1 /*
2 * Copyright 2014 Google Inc.
3 *
4 * Use of this source code is governed by a BSD-style license that can be
5 * found in the LICENSE file.
6 */
7
8 #include "include/core/SkRSXform.h"
9 #include "include/core/SkTextBlob.h"
10 #include "include/core/SkTypeface.h"
11 #include "src/core/SkFontPriv.h"
12 #include "src/core/SkGlyphRun.h"
13 #include "src/core/SkPaintPriv.h"
14 #include "src/core/SkReadBuffer.h"
15 #include "src/core/SkSafeMath.h"
16 #include "src/core/SkStrikeCache.h"
17 #include "src/core/SkStrikeSpec.h"
18 #include "src/core/SkTextBlobPriv.h"
19 #include "src/core/SkWriteBuffer.h"
20
21 #include <atomic>
22 #include <limits>
23 #include <new>
24
25 #if SK_SUPPORT_GPU
26 #include "src/gpu/text/GrTextBlobCache.h"
27 #endif
28
29 namespace {
30 struct RunFontStorageEquivalent {
31 SkScalar fSize, fScaleX;
32 void* fTypeface;
33 SkScalar fSkewX;
34 uint32_t fFlags;
35 };
36 static_assert(sizeof(SkFont) == sizeof(RunFontStorageEquivalent), "runfont_should_stay_packed");
37 }
38
StorageSize(uint32_t glyphCount,uint32_t textSize,SkTextBlob::GlyphPositioning positioning,SkSafeMath * safe)39 size_t SkTextBlob::RunRecord::StorageSize(uint32_t glyphCount, uint32_t textSize,
40 SkTextBlob::GlyphPositioning positioning,
41 SkSafeMath* safe) {
42 static_assert(SkIsAlign4(sizeof(SkScalar)), "SkScalar size alignment");
43
44 auto glyphSize = safe->mul(glyphCount, sizeof(uint16_t)),
45 posSize = safe->mul(PosCount(glyphCount, positioning, safe), sizeof(SkScalar));
46
47 // RunRecord object + (aligned) glyph buffer + position buffer
48 auto size = sizeof(SkTextBlob::RunRecord);
49 size = safe->add(size, safe->alignUp(glyphSize, 4));
50 size = safe->add(size, posSize);
51
52 if (textSize) { // Extended run.
53 size = safe->add(size, sizeof(uint32_t));
54 size = safe->add(size, safe->mul(glyphCount, sizeof(uint32_t)));
55 size = safe->add(size, textSize);
56 }
57
58 return safe->alignUp(size, sizeof(void*));
59 }
60
First(const SkTextBlob * blob)61 const SkTextBlob::RunRecord* SkTextBlob::RunRecord::First(const SkTextBlob* blob) {
62 // The first record (if present) is stored following the blob object.
63 // (aligned up to make the RunRecord aligned too)
64 return reinterpret_cast<const RunRecord*>(SkAlignPtr((uintptr_t)(blob + 1)));
65 }
66
Next(const RunRecord * run)67 const SkTextBlob::RunRecord* SkTextBlob::RunRecord::Next(const RunRecord* run) {
68 return SkToBool(run->fFlags & kLast_Flag) ? nullptr : NextUnchecked(run);
69 }
70
71 namespace {
72 struct RunRecordStorageEquivalent {
73 SkFont fFont;
74 SkPoint fOffset;
75 uint32_t fCount;
76 uint32_t fFlags;
77 SkDEBUGCODE(unsigned fMagic;)
78 };
79 }
80
validate(const uint8_t * storageTop) const81 void SkTextBlob::RunRecord::validate(const uint8_t* storageTop) const {
82 SkASSERT(kRunRecordMagic == fMagic);
83 SkASSERT((uint8_t*)NextUnchecked(this) <= storageTop);
84
85 SkASSERT(glyphBuffer() + fCount <= (uint16_t*)posBuffer());
86 SkASSERT(posBuffer() + fCount * ScalarsPerGlyph(positioning())
87 <= (SkScalar*)NextUnchecked(this));
88 if (isExtended()) {
89 SkASSERT(textSize() > 0);
90 SkASSERT(textSizePtr() < (uint32_t*)NextUnchecked(this));
91 SkASSERT(clusterBuffer() < (uint32_t*)NextUnchecked(this));
92 SkASSERT(textBuffer() + textSize() <= (char*)NextUnchecked(this));
93 }
94 static_assert(sizeof(SkTextBlob::RunRecord) == sizeof(RunRecordStorageEquivalent),
95 "runrecord_should_stay_packed");
96 }
97
NextUnchecked(const RunRecord * run)98 const SkTextBlob::RunRecord* SkTextBlob::RunRecord::NextUnchecked(const RunRecord* run) {
99 SkSafeMath safe;
100 auto res = reinterpret_cast<const RunRecord*>(
101 reinterpret_cast<const uint8_t*>(run)
102 + StorageSize(run->glyphCount(), run->textSize(), run->positioning(), &safe));
103 SkASSERT(safe);
104 return res;
105 }
106
PosCount(uint32_t glyphCount,SkTextBlob::GlyphPositioning positioning,SkSafeMath * safe)107 size_t SkTextBlob::RunRecord::PosCount(uint32_t glyphCount,
108 SkTextBlob::GlyphPositioning positioning,
109 SkSafeMath* safe) {
110 return safe->mul(glyphCount, ScalarsPerGlyph(positioning));
111 }
112
textSizePtr() const113 uint32_t* SkTextBlob::RunRecord::textSizePtr() const {
114 // textSize follows the position buffer.
115 SkASSERT(isExtended());
116 SkSafeMath safe;
117 auto res = (uint32_t*)(&this->posBuffer()[PosCount(fCount, positioning(), &safe)]);
118 SkASSERT(safe);
119 return res;
120 }
121
grow(uint32_t count)122 void SkTextBlob::RunRecord::grow(uint32_t count) {
123 SkScalar* initialPosBuffer = posBuffer();
124 uint32_t initialCount = fCount;
125 fCount += count;
126
127 // Move the initial pos scalars to their new location.
128 size_t copySize = initialCount * sizeof(SkScalar) * ScalarsPerGlyph(positioning());
129 SkASSERT((uint8_t*)posBuffer() + copySize <= (uint8_t*)NextUnchecked(this));
130
131 // memmove, as the buffers may overlap
132 memmove(posBuffer(), initialPosBuffer, copySize);
133 }
134
next_id()135 static int32_t next_id() {
136 static std::atomic<int32_t> nextID{1};
137 int32_t id;
138 do {
139 id = nextID++;
140 } while (id == SK_InvalidGenID);
141 return id;
142 }
143
SkTextBlob(const SkRect & bounds)144 SkTextBlob::SkTextBlob(const SkRect& bounds)
145 : fBounds(bounds)
146 , fUniqueID(next_id())
147 , fCacheID(SK_InvalidUniqueID) {}
148
~SkTextBlob()149 SkTextBlob::~SkTextBlob() {
150 #if SK_SUPPORT_GPU
151 if (SK_InvalidUniqueID != fCacheID.load()) {
152 GrTextBlobCache::PostPurgeBlobMessage(fUniqueID, fCacheID);
153 }
154 #endif
155
156 const auto* run = RunRecord::First(this);
157 do {
158 const auto* nextRun = RunRecord::Next(run);
159 SkDEBUGCODE(run->validate((uint8_t*)this + fStorageSize);)
160 run->~RunRecord();
161 run = nextRun;
162 } while (run);
163 }
164
165 namespace {
166
167 union PositioningAndExtended {
168 int32_t intValue;
169 struct {
170 uint8_t positioning;
171 uint8_t extended;
172 uint16_t padding;
173 };
174 };
175
176 static_assert(sizeof(PositioningAndExtended) == sizeof(int32_t), "");
177
178 } // namespace
179
180 enum SkTextBlob::GlyphPositioning : uint8_t {
181 kDefault_Positioning = 0, // Default glyph advances -- zero scalars per glyph.
182 kHorizontal_Positioning = 1, // Horizontal positioning -- one scalar per glyph.
183 kFull_Positioning = 2, // Point positioning -- two scalars per glyph.
184 kRSXform_Positioning = 3, // RSXform positioning -- four scalars per glyph.
185 };
186
ScalarsPerGlyph(GlyphPositioning pos)187 unsigned SkTextBlob::ScalarsPerGlyph(GlyphPositioning pos) {
188 const uint8_t gScalarsPerPositioning[] = {
189 0, // kDefault_Positioning
190 1, // kHorizontal_Positioning
191 2, // kFull_Positioning
192 4, // kRSXform_Positioning
193 };
194 SkASSERT((unsigned)pos <= 3);
195 return gScalarsPerPositioning[pos];
196 }
197
operator delete(void * p)198 void SkTextBlob::operator delete(void* p) {
199 sk_free(p);
200 }
201
operator new(size_t)202 void* SkTextBlob::operator new(size_t) {
203 SK_ABORT("All blobs are created by placement new.");
204 }
205
operator new(size_t,void * p)206 void* SkTextBlob::operator new(size_t, void* p) {
207 return p;
208 }
209
SkTextBlobRunIterator(const SkTextBlob * blob)210 SkTextBlobRunIterator::SkTextBlobRunIterator(const SkTextBlob* blob)
211 : fCurrentRun(SkTextBlob::RunRecord::First(blob)) {
212 SkDEBUGCODE(fStorageTop = (uint8_t*)blob + blob->fStorageSize;)
213 }
214
next()215 void SkTextBlobRunIterator::next() {
216 SkASSERT(!this->done());
217
218 if (!this->done()) {
219 SkDEBUGCODE(fCurrentRun->validate(fStorageTop);)
220 fCurrentRun = SkTextBlob::RunRecord::Next(fCurrentRun);
221 }
222 }
223
positioning() const224 SkTextBlobRunIterator::GlyphPositioning SkTextBlobRunIterator::positioning() const {
225 SkASSERT(!this->done());
226 static_assert(static_cast<GlyphPositioning>(SkTextBlob::kDefault_Positioning) ==
227 kDefault_Positioning, "");
228 static_assert(static_cast<GlyphPositioning>(SkTextBlob::kHorizontal_Positioning) ==
229 kHorizontal_Positioning, "");
230 static_assert(static_cast<GlyphPositioning>(SkTextBlob::kFull_Positioning) ==
231 kFull_Positioning, "");
232 static_assert(static_cast<GlyphPositioning>(SkTextBlob::kRSXform_Positioning) ==
233 kRSXform_Positioning, "");
234
235 return SkTo<GlyphPositioning>(fCurrentRun->positioning());
236 }
237
isLCD() const238 bool SkTextBlobRunIterator::isLCD() const {
239 return fCurrentRun->font().getEdging() == SkFont::Edging::kSubpixelAntiAlias;
240 }
241
SkTextBlobBuilder()242 SkTextBlobBuilder::SkTextBlobBuilder()
243 : fStorageSize(0)
244 , fStorageUsed(0)
245 , fRunCount(0)
246 , fDeferredBounds(false)
247 , fLastRun(0) {
248 fBounds.setEmpty();
249 }
250
~SkTextBlobBuilder()251 SkTextBlobBuilder::~SkTextBlobBuilder() {
252 if (nullptr != fStorage.get()) {
253 // We are abandoning runs and must destruct the associated font data.
254 // The easiest way to accomplish that is to use the blob destructor.
255 this->make();
256 }
257 }
258
TightRunBounds(const SkTextBlob::RunRecord & run)259 SkRect SkTextBlobBuilder::TightRunBounds(const SkTextBlob::RunRecord& run) {
260 const SkFont& font = run.font();
261 SkRect bounds;
262
263 if (SkTextBlob::kDefault_Positioning == run.positioning()) {
264 font.measureText(run.glyphBuffer(), run.glyphCount() * sizeof(uint16_t),
265 SkTextEncoding::kGlyphID, &bounds);
266 return bounds.makeOffset(run.offset().x(), run.offset().y());
267 }
268
269 SkAutoSTArray<16, SkRect> glyphBounds(run.glyphCount());
270 font.getBounds(run.glyphBuffer(), run.glyphCount(), glyphBounds.get(), nullptr);
271
272 SkASSERT(SkTextBlob::kFull_Positioning == run.positioning() ||
273 SkTextBlob::kHorizontal_Positioning == run.positioning());
274 // kFull_Positioning => [ x, y, x, y... ]
275 // kHorizontal_Positioning => [ x, x, x... ]
276 // (const y applied by runBounds.offset(run->offset()) later)
277 const SkScalar horizontalConstY = 0;
278 const SkScalar* glyphPosX = run.posBuffer();
279 const SkScalar* glyphPosY = (run.positioning() == SkTextBlob::kFull_Positioning) ?
280 glyphPosX + 1 : &horizontalConstY;
281 const unsigned posXInc = SkTextBlob::ScalarsPerGlyph(run.positioning());
282 const unsigned posYInc = (run.positioning() == SkTextBlob::kFull_Positioning) ?
283 posXInc : 0;
284
285 bounds.setEmpty();
286 for (unsigned i = 0; i < run.glyphCount(); ++i) {
287 bounds.join(glyphBounds[i].makeOffset(*glyphPosX, *glyphPosY));
288 glyphPosX += posXInc;
289 glyphPosY += posYInc;
290 }
291
292 SkASSERT((void*)glyphPosX <= SkTextBlob::RunRecord::Next(&run));
293
294 return bounds.makeOffset(run.offset().x(), run.offset().y());
295 }
296
map_quad_to_rect(const SkRSXform & xform,const SkRect & rect)297 static SkRect map_quad_to_rect(const SkRSXform& xform, const SkRect& rect) {
298 return SkMatrix().setRSXform(xform).mapRect(rect);
299 }
300
ConservativeRunBounds(const SkTextBlob::RunRecord & run)301 SkRect SkTextBlobBuilder::ConservativeRunBounds(const SkTextBlob::RunRecord& run) {
302 SkASSERT(run.glyphCount() > 0);
303 SkASSERT(SkTextBlob::kFull_Positioning == run.positioning() ||
304 SkTextBlob::kHorizontal_Positioning == run.positioning() ||
305 SkTextBlob::kRSXform_Positioning == run.positioning());
306
307 const SkRect fontBounds = SkFontPriv::GetFontBounds(run.font());
308 if (fontBounds.isEmpty()) {
309 // Empty font bounds are likely a font bug. TightBounds has a better chance of
310 // producing useful results in this case.
311 return TightRunBounds(run);
312 }
313
314 // Compute the glyph position bbox.
315 SkRect bounds;
316 switch (run.positioning()) {
317 case SkTextBlob::kHorizontal_Positioning: {
318 const SkScalar* glyphPos = run.posBuffer();
319 SkASSERT((void*)(glyphPos + run.glyphCount()) <= SkTextBlob::RunRecord::Next(&run));
320
321 SkScalar minX = *glyphPos;
322 SkScalar maxX = *glyphPos;
323 for (unsigned i = 1; i < run.glyphCount(); ++i) {
324 SkScalar x = glyphPos[i];
325 minX = SkMinScalar(x, minX);
326 maxX = SkMaxScalar(x, maxX);
327 }
328
329 bounds.setLTRB(minX, 0, maxX, 0);
330 } break;
331 case SkTextBlob::kFull_Positioning: {
332 const SkPoint* glyphPosPts = run.pointBuffer();
333 SkASSERT((void*)(glyphPosPts + run.glyphCount()) <= SkTextBlob::RunRecord::Next(&run));
334
335 bounds.setBounds(glyphPosPts, run.glyphCount());
336 } break;
337 case SkTextBlob::kRSXform_Positioning: {
338 const SkRSXform* xform = run.xformBuffer();
339 SkASSERT((void*)(xform + run.glyphCount()) <= SkTextBlob::RunRecord::Next(&run));
340 bounds = map_quad_to_rect(xform[0], fontBounds);
341 for (unsigned i = 1; i < run.glyphCount(); ++i) {
342 bounds.join(map_quad_to_rect(xform[i], fontBounds));
343 }
344 } break;
345 default:
346 SK_ABORT("unsupported positioning mode");
347 }
348
349 if (run.positioning() != SkTextBlob::kRSXform_Positioning) {
350 // Expand by typeface glyph bounds.
351 bounds.fLeft += fontBounds.left();
352 bounds.fTop += fontBounds.top();
353 bounds.fRight += fontBounds.right();
354 bounds.fBottom += fontBounds.bottom();
355 }
356
357 // Offset by run position.
358 return bounds.makeOffset(run.offset().x(), run.offset().y());
359 }
360
updateDeferredBounds()361 void SkTextBlobBuilder::updateDeferredBounds() {
362 SkASSERT(!fDeferredBounds || fRunCount > 0);
363
364 if (!fDeferredBounds) {
365 return;
366 }
367
368 SkASSERT(fLastRun >= SkAlignPtr(sizeof(SkTextBlob)));
369 SkTextBlob::RunRecord* run = reinterpret_cast<SkTextBlob::RunRecord*>(fStorage.get() +
370 fLastRun);
371
372 // FIXME: we should also use conservative bounds for kDefault_Positioning.
373 SkRect runBounds = SkTextBlob::kDefault_Positioning == run->positioning() ?
374 TightRunBounds(*run) : ConservativeRunBounds(*run);
375 fBounds.join(runBounds);
376 fDeferredBounds = false;
377 }
378
reserve(size_t size)379 void SkTextBlobBuilder::reserve(size_t size) {
380 SkSafeMath safe;
381
382 // We don't currently pre-allocate, but maybe someday...
383 if (safe.add(fStorageUsed, size) <= fStorageSize && safe) {
384 return;
385 }
386
387 if (0 == fRunCount) {
388 SkASSERT(nullptr == fStorage.get());
389 SkASSERT(0 == fStorageSize);
390 SkASSERT(0 == fStorageUsed);
391
392 // the first allocation also includes blob storage
393 // aligned up to a pointer alignment so SkTextBlob::RunRecords after it stay aligned.
394 fStorageUsed = SkAlignPtr(sizeof(SkTextBlob));
395 }
396
397 fStorageSize = safe.add(fStorageUsed, size);
398
399 // FYI: This relies on everything we store being relocatable, particularly SkPaint.
400 // Also, this is counting on the underlying realloc to throw when passed max().
401 fStorage.realloc(safe ? fStorageSize : std::numeric_limits<size_t>::max());
402 }
403
mergeRun(const SkFont & font,SkTextBlob::GlyphPositioning positioning,uint32_t count,SkPoint offset)404 bool SkTextBlobBuilder::mergeRun(const SkFont& font, SkTextBlob::GlyphPositioning positioning,
405 uint32_t count, SkPoint offset) {
406 if (0 == fLastRun) {
407 SkASSERT(0 == fRunCount);
408 return false;
409 }
410
411 SkASSERT(fLastRun >= SkAlignPtr(sizeof(SkTextBlob)));
412 SkTextBlob::RunRecord* run = reinterpret_cast<SkTextBlob::RunRecord*>(fStorage.get() +
413 fLastRun);
414 SkASSERT(run->glyphCount() > 0);
415
416 if (run->textSize() != 0) {
417 return false;
418 }
419
420 if (run->positioning() != positioning
421 || run->font() != font
422 || (run->glyphCount() + count < run->glyphCount())) {
423 return false;
424 }
425
426 // we can merge same-font/same-positioning runs in the following cases:
427 // * fully positioned run following another fully positioned run
428 // * horizontally postioned run following another horizontally positioned run with the same
429 // y-offset
430 if (SkTextBlob::kFull_Positioning != positioning
431 && (SkTextBlob::kHorizontal_Positioning != positioning
432 || run->offset().y() != offset.y())) {
433 return false;
434 }
435
436 SkSafeMath safe;
437 size_t sizeDelta =
438 SkTextBlob::RunRecord::StorageSize(run->glyphCount() + count, 0, positioning, &safe) -
439 SkTextBlob::RunRecord::StorageSize(run->glyphCount() , 0, positioning, &safe);
440 if (!safe) {
441 return false;
442 }
443
444 this->reserve(sizeDelta);
445
446 // reserve may have realloced
447 run = reinterpret_cast<SkTextBlob::RunRecord*>(fStorage.get() + fLastRun);
448 uint32_t preMergeCount = run->glyphCount();
449 run->grow(count);
450
451 // Callers expect the buffers to point at the newly added slice, ant not at the beginning.
452 fCurrentRunBuffer.glyphs = run->glyphBuffer() + preMergeCount;
453 fCurrentRunBuffer.pos = run->posBuffer()
454 + preMergeCount * SkTextBlob::ScalarsPerGlyph(positioning);
455
456 fStorageUsed += sizeDelta;
457
458 SkASSERT(fStorageUsed <= fStorageSize);
459 run->validate(fStorage.get() + fStorageUsed);
460
461 return true;
462 }
463
allocInternal(const SkFont & font,SkTextBlob::GlyphPositioning positioning,int count,int textSize,SkPoint offset,const SkRect * bounds)464 void SkTextBlobBuilder::allocInternal(const SkFont& font,
465 SkTextBlob::GlyphPositioning positioning,
466 int count, int textSize, SkPoint offset,
467 const SkRect* bounds) {
468 if (count <= 0 || textSize < 0) {
469 fCurrentRunBuffer = { nullptr, nullptr, nullptr, nullptr };
470 return;
471 }
472
473 if (textSize != 0 || !this->mergeRun(font, positioning, count, offset)) {
474 this->updateDeferredBounds();
475
476 SkSafeMath safe;
477 size_t runSize = SkTextBlob::RunRecord::StorageSize(count, textSize, positioning, &safe);
478 if (!safe) {
479 fCurrentRunBuffer = { nullptr, nullptr, nullptr, nullptr };
480 return;
481 }
482
483 this->reserve(runSize);
484
485 SkASSERT(fStorageUsed >= SkAlignPtr(sizeof(SkTextBlob)));
486 SkASSERT(fStorageUsed + runSize <= fStorageSize);
487
488 SkTextBlob::RunRecord* run = new (fStorage.get() + fStorageUsed)
489 SkTextBlob::RunRecord(count, textSize, offset, font, positioning);
490 fCurrentRunBuffer.glyphs = run->glyphBuffer();
491 fCurrentRunBuffer.pos = run->posBuffer();
492 fCurrentRunBuffer.utf8text = run->textBuffer();
493 fCurrentRunBuffer.clusters = run->clusterBuffer();
494
495 fLastRun = fStorageUsed;
496 fStorageUsed += runSize;
497 fRunCount++;
498
499 SkASSERT(fStorageUsed <= fStorageSize);
500 run->validate(fStorage.get() + fStorageUsed);
501 }
502 SkASSERT(textSize > 0 || nullptr == fCurrentRunBuffer.utf8text);
503 SkASSERT(textSize > 0 || nullptr == fCurrentRunBuffer.clusters);
504 if (!fDeferredBounds) {
505 if (bounds) {
506 fBounds.join(*bounds);
507 } else {
508 fDeferredBounds = true;
509 }
510 }
511 }
512
513 // SkFont versions
514
allocRun(const SkFont & font,int count,SkScalar x,SkScalar y,const SkRect * bounds)515 const SkTextBlobBuilder::RunBuffer& SkTextBlobBuilder::allocRun(const SkFont& font, int count,
516 SkScalar x, SkScalar y,
517 const SkRect* bounds) {
518 this->allocInternal(font, SkTextBlob::kDefault_Positioning, count, 0, {x, y}, bounds);
519 return fCurrentRunBuffer;
520 }
521
allocRunPosH(const SkFont & font,int count,SkScalar y,const SkRect * bounds)522 const SkTextBlobBuilder::RunBuffer& SkTextBlobBuilder::allocRunPosH(const SkFont& font, int count,
523 SkScalar y,
524 const SkRect* bounds) {
525 this->allocInternal(font, SkTextBlob::kHorizontal_Positioning, count, 0, {0, y}, bounds);
526 return fCurrentRunBuffer;
527 }
528
allocRunPos(const SkFont & font,int count,const SkRect * bounds)529 const SkTextBlobBuilder::RunBuffer& SkTextBlobBuilder::allocRunPos(const SkFont& font, int count,
530 const SkRect* bounds) {
531 this->allocInternal(font, SkTextBlob::kFull_Positioning, count, 0, {0, 0}, bounds);
532 return fCurrentRunBuffer;
533 }
534
535 const SkTextBlobBuilder::RunBuffer&
allocRunRSXform(const SkFont & font,int count)536 SkTextBlobBuilder::allocRunRSXform(const SkFont& font, int count) {
537 this->allocInternal(font, SkTextBlob::kRSXform_Positioning, count, 0, {0, 0}, nullptr);
538 return fCurrentRunBuffer;
539 }
540
allocRunText(const SkFont & font,int count,SkScalar x,SkScalar y,int textByteCount,SkString lang,const SkRect * bounds)541 const SkTextBlobBuilder::RunBuffer& SkTextBlobBuilder::allocRunText(const SkFont& font, int count,
542 SkScalar x, SkScalar y,
543 int textByteCount,
544 SkString lang,
545 const SkRect* bounds) {
546 this->allocInternal(font,
547 SkTextBlob::kDefault_Positioning,
548 count,
549 textByteCount,
550 SkPoint::Make(x, y),
551 bounds);
552 return fCurrentRunBuffer;
553 }
554
allocRunTextPosH(const SkFont & font,int count,SkScalar y,int textByteCount,SkString lang,const SkRect * bounds)555 const SkTextBlobBuilder::RunBuffer& SkTextBlobBuilder::allocRunTextPosH(const SkFont& font, int count,
556 SkScalar y,
557 int textByteCount,
558 SkString lang,
559 const SkRect* bounds) {
560 this->allocInternal(font,
561 SkTextBlob::kHorizontal_Positioning,
562 count,
563 textByteCount,
564 SkPoint::Make(0, y),
565 bounds);
566 return fCurrentRunBuffer;
567 }
568
allocRunTextPos(const SkFont & font,int count,int textByteCount,SkString lang,const SkRect * bounds)569 const SkTextBlobBuilder::RunBuffer& SkTextBlobBuilder::allocRunTextPos(const SkFont& font, int count,
570 int textByteCount,
571 SkString lang,
572 const SkRect *bounds) {
573 this->allocInternal(font,
574 SkTextBlob::kFull_Positioning,
575 count, textByteCount,
576 SkPoint::Make(0, 0),
577 bounds);
578 return fCurrentRunBuffer;
579 }
580
allocRunRSXform(const SkFont & font,int count,int textByteCount,SkString lang,const SkRect * bounds)581 const SkTextBlobBuilder::RunBuffer& SkTextBlobBuilder::allocRunRSXform(const SkFont& font, int count,
582 int textByteCount,
583 SkString lang,
584 const SkRect* bounds) {
585 this->allocInternal(font,
586 SkTextBlob::kRSXform_Positioning,
587 count,
588 textByteCount,
589 {0, 0},
590 bounds);
591 return fCurrentRunBuffer;
592 }
593
make()594 sk_sp<SkTextBlob> SkTextBlobBuilder::make() {
595 if (!fRunCount) {
596 // We don't instantiate empty blobs.
597 SkASSERT(!fStorage.get());
598 SkASSERT(fStorageUsed == 0);
599 SkASSERT(fStorageSize == 0);
600 SkASSERT(fLastRun == 0);
601 SkASSERT(fBounds.isEmpty());
602 return nullptr;
603 }
604
605 this->updateDeferredBounds();
606
607 // Tag the last run as such.
608 auto* lastRun = reinterpret_cast<SkTextBlob::RunRecord*>(fStorage.get() + fLastRun);
609 lastRun->fFlags |= SkTextBlob::RunRecord::kLast_Flag;
610
611 SkTextBlob* blob = new (fStorage.release()) SkTextBlob(fBounds);
612 SkDEBUGCODE(const_cast<SkTextBlob*>(blob)->fStorageSize = fStorageSize;)
613
614 SkDEBUGCODE(
615 SkSafeMath safe;
616 size_t validateSize = SkAlignPtr(sizeof(SkTextBlob));
617 for (const auto* run = SkTextBlob::RunRecord::First(blob); run;
618 run = SkTextBlob::RunRecord::Next(run)) {
619 validateSize += SkTextBlob::RunRecord::StorageSize(
620 run->fCount, run->textSize(), run->positioning(), &safe);
621 run->validate(reinterpret_cast<const uint8_t*>(blob) + fStorageUsed);
622 fRunCount--;
623 }
624 SkASSERT(validateSize == fStorageUsed);
625 SkASSERT(fRunCount == 0);
626 SkASSERT(safe);
627 )
628
629 fStorageUsed = 0;
630 fStorageSize = 0;
631 fRunCount = 0;
632 fLastRun = 0;
633 fBounds.setEmpty();
634
635 return sk_sp<SkTextBlob>(blob);
636 }
637
638 ///////////////////////////////////////////////////////////////////////////////////////////////////
639
Flatten(const SkTextBlob & blob,SkWriteBuffer & buffer)640 void SkTextBlobPriv::Flatten(const SkTextBlob& blob, SkWriteBuffer& buffer) {
641 // seems like we could skip this, and just recompute bounds in unflatten, but
642 // some cc_unittests fail if we remove this...
643 buffer.writeRect(blob.bounds());
644
645 SkTextBlobRunIterator it(&blob);
646 while (!it.done()) {
647 SkASSERT(it.glyphCount() > 0);
648
649 buffer.write32(it.glyphCount());
650 PositioningAndExtended pe;
651 pe.intValue = 0;
652 pe.positioning = it.positioning();
653 SkASSERT((int32_t)it.positioning() == pe.intValue); // backwards compat.
654
655 uint32_t textSize = it.textSize();
656 pe.extended = textSize > 0;
657 buffer.write32(pe.intValue);
658 if (pe.extended) {
659 buffer.write32(textSize);
660 }
661 buffer.writePoint(it.offset());
662
663 SkFontPriv::Flatten(it.font(), buffer);
664
665 buffer.writeByteArray(it.glyphs(), it.glyphCount() * sizeof(uint16_t));
666 buffer.writeByteArray(it.pos(),
667 it.glyphCount() * sizeof(SkScalar) *
668 SkTextBlob::ScalarsPerGlyph(
669 SkTo<SkTextBlob::GlyphPositioning>(it.positioning())));
670 if (pe.extended) {
671 buffer.writeByteArray(it.clusters(), sizeof(uint32_t) * it.glyphCount());
672 buffer.writeByteArray(it.text(), it.textSize());
673 }
674
675 it.next();
676 }
677
678 // Marker for the last run (0 is not a valid glyph count).
679 buffer.write32(0);
680 }
681
MakeFromBuffer(SkReadBuffer & reader)682 sk_sp<SkTextBlob> SkTextBlobPriv::MakeFromBuffer(SkReadBuffer& reader) {
683 SkRect bounds;
684 reader.readRect(&bounds);
685
686 SkTextBlobBuilder blobBuilder;
687 SkSafeMath safe;
688 for (;;) {
689 int glyphCount = reader.read32();
690 if (glyphCount == 0) {
691 // End-of-runs marker.
692 break;
693 }
694
695 PositioningAndExtended pe;
696 pe.intValue = reader.read32();
697 const auto pos = SkTo<SkTextBlob::GlyphPositioning>(pe.positioning);
698 if (glyphCount <= 0 || pos > SkTextBlob::kRSXform_Positioning) {
699 return nullptr;
700 }
701 int textSize = pe.extended ? reader.read32() : 0;
702 if (textSize < 0) {
703 return nullptr;
704 }
705
706 SkPoint offset;
707 reader.readPoint(&offset);
708 SkFont font;
709 if (reader.isVersionLT(SkPicturePriv::kSerializeFonts_Version)) {
710 SkPaint paint;
711 reader.readPaint(&paint, &font);
712 } else {
713 SkFontPriv::Unflatten(&font, reader);
714 }
715
716 // Compute the expected size of the buffer and ensure we have enough to deserialize
717 // a run before allocating it.
718 const size_t glyphSize = safe.mul(glyphCount, sizeof(uint16_t)),
719 posSize =
720 safe.mul(glyphCount, safe.mul(sizeof(SkScalar),
721 SkTextBlob::ScalarsPerGlyph(pos))),
722 clusterSize = pe.extended ? safe.mul(glyphCount, sizeof(uint32_t)) : 0;
723 const size_t totalSize =
724 safe.add(safe.add(glyphSize, posSize), safe.add(clusterSize, textSize));
725
726 if (!reader.isValid() || !safe || totalSize > reader.available()) {
727 return nullptr;
728 }
729
730 const SkTextBlobBuilder::RunBuffer* buf = nullptr;
731 switch (pos) {
732 case SkTextBlob::kDefault_Positioning:
733 buf = &blobBuilder.allocRunText(font, glyphCount, offset.x(), offset.y(),
734 textSize, SkString(), &bounds);
735 break;
736 case SkTextBlob::kHorizontal_Positioning:
737 buf = &blobBuilder.allocRunTextPosH(font, glyphCount, offset.y(),
738 textSize, SkString(), &bounds);
739 break;
740 case SkTextBlob::kFull_Positioning:
741 buf = &blobBuilder.allocRunTextPos(font, glyphCount, textSize, SkString(), &bounds);
742 break;
743 case SkTextBlob::kRSXform_Positioning:
744 buf = &blobBuilder.allocRunRSXform(font, glyphCount, textSize, SkString(), &bounds);
745 break;
746 }
747
748 if (!buf->glyphs ||
749 !buf->pos ||
750 (pe.extended && (!buf->clusters || !buf->utf8text))) {
751 return nullptr;
752 }
753
754 if (!reader.readByteArray(buf->glyphs, glyphSize) ||
755 !reader.readByteArray(buf->pos, posSize)) {
756 return nullptr;
757 }
758
759 if (pe.extended) {
760 if (!reader.readByteArray(buf->clusters, clusterSize) ||
761 !reader.readByteArray(buf->utf8text, textSize)) {
762 return nullptr;
763 }
764 }
765 }
766
767 return blobBuilder.make();
768 }
769
MakeFromText(const void * text,size_t byteLength,const SkFont & font,SkTextEncoding encoding)770 sk_sp<SkTextBlob> SkTextBlob::MakeFromText(const void* text, size_t byteLength, const SkFont& font,
771 SkTextEncoding encoding) {
772 // Note: we deliberately promote this to fully positioned blobs, since we'd have to pay the
773 // same cost down stream (i.e. computing bounds), so its cheaper to pay the cost once now.
774 const int count = font.countText(text, byteLength, encoding);
775 SkTextBlobBuilder builder;
776 auto buffer = builder.allocRunPos(font, count);
777 font.textToGlyphs(text, byteLength, encoding, buffer.glyphs, count);
778 font.getPos(buffer.glyphs, count, buffer.points(), {0, 0});
779 return builder.make();
780 }
781
MakeFromPosText(const void * text,size_t byteLength,const SkPoint pos[],const SkFont & font,SkTextEncoding encoding)782 sk_sp<SkTextBlob> SkTextBlob::MakeFromPosText(const void* text, size_t byteLength,
783 const SkPoint pos[], const SkFont& font,
784 SkTextEncoding encoding) {
785 const int count = font.countText(text, byteLength, encoding);
786 SkTextBlobBuilder builder;
787 auto buffer = builder.allocRunPos(font, count);
788 font.textToGlyphs(text, byteLength, encoding, buffer.glyphs, count);
789 memcpy(buffer.points(), pos, count * sizeof(SkPoint));
790 return builder.make();
791 }
792
MakeFromPosTextH(const void * text,size_t byteLength,const SkScalar xpos[],SkScalar constY,const SkFont & font,SkTextEncoding encoding)793 sk_sp<SkTextBlob> SkTextBlob::MakeFromPosTextH(const void* text, size_t byteLength,
794 const SkScalar xpos[], SkScalar constY,
795 const SkFont& font, SkTextEncoding encoding) {
796 const int count = font.countText(text, byteLength, encoding);
797 SkTextBlobBuilder builder;
798 auto buffer = builder.allocRunPosH(font, count, constY);
799 font.textToGlyphs(text, byteLength, encoding, buffer.glyphs, count);
800 memcpy(buffer.pos, xpos, count * sizeof(SkScalar));
801 return builder.make();
802 }
803
MakeFromRSXform(const void * text,size_t byteLength,const SkRSXform xform[],const SkFont & font,SkTextEncoding encoding)804 sk_sp<SkTextBlob> SkTextBlob::MakeFromRSXform(const void* text, size_t byteLength,
805 const SkRSXform xform[], const SkFont& font,
806 SkTextEncoding encoding) {
807 const int count = font.countText(text, byteLength, encoding);
808 SkTextBlobBuilder builder;
809 auto buffer = builder.allocRunRSXform(font, count);
810 font.textToGlyphs(text, byteLength, encoding, buffer.glyphs, count);
811 memcpy(buffer.xforms(), xform, count * sizeof(SkRSXform));
812 return builder.make();
813 }
814
serialize(const SkSerialProcs & procs) const815 sk_sp<SkData> SkTextBlob::serialize(const SkSerialProcs& procs) const {
816 SkBinaryWriteBuffer buffer;
817 buffer.setSerialProcs(procs);
818 SkTextBlobPriv::Flatten(*this, buffer);
819
820 size_t total = buffer.bytesWritten();
821 sk_sp<SkData> data = SkData::MakeUninitialized(total);
822 buffer.writeToMemory(data->writable_data());
823 return data;
824 }
825
Deserialize(const void * data,size_t length,const SkDeserialProcs & procs)826 sk_sp<SkTextBlob> SkTextBlob::Deserialize(const void* data, size_t length,
827 const SkDeserialProcs& procs) {
828 SkReadBuffer buffer(data, length);
829 buffer.setDeserialProcs(procs);
830 return SkTextBlobPriv::MakeFromBuffer(buffer);
831 }
832
dump(std::string & desc,int depth) const833 void SkTextBlob::dump(std::string& desc, int depth) const {
834 std::string split(depth, '\t');
835 desc += split + "\n SkTextBlob:{ \n";
836 fBounds.dump(desc, depth + 1);
837 desc += split + "\t fUniqueID:" + std::to_string(fUniqueID) + "\n";
838 desc += split + "}\n";
839 }
840
841 ///////////////////////////////////////////////////////////////////////////////////////////////////
842
serialize(const SkSerialProcs & procs,void * memory,size_t memory_size) const843 size_t SkTextBlob::serialize(const SkSerialProcs& procs, void* memory, size_t memory_size) const {
844 SkBinaryWriteBuffer buffer(memory, memory_size);
845 buffer.setSerialProcs(procs);
846 SkTextBlobPriv::Flatten(*this, buffer);
847 return buffer.usingInitialStorage() ? buffer.bytesWritten() : 0u;
848 }
849
850 ///////////////////////////////////////////////////////////////////////////////////////////////////
851
852 namespace {
get_glyph_run_intercepts(const SkGlyphRun & glyphRun,const SkPaint & paint,const SkScalar bounds[2],SkScalar intervals[],int * intervalCount)853 int get_glyph_run_intercepts(const SkGlyphRun& glyphRun,
854 const SkPaint& paint,
855 const SkScalar bounds[2],
856 SkScalar intervals[],
857 int* intervalCount) {
858 SkScalar scale = SK_Scalar1;
859 SkPaint interceptPaint{paint};
860 SkFont interceptFont{glyphRun.font()};
861
862 interceptPaint.setMaskFilter(nullptr); // don't want this affecting our path-cache lookup
863
864 // can't use our canonical size if we need to apply path effects
865 if (interceptPaint.getPathEffect() == nullptr) {
866 // If the wrong size is going to be used, don't hint anything.
867 interceptFont.setHinting(SkFontHinting::kNone);
868 interceptFont.setSubpixel(true);
869 scale = interceptFont.getSize() / SkFontPriv::kCanonicalTextSizeForPaths;
870 interceptFont.setSize(SkIntToScalar(SkFontPriv::kCanonicalTextSizeForPaths));
871 // Note: fScale can be zero here (even if it wasn't before the divide). It can also
872 // be very very small. We call sk_ieee_float_divide below to ensure IEEE divide behavior,
873 // since downstream we will check for the resulting coordinates being non-finite anyway.
874 // Thus we don't need to check for zero here.
875 if (interceptPaint.getStrokeWidth() > 0
876 && interceptPaint.getStyle() != SkPaint::kFill_Style) {
877 interceptPaint.setStrokeWidth(
878 sk_ieee_float_divide(interceptPaint.getStrokeWidth(), scale));
879 }
880 }
881
882 interceptPaint.setStyle(SkPaint::kFill_Style);
883 interceptPaint.setPathEffect(nullptr);
884
885 SkStrikeSpec strikeSpec = SkStrikeSpec::MakeWithNoDevice(interceptFont, &interceptPaint);
886 auto cache = strikeSpec.findOrCreateExclusiveStrike();
887
888 SkScalar xOffset = 0;
889 SkScalar xPos = xOffset;
890 SkScalar prevAdvance = 0;
891
892 // The typeface is scaled, so un-scale the bounds to be in the space of the typeface.
893 SkScalar scaledBounds[2] = {bounds[0] / scale, bounds[1] / scale};
894
895 const SkPoint* posCursor = glyphRun.positions().begin();
896 for (auto glyphID : glyphRun.glyphsIDs()) {
897 SkPoint pos = *posCursor++;
898
899 SkGlyph* glyph = cache->glyph(glyphID);
900 xPos += prevAdvance * scale;
901 prevAdvance = glyph->advanceX();
902 if (cache->preparePath(glyph) != nullptr) {
903 cache->findIntercepts(scaledBounds, scale, pos.x(), glyph, intervals, intervalCount);
904 }
905 }
906 return *intervalCount;
907 }
908 } // namespace
909
getIntercepts(const SkScalar bounds[2],SkScalar intervals[],const SkPaint * paint) const910 int SkTextBlob::getIntercepts(const SkScalar bounds[2], SkScalar intervals[],
911 const SkPaint* paint) const {
912
913 SkTLazy<SkPaint> defaultPaint;
914 if (paint == nullptr) {
915 defaultPaint.init();
916 paint = defaultPaint.get();
917 }
918
919 SkGlyphRunBuilder builder;
920 builder.textBlobToGlyphRunListIgnoringRSXForm(*paint, *this, SkPoint{0, 0});
921 auto glyphRunList = builder.useGlyphRunList();
922
923 int intervalCount = 0;
924 for (const SkGlyphRun& glyphRun : glyphRunList) {
925 intervalCount = get_glyph_run_intercepts(glyphRun, *paint, bounds, intervals, &intervalCount);
926 }
927
928 return intervalCount;
929 }
930