1 /*
2 * Copyright 2018 The Android Open Source Project
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 "src/core/SkGlyphRun.h"
9
10 #include "include/core/SkFont.h"
11 #include "include/core/SkPaint.h"
12 #include "include/core/SkRSXform.h"
13 #include "include/core/SkTextBlob.h"
14 #include "include/private/SkTo.h"
15 #include "src/core/SkDevice.h"
16 #include "src/core/SkFontPriv.h"
17 #include "src/core/SkScalerCache.h"
18 #include "src/core/SkStrikeCache.h"
19 #include "src/core/SkStrikeSpec.h"
20 #include "src/core/SkTextBlobPriv.h"
21 #include "src/core/SkUtils.h"
22
23 // -- SkGlyphRun -----------------------------------------------------------------------------------
SkGlyphRun(const SkFont & font,SkSpan<const SkPoint> positions,SkSpan<const SkGlyphID> glyphIDs,SkSpan<const char> text,SkSpan<const uint32_t> clusters,SkSpan<const SkVector> scaledRotations)24 SkGlyphRun::SkGlyphRun(const SkFont& font,
25 SkSpan<const SkPoint> positions,
26 SkSpan<const SkGlyphID> glyphIDs,
27 SkSpan<const char> text,
28 SkSpan<const uint32_t> clusters,
29 SkSpan<const SkVector> scaledRotations)
30 : fSource{SkMakeZip(glyphIDs, positions)}
31 , fText{text}
32 , fClusters{clusters}
33 , fScaledRotations{scaledRotations}
34 , fFont{font} {}
35
SkGlyphRun(const SkGlyphRun & that,const SkFont & font)36 SkGlyphRun::SkGlyphRun(const SkGlyphRun& that, const SkFont& font)
37 : fSource{that.fSource}
38 , fText{that.fText}
39 , fClusters{that.fClusters}
40 , fFont{font} {}
41
sourceBounds(const SkPaint & paint) const42 SkRect SkGlyphRun::sourceBounds(const SkPaint& paint) const {
43 SkASSERT(this->runSize() > 0);
44 const SkRect fontBounds = SkFontPriv::GetFontBounds(fFont);
45
46 if (fontBounds.isEmpty()) {
47 // Empty font bounds are likely a font bug. TightBounds has a better chance of
48 // producing useful results in this case.
49 auto [strikeSpec, strikeToSourceScale] = SkStrikeSpec::MakeCanonicalized(fFont, &paint);
50 SkBulkGlyphMetrics metrics{strikeSpec};
51 SkSpan<const SkGlyph*> glyphs = metrics.glyphs(this->glyphsIDs());
52 if (fScaledRotations.empty()) {
53 // No RSXForm data - glyphs x/y aligned.
54 auto scaleAndTranslateRect =
55 [scale = strikeToSourceScale](const SkRect& in, const SkPoint& pos) {
56 return SkRect::MakeLTRB(in.left() * scale + pos.x(),
57 in.top() * scale + pos.y(),
58 in.right() * scale + pos.x(),
59 in.bottom() * scale + pos.y());
60 };
61
62 SkRect bounds = SkRect::MakeEmpty();
63 for (auto [pos, glyph] : SkMakeZip(this->positions(), glyphs)) {
64 if (SkRect r = glyph->rect(); !r.isEmpty()) {
65 bounds.join(scaleAndTranslateRect(r, pos));
66 }
67 }
68 return bounds;
69 } else {
70 // RSXForm - glyphs can be any scale or rotation.
71 SkRect bounds = SkRect::MakeEmpty();
72 for (auto [pos, scaleRotate, glyph] :
73 SkMakeZip(this->positions(), fScaledRotations, glyphs)) {
74 if (!glyph->rect().isEmpty()) {
75 SkMatrix xform = SkMatrix().setRSXform(
76 SkRSXform{pos.x(), pos.y(), scaleRotate.x(), scaleRotate.y()});
77 xform.preScale(strikeToSourceScale, strikeToSourceScale);
78 bounds.join(xform.mapRect(glyph->rect()));
79 }
80 }
81 return bounds;
82 }
83 }
84
85 // Use conservative bounds. All glyph have a box of fontBounds size.
86 if (fScaledRotations.empty()) {
87 SkRect bounds;
88 bounds.setBounds(this->positions().data(), SkCount(this->positions()));
89 bounds.fLeft += fontBounds.left();
90 bounds.fTop += fontBounds.top();
91 bounds.fRight += fontBounds.right();
92 bounds.fBottom += fontBounds.bottom();
93 return bounds;
94 } else {
95 // RSXForm case glyphs can be any scale or rotation.
96 SkRect bounds;
97 bounds.setEmpty();
98 for (auto [pos, scaleRotate] : SkMakeZip(this->positions(), fScaledRotations)) {
99 const SkRSXform xform{pos.x(), pos.y(), scaleRotate.x(), scaleRotate.y()};
100 bounds.join(SkMatrix().setRSXform(xform).mapRect(fontBounds));
101 }
102 return bounds;
103 }
104 }
105
106 // -- SkGlyphRunList -------------------------------------------------------------------------------
107 SkGlyphRunList::SkGlyphRunList() = default;
SkGlyphRunList(const SkTextBlob * blob,SkRect bounds,SkPoint origin,SkSpan<const SkGlyphRun> glyphRunList)108 SkGlyphRunList::SkGlyphRunList(
109 const SkTextBlob* blob,
110 SkRect bounds,
111 SkPoint origin,
112 SkSpan<const SkGlyphRun> glyphRunList)
113 : fGlyphRuns{glyphRunList}
114 , fOriginalTextBlob{blob}
115 , fSourceBounds{bounds}
116 , fOrigin{origin} { }
117
SkGlyphRunList(const SkGlyphRun & glyphRun,const SkRect & bounds,SkPoint origin)118 SkGlyphRunList::SkGlyphRunList(const SkGlyphRun& glyphRun, const SkRect& bounds, SkPoint origin)
119 : fGlyphRuns{SkSpan<const SkGlyphRun>{&glyphRun, 1}}
120 , fOriginalTextBlob{nullptr}
121 , fSourceBounds{bounds}
122 , fOrigin{origin} {}
123
uniqueID() const124 uint64_t SkGlyphRunList::uniqueID() const {
125 return fOriginalTextBlob != nullptr ? fOriginalTextBlob->uniqueID()
126 : SK_InvalidUniqueID;
127 }
128
anyRunsLCD() const129 bool SkGlyphRunList::anyRunsLCD() const {
130 for (const auto& r : fGlyphRuns) {
131 if (r.font().getEdging() == SkFont::Edging::kSubpixelAntiAlias) {
132 return true;
133 }
134 }
135 return false;
136 }
137
temporaryShuntBlobNotifyAddedToCache(uint32_t cacheID) const138 void SkGlyphRunList::temporaryShuntBlobNotifyAddedToCache(uint32_t cacheID) const {
139 SkASSERT(fOriginalTextBlob != nullptr);
140 fOriginalTextBlob->notifyAddedToCache(cacheID);
141 }
142
makeBlob() const143 sk_sp<SkTextBlob> SkGlyphRunList::makeBlob() const {
144 SkTextBlobBuilder builder;
145 for (auto& run : *this) {
146 SkTextBlobBuilder::RunBuffer buffer;
147 if (run.scaledRotations().empty()) {
148 if (run.text().empty()) {
149 buffer = builder.allocRunPos(run.font(), run.runSize(), nullptr);
150 } else {
151 buffer = builder.allocRunTextPos(run.font(), run.runSize(), run.text().size(), nullptr);
152 auto text = run.text();
153 memcpy(buffer.utf8text, text.data(), text.size_bytes());
154 auto clusters = run.clusters();
155 memcpy(buffer.clusters, clusters.data(), clusters.size_bytes());
156 }
157 auto positions = run.positions();
158 memcpy(buffer.points(), positions.data(), positions.size_bytes());
159 } else {
160 buffer = builder.allocRunRSXform(run.font(), run.runSize());
161 for (auto [xform, pos, sr] : SkMakeZip(buffer.xforms(),
162 run.positions(),
163 run.scaledRotations())) {
164 xform = SkRSXform::Make(sr.x(), sr.y(), pos.x(), pos.y());
165 }
166 }
167 auto glyphIDs = run.glyphsIDs();
168 memcpy(buffer.glyphs, glyphIDs.data(), glyphIDs.size_bytes());
169 }
170 return builder.make();
171 }
172
173 // -- SkGlyphRunBuilder ----------------------------------------------------------------------------
draw_text_positions(const SkFont & font,SkSpan<const SkGlyphID> glyphIDs,SkPoint origin,SkPoint * buffer)174 static SkSpan<const SkPoint> draw_text_positions(
175 const SkFont& font, SkSpan<const SkGlyphID> glyphIDs, SkPoint origin, SkPoint* buffer) {
176 SkStrikeSpec strikeSpec = SkStrikeSpec::MakeWithNoDevice(font);
177 SkBulkGlyphMetrics storage{strikeSpec};
178 auto glyphs = storage.glyphs(glyphIDs);
179
180 SkPoint* positionCursor = buffer;
181 SkPoint endOfLastGlyph = origin;
182 for (auto glyph : glyphs) {
183 *positionCursor++ = endOfLastGlyph;
184 endOfLastGlyph += glyph->advanceVector();
185 }
186 return SkMakeSpan(buffer, glyphIDs.size());
187 }
188
textToGlyphRunList(const SkFont & font,const SkPaint & paint,const void * bytes,size_t byteLength,SkPoint origin,SkTextEncoding encoding)189 const SkGlyphRunList& SkGlyphRunBuilder::textToGlyphRunList(
190 const SkFont& font, const SkPaint& paint,
191 const void* bytes, size_t byteLength, SkPoint origin,
192 SkTextEncoding encoding) {
193 auto glyphIDs = textToGlyphIDs(font, bytes, byteLength, encoding);
194 SkRect bounds = SkRect::MakeEmpty();
195 this->prepareBuffers(glyphIDs.size(), 0);
196 if (!glyphIDs.empty()) {
197 SkSpan<const SkPoint> positions = draw_text_positions(font, glyphIDs, {0, 0}, fPositions);
198 this->makeGlyphRun(font,
199 glyphIDs,
200 positions,
201 SkSpan<const char>{},
202 SkSpan<const uint32_t>{},
203 SkSpan<const SkVector>{});
204 bounds = fGlyphRunListStorage.front().sourceBounds(paint);
205 }
206
207 return this->makeGlyphRunList(nullptr, bounds.makeOffset(origin), origin);
208 }
209
blobToGlyphRunList(const SkTextBlob & blob,SkPoint origin)210 const SkGlyphRunList& SkGlyphRunBuilder::blobToGlyphRunList(
211 const SkTextBlob& blob, SkPoint origin) {
212 // Pre-size all the buffers so they don't move during processing.
213 this->initialize(blob);
214
215 SkPoint* positionCursor = fPositions;
216 SkVector* scaledRotationsCursor = fScaledRotations;
217 for (SkTextBlobRunIterator it(&blob); !it.done(); it.next()) {
218 size_t runSize = it.glyphCount();
219 if (runSize == 0 || !SkFontPriv::IsFinite(it.font())) {
220 // If no glyphs or the font is not finite, don't add the run.
221 continue;
222 }
223
224 const SkFont& font = it.font();
225 auto glyphIDs = SkSpan<const SkGlyphID>{it.glyphs(), runSize};
226
227 SkSpan<const SkPoint> positions;
228 SkSpan<const SkVector> scaledRotations;
229 switch (it.positioning()) {
230 case SkTextBlobRunIterator::kDefault_Positioning: {
231 positions = draw_text_positions(font, glyphIDs, it.offset(), positionCursor);
232 positionCursor += positions.size();
233 break;
234 }
235 case SkTextBlobRunIterator::kHorizontal_Positioning: {
236 positions = SkMakeSpan(positionCursor, runSize);
237 for (auto x : SkSpan<const SkScalar>{it.pos(), glyphIDs.size()}) {
238 *positionCursor++ = SkPoint::Make(x, it.offset().y());
239 }
240 break;
241 }
242 case SkTextBlobRunIterator::kFull_Positioning: {
243 positions = SkMakeSpan(it.points(), runSize);
244 break;
245 }
246 case SkTextBlobRunIterator::kRSXform_Positioning: {
247 positions = SkMakeSpan(positionCursor, runSize);
248 scaledRotations = SkMakeSpan(scaledRotationsCursor, runSize);
249 for (const SkRSXform& xform : SkMakeSpan(it.xforms(), runSize)) {
250 *positionCursor++ = {xform.fTx, xform.fTy};
251 *scaledRotationsCursor++ = {xform.fSCos, xform.fSSin};
252 }
253 break;
254 }
255 }
256
257 this->makeGlyphRun(
258 font,
259 glyphIDs,
260 positions,
261 SkSpan<const char>(it.text(), it.textSize()),
262 SkSpan<const uint32_t>(it.clusters(), runSize),
263 scaledRotations);
264 }
265
266 return this->makeGlyphRunList(&blob, blob.bounds().makeOffset(origin), origin);
267 }
268
269 std::tuple<SkSpan<const SkPoint>, SkSpan<const SkVector>>
convertRSXForm(SkSpan<const SkRSXform> xforms)270 SkGlyphRunBuilder::convertRSXForm(SkSpan<const SkRSXform> xforms) {
271 const int count = SkCount(xforms);
272 this->prepareBuffers(count, count);
273 auto positions = SkMakeSpan(fPositions.get(), count);
274 auto scaledRotations = SkMakeSpan(fScaledRotations.get(), count);
275 for (auto [pos, sr, xform] : SkMakeZip(positions, scaledRotations, xforms)) {
276 auto [scos, ssin, tx, ty] = xform;
277 pos = {tx, ty};
278 sr = {scos, ssin};
279 }
280 return {positions, scaledRotations};
281 }
282
initialize(const SkTextBlob & blob)283 void SkGlyphRunBuilder::initialize(const SkTextBlob& blob) {
284 int positionCount = 0;
285 int rsxFormCount = 0;
286 for (SkTextBlobRunIterator it(&blob); !it.done(); it.next()) {
287 if (it.positioning() != SkTextBlobRunIterator::kFull_Positioning) {
288 positionCount += it.glyphCount();
289 }
290 if (it.positioning() == SkTextBlobRunIterator::kRSXform_Positioning) {
291 rsxFormCount += it.glyphCount();
292 }
293 }
294
295 prepareBuffers(positionCount, rsxFormCount);
296 }
297
prepareBuffers(int positionCount,int RSXFormCount)298 void SkGlyphRunBuilder::prepareBuffers(int positionCount, int RSXFormCount) {
299 if (positionCount > fMaxTotalRunSize) {
300 fMaxTotalRunSize = positionCount;
301 fPositions.reset(fMaxTotalRunSize);
302 }
303
304 if (RSXFormCount > fMaxScaledRotations) {
305 fMaxScaledRotations = RSXFormCount;
306 fScaledRotations.reset(RSXFormCount);
307 }
308
309 fGlyphRunListStorage.clear();
310 }
311
textToGlyphIDs(const SkFont & font,const void * bytes,size_t byteLength,SkTextEncoding encoding)312 SkSpan<const SkGlyphID> SkGlyphRunBuilder::textToGlyphIDs(
313 const SkFont& font, const void* bytes, size_t byteLength, SkTextEncoding encoding) {
314 if (encoding != SkTextEncoding::kGlyphID) {
315 int count = font.countText(bytes, byteLength, encoding);
316 if (count > 0) {
317 fScratchGlyphIDs.resize(count);
318 font.textToGlyphs(bytes, byteLength, encoding, fScratchGlyphIDs.data(), count);
319 return SkMakeSpan(fScratchGlyphIDs);
320 } else {
321 return SkSpan<const SkGlyphID>();
322 }
323 } else {
324 return SkSpan<const SkGlyphID>((const SkGlyphID*)bytes, byteLength / 2);
325 }
326 }
327
makeGlyphRun(const SkFont & font,SkSpan<const SkGlyphID> glyphIDs,SkSpan<const SkPoint> positions,SkSpan<const char> text,SkSpan<const uint32_t> clusters,SkSpan<const SkVector> scaledRotations)328 void SkGlyphRunBuilder::makeGlyphRun(
329 const SkFont& font,
330 SkSpan<const SkGlyphID> glyphIDs,
331 SkSpan<const SkPoint> positions,
332 SkSpan<const char> text,
333 SkSpan<const uint32_t> clusters,
334 SkSpan<const SkVector> scaledRotations) {
335
336 // Ignore empty runs.
337 if (!glyphIDs.empty()) {
338 fGlyphRunListStorage.emplace_back(
339 font,
340 positions,
341 glyphIDs,
342 text,
343 clusters,
344 scaledRotations);
345 }
346 }
347
makeGlyphRunList(const SkTextBlob * blob,const SkRect & bounds,SkPoint origin)348 const SkGlyphRunList& SkGlyphRunBuilder::makeGlyphRunList(
349 const SkTextBlob* blob, const SkRect& bounds, SkPoint origin) {
350 fGlyphRunList.~SkGlyphRunList();
351 return *new (&fGlyphRunList)
352 SkGlyphRunList{blob, bounds, origin, SkMakeSpan(fGlyphRunListStorage)};
353 }
354