineGlyphRange(std::shared_ptr<Run> run, size_t glyphStart, size_t glyphEnd,
158     size_t charStart) const
159 {
160     if (run == nullptr ||
161         (fParagraph != nullptr && !fParagraph->codeUnitHasProperty(charStart, SkUnicode::kCombine))) {
162         return true;
163     }
164     size_t iterGlyphEnd = std::min(run->fGlyphs.size(), glyphEnd);
165     for (size_t glyph = glyphStart; glyph < iterGlyphEnd; ++glyph) {
166         if (run->fGlyphs[glyph] != 0) {
167             return false;
168         }
169     }
170 
171     return true;
172 }
173 
174 // split unresolvedBlock.
175 // extract resolvedBlock(which isUnresolvedGlyphRange is false), emplace back to stagedUnresolvedBlocks.
176 // the rest block emplace back to fUnresolvedBlocks without run.
splitUnresolvedBlockAndStageResolvedSubBlock(std::deque<RunBlock> & stagedUnresolvedBlocks,const RunBlock & unresolvedBlock)177 void OneLineShaper::splitUnresolvedBlockAndStageResolvedSubBlock(
178     std::deque<RunBlock>& stagedUnresolvedBlocks, const RunBlock& unresolvedBlock)
179 {
180     if (unresolvedBlock.fRun == nullptr) {
181         return;
182     }
183     std::shared_ptr<Run> run = unresolvedBlock.fRun;
184     bool hasUnresolvedText = false;
185     size_t curTextStart = EMPTY_INDEX;
186     size_t curGlyphEdge = EMPTY_INDEX;
187     run->iterateGlyphRangeInTextOrder(unresolvedBlock.fGlyphs,
188         [&stagedUnresolvedBlocks, &hasUnresolvedText, &curTextStart, &curGlyphEdge, run, this]
189         (size_t glyphStart, size_t glyphEnd, size_t charStart, size_t charEnd) {
190             if (!isUnresolvedCombineGlyphRange(run, glyphStart, glyphEnd, charStart)) {
191                 if (curTextStart == EMPTY_INDEX) {
192                     curTextStart = charStart;
193                 }
194                 if (curGlyphEdge == EMPTY_INDEX) {
195                     curGlyphEdge = run->leftToRight() ? glyphStart : glyphEnd;
196                 }
197                 return;
198             }
199             hasUnresolvedText = true;
200             this->fUnresolvedBlocks.emplace_back(RunBlock(TextRange(charStart, charEnd)));
201             if (curTextStart == EMPTY_INDEX) {
202                 return;
203             }
204             if (run->leftToRight()) {
205                 stagedUnresolvedBlocks.emplace_back(
206                     run, TextRange(curTextStart, charStart), GlyphRange(curGlyphEdge, glyphStart), 0);
207             } else {
208                 stagedUnresolvedBlocks.emplace_back(
209                     run, TextRange(curTextStart, charStart), GlyphRange(glyphEnd, curGlyphEdge), 0);
210             }
211             curTextStart = EMPTY_INDEX;
212             curGlyphEdge = EMPTY_INDEX;
213         });
214     if (!hasUnresolvedText) {
215         stagedUnresolvedBlocks.emplace_back(unresolvedBlock);
216         return;
217     }
218     if (curTextStart == EMPTY_INDEX) {
219         return;
220     }
221     if (run->leftToRight()) {
222         stagedUnresolvedBlocks.emplace_back(run, TextRange(curTextStart, unresolvedBlock.fText.end),
223             GlyphRange(curGlyphEdge, unresolvedBlock.fGlyphs.end), 0);
224     } else {
225         stagedUnresolvedBlocks.emplace_back(run, TextRange(curTextStart, unresolvedBlock.fText.end),
226             GlyphRange(unresolvedBlock.fGlyphs.start, curGlyphEdge), 0);
227     }
228 }
229 
230 // shape unresolved text separately.
shapeUnresolvedTextSeparatelyFromUnresolvedBlock(const TextStyle & textStyle,const TypefaceVisitor & visitor)231 void OneLineShaper::shapeUnresolvedTextSeparatelyFromUnresolvedBlock(
232     const TextStyle& textStyle, const TypefaceVisitor& visitor)
233 {
234     if (fUnresolvedBlocks.empty()) {
235         return;
236     }
237     std::deque<OneLineShaper::RunBlock> stagedUnresolvedBlocks;
238     size_t unresolvedBlockCount = fUnresolvedBlocks.size();
239     while (unresolvedBlockCount-- > 0) {
240         RunBlock unresolvedBlock = fUnresolvedBlocks.front();
241         fUnresolvedBlocks.pop_front();
242 
243         if (unresolvedBlock.fText.width() <= 1 || unresolvedBlock.fRun == nullptr) {
244             stagedUnresolvedBlocks.emplace_back(unresolvedBlock);
245             continue;
246         }
247 
248         splitUnresolvedBlockAndStageResolvedSubBlock(stagedUnresolvedBlocks, unresolvedBlock);
249     }
250 
251     this->matchResolvedFonts(textStyle, visitor);
252 
253     while (!stagedUnresolvedBlocks.empty()) {
254         auto block = stagedUnresolvedBlocks.front();
255         stagedUnresolvedBlocks.pop_front();
256         fUnresolvedBlocks.emplace_back(block);
257     }
258 }
259 #endif
260 
finish(const Block & block,SkScalar height,SkScalar & advanceX)261 void OneLineShaper::finish(const Block& block, SkScalar height, SkScalar& advanceX) {
262     auto blockText = block.fRange;
263 
264     // Add all unresolved blocks to resolved blocks
265     while (!fUnresolvedBlocks.empty()) {
266         auto unresolved = fUnresolvedBlocks.front();
267         fUnresolvedBlocks.pop_front();
268         if (unresolved.fText.width() == 0) {
269             continue;
270         }
271         fResolvedBlocks.emplace_back(unresolved);
272         fUnresolvedGlyphs += unresolved.fGlyphs.width();
273         fParagraph->addUnresolvedCodepoints(unresolved.fText);
274     }
275 
276     // Sort all pieces by text
277     std::sort(fResolvedBlocks.begin(), fResolvedBlocks.end(),
278               [](const RunBlock& a, const RunBlock& b) {
279                 return a.fText.start < b.fText.start;
280               });
281 
282     // Go through all of them
283     size_t lastTextEnd = blockText.start;
284     for (auto& resolvedBlock : fResolvedBlocks) {
285 
286         if (resolvedBlock.fText.end <= blockText.start) {
287             continue;
288         }
289 
290         if (resolvedBlock.fRun != nullptr) {
291             fParagraph->fFontSwitches.emplace_back(resolvedBlock.fText.start, resolvedBlock.fRun->fFont);
292         }
293 
294         auto run = resolvedBlock.fRun;
295         auto glyphs = resolvedBlock.fGlyphs;
296         auto text = resolvedBlock.fText;
297         if (lastTextEnd != text.start) {
298             SkDEBUGF("Text ranges mismatch: ...:%zu] - [%zu:%zu] (%zu-%zu)\n",
299                      lastTextEnd, text.start, text.end,  glyphs.start, glyphs.end);
300             SkASSERT(false);
301         }
302         lastTextEnd = text.end;
303 
304         if (resolvedBlock.isFullyResolved()) {
305             // Just move the entire run
306             resolvedBlock.fRun->fIndex = this->fParagraph->fRuns.size();
307             this->fParagraph->fRuns.emplace_back(*resolvedBlock.fRun);
308             resolvedBlock.fRun.reset();
309             continue;
310         } else if (run == nullptr) {
311             continue;
312         }
313 
314         auto runAdvance = SkVector::Make(run->posX(glyphs.end) - run->posX(glyphs.start), run->fAdvance.fY);
315         const SkShaper::RunHandler::RunInfo info = {
316                 run->fFont,
317                 run->fBidiLevel,
318                 runAdvance,
319                 glyphs.width(),
320                 SkShaper::RunHandler::Range(text.start - run->fClusterStart, text.width())
321         };
322         this->fParagraph->fRuns.emplace_back(
323                     this->fParagraph,
324                     info,
325                     run->fClusterStart,
326                     height,
327                     block.fStyle.getHalfLeading(),
328                     block.fStyle.getBaselineShift(),
329                     this->fParagraph->fRuns.size(),
330                     advanceX
331                 );
332         auto piece = &this->fParagraph->fRuns.back();
333 
334         // TODO: Optimize copying
335         SkPoint zero = {run->fPositions[glyphs.start].fX, 0};
336         for (size_t i = glyphs.start; i <= glyphs.end; ++i) {
337 
338             auto index = i - glyphs.start;
339             if (i < glyphs.end) {
340                 piece->fGlyphs[index] = run->fGlyphs[i];
341             }
342             piece->fClusterIndexes[index] = run->fClusterIndexes[i];
343             piece->fPositions[index] = run->fPositions[i] - zero;
344             piece->fOffsets[index] = run->fOffsets[i];
345             piece->addX(index, advanceX);
346         }
347 
348         // Carve out the line text out of the entire run text
349         fAdvance.fX += runAdvance.fX;
350         fAdvance.fY = std::max(fAdvance.fY, runAdvance.fY);
351     }
352 
353     advanceX = fAdvance.fX;
354     if (lastTextEnd != blockText.end) {
355         SkDEBUGF("Last range mismatch: %zu - %zu\n", lastTextEnd, blockText.end);
356         SkASSERT(false);
357     }
358 }
359 
360 // Make it [left:right) regardless of a text direction
normalizeTextRange(GlyphRange glyphRange)361 TextRange OneLineShaper::normalizeTextRange(GlyphRange glyphRange) {
362 
363     if (fCurrentRun->leftToRight()) {
364         return TextRange(clusterIndex(glyphRange.start), clusterIndex(glyphRange.end));
365     } else {
366         return TextRange(clusterIndex(glyphRange.end - 1),
367                 glyphRange.start > 0
368                 ? clusterIndex(glyphRange.start - 1)
369                 : fCurrentRun->fTextRange.end);
370     }
371 }
372 
addFullyResolved()373 void OneLineShaper::addFullyResolved() {
374     if (this->fCurrentRun->size() == 0) {
375         return;
376     }
377     RunBlock resolved(fCurrentRun,
378                       this->fCurrentRun->fTextRange,
379                       GlyphRange(0, this->fCurrentRun->size()),
380                       this->fCurrentRun->size());
381     fResolvedBlocks.emplace_back(resolved);
382 }
383 
addUnresolvedWithRun(GlyphRange glyphRange)384 void OneLineShaper::addUnresolvedWithRun(GlyphRange glyphRange) {
385     auto extendedText = this->clusteredText(glyphRange); // It also modifies glyphRange if needed
386     RunBlock unresolved(fCurrentRun, extendedText, glyphRange, 0);
387     if (unresolved.fGlyphs.width() == fCurrentRun->size()) {
388         SkASSERT(unresolved.fText.width() == fCurrentRun->fTextRange.width());
389     } else if (fUnresolvedBlocks.size() > 0) {
390         auto& lastUnresolved = fUnresolvedBlocks.back();
391         if (lastUnresolved.fRun != nullptr &&
392             lastUnresolved.fRun->fIndex == fCurrentRun->fIndex) {
393 
394             if (lastUnresolved.fText.end == unresolved.fText.start) {
395               // Two pieces next to each other - can join them
396               lastUnresolved.fText.end = unresolved.fText.end;
397               lastUnresolved.fGlyphs.end = glyphRange.end;
398               return;
399             } else if(lastUnresolved.fText == unresolved.fText) {
400                 // Nothing was resolved; ignore it
401                 return;
402             } else if (lastUnresolved.fText.contains(unresolved.fText)) {
403                 // We get here for the very first unresolved piece
404                 return;
405             } else if (lastUnresolved.fText.intersects(unresolved.fText)) {
406                 // Few pieces of the same unresolved text block can ignore the second one
407                 lastUnresolved.fGlyphs.start = std::min(lastUnresolved.fGlyphs.start, glyphRange.start);
408                 lastUnresolved.fGlyphs.end = std::max(lastUnresolved.fGlyphs.end, glyphRange.end);
409                 lastUnresolved.fText = this->clusteredText(lastUnresolved.fGlyphs);
410                 return;
411             }
412         }
413     }
414     fUnresolvedBlocks.emplace_back(unresolved);
415 }
416 
417 // Glue whitespaces to the next/prev unresolved blocks
418 // (so we don't have chinese text with english whitespaces broken into millions of tiny runs)
sortOutGlyphs(std::function<void (GlyphRange)> && sortOutUnresolvedBLock)419 void OneLineShaper::sortOutGlyphs(std::function<void(GlyphRange)>&& sortOutUnresolvedBLock) {
420 
421     GlyphRange block = EMPTY_RANGE;
422     bool graphemeResolved = false;
423     TextIndex graphemeStart = EMPTY_INDEX;
424     for (size_t i = 0; i < fCurrentRun->size(); ++i) {
425 
426         ClusterIndex ci = clusterIndex(i);
427         // Removing all pretty optimizations for whitespaces
428         // because they get in a way of grapheme rounding
429         // Inspect the glyph
430         auto glyph = fCurrentRun->fGlyphs[i];
431 
432         GraphemeIndex gi = fParagraph->findPreviousGraphemeBoundary(ci);
433         if ((fCurrentRun->leftToRight() ? gi > graphemeStart : gi < graphemeStart) || graphemeStart == EMPTY_INDEX) {
434             // This is the Flutter change
435             // Do not count control codepoints as unresolved
436             bool isControl8 = fParagraph->codeUnitHasProperty(ci,
437                                                               SkUnicode::CodeUnitFlags::kControl);
438             // We only count glyph resolved if all the glyphs in its grapheme are resolved
439             graphemeResolved = glyph != 0 || isControl8;
440             graphemeStart = gi;
441         } else if (glyph == 0) {
442             // Found unresolved glyph - the entire grapheme is unresolved now
443             graphemeResolved = false;
444         }
445 
446         if (!graphemeResolved) { // Unresolved glyph and not control codepoint
447             if (block.start == EMPTY_INDEX) {
448                 // Start new unresolved block
449                 block.start = i;
450                 block.end = EMPTY_INDEX;
451             } else {
452                 // Keep skipping unresolved block
453             }
454         } else { // Resolved glyph or control codepoint
455             if (block.start == EMPTY_INDEX) {
456                 // Keep skipping resolved code points
457             } else {
458                 // This is the end of unresolved block
459                 block.end = i;
460                 sortOutUnresolvedBLock(block);
461                 block = EMPTY_RANGE;
462             }
463         }
464     }
465 
466     // One last block could have been left
467     if (block.start != EMPTY_INDEX) {
468         block.end = fCurrentRun->size();
469         sortOutUnresolvedBLock(block);
470     }
471 }
472 
generateBlockRange(const Block & block,const TextRange & textRange)473 BlockRange OneLineShaper::generateBlockRange(const Block& block, const TextRange& textRange)
474 {
475     size_t start = std::max(block.fRange.start, textRange.start);
476     size_t end = std::min(block.fRange.end, textRange.end);
477     if (fParagraph->fParagraphStyle.getMaxLines() == 1 &&
478         fParagraph->fParagraphStyle.getEllipsisMod() == EllipsisModal::MIDDLE &&
479         !fParagraph->getEllipsisState()) {
480         end = fParagraph->fText.size();
481     }
482     return BlockRange(start, end);
483 }
484 
iterateThroughFontStyles(TextRange textRange,SkSpan<Block> styleSpan,const ShapeSingleFontVisitor & visitor)485 void OneLineShaper::iterateThroughFontStyles(TextRange textRange,
486                                              SkSpan<Block> styleSpan,
487                                              const ShapeSingleFontVisitor& visitor) {
488     Block combinedBlock;
489     SkTArray<SkShaper::Feature> features;
490 
491     auto addFeatures = [&features](const Block& block) {
492         for (auto& ff : block.fStyle.getFontFeatures()) {
493             if (ff.fName.size() != 4) {
494                 SkDEBUGF("Incorrect font feature: %s=%d\n", ff.fName.c_str(), ff.fValue);
495                 continue;
496             }
497             SkShaper::Feature feature = {
498                 SkSetFourByteTag(ff.fName[0], ff.fName[1], ff.fName[2], ff.fName[3]),
499                 SkToU32(ff.fValue),
500                 block.fRange.start,
501                 block.fRange.end
502             };
503             features.emplace_back(feature);
504         }
505         // Disable ligatures if letter spacing is enabled.
506         if (block.fStyle.getLetterSpacing() > 0) {
507             features.emplace_back(SkShaper::Feature{
508                 SkSetFourByteTag('l', 'i', 'g', 'a'), 0, block.fRange.start, block.fRange.end
509             });
510         }
511     };
512 
513     for (auto& block : styleSpan) {
514         BlockRange blockRange = generateBlockRange(block, textRange);
515         if (blockRange.empty()) {
516             continue;
517         }
518         SkASSERT(combinedBlock.fRange.width() == 0 || combinedBlock.fRange.end == block.fRange.start);
519 
520         if (!combinedBlock.fRange.empty()) {
521             if (block.fStyle.matchOneAttribute(StyleType::kFont, combinedBlock.fStyle)) {
522                 combinedBlock.add(blockRange);
523                 addFeatures(block);
524                 continue;
525             }
526             // Resolve all characters in the block for this style
527             visitor(combinedBlock, features);
528         }
529 
530         combinedBlock.fRange = blockRange;
531         combinedBlock.fStyle = block.fStyle;
532         features.reset();
533         addFeatures(block);
534     }
535 
536     visitor(combinedBlock, features);
537 #ifdef SK_DEBUG
538     //printState();
539 #endif
540 }
541 
matchResolvedFonts(const TextStyle & textStyle,const TypefaceVisitor & visitor)542 void OneLineShaper::matchResolvedFonts(const TextStyle& textStyle,
543                                        const TypefaceVisitor& visitor) {
544 #ifndef USE_SKIA_TXT
545     std::vector<sk_sp<SkTypeface>> typefaces = fParagraph->fFontCollection->findTypefaces(textStyle.getFontFamilies(), textStyle.getFontStyle(), textStyle.getFontArguments());
546 #else
547     std::vector<std::shared_ptr<RSTypeface>> typefaces = fParagraph->fFontCollection->findTypefaces(
548         textStyle.getFontFamilies(), textStyle.getFontStyle(), textStyle.getFontArguments());
549 #endif
550 
551     for (const auto& typeface : typefaces) {
552         if (visitor(typeface) == Resolved::Everything) {
553             // Resolved everything
554             return;
555         }
556     }
557 
558     if (fParagraph->fFontCollection->fontFallbackEnabled()) {
559         // Give fallback a clue
560         // Some unresolved subblocks might be resolved with different fallback fonts
561         std::vector<RunBlock> hopelessBlocks;
562         while (!fUnresolvedBlocks.empty()) {
563             auto unresolvedRange = fUnresolvedBlocks.front().fText;
564             auto unresolvedText = fParagraph->text(unresolvedRange);
565             const char* ch = unresolvedText.begin();
566             // We have the global cache for all already found typefaces for SkUnichar
567             // but we still need to keep track of all SkUnichars used in this unresolved block
568             SkTHashSet<SkUnichar> alreadyTriedCodepoints;
569             SkTHashSet<uint32_t> alreadyTriedTypefaces;
570             while (true) {
571 
572                 if (ch == unresolvedText.end()) {
573                     // Not a single codepoint could be resolved but we finished the block
574                     hopelessBlocks.push_back(fUnresolvedBlocks.front());
575                     fUnresolvedBlocks.pop_front();
576                     break;
577                 }
578 
579                 // See if we can switch to the next DIFFERENT codepoint
580                 SkUnichar unicode = -1;
581                 while (ch != unresolvedText.end()) {
582                     unicode = nextUtf8Unit(&ch, unresolvedText.end());
583                     if (!alreadyTriedCodepoints.contains(unicode)) {
584                         alreadyTriedCodepoints.add(unicode);
585                         break;
586                     }
587                 }
588                 SkASSERT(unicode != -1);
589 
590                 // First try to find in in a cache
591 #ifndef USE_SKIA_TXT
592                 sk_sp<SkTypeface> typeface;
593 #else
594                 std::shared_ptr<RSTypeface> typeface;
595 #endif
596                 FontKey fontKey(unicode, textStyle.getFontStyle(), textStyle.getLocale());
597                 auto found = fFallbackFonts.find(fontKey);
598 #ifndef USE_SKIA_TXT
599                 if (found != nullptr) {
600                     typeface = *found;
601 #else
602                 if (found != fFallbackFonts.end()) {
603                     typeface = found->second;
604 #endif
605                 } else {
606                     typeface = fParagraph->fFontCollection->defaultFallback(
607                             unicode, textStyle.getFontStyle(), textStyle.getLocale());
608 
609                     if (typeface == nullptr) {
610                         // There is no fallback font for this character, so move on to the next character.
611                         continue;
612                     }
613 #ifndef USE_SKIA_TXT
614                     fFallbackFonts.set(fontKey, typeface);
615 #else
616                     fFallbackFonts.emplace(fontKey, typeface);
617 #endif
618                 }
619 
620                 // Check if we already tried this font on this text range
621 #ifndef USE_SKIA_TXT
622                 if (!alreadyTriedTypefaces.contains(typeface->uniqueID())) {
623                     alreadyTriedTypefaces.add(typeface->uniqueID());
624 #else
625                 if (!alreadyTriedTypefaces.contains(typeface->GetUniqueID())) {
626                     alreadyTriedTypefaces.add(typeface->GetUniqueID());
627 #endif
628                 } else {
629                     continue;
630                 }
631 
632                 if (typeface && textStyle.getFontArguments()) {
633                     typeface = fParagraph->fFontCollection->CloneTypeface(typeface, textStyle.getFontArguments());
634                 }
635 
636                 auto resolvedBlocksBefore = fResolvedBlocks.size();
637                 auto resolved = visitor(typeface);
638                 if (resolved == Resolved::Everything) {
639                     if (hopelessBlocks.empty()) {
640                         // Resolved everything, no need to try another font
641                         return;
642                     } else if (resolvedBlocksBefore < fResolvedBlocks.size()) {
643                         // There are some resolved blocks
644                         resolved = Resolved::Something;
645                     } else {
646                         // All blocks are hopeless
647                         resolved = Resolved::Nothing;
648                     }
649                 }
650 
651                 if (resolved == Resolved::Something) {
652                     // Resolved something, no need to try another codepoint
653                     break;
654                 }
655             }
656         }
657 
658         // Return hopeless blocks back
659         for (auto& block : hopelessBlocks) {
660             fUnresolvedBlocks.emplace_front(block);
661         }
662     }
663 }
664 
665 bool OneLineShaper::iterateThroughShapingRegions(const ShapeVisitor& shape) {
666 
667     size_t bidiIndex = 0;
668 
669     SkScalar advanceX = 0;
670     for (auto& placeholder : fParagraph->fPlaceholders) {
671 
672         if (placeholder.fTextBefore.width() > 0) {
673             // Shape the text by bidi regions
674             while (bidiIndex < fParagraph->fBidiRegions.size()) {
675                 SkUnicode::BidiRegion& bidiRegion = fParagraph->fBidiRegions[bidiIndex];
676                 auto start = std::max(bidiRegion.start, placeholder.fTextBefore.start);
677                 auto end = std::min(bidiRegion.end, placeholder.fTextBefore.end);
678                 if (fParagraph->fParagraphStyle.getMaxLines() == 1
679                     && fParagraph->fParagraphStyle.getEllipsisMod() == EllipsisModal::MIDDLE
680                     && !fParagraph->getEllipsisState()) {
681                     end = fParagraph->fText.size();
682                 }
683 
684                 // Set up the iterators (the style iterator points to a bigger region that it could
685                 TextRange textRange(start, end);
686                 auto blockRange = fParagraph->findAllBlocks(textRange);
687                 if (!blockRange.empty()) {
688                     SkSpan<Block> styleSpan(fParagraph->blocks(blockRange));
689 
690                     // Shape the text between placeholders
691                     if (!shape(textRange, styleSpan, advanceX, start, bidiRegion.level)) {
692                         return false;
693                     }
694                 }
695 
696                 if (end == bidiRegion.end) {
697                     ++bidiIndex;
698                 } else /*if (end == placeholder.fTextBefore.end)*/ {
699                     break;
700                 }
701             }
702         }
703 
704         if (placeholder.fRange.width() == 0) {
705             continue;
706         }
707 
708         // Get the placeholder font
709         auto typefaces = fParagraph->fFontCollection->findTypefaces(
710             placeholder.fTextStyle.getFontFamilies(),
711             placeholder.fTextStyle.getFontStyle(),
712             placeholder.fTextStyle.getFontArguments());
713         auto typeface = typefaces.size() ? typefaces.front() : nullptr;
714 #ifndef USE_SKIA_TXT
715         SkFont font(typeface, placeholder.fTextStyle.getFontSize());
716 #else
717         RSFont font(typeface, placeholder.fTextStyle.getFontSize(), 1, 0);
718 #endif
719 
720         // "Shape" the placeholder
721         uint8_t bidiLevel = (bidiIndex < fParagraph->fBidiRegions.size())
722             ? fParagraph->fBidiRegions[bidiIndex].level
723             : 2;
724         const SkShaper::RunHandler::RunInfo runInfo = {
725             font,
726             bidiLevel,
727             SkPoint::Make(placeholder.fStyle.fWidth, placeholder.fStyle.fHeight),
728             1,
729             SkShaper::RunHandler::Range(0, placeholder.fRange.width())
730         };
731         auto& run = fParagraph->fRuns.emplace_back(this->fParagraph,
732                                        runInfo,
733                                        placeholder.fRange.start,
734                                        0.0f,
735                                        0.0f,
736                                        false,
737                                        fParagraph->fRuns.size(),
738                                        advanceX);
739 
740         run.fPositions[0] = { advanceX, 0 };
741         run.fOffsets[0] = {0, 0};
742         run.fClusterIndexes[0] = 0;
743         run.fPlaceholderIndex = &placeholder - fParagraph->fPlaceholders.begin();
744         advanceX += placeholder.fStyle.fWidth;
745     }
746     return true;
747 }
748 
749 bool OneLineShaper::shape() {
750 
751     // The text can be broken into many shaping sequences
752     // (by place holders, possibly, by hard line breaks or tabs, too)
753     auto limitlessWidth = std::numeric_limits<SkScalar>::max();
754 
755     auto result = iterateThroughShapingRegions(
756             [this, limitlessWidth]
757             (TextRange textRange, SkSpan<Block> styleSpan, SkScalar& advanceX, TextIndex textStart, uint8_t defaultBidiLevel) {
758 
759         // Set up the shaper and shape the next
760         auto shaper = SkShaper::MakeShapeDontWrapOrReorder(fParagraph->fUnicode->copy());
761         if (shaper == nullptr) {
762             // For instance, loadICU does not work. We have to stop the process
763             return false;
764         }
765 
766         iterateThroughFontStyles(textRange, styleSpan,
767                 [this, &shaper, defaultBidiLevel, limitlessWidth, &advanceX]
768                 (Block block, SkTArray<SkShaper::Feature> features) {
769             auto blockSpan = SkSpan<Block>(&block, 1);
770 
771             // Start from the beginning (hoping that it's a simple case one block - one run)
772             fHeight = block.fStyle.getHeightOverride() ? block.fStyle.getHeight() : 0;
773             fUseHalfLeading = block.fStyle.getHalfLeading();
774             fBaselineShift = block.fStyle.getBaselineShift();
775             fAdvance = SkVector::Make(advanceX, 0);
776             fCurrentText = block.fRange;
777             fUnresolvedBlocks.emplace_back(RunBlock(block.fRange));
778 
779 #ifdef OHOS_SUPPORT
780 #ifdef USE_SKIA_TXT
781             auto typefaceVisitor = [&](std::shared_ptr<RSTypeface> typeface) {
782 #else
783             auto typefaceVisitor = [&](sk_sp<SkTypeface> typeface) {
784 #endif
785 #else
786             this->matchResolvedFonts(block.fStyle, [&](sk_sp<SkTypeface> typeface) {
787 #endif
788                 // Create one more font to try
789 #ifndef USE_SKIA_TXT
790                 SkFont font(std::move(typeface), block.fStyle.getFontSize());
791                 font.setEdging(SkFont::Edging::kAntiAlias);
792                 font.setHinting(SkFontHinting::kNone);
793                 font.setSubpixel(true);
794                 font.setBaselineSnap(false);
795 #else
796                 RSFont font(std::move(typeface), block.fStyle.getFontSize(), 1, 0);
797                 font.SetEdging(RSDrawing::FontEdging::ANTI_ALIAS);
798                 font.SetHinting(RSDrawing::FontHinting::NONE);
799                 font.SetSubpixel(true);
800                 font.SetBaselineSnap(false);
801 #endif
802 
803 #ifdef OHOS_SUPPORT
804                 scaleFontWithCompressionConfig(font, ScaleOP::COMPRESS);
805 #endif
806                 // Apply fake bold and/or italic settings to the font if the
807                 // typeface's attributes do not match the intended font style.
808 #ifndef USE_SKIA_TXT
809                 int wantedWeight = block.fStyle.getFontStyle().weight();
810                 bool fakeBold =
811                     wantedWeight >= SkFontStyle::kSemiBold_Weight &&
812                     wantedWeight - font.getTypeface()->fontStyle().weight() >= 200;
813                 bool fakeItalic =
814                     block.fStyle.getFontStyle().slant() == SkFontStyle::kItalic_Slant &&
815                     font.getTypeface()->fontStyle().slant() != SkFontStyle::kItalic_Slant;
816                 font.setEmbolden(fakeBold);
817                 font.setSkewX(fakeItalic ? -SK_Scalar1 / 4 : 0);
818 #else
819                 int wantedWeight = block.fStyle.getFontStyle().GetWeight();
820                 bool fakeBold =
821                     wantedWeight >= RSFontStyle::SEMI_BOLD_WEIGHT &&
822                     wantedWeight - font.GetTypeface()->GetFontStyle().GetWeight() >= 200;
823                 bool fakeItalic =
824                     block.fStyle.getFontStyle().GetSlant() == RSFontStyle::ITALIC_SLANT &&
825                     font.GetTypeface()->GetFontStyle().GetSlant() != RSFontStyle::ITALIC_SLANT;
826                 font.SetEmbolden(fakeBold);
827                 font.SetSkewX(fakeItalic ? -SK_Scalar1 / 4 : 0);
828 #endif
829 
830                 // Walk through all the currently unresolved blocks
831                 // (ignoring those that appear later)
832                 auto resolvedCount = fResolvedBlocks.size();
833                 auto unresolvedCount = fUnresolvedBlocks.size();
834                 while (unresolvedCount-- > 0) {
835                     auto unresolvedRange = fUnresolvedBlocks.front().fText;
836                     if (unresolvedRange == EMPTY_TEXT) {
837                         // Duplicate blocks should be ignored
838                         fUnresolvedBlocks.pop_front();
839                         continue;
840                     }
841                     auto unresolvedText = fParagraph->text(unresolvedRange);
842 
843                     SkShaper::TrivialFontRunIterator fontIter(font, unresolvedText.size());
844                     LangIterator langIter(unresolvedText, blockSpan,
845                                       fParagraph->paragraphStyle().getTextStyle());
846                     SkShaper::TrivialBiDiRunIterator bidiIter(defaultBidiLevel, unresolvedText.size());
847                     auto scriptIter = SkShaper::MakeSkUnicodeHbScriptRunIterator(
848                             unresolvedText.begin(), unresolvedText.size());
849                     fCurrentText = unresolvedRange;
850 
851                     // Map the block's features to subranges within the unresolved range.
852                     SkTArray<SkShaper::Feature> adjustedFeatures(features.size());
853                     for (const SkShaper::Feature& feature : features) {
854                         SkRange<size_t> featureRange(feature.start, feature.end);
855                         if (unresolvedRange.intersects(featureRange)) {
856                             SkRange<size_t> adjustedRange = unresolvedRange.intersection(featureRange);
857                             adjustedRange.Shift(-static_cast<std::make_signed_t<size_t>>(unresolvedRange.start));
858                             adjustedFeatures.push_back({feature.tag, feature.value, adjustedRange.start, adjustedRange.end});
859                         }
860                     }
861 
862                     shaper->shape(unresolvedText.begin(), unresolvedText.size(),
863                             fontIter, bidiIter,*scriptIter, langIter,
864                             adjustedFeatures.data(), adjustedFeatures.size(),
865                             limitlessWidth, this);
866 
867                     // Take off the queue the block we tried to resolved -
868                     // whatever happened, we have now smaller pieces of it to deal with
869                     fUnresolvedBlocks.pop_front();
870                 }
871 
872                 if (fUnresolvedBlocks.empty()) {
873                     // In some cases it does not mean everything
874                     // (when we excluded some hopeless blocks from the list)
875                     return Resolved::Everything;
876                 } else if (resolvedCount < fResolvedBlocks.size()) {
877                     return Resolved::Something;
878                 } else {
879                     return Resolved::Nothing;
880                 }
881 #ifdef OHOS_SUPPORT
882             };
883             this->matchResolvedFonts(block.fStyle, typefaceVisitor);
884             this->shapeUnresolvedTextSeparatelyFromUnresolvedBlock(block.fStyle, typefaceVisitor);
885 #else
886             });
887 #endif
888             this->finish(block, fHeight, advanceX);
889         });
890 
891         return true;
892     });
893 
894     return result;
895 }
896 
897 // When we extend TextRange to the grapheme edges, we also extend glyphs range
898 TextRange OneLineShaper::clusteredText(GlyphRange& glyphs) {
899 
900     enum class Dir { left, right };
901     enum class Pos { inclusive, exclusive };
902 
903     // [left: right)
904     auto findBaseChar = [&](TextIndex index, Dir dir) -> TextIndex {
905 
906         if (dir == Dir::right) {
907             while (index < fCurrentRun->fTextRange.end) {
908                 if (this->fParagraph->codeUnitHasProperty(index,
909                                                       SkUnicode::CodeUnitFlags::kGraphemeStart)) {
910                     return index;
911                 }
912                 ++index;
913             }
914             return fCurrentRun->fTextRange.end;
915         } else {
916             while (index > fCurrentRun->fTextRange.start) {
917                 if (this->fParagraph->codeUnitHasProperty(index,
918                                                       SkUnicode::CodeUnitFlags::kGraphemeStart)) {
919                     return index;
920                 }
921                 --index;
922             }
923             return fCurrentRun->fTextRange.start;
924         }
925     };
926 
927     TextRange textRange(normalizeTextRange(glyphs));
928     textRange.start = findBaseChar(textRange.start, Dir::left);
929     textRange.end = findBaseChar(textRange.end, Dir::right);
930 
931     // Correct the glyphRange in case we extended the text to the grapheme edges
932     // TODO: code it without if (as a part of LTR/RTL refactoring)
933     if (fCurrentRun->leftToRight()) {
934         while (glyphs.start > 0 && clusterIndex(glyphs.start) > textRange.start) {
935           glyphs.start--;
936         }
937         while (glyphs.end < fCurrentRun->size() && clusterIndex(glyphs.end) < textRange.end) {
938           glyphs.end++;
939         }
940     } else {
941         while (glyphs.start > 0 && clusterIndex(glyphs.start - 1) < textRange.end) {
942           glyphs.start--;
943         }
944         while (glyphs.end < fCurrentRun->size() && clusterIndex(glyphs.end) > textRange.start) {
945           glyphs.end++;
946         }
947     }
948 
949     return { textRange.start, textRange.end };
950 }
951 
952 bool OneLineShaper::FontKey::operator==(const OneLineShaper::FontKey& other) const {
953     return fUnicode == other.fUnicode && fFontStyle == other.fFontStyle && fLocale == other.fLocale;
954 }
955 
956 uint32_t OneLineShaper::FontKey::Hasher::operator()(const OneLineShaper::FontKey& key) const {
957     return SkGoodHash()(key.fUnicode) ^
958            SkGoodHash()(key.fFontStyle) ^
959            SkGoodHash()(key.fLocale);
960 }
961 
962 }  // namespace textlayout
963 }  // namespace skia
964