Layout.cpp revision aaa4e3470270496e6eb80704eadecb2cb7c56bf0 
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
45using std::string;
46using std::vector;
47
48namespace minikin {
49
50Bitmap::Bitmap(int width, int height) : width(width), height(height) {
51    buf = new uint8_t[width * height]();
52}
53
54Bitmap::~Bitmap() {
55    delete[] buf;
56}
57
58void 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
66void 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
90namespace android {
91
92const int kDirection_Mask = 0x1;
93
94struct LayoutContext {
95    MinikinPaint paint;
96    FontStyle style;
97    std::vector<hb_font_t*> hbFonts;  // parallel to mFaces
98
99    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
110class LayoutCacheKey {
111public:
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
123    hash_t hash() const {
124        return mHash;
125    }
126
127    void copyText() {
128        uint16_t* charsCopy = new uint16_t[mNchars];
129        memcpy(charsCopy, mChars, mNchars * sizeof(uint16_t));
130        mChars = charsCopy;
131    }
132    void freeText() {
133        delete[] mChars;
134        mChars = NULL;
135    }
136
137    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
144private:
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
165class LayoutCache : private OnEntryRemoved<LayoutCacheKey, Layout*> {
166public:
167    LayoutCache() : mCache(kMaxEntries) {
168        mCache.setOnEntryRemovedListener(this);
169    }
170
171    void clear() {
172        mCache.clear();
173    }
174
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
186private:
187    // callback for OnEntryRemoved
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
202static unsigned int disabledDecomposeCompatibility(hb_unicode_funcs_t*, hb_codepoint_t,
203                                                   hb_codepoint_t*, void*) {
204    return 0;
205}
206
207class LayoutEngine : public Singleton<LayoutEngine> {
208public:
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
223ANDROID_SINGLETON_STATIC_INSTANCE(LayoutEngine);
224
225bool 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
241hash_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
257hash_t hash_type(const LayoutCacheKey& key) {
258    return key.hash();
259}
260
261void 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.
273void Layout::init() {
274}
275
276void Layout::reset() {
277    mGlyphs.clear();
278    mFaces.clear();
279    mBounds.setEmpty();
280    mAdvances.clear();
281    mAdvance = 0;
282}
283
284void Layout::setFontCollection(const FontCollection* collection) {
285    mCollection = collection;
286}
287
288static 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
296static 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
304hb_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
316static float HBFixedToFloat(hb_position_t v)
317{
318    return scalbnf (v, -8);
319}
320
321static hb_position_t HBFloatToFixed(float v)
322{
323    return scalbnf (v, +8);
324}
325
326void 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
333int 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
351static 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
359static 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
382static 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 */
418static 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
437class BidiText {
438public:
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
449        bool operator!= (const Iter& other) const {
450            return mIsEnd != other.mIsEnd || mNextRunIndex != other.mNextRunIndex
451                    || mBidi != other.mBidi;
452        }
453
454        const RunInfo& operator* () const {
455            return mRunInfo;
456        }
457
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
477    ~BidiText() {
478        if (mBidi) {
479            ubidi_close(mBidi);
480        }
481    }
482
483    Iter begin () const {
484        return Iter(mBidi, mStart, mEnd, 0, mRunCount, mIsRtl);
485    }
486
487    Iter end() const {
488        return Iter(mBidi, mStart, mEnd, mRunCount, mRunCount, mIsRtl);
489    }
490
491private:
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
502BidiText::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
516void 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
543BidiText::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
579void 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
597float 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
617float 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
656float 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
684static 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
705void 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
863void 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
898void 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
926size_t Layout::nGlyphs() const {
927    return mGlyphs.size();
928}
929
930MinikinFont* Layout::getFont(int i) const {
931    const LayoutGlyph& glyph = mGlyphs[i];
932    return mFaces[glyph.font_ix].font;
933}
934
935FontFakery Layout::getFakery(int i) const {
936    const LayoutGlyph& glyph = mGlyphs[i];
937    return mFaces[glyph.font_ix].fakery;
938}
939
940unsigned int Layout::getGlyphId(int i) const {
941    const LayoutGlyph& glyph = mGlyphs[i];
942    return glyph.glyph_id;
943}
944
945float Layout::getX(int i) const {
946    const LayoutGlyph& glyph = mGlyphs[i];
947    return glyph.x;
948}
949
950float Layout::getY(int i) const {
951    const LayoutGlyph& glyph = mGlyphs[i];
952    return glyph.y;
953}
954
955float Layout::getAdvance() const {
956    return mAdvance;
957}
958
959void Layout::getAdvances(float* advances) {
960    memcpy(advances, &mAdvances[0], mAdvances.size() * sizeof(float));
961}
962
963void Layout::getBounds(MinikinRect* bounds) {
964    bounds->set(mBounds);
965}
966
967void Layout::purgeCaches() {
968    AutoMutex _l(gMinikinLock);
969    LayoutCache& layoutCache = LayoutEngine::getInstance().layoutCache;
970    layoutCache.clear();
971    purgeHbFontCacheLocked();
972}
973
974}  // namespace android
975