1 /*
2  * Copyright (C) 2013 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #define LOG_TAG "Minikin"
18 #include <cutils/log.h>
19 
20 #include <math.h>
21 
22 #include <algorithm>
23 #include <fstream>
24 #include <iostream>  // for debugging
25 #include <string>
26 #include <vector>
27 
28 #include <utils/JenkinsHash.h>
29 #include <utils/LruCache.h>
30 #include <utils/Singleton.h>
31 #include <utils/String16.h>
32 
33 #include <unicode/ubidi.h>
34 #include <hb-icu.h>
35 #include <hb-ot.h>
36 
37 #include "FontLanguage.h"
38 #include "FontLanguageListCache.h"
39 #include "LayoutUtils.h"
40 #include "HbFontCache.h"
41 #include "MinikinInternal.h"
42 #include <minikin/MinikinFontFreeType.h>
43 #include <minikin/Layout.h>
44 
45 using std::string;
46 using std::vector;
47 
48 namespace minikin {
49 
Bitmap(int width,int height)50 Bitmap::Bitmap(int width, int height) : width(width), height(height) {
51     buf = new uint8_t[width * height]();
52 }
53 
~Bitmap()54 Bitmap::~Bitmap() {
55     delete[] buf;
56 }
57 
writePnm(std::ofstream & o) const58 void Bitmap::writePnm(std::ofstream &o) const {
59     o << "P5" << std::endl;
60     o << width << " " << height << std::endl;
61     o << "255" << std::endl;
62     o.write((const char *)buf, width * height);
63     o.close();
64 }
65 
drawGlyph(const android::GlyphBitmap & bitmap,int x,int y)66 void Bitmap::drawGlyph(const android::GlyphBitmap& bitmap, int x, int y) {
67     int bmw = bitmap.width;
68     int bmh = bitmap.height;
69     x += bitmap.left;
70     y -= bitmap.top;
71     int x0 = std::max(0, x);
72     int x1 = std::min(width, x + bmw);
73     int y0 = std::max(0, y);
74     int y1 = std::min(height, y + bmh);
75     const unsigned char* src = bitmap.buffer + (y0 - y) * bmw + (x0 - x);
76     uint8_t* dst = buf + y0 * width;
77     for (int yy = y0; yy < y1; yy++) {
78         for (int xx = x0; xx < x1; xx++) {
79             int pixel = (int)dst[xx] + (int)src[xx - x];
80             pixel = pixel > 0xff ? 0xff : pixel;
81             dst[xx] = pixel;
82         }
83         src += bmw;
84         dst += width;
85     }
86 }
87 
88 } // namespace minikin
89 
90 namespace android {
91 
92 const int kDirection_Mask = 0x1;
93 
94 struct LayoutContext {
95     MinikinPaint paint;
96     FontStyle style;
97     std::vector<hb_font_t*> hbFonts;  // parallel to mFaces
98 
clearHbFontsandroid::LayoutContext99     void clearHbFonts() {
100         for (size_t i = 0; i < hbFonts.size(); i++) {
101             hb_font_set_funcs(hbFonts[i], nullptr, nullptr, nullptr);
102             hb_font_destroy(hbFonts[i]);
103         }
104         hbFonts.clear();
105     }
106 };
107 
108 // Layout cache datatypes
109 
110 class LayoutCacheKey {
111 public:
LayoutCacheKey(const FontCollection * collection,const MinikinPaint & paint,FontStyle style,const uint16_t * chars,size_t start,size_t count,size_t nchars,bool dir)112     LayoutCacheKey(const FontCollection* collection, const MinikinPaint& paint, FontStyle style,
113             const uint16_t* chars, size_t start, size_t count, size_t nchars, bool dir)
114             : mChars(chars), mNchars(nchars),
115             mStart(start), mCount(count), mId(collection->getId()), mStyle(style),
116             mSize(paint.size), mScaleX(paint.scaleX), mSkewX(paint.skewX),
117             mLetterSpacing(paint.letterSpacing),
118             mPaintFlags(paint.paintFlags), mHyphenEdit(paint.hyphenEdit), mIsRtl(dir),
119             mHash(computeHash()) {
120     }
121     bool operator==(const LayoutCacheKey &other) const;
122 
hash() const123     hash_t hash() const {
124         return mHash;
125     }
126 
copyText()127     void copyText() {
128         uint16_t* charsCopy = new uint16_t[mNchars];
129         memcpy(charsCopy, mChars, mNchars * sizeof(uint16_t));
130         mChars = charsCopy;
131     }
freeText()132     void freeText() {
133         delete[] mChars;
134         mChars = NULL;
135     }
136 
doLayout(Layout * layout,LayoutContext * ctx,const FontCollection * collection) const137     void doLayout(Layout* layout, LayoutContext* ctx, const FontCollection* collection) const {
138         layout->setFontCollection(collection);
139         layout->mAdvances.resize(mCount, 0);
140         ctx->clearHbFonts();
141         layout->doLayoutRun(mChars, mStart, mCount, mNchars, mIsRtl, ctx);
142     }
143 
144 private:
145     const uint16_t* mChars;
146     size_t mNchars;
147     size_t mStart;
148     size_t mCount;
149     uint32_t mId;  // for the font collection
150     FontStyle mStyle;
151     float mSize;
152     float mScaleX;
153     float mSkewX;
154     float mLetterSpacing;
155     int32_t mPaintFlags;
156     HyphenEdit mHyphenEdit;
157     bool mIsRtl;
158     // Note: any fields added to MinikinPaint must also be reflected here.
159     // TODO: language matching (possibly integrate into style)
160     hash_t mHash;
161 
162     hash_t computeHash() const;
163 };
164 
165 class LayoutCache : private OnEntryRemoved<LayoutCacheKey, Layout*> {
166 public:
LayoutCache()167     LayoutCache() : mCache(kMaxEntries) {
168         mCache.setOnEntryRemovedListener(this);
169     }
170 
clear()171     void clear() {
172         mCache.clear();
173     }
174 
get(LayoutCacheKey & key,LayoutContext * ctx,const FontCollection * collection)175     Layout* get(LayoutCacheKey& key, LayoutContext* ctx, const FontCollection* collection) {
176         Layout* layout = mCache.get(key);
177         if (layout == NULL) {
178             key.copyText();
179             layout = new Layout();
180             key.doLayout(layout, ctx, collection);
181             mCache.put(key, layout);
182         }
183         return layout;
184     }
185 
186 private:
187     // callback for OnEntryRemoved
operator ()(LayoutCacheKey & key,Layout * & value)188     void operator()(LayoutCacheKey& key, Layout*& value) {
189         key.freeText();
190         delete value;
191     }
192 
193     LruCache<LayoutCacheKey, Layout*> mCache;
194 
195     //static const size_t kMaxEntries = LruCache<LayoutCacheKey, Layout*>::kUnlimitedCapacity;
196 
197     // TODO: eviction based on memory footprint; for now, we just use a constant
198     // number of strings
199     static const size_t kMaxEntries = 5000;
200 };
201 
disabledDecomposeCompatibility(hb_unicode_funcs_t *,hb_codepoint_t,hb_codepoint_t *,void *)202 static unsigned int disabledDecomposeCompatibility(hb_unicode_funcs_t*, hb_codepoint_t,
203                                                    hb_codepoint_t*, void*) {
204     return 0;
205 }
206 
207 class LayoutEngine : public Singleton<LayoutEngine> {
208 public:
LayoutEngine()209     LayoutEngine() {
210         unicodeFunctions = hb_unicode_funcs_create(hb_icu_get_unicode_funcs());
211         /* Disable the function used for compatibility decomposition */
212         hb_unicode_funcs_set_decompose_compatibility_func(
213                 unicodeFunctions, disabledDecomposeCompatibility, NULL, NULL);
214         hbBuffer = hb_buffer_create();
215         hb_buffer_set_unicode_funcs(hbBuffer, unicodeFunctions);
216     }
217 
218     hb_buffer_t* hbBuffer;
219     hb_unicode_funcs_t* unicodeFunctions;
220     LayoutCache layoutCache;
221 };
222 
223 ANDROID_SINGLETON_STATIC_INSTANCE(LayoutEngine);
224 
operator ==(const LayoutCacheKey & other) const225 bool LayoutCacheKey::operator==(const LayoutCacheKey& other) const {
226     return mId == other.mId
227             && mStart == other.mStart
228             && mCount == other.mCount
229             && mStyle == other.mStyle
230             && mSize == other.mSize
231             && mScaleX == other.mScaleX
232             && mSkewX == other.mSkewX
233             && mLetterSpacing == other.mLetterSpacing
234             && mPaintFlags == other.mPaintFlags
235             && mHyphenEdit == other.mHyphenEdit
236             && mIsRtl == other.mIsRtl
237             && mNchars == other.mNchars
238             && !memcmp(mChars, other.mChars, mNchars * sizeof(uint16_t));
239 }
240 
computeHash() const241 hash_t LayoutCacheKey::computeHash() const {
242     uint32_t hash = JenkinsHashMix(0, mId);
243     hash = JenkinsHashMix(hash, mStart);
244     hash = JenkinsHashMix(hash, mCount);
245     hash = JenkinsHashMix(hash, hash_type(mStyle));
246     hash = JenkinsHashMix(hash, hash_type(mSize));
247     hash = JenkinsHashMix(hash, hash_type(mScaleX));
248     hash = JenkinsHashMix(hash, hash_type(mSkewX));
249     hash = JenkinsHashMix(hash, hash_type(mLetterSpacing));
250     hash = JenkinsHashMix(hash, hash_type(mPaintFlags));
251     hash = JenkinsHashMix(hash, hash_type(mHyphenEdit.hasHyphen()));
252     hash = JenkinsHashMix(hash, hash_type(mIsRtl));
253     hash = JenkinsHashMixShorts(hash, mChars, mNchars);
254     return JenkinsHashWhiten(hash);
255 }
256 
hash_type(const LayoutCacheKey & key)257 hash_t hash_type(const LayoutCacheKey& key) {
258     return key.hash();
259 }
260 
join(const MinikinRect & r)261 void MinikinRect::join(const MinikinRect& r) {
262     if (isEmpty()) {
263         set(r);
264     } else if (!r.isEmpty()) {
265         mLeft = std::min(mLeft, r.mLeft);
266         mTop = std::min(mTop, r.mTop);
267         mRight = std::max(mRight, r.mRight);
268         mBottom = std::max(mBottom, r.mBottom);
269     }
270 }
271 
272 // Deprecated. Remove when callers are removed.
init()273 void Layout::init() {
274 }
275 
reset()276 void Layout::reset() {
277     mGlyphs.clear();
278     mFaces.clear();
279     mBounds.setEmpty();
280     mAdvances.clear();
281     mAdvance = 0;
282 }
283 
setFontCollection(const FontCollection * collection)284 void Layout::setFontCollection(const FontCollection* collection) {
285     mCollection = collection;
286 }
287 
harfbuzzGetGlyphHorizontalAdvance(hb_font_t *,void * fontData,hb_codepoint_t glyph,void *)288 static hb_position_t harfbuzzGetGlyphHorizontalAdvance(hb_font_t* /* hbFont */, void* fontData,
289         hb_codepoint_t glyph, void* /* userData */) {
290     MinikinPaint* paint = reinterpret_cast<MinikinPaint*>(fontData);
291     MinikinFont* font = paint->font;
292     float advance = font->GetHorizontalAdvance(glyph, *paint);
293     return 256 * advance + 0.5;
294 }
295 
harfbuzzGetGlyphHorizontalOrigin(hb_font_t *,void *,hb_codepoint_t,hb_position_t *,hb_position_t *,void *)296 static hb_bool_t harfbuzzGetGlyphHorizontalOrigin(hb_font_t* /* hbFont */, void* /* fontData */,
297         hb_codepoint_t /* glyph */, hb_position_t* /* x */, hb_position_t* /* y */,
298         void* /* userData */) {
299     // Just return true, following the way that Harfbuzz-FreeType
300     // implementation does.
301     return true;
302 }
303 
getHbFontFuncs()304 hb_font_funcs_t* getHbFontFuncs() {
305     static hb_font_funcs_t* hbFontFuncs = 0;
306 
307     if (hbFontFuncs == 0) {
308         hbFontFuncs = hb_font_funcs_create();
309         hb_font_funcs_set_glyph_h_advance_func(hbFontFuncs, harfbuzzGetGlyphHorizontalAdvance, 0, 0);
310         hb_font_funcs_set_glyph_h_origin_func(hbFontFuncs, harfbuzzGetGlyphHorizontalOrigin, 0, 0);
311         hb_font_funcs_make_immutable(hbFontFuncs);
312     }
313     return hbFontFuncs;
314 }
315 
HBFixedToFloat(hb_position_t v)316 static float HBFixedToFloat(hb_position_t v)
317 {
318     return scalbnf (v, -8);
319 }
320 
HBFloatToFixed(float v)321 static hb_position_t HBFloatToFixed(float v)
322 {
323     return scalbnf (v, +8);
324 }
325 
dump() const326 void Layout::dump() const {
327     for (size_t i = 0; i < mGlyphs.size(); i++) {
328         const LayoutGlyph& glyph = mGlyphs[i];
329         std::cout << glyph.glyph_id << ": " << glyph.x << ", " << glyph.y << std::endl;
330     }
331 }
332 
findFace(FakedFont face,LayoutContext * ctx)333 int Layout::findFace(FakedFont face, LayoutContext* ctx) {
334     unsigned int ix;
335     for (ix = 0; ix < mFaces.size(); ix++) {
336         if (mFaces[ix].font == face.font) {
337             return ix;
338         }
339     }
340     mFaces.push_back(face);
341     // Note: ctx == NULL means we're copying from the cache, no need to create
342     // corresponding hb_font object.
343     if (ctx != NULL) {
344         hb_font_t* font = getHbFontLocked(face.font);
345         hb_font_set_funcs(font, getHbFontFuncs(), &ctx->paint, 0);
346         ctx->hbFonts.push_back(font);
347     }
348     return ix;
349 }
350 
codePointToScript(hb_codepoint_t codepoint)351 static hb_script_t codePointToScript(hb_codepoint_t codepoint) {
352     static hb_unicode_funcs_t* u = 0;
353     if (!u) {
354         u = LayoutEngine::getInstance().unicodeFunctions;
355     }
356     return hb_unicode_script(u, codepoint);
357 }
358 
decodeUtf16(const uint16_t * chars,size_t len,ssize_t * iter)359 static hb_codepoint_t decodeUtf16(const uint16_t* chars, size_t len, ssize_t* iter) {
360     const uint16_t v = chars[(*iter)++];
361     // test whether v in (0xd800..0xdfff), lead or trail surrogate
362     if ((v & 0xf800) == 0xd800) {
363         // test whether v in (0xd800..0xdbff), lead surrogate
364         if (size_t(*iter) < len && (v & 0xfc00) == 0xd800) {
365             const uint16_t v2 = chars[(*iter)++];
366             // test whether v2 in (0xdc00..0xdfff), trail surrogate
367             if ((v2 & 0xfc00) == 0xdc00) {
368                 // (0xd800 0xdc00) in utf-16 maps to 0x10000 in ucs-32
369                 const hb_codepoint_t delta = (0xd800 << 10) + 0xdc00 - 0x10000;
370                 return (((hb_codepoint_t)v) << 10) + v2 - delta;
371             }
372             (*iter) -= 1;
373             return 0xFFFDu;
374         } else {
375             return 0xFFFDu;
376         }
377     } else {
378         return v;
379     }
380 }
381 
getScriptRun(const uint16_t * chars,size_t len,ssize_t * iter)382 static hb_script_t getScriptRun(const uint16_t* chars, size_t len, ssize_t* iter) {
383     if (size_t(*iter) == len) {
384         return HB_SCRIPT_UNKNOWN;
385     }
386     uint32_t cp = decodeUtf16(chars, len, iter);
387     hb_script_t current_script = codePointToScript(cp);
388     for (;;) {
389         if (size_t(*iter) == len)
390             break;
391         const ssize_t prev_iter = *iter;
392         cp = decodeUtf16(chars, len, iter);
393         const hb_script_t script = codePointToScript(cp);
394         if (script != current_script) {
395             if (current_script == HB_SCRIPT_INHERITED ||
396                 current_script == HB_SCRIPT_COMMON) {
397                 current_script = script;
398             } else if (script == HB_SCRIPT_INHERITED ||
399                 script == HB_SCRIPT_COMMON) {
400                 continue;
401             } else {
402                 *iter = prev_iter;
403                 break;
404             }
405         }
406     }
407     if (current_script == HB_SCRIPT_INHERITED) {
408         current_script = HB_SCRIPT_COMMON;
409     }
410 
411     return current_script;
412 }
413 
414 /**
415  * Disable certain scripts (mostly those with cursive connection) from having letterspacing
416  * applied. See https://github.com/behdad/harfbuzz/issues/64 for more details.
417  */
isScriptOkForLetterspacing(hb_script_t script)418 static bool isScriptOkForLetterspacing(hb_script_t script) {
419     return !(
420             script == HB_SCRIPT_ARABIC ||
421             script == HB_SCRIPT_NKO ||
422             script == HB_SCRIPT_PSALTER_PAHLAVI ||
423             script == HB_SCRIPT_MANDAIC ||
424             script == HB_SCRIPT_MONGOLIAN ||
425             script == HB_SCRIPT_PHAGS_PA ||
426             script == HB_SCRIPT_DEVANAGARI ||
427             script == HB_SCRIPT_BENGALI ||
428             script == HB_SCRIPT_GURMUKHI ||
429             script == HB_SCRIPT_MODI ||
430             script == HB_SCRIPT_SHARADA ||
431             script == HB_SCRIPT_SYLOTI_NAGRI ||
432             script == HB_SCRIPT_TIRHUTA ||
433             script == HB_SCRIPT_OGHAM
434             );
435 }
436 
437 class BidiText {
438 public:
439     class Iter {
440     public:
441         struct RunInfo {
442             int32_t mRunStart;
443             int32_t mRunLength;
444             bool mIsRtl;
445         };
446 
447         Iter(UBiDi* bidi, size_t start, size_t end, size_t runIndex, size_t runCount, bool isRtl);
448 
operator !=(const Iter & other) const449         bool operator!= (const Iter& other) const {
450             return mIsEnd != other.mIsEnd || mNextRunIndex != other.mNextRunIndex
451                     || mBidi != other.mBidi;
452         }
453 
operator *() const454         const RunInfo& operator* () const {
455             return mRunInfo;
456         }
457 
operator ++()458         const Iter& operator++ () {
459             updateRunInfo();
460             return *this;
461         }
462 
463     private:
464         UBiDi* const mBidi;
465         bool mIsEnd;
466         size_t mNextRunIndex;
467         const size_t mRunCount;
468         const int32_t mStart;
469         const int32_t mEnd;
470         RunInfo mRunInfo;
471 
472         void updateRunInfo();
473     };
474 
475     BidiText(const uint16_t* buf, size_t start, size_t count, size_t bufSize, int bidiFlags);
476 
~BidiText()477     ~BidiText() {
478         if (mBidi) {
479             ubidi_close(mBidi);
480         }
481     }
482 
begin() const483     Iter begin () const {
484         return Iter(mBidi, mStart, mEnd, 0, mRunCount, mIsRtl);
485     }
486 
end() const487     Iter end() const {
488         return Iter(mBidi, mStart, mEnd, mRunCount, mRunCount, mIsRtl);
489     }
490 
491 private:
492     const size_t mStart;
493     const size_t mEnd;
494     const size_t mBufSize;
495     UBiDi* mBidi;
496     size_t mRunCount;
497     bool mIsRtl;
498 
499     DISALLOW_COPY_AND_ASSIGN(BidiText);
500 };
501 
Iter(UBiDi * bidi,size_t start,size_t end,size_t runIndex,size_t runCount,bool isRtl)502 BidiText::Iter::Iter(UBiDi* bidi, size_t start, size_t end, size_t runIndex, size_t runCount,
503         bool isRtl)
504     : mBidi(bidi), mIsEnd(runIndex == runCount), mNextRunIndex(runIndex), mRunCount(runCount),
505       mStart(start), mEnd(end), mRunInfo() {
506     if (mRunCount == 1) {
507         mRunInfo.mRunStart = start;
508         mRunInfo.mRunLength = end - start;
509         mRunInfo.mIsRtl = isRtl;
510         mNextRunIndex = mRunCount;
511         return;
512     }
513     updateRunInfo();
514 }
515 
updateRunInfo()516 void BidiText::Iter::updateRunInfo() {
517     if (mNextRunIndex == mRunCount) {
518         // All runs have been iterated.
519         mIsEnd = true;
520         return;
521     }
522     int32_t startRun = -1;
523     int32_t lengthRun = -1;
524     const UBiDiDirection runDir = ubidi_getVisualRun(mBidi, mNextRunIndex, &startRun, &lengthRun);
525     mNextRunIndex++;
526     if (startRun == -1 || lengthRun == -1) {
527         ALOGE("invalid visual run");
528         // skip the invalid run.
529         updateRunInfo();
530         return;
531     }
532     const int32_t runEnd = std::min(startRun + lengthRun, mEnd);
533     mRunInfo.mRunStart = std::max(startRun, mStart);
534     mRunInfo.mRunLength = runEnd - mRunInfo.mRunStart;
535     if (mRunInfo.mRunLength <= 0) {
536         // skip the empty run.
537         updateRunInfo();
538         return;
539     }
540     mRunInfo.mIsRtl = (runDir == UBIDI_RTL);
541 }
542 
BidiText(const uint16_t * buf,size_t start,size_t count,size_t bufSize,int bidiFlags)543 BidiText::BidiText(const uint16_t* buf, size_t start, size_t count, size_t bufSize, int bidiFlags)
544     : mStart(start), mEnd(start + count), mBufSize(bufSize), mBidi(NULL), mRunCount(1),
545       mIsRtl((bidiFlags & kDirection_Mask) != 0) {
546     if (bidiFlags == kBidi_Force_LTR || bidiFlags == kBidi_Force_RTL) {
547         // force single run.
548         return;
549     }
550     mBidi = ubidi_open();
551     if (!mBidi) {
552         ALOGE("error creating bidi object");
553         return;
554     }
555     UErrorCode status = U_ZERO_ERROR;
556     UBiDiLevel bidiReq = bidiFlags;
557     if (bidiFlags == kBidi_Default_LTR) {
558         bidiReq = UBIDI_DEFAULT_LTR;
559     } else if (bidiFlags == kBidi_Default_RTL) {
560         bidiReq = UBIDI_DEFAULT_RTL;
561     }
562     ubidi_setPara(mBidi, buf, mBufSize, bidiReq, NULL, &status);
563     if (!U_SUCCESS(status)) {
564         ALOGE("error calling ubidi_setPara, status = %d", status);
565         return;
566     }
567     const int paraDir = ubidi_getParaLevel(mBidi) & kDirection_Mask;
568     const ssize_t rc = ubidi_countRuns(mBidi, &status);
569     if (!U_SUCCESS(status) || rc < 0) {
570         ALOGW("error counting bidi runs, status = %d", status);
571     }
572     if (!U_SUCCESS(status) || rc <= 1) {
573         mIsRtl = (paraDir == kBidi_RTL);
574         return;
575     }
576     mRunCount = rc;
577 }
578 
doLayout(const uint16_t * buf,size_t start,size_t count,size_t bufSize,int bidiFlags,const FontStyle & style,const MinikinPaint & paint)579 void Layout::doLayout(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
580         int bidiFlags, const FontStyle &style, const MinikinPaint &paint) {
581     AutoMutex _l(gMinikinLock);
582 
583     LayoutContext ctx;
584     ctx.style = style;
585     ctx.paint = paint;
586 
587     reset();
588     mAdvances.resize(count, 0);
589 
590     for (const BidiText::Iter::RunInfo& runInfo : BidiText(buf, start, count, bufSize, bidiFlags)) {
591         doLayoutRunCached(buf, runInfo.mRunStart, runInfo.mRunLength, bufSize, runInfo.mIsRtl, &ctx,
592                 start, mCollection, this, NULL);
593     }
594     ctx.clearHbFonts();
595 }
596 
measureText(const uint16_t * buf,size_t start,size_t count,size_t bufSize,int bidiFlags,const FontStyle & style,const MinikinPaint & paint,const FontCollection * collection,float * advances)597 float Layout::measureText(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
598         int bidiFlags, const FontStyle &style, const MinikinPaint &paint,
599         const FontCollection* collection, float* advances) {
600     AutoMutex _l(gMinikinLock);
601 
602     LayoutContext ctx;
603     ctx.style = style;
604     ctx.paint = paint;
605 
606     float advance = 0;
607     for (const BidiText::Iter::RunInfo& runInfo : BidiText(buf, start, count, bufSize, bidiFlags)) {
608         float* advancesForRun = advances ? advances + (runInfo.mRunStart - start) : advances;
609         advance += doLayoutRunCached(buf, runInfo.mRunStart, runInfo.mRunLength, bufSize,
610                 runInfo.mIsRtl, &ctx, 0, collection, NULL, advancesForRun);
611     }
612 
613     ctx.clearHbFonts();
614     return advance;
615 }
616 
doLayoutRunCached(const uint16_t * buf,size_t start,size_t count,size_t bufSize,bool isRtl,LayoutContext * ctx,size_t dstStart,const FontCollection * collection,Layout * layout,float * advances)617 float Layout::doLayoutRunCached(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
618         bool isRtl, LayoutContext* ctx, size_t dstStart, const FontCollection* collection,
619         Layout* layout, float* advances) {
620     HyphenEdit hyphen = ctx->paint.hyphenEdit;
621     float advance = 0;
622     if (!isRtl) {
623         // left to right
624         size_t wordstart =
625                 start == bufSize ? start : getPrevWordBreakForCache(buf, start + 1, bufSize);
626         size_t wordend;
627         for (size_t iter = start; iter < start + count; iter = wordend) {
628             wordend = getNextWordBreakForCache(buf, iter, bufSize);
629             // Only apply hyphen to the last word in the string.
630             ctx->paint.hyphenEdit = wordend >= start + count ? hyphen : HyphenEdit();
631             size_t wordcount = std::min(start + count, wordend) - iter;
632             advance += doLayoutWord(buf + wordstart, iter - wordstart, wordcount,
633                     wordend - wordstart, isRtl, ctx, iter - dstStart, collection, layout,
634                     advances ? advances + (iter - start) : advances);
635             wordstart = wordend;
636         }
637     } else {
638         // right to left
639         size_t wordstart;
640         size_t end = start + count;
641         size_t wordend = end == 0 ? 0 : getNextWordBreakForCache(buf, end - 1, bufSize);
642         for (size_t iter = end; iter > start; iter = wordstart) {
643             wordstart = getPrevWordBreakForCache(buf, iter, bufSize);
644             // Only apply hyphen to the last (leftmost) word in the string.
645             ctx->paint.hyphenEdit = iter == end ? hyphen : HyphenEdit();
646             size_t bufStart = std::max(start, wordstart);
647             advance += doLayoutWord(buf + wordstart, bufStart - wordstart, iter - bufStart,
648                     wordend - wordstart, isRtl, ctx, bufStart - dstStart, collection, layout,
649                     advances ? advances + (bufStart - start) : advances);
650             wordend = wordstart;
651         }
652     }
653     return advance;
654 }
655 
doLayoutWord(const uint16_t * buf,size_t start,size_t count,size_t bufSize,bool isRtl,LayoutContext * ctx,size_t bufStart,const FontCollection * collection,Layout * layout,float * advances)656 float Layout::doLayoutWord(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
657         bool isRtl, LayoutContext* ctx, size_t bufStart, const FontCollection* collection,
658         Layout* layout, float* advances) {
659     LayoutCache& cache = LayoutEngine::getInstance().layoutCache;
660     LayoutCacheKey key(collection, ctx->paint, ctx->style, buf, start, count, bufSize, isRtl);
661     bool skipCache = ctx->paint.skipCache();
662     if (skipCache) {
663         Layout layoutForWord;
664         key.doLayout(&layoutForWord, ctx, collection);
665         if (layout) {
666             layout->appendLayout(&layoutForWord, bufStart);
667         }
668         if (advances) {
669             layoutForWord.getAdvances(advances);
670         }
671         return layoutForWord.getAdvance();
672     } else {
673         Layout* layoutForWord = cache.get(key, ctx, collection);
674         if (layout) {
675             layout->appendLayout(layoutForWord, bufStart);
676         }
677         if (advances) {
678             layoutForWord->getAdvances(advances);
679         }
680         return layoutForWord->getAdvance();
681     }
682 }
683 
addFeatures(const string & str,vector<hb_feature_t> * features)684 static void addFeatures(const string &str, vector<hb_feature_t>* features) {
685     if (!str.size())
686         return;
687 
688     const char* start = str.c_str();
689     const char* end = start + str.size();
690 
691     while (start < end) {
692         static hb_feature_t feature;
693         const char* p = strchr(start, ',');
694         if (!p)
695             p = end;
696         /* We do not allow setting features on ranges.  As such, reject any
697          * setting that has non-universal range. */
698         if (hb_feature_from_string (start, p - start, &feature)
699                 && feature.start == 0 && feature.end == (unsigned int) -1)
700             features->push_back(feature);
701         start = p + 1;
702     }
703 }
704 
doLayoutRun(const uint16_t * buf,size_t start,size_t count,size_t bufSize,bool isRtl,LayoutContext * ctx)705 void Layout::doLayoutRun(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
706         bool isRtl, LayoutContext* ctx) {
707     hb_buffer_t* buffer = LayoutEngine::getInstance().hbBuffer;
708     vector<FontCollection::Run> items;
709     mCollection->itemize(buf + start, count, ctx->style, &items);
710     if (isRtl) {
711         std::reverse(items.begin(), items.end());
712     }
713 
714     vector<hb_feature_t> features;
715     // Disable default-on non-required ligature features if letter-spacing
716     // See http://dev.w3.org/csswg/css-text-3/#letter-spacing-property
717     // "When the effective spacing between two characters is not zero (due to
718     // either justification or a non-zero value of letter-spacing), user agents
719     // should not apply optional ligatures."
720     if (fabs(ctx->paint.letterSpacing) > 0.03)
721     {
722         static const hb_feature_t no_liga = { HB_TAG('l', 'i', 'g', 'a'), 0, 0, ~0u };
723         static const hb_feature_t no_clig = { HB_TAG('c', 'l', 'i', 'g'), 0, 0, ~0u };
724         features.push_back(no_liga);
725         features.push_back(no_clig);
726     }
727     addFeatures(ctx->paint.fontFeatureSettings, &features);
728 
729     double size = ctx->paint.size;
730     double scaleX = ctx->paint.scaleX;
731 
732     float x = mAdvance;
733     float y = 0;
734     for (size_t run_ix = 0; run_ix < items.size(); run_ix++) {
735         FontCollection::Run &run = items[run_ix];
736         if (run.fakedFont.font == NULL) {
737             ALOGE("no font for run starting u+%04x length %d", buf[run.start], run.end - run.start);
738             continue;
739         }
740         int font_ix = findFace(run.fakedFont, ctx);
741         ctx->paint.font = mFaces[font_ix].font;
742         ctx->paint.fakery = mFaces[font_ix].fakery;
743         hb_font_t* hbFont = ctx->hbFonts[font_ix];
744 #ifdef VERBOSE_DEBUG
745         ALOGD("Run %zu, font %d [%d:%d]", run_ix, font_ix, run.start, run.end);
746 #endif
747 
748         hb_font_set_ppem(hbFont, size * scaleX, size);
749         hb_font_set_scale(hbFont, HBFloatToFixed(size * scaleX), HBFloatToFixed(size));
750 
751         // TODO: if there are multiple scripts within a font in an RTL run,
752         // we need to reorder those runs. This is unlikely with our current
753         // font stack, but should be done for correctness.
754         ssize_t srunend;
755         for (ssize_t srunstart = run.start; srunstart < run.end; srunstart = srunend) {
756             srunend = srunstart;
757             hb_script_t script = getScriptRun(buf + start, run.end, &srunend);
758 
759             double letterSpace = 0.0;
760             double letterSpaceHalfLeft = 0.0;
761             double letterSpaceHalfRight = 0.0;
762 
763             if (ctx->paint.letterSpacing != 0.0 && isScriptOkForLetterspacing(script)) {
764                 letterSpace = ctx->paint.letterSpacing * size * scaleX;
765                 if ((ctx->paint.paintFlags & LinearTextFlag) == 0) {
766                     letterSpace = round(letterSpace);
767                     letterSpaceHalfLeft = floor(letterSpace * 0.5);
768                 } else {
769                     letterSpaceHalfLeft = letterSpace * 0.5;
770                 }
771                 letterSpaceHalfRight = letterSpace - letterSpaceHalfLeft;
772             }
773 
774             hb_buffer_clear_contents(buffer);
775             hb_buffer_set_script(buffer, script);
776             hb_buffer_set_direction(buffer, isRtl? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
777             const FontLanguages& langList =
778                     FontLanguageListCache::getById(ctx->style.getLanguageListId());
779             if (langList.size() != 0) {
780                 const FontLanguage* hbLanguage = &langList[0];
781                 for (size_t i = 0; i < langList.size(); ++i) {
782                     if (langList[i].supportsHbScript(script)) {
783                         hbLanguage = &langList[i];
784                         break;
785                     }
786                 }
787                 hb_buffer_set_language(buffer,
788                         hb_language_from_string(hbLanguage->getString().c_str(), -1));
789             }
790             hb_buffer_add_utf16(buffer, buf, bufSize, srunstart + start, srunend - srunstart);
791             if (ctx->paint.hyphenEdit.hasHyphen() && srunend > srunstart) {
792                 // TODO: check whether this is really the desired semantics. It could have the
793                 // effect of assigning the hyphen width to a nonspacing mark
794                 unsigned int lastCluster = start + srunend - 1;
795 
796                 hb_codepoint_t hyphenChar = 0x2010; // HYPHEN
797                 hb_codepoint_t glyph;
798                 // Fallback to ASCII HYPHEN-MINUS if the font didn't have a glyph for HYPHEN. Note
799                 // that we intentionally don't do anything special if the font doesn't have a
800                 // HYPHEN-MINUS either, so a tofu could be shown, hinting towards something
801                 // missing.
802                 if (!hb_font_get_glyph(hbFont, hyphenChar, 0, &glyph)) {
803                     hyphenChar = 0x002D; // HYPHEN-MINUS
804                 }
805                 hb_buffer_add(buffer, hyphenChar, lastCluster);
806             }
807             hb_shape(hbFont, buffer, features.empty() ? NULL : &features[0], features.size());
808             unsigned int numGlyphs;
809             hb_glyph_info_t* info = hb_buffer_get_glyph_infos(buffer, &numGlyphs);
810             hb_glyph_position_t* positions = hb_buffer_get_glyph_positions(buffer, NULL);
811             if (numGlyphs)
812             {
813                 mAdvances[info[0].cluster - start] += letterSpaceHalfLeft;
814                 x += letterSpaceHalfLeft;
815             }
816             for (unsigned int i = 0; i < numGlyphs; i++) {
817 #ifdef VERBOSE_DEBUG
818                 ALOGD("%d %d %d %d",
819                         positions[i].x_advance, positions[i].y_advance,
820                         positions[i].x_offset, positions[i].y_offset);
821                 ALOGD("DoLayout %u: %f; %d, %d",
822                         info[i].codepoint, HBFixedToFloat(positions[i].x_advance),
823                         positions[i].x_offset, positions[i].y_offset);
824 #endif
825                 if (i > 0 && info[i - 1].cluster != info[i].cluster) {
826                     mAdvances[info[i - 1].cluster - start] += letterSpaceHalfRight;
827                     mAdvances[info[i].cluster - start] += letterSpaceHalfLeft;
828                     x += letterSpace;
829                 }
830 
831                 hb_codepoint_t glyph_ix = info[i].codepoint;
832                 float xoff = HBFixedToFloat(positions[i].x_offset);
833                 float yoff = -HBFixedToFloat(positions[i].y_offset);
834                 xoff += yoff * ctx->paint.skewX;
835                 LayoutGlyph glyph = {font_ix, glyph_ix, x + xoff, y + yoff};
836                 mGlyphs.push_back(glyph);
837                 float xAdvance = HBFixedToFloat(positions[i].x_advance);
838                 if ((ctx->paint.paintFlags & LinearTextFlag) == 0) {
839                     xAdvance = roundf(xAdvance);
840                 }
841                 MinikinRect glyphBounds;
842                 ctx->paint.font->GetBounds(&glyphBounds, glyph_ix, ctx->paint);
843                 glyphBounds.offset(x + xoff, y + yoff);
844                 mBounds.join(glyphBounds);
845                 if (info[i].cluster - start < count) {
846                     mAdvances[info[i].cluster - start] += xAdvance;
847                 } else {
848                     ALOGE("cluster %zu (start %zu) out of bounds of count %zu",
849                         info[i].cluster - start, start, count);
850                 }
851                 x += xAdvance;
852             }
853             if (numGlyphs)
854             {
855                 mAdvances[info[numGlyphs - 1].cluster - start] += letterSpaceHalfRight;
856                 x += letterSpaceHalfRight;
857             }
858         }
859     }
860     mAdvance = x;
861 }
862 
appendLayout(Layout * src,size_t start)863 void Layout::appendLayout(Layout* src, size_t start) {
864     int fontMapStack[16];
865     int* fontMap;
866     if (src->mFaces.size() < sizeof(fontMapStack) / sizeof(fontMapStack[0])) {
867         fontMap = fontMapStack;
868     } else {
869         fontMap = new int[src->mFaces.size()];
870     }
871     for (size_t i = 0; i < src->mFaces.size(); i++) {
872         int font_ix = findFace(src->mFaces[i], NULL);
873         fontMap[i] = font_ix;
874     }
875     int x0 = mAdvance;
876     for (size_t i = 0; i < src->mGlyphs.size(); i++) {
877         LayoutGlyph& srcGlyph = src->mGlyphs[i];
878         int font_ix = fontMap[srcGlyph.font_ix];
879         unsigned int glyph_id = srcGlyph.glyph_id;
880         float x = x0 + srcGlyph.x;
881         float y = srcGlyph.y;
882         LayoutGlyph glyph = {font_ix, glyph_id, x, y};
883         mGlyphs.push_back(glyph);
884     }
885     for (size_t i = 0; i < src->mAdvances.size(); i++) {
886         mAdvances[i + start] = src->mAdvances[i];
887     }
888     MinikinRect srcBounds(src->mBounds);
889     srcBounds.offset(x0, 0);
890     mBounds.join(srcBounds);
891     mAdvance += src->mAdvance;
892 
893     if (fontMap != fontMapStack) {
894         delete[] fontMap;
895     }
896 }
897 
draw(minikin::Bitmap * surface,int x0,int y0,float size) const898 void Layout::draw(minikin::Bitmap* surface, int x0, int y0, float size) const {
899     /*
900     TODO: redo as MinikinPaint settings
901     if (mProps.hasTag(minikinHinting)) {
902         int hintflags = mProps.value(minikinHinting).getIntValue();
903         if (hintflags & 1) load_flags |= FT_LOAD_NO_HINTING;
904         if (hintflags & 2) load_flags |= FT_LOAD_NO_AUTOHINT;
905     }
906     */
907     for (size_t i = 0; i < mGlyphs.size(); i++) {
908         const LayoutGlyph& glyph = mGlyphs[i];
909         MinikinFont* mf = mFaces[glyph.font_ix].font;
910         MinikinFontFreeType* face = static_cast<MinikinFontFreeType*>(mf);
911         GlyphBitmap glyphBitmap;
912         MinikinPaint paint;
913         paint.size = size;
914         bool ok = face->Render(glyph.glyph_id, paint, &glyphBitmap);
915 #ifdef VERBOSE_DEBUG
916         ALOGD("glyphBitmap.width=%d, glyphBitmap.height=%d (%d, %d) x=%f, y=%f, ok=%d",
917             glyphBitmap.width, glyphBitmap.height, glyphBitmap.left, glyphBitmap.top, glyph.x, glyph.y, ok);
918 #endif
919         if (ok) {
920             surface->drawGlyph(glyphBitmap,
921                 x0 + int(floor(glyph.x + 0.5)), y0 + int(floor(glyph.y + 0.5)));
922         }
923     }
924 }
925 
nGlyphs() const926 size_t Layout::nGlyphs() const {
927     return mGlyphs.size();
928 }
929 
getFont(int i) const930 MinikinFont* Layout::getFont(int i) const {
931     const LayoutGlyph& glyph = mGlyphs[i];
932     return mFaces[glyph.font_ix].font;
933 }
934 
getFakery(int i) const935 FontFakery Layout::getFakery(int i) const {
936     const LayoutGlyph& glyph = mGlyphs[i];
937     return mFaces[glyph.font_ix].fakery;
938 }
939 
getGlyphId(int i) const940 unsigned int Layout::getGlyphId(int i) const {
941     const LayoutGlyph& glyph = mGlyphs[i];
942     return glyph.glyph_id;
943 }
944 
getX(int i) const945 float Layout::getX(int i) const {
946     const LayoutGlyph& glyph = mGlyphs[i];
947     return glyph.x;
948 }
949 
getY(int i) const950 float Layout::getY(int i) const {
951     const LayoutGlyph& glyph = mGlyphs[i];
952     return glyph.y;
953 }
954 
getAdvance() const955 float Layout::getAdvance() const {
956     return mAdvance;
957 }
958 
getAdvances(float * advances)959 void Layout::getAdvances(float* advances) {
960     memcpy(advances, &mAdvances[0], mAdvances.size() * sizeof(float));
961 }
962 
getBounds(MinikinRect * bounds)963 void Layout::getBounds(MinikinRect* bounds) {
964     bounds->set(mBounds);
965 }
966 
purgeCaches()967 void Layout::purgeCaches() {
968     AutoMutex _l(gMinikinLock);
969     LayoutCache& layoutCache = LayoutEngine::getInstance().layoutCache;
970     layoutCache.clear();
971     purgeHbFontCacheLocked();
972 }
973 
974 }  // namespace android
975