Layout.cpp revision 2a79f59e73294e43f32cc0138e23fcde34eec28a 
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 "LayoutUtils.h"
38#include "MinikinInternal.h"
39#include <minikin/MinikinFontFreeType.h>
40#include <minikin/Layout.h>
41
42using std::string;
43using std::vector;
44
45namespace minikin {
46
47Bitmap::Bitmap(int width, int height) : width(width), height(height) {
48    buf = new uint8_t[width * height]();
49}
50
51Bitmap::~Bitmap() {
52    delete[] buf;
53}
54
55void Bitmap::writePnm(std::ofstream &o) const {
56    o << "P5" << std::endl;
57    o << width << " " << height << std::endl;
58    o << "255" << std::endl;
59    o.write((const char *)buf, width * height);
60    o.close();
61}
62
63void Bitmap::drawGlyph(const android::GlyphBitmap& bitmap, int x, int y) {
64    int bmw = bitmap.width;
65    int bmh = bitmap.height;
66    x += bitmap.left;
67    y -= bitmap.top;
68    int x0 = std::max(0, x);
69    int x1 = std::min(width, x + bmw);
70    int y0 = std::max(0, y);
71    int y1 = std::min(height, y + bmh);
72    const unsigned char* src = bitmap.buffer + (y0 - y) * bmw + (x0 - x);
73    uint8_t* dst = buf + y0 * width;
74    for (int yy = y0; yy < y1; yy++) {
75        for (int xx = x0; xx < x1; xx++) {
76            int pixel = (int)dst[xx] + (int)src[xx - x];
77            pixel = pixel > 0xff ? 0xff : pixel;
78            dst[xx] = pixel;
79        }
80        src += bmw;
81        dst += width;
82    }
83}
84
85} // namespace minikin
86
87namespace android {
88
89const int kDirection_Mask = 0x1;
90
91struct LayoutContext {
92    MinikinPaint paint;
93    FontStyle style;
94    std::vector<hb_font_t*> hbFonts;  // parallel to mFaces
95
96    void clearHbFonts() {
97        for (size_t i = 0; i < hbFonts.size(); i++) {
98            hb_font_destroy(hbFonts[i]);
99        }
100        hbFonts.clear();
101    }
102};
103
104// Layout cache datatypes
105
106class LayoutCacheKey {
107public:
108    LayoutCacheKey(const FontCollection* collection, const MinikinPaint& paint, FontStyle style,
109            const uint16_t* chars, size_t start, size_t count, size_t nchars, bool dir)
110            : mChars(chars), mNchars(nchars),
111            mStart(start), mCount(count), mId(collection->getId()), mStyle(style),
112            mSize(paint.size), mScaleX(paint.scaleX), mSkewX(paint.skewX),
113            mLetterSpacing(paint.letterSpacing),
114            mPaintFlags(paint.paintFlags), mHyphenEdit(paint.hyphenEdit), mIsRtl(dir) {
115    }
116    bool operator==(const LayoutCacheKey &other) const;
117    hash_t hash() const;
118
119    void copyText() {
120        uint16_t* charsCopy = new uint16_t[mNchars];
121        memcpy(charsCopy, mChars, mNchars * sizeof(uint16_t));
122        mChars = charsCopy;
123    }
124    void freeText() {
125        delete[] mChars;
126        mChars = NULL;
127    }
128
129    void doLayout(Layout* layout, LayoutContext* ctx, const FontCollection* collection) const {
130        layout->setFontCollection(collection);
131        layout->mAdvances.resize(mCount, 0);
132        ctx->clearHbFonts();
133        layout->doLayoutRun(mChars, mStart, mCount, mNchars, mIsRtl, ctx);
134    }
135
136private:
137    const uint16_t* mChars;
138    size_t mNchars;
139    size_t mStart;
140    size_t mCount;
141    uint32_t mId;  // for the font collection
142    FontStyle mStyle;
143    float mSize;
144    float mScaleX;
145    float mSkewX;
146    float mLetterSpacing;
147    int32_t mPaintFlags;
148    HyphenEdit mHyphenEdit;
149    bool mIsRtl;
150    // Note: any fields added to MinikinPaint must also be reflected here.
151    // TODO: language matching (possibly integrate into style)
152};
153
154class LayoutCache : private OnEntryRemoved<LayoutCacheKey, Layout*> {
155public:
156    LayoutCache() : mCache(kMaxEntries) {
157        mCache.setOnEntryRemovedListener(this);
158    }
159
160    void clear() {
161        mCache.clear();
162    }
163
164    Layout* get(LayoutCacheKey& key, LayoutContext* ctx, const FontCollection* collection) {
165        Layout* layout = mCache.get(key);
166        if (layout == NULL) {
167            key.copyText();
168            layout = new Layout();
169            key.doLayout(layout, ctx, collection);
170            mCache.put(key, layout);
171        }
172        return layout;
173    }
174
175private:
176    // callback for OnEntryRemoved
177    void operator()(LayoutCacheKey& key, Layout*& value) {
178        key.freeText();
179        delete value;
180    }
181
182    LruCache<LayoutCacheKey, Layout*> mCache;
183
184    //static const size_t kMaxEntries = LruCache<LayoutCacheKey, Layout*>::kUnlimitedCapacity;
185
186    // TODO: eviction based on memory footprint; for now, we just use a constant
187    // number of strings
188    static const size_t kMaxEntries = 5000;
189};
190
191class HbFaceCache : private OnEntryRemoved<int32_t, hb_face_t*> {
192public:
193    HbFaceCache() : mCache(kMaxEntries) {
194        mCache.setOnEntryRemovedListener(this);
195    }
196
197    // callback for OnEntryRemoved
198    void operator()(int32_t& key, hb_face_t*& value) {
199        hb_face_destroy(value);
200    }
201
202    LruCache<int32_t, hb_face_t*> mCache;
203private:
204    static const size_t kMaxEntries = 100;
205};
206
207static unsigned int disabledDecomposeCompatibility(hb_unicode_funcs_t*, hb_codepoint_t,
208                                                   hb_codepoint_t*, void*) {
209    return 0;
210}
211
212class LayoutEngine : public Singleton<LayoutEngine> {
213public:
214    LayoutEngine() {
215        unicodeFunctions = hb_unicode_funcs_create(hb_icu_get_unicode_funcs());
216        /* Disable the function used for compatibility decomposition */
217        hb_unicode_funcs_set_decompose_compatibility_func(
218                unicodeFunctions, disabledDecomposeCompatibility, NULL, NULL);
219        hbBuffer = hb_buffer_create();
220        hb_buffer_set_unicode_funcs(hbBuffer, unicodeFunctions);
221    }
222
223    hb_buffer_t* hbBuffer;
224    hb_unicode_funcs_t* unicodeFunctions;
225    LayoutCache layoutCache;
226    HbFaceCache hbFaceCache;
227};
228
229ANDROID_SINGLETON_STATIC_INSTANCE(LayoutEngine);
230
231bool LayoutCacheKey::operator==(const LayoutCacheKey& other) const {
232    return mId == other.mId
233            && mStart == other.mStart
234            && mCount == other.mCount
235            && mStyle == other.mStyle
236            && mSize == other.mSize
237            && mScaleX == other.mScaleX
238            && mSkewX == other.mSkewX
239            && mLetterSpacing == other.mLetterSpacing
240            && mPaintFlags == other.mPaintFlags
241            && mHyphenEdit == other.mHyphenEdit
242            && mIsRtl == other.mIsRtl
243            && mNchars == other.mNchars
244            && !memcmp(mChars, other.mChars, mNchars * sizeof(uint16_t));
245}
246
247hash_t LayoutCacheKey::hash() const {
248    uint32_t hash = JenkinsHashMix(0, mId);
249    hash = JenkinsHashMix(hash, mStart);
250    hash = JenkinsHashMix(hash, mCount);
251    hash = JenkinsHashMix(hash, hash_type(mStyle));
252    hash = JenkinsHashMix(hash, hash_type(mSize));
253    hash = JenkinsHashMix(hash, hash_type(mScaleX));
254    hash = JenkinsHashMix(hash, hash_type(mSkewX));
255    hash = JenkinsHashMix(hash, hash_type(mLetterSpacing));
256    hash = JenkinsHashMix(hash, hash_type(mPaintFlags));
257    hash = JenkinsHashMix(hash, hash_type(mHyphenEdit.hasHyphen()));
258    hash = JenkinsHashMix(hash, hash_type(mIsRtl));
259    hash = JenkinsHashMixShorts(hash, mChars, mNchars);
260    return JenkinsHashWhiten(hash);
261}
262
263hash_t hash_type(const LayoutCacheKey& key) {
264    return key.hash();
265}
266
267void MinikinRect::join(const MinikinRect& r) {
268    if (isEmpty()) {
269        set(r);
270    } else if (!r.isEmpty()) {
271        mLeft = std::min(mLeft, r.mLeft);
272        mTop = std::min(mTop, r.mTop);
273        mRight = std::max(mRight, r.mRight);
274        mBottom = std::max(mBottom, r.mBottom);
275    }
276}
277
278// Deprecated. Remove when callers are removed.
279void Layout::init() {
280}
281
282void Layout::reset() {
283    mGlyphs.clear();
284    mFaces.clear();
285    mBounds.setEmpty();
286    mAdvances.clear();
287    mAdvance = 0;
288}
289
290void Layout::setFontCollection(const FontCollection* collection) {
291    mCollection = collection;
292}
293
294hb_blob_t* referenceTable(hb_face_t* face, hb_tag_t tag, void* userData)  {
295    MinikinFont* font = reinterpret_cast<MinikinFont*>(userData);
296    size_t length = 0;
297    bool ok = font->GetTable(tag, NULL, &length);
298    if (!ok) {
299        return 0;
300    }
301    char* buffer = reinterpret_cast<char*>(malloc(length));
302    if (!buffer) {
303        return 0;
304    }
305    ok = font->GetTable(tag, reinterpret_cast<uint8_t*>(buffer), &length);
306#ifdef VERBOSE_DEBUG
307    ALOGD("referenceTable %c%c%c%c length=%d %d",
308        (tag >>24) & 0xff, (tag>>16)&0xff, (tag>>8)&0xff, tag&0xff, length, ok);
309#endif
310    if (!ok) {
311        free(buffer);
312        return 0;
313    }
314    return hb_blob_create(const_cast<char*>(buffer), length,
315        HB_MEMORY_MODE_WRITABLE, buffer, free);
316}
317
318static hb_position_t harfbuzzGetGlyphHorizontalAdvance(hb_font_t* hbFont, void* fontData, hb_codepoint_t glyph, void* userData)
319{
320    MinikinPaint* paint = reinterpret_cast<MinikinPaint*>(fontData);
321    MinikinFont* font = paint->font;
322    float advance = font->GetHorizontalAdvance(glyph, *paint);
323    return 256 * advance + 0.5;
324}
325
326static hb_bool_t harfbuzzGetGlyphHorizontalOrigin(hb_font_t* hbFont, void* fontData, hb_codepoint_t glyph, hb_position_t* x, hb_position_t* y, void* userData)
327{
328    // Just return true, following the way that Harfbuzz-FreeType
329    // implementation does.
330    return true;
331}
332
333hb_font_funcs_t* getHbFontFuncs() {
334    static hb_font_funcs_t* hbFontFuncs = 0;
335
336    if (hbFontFuncs == 0) {
337        hbFontFuncs = hb_font_funcs_create();
338        hb_font_funcs_set_glyph_h_advance_func(hbFontFuncs, harfbuzzGetGlyphHorizontalAdvance, 0, 0);
339        hb_font_funcs_set_glyph_h_origin_func(hbFontFuncs, harfbuzzGetGlyphHorizontalOrigin, 0, 0);
340        hb_font_funcs_make_immutable(hbFontFuncs);
341    }
342    return hbFontFuncs;
343}
344
345static hb_face_t* getHbFace(MinikinFont* minikinFont) {
346    HbFaceCache& cache = LayoutEngine::getInstance().hbFaceCache;
347    int32_t fontId = minikinFont->GetUniqueId();
348    hb_face_t* face = cache.mCache.get(fontId);
349    if (face == NULL) {
350        face = hb_face_create_for_tables(referenceTable, minikinFont, NULL);
351        cache.mCache.put(fontId, face);
352    }
353    return face;
354}
355
356static hb_font_t* create_hb_font(MinikinFont* minikinFont, MinikinPaint* minikinPaint) {
357    hb_face_t* face = getHbFace(minikinFont);
358    hb_font_t* parent_font = hb_font_create(face);
359    hb_ot_font_set_funcs(parent_font);
360
361    unsigned int upem = hb_face_get_upem(face);
362    hb_font_set_scale(parent_font, upem, upem);
363
364    hb_font_t* font = hb_font_create_sub_font(parent_font);
365    hb_font_destroy(parent_font);
366
367    hb_font_set_funcs(font, getHbFontFuncs(), minikinPaint, 0);
368    return font;
369}
370
371static float HBFixedToFloat(hb_position_t v)
372{
373    return scalbnf (v, -8);
374}
375
376static hb_position_t HBFloatToFixed(float v)
377{
378    return scalbnf (v, +8);
379}
380
381void Layout::dump() const {
382    for (size_t i = 0; i < mGlyphs.size(); i++) {
383        const LayoutGlyph& glyph = mGlyphs[i];
384        std::cout << glyph.glyph_id << ": " << glyph.x << ", " << glyph.y << std::endl;
385    }
386}
387
388int Layout::findFace(FakedFont face, LayoutContext* ctx) {
389    unsigned int ix;
390    for (ix = 0; ix < mFaces.size(); ix++) {
391        if (mFaces[ix].font == face.font) {
392            return ix;
393        }
394    }
395    mFaces.push_back(face);
396    // Note: ctx == NULL means we're copying from the cache, no need to create
397    // corresponding hb_font object.
398    if (ctx != NULL) {
399        hb_font_t* font = create_hb_font(face.font, &ctx->paint);
400        ctx->hbFonts.push_back(font);
401    }
402    return ix;
403}
404
405static hb_script_t codePointToScript(hb_codepoint_t codepoint) {
406    static hb_unicode_funcs_t* u = 0;
407    if (!u) {
408        u = LayoutEngine::getInstance().unicodeFunctions;
409    }
410    return hb_unicode_script(u, codepoint);
411}
412
413static hb_codepoint_t decodeUtf16(const uint16_t* chars, size_t len, ssize_t* iter) {
414    const uint16_t v = chars[(*iter)++];
415    // test whether v in (0xd800..0xdfff), lead or trail surrogate
416    if ((v & 0xf800) == 0xd800) {
417        // test whether v in (0xd800..0xdbff), lead surrogate
418        if (size_t(*iter) < len && (v & 0xfc00) == 0xd800) {
419            const uint16_t v2 = chars[(*iter)++];
420            // test whether v2 in (0xdc00..0xdfff), trail surrogate
421            if ((v2 & 0xfc00) == 0xdc00) {
422                // (0xd800 0xdc00) in utf-16 maps to 0x10000 in ucs-32
423                const hb_codepoint_t delta = (0xd800 << 10) + 0xdc00 - 0x10000;
424                return (((hb_codepoint_t)v) << 10) + v2 - delta;
425            }
426            (*iter) -= 1;
427            return 0xFFFDu;
428        } else {
429            return 0xFFFDu;
430        }
431    } else {
432        return v;
433    }
434}
435
436static hb_script_t getScriptRun(const uint16_t* chars, size_t len, ssize_t* iter) {
437    if (size_t(*iter) == len) {
438        return HB_SCRIPT_UNKNOWN;
439    }
440    uint32_t cp = decodeUtf16(chars, len, iter);
441    hb_script_t current_script = codePointToScript(cp);
442    for (;;) {
443        if (size_t(*iter) == len)
444            break;
445        const ssize_t prev_iter = *iter;
446        cp = decodeUtf16(chars, len, iter);
447        const hb_script_t script = codePointToScript(cp);
448        if (script != current_script) {
449            if (current_script == HB_SCRIPT_INHERITED ||
450                current_script == HB_SCRIPT_COMMON) {
451                current_script = script;
452            } else if (script == HB_SCRIPT_INHERITED ||
453                script == HB_SCRIPT_COMMON) {
454                continue;
455            } else {
456                *iter = prev_iter;
457                break;
458            }
459        }
460    }
461    if (current_script == HB_SCRIPT_INHERITED) {
462        current_script = HB_SCRIPT_COMMON;
463    }
464
465    return current_script;
466}
467
468/**
469 * Disable certain scripts (mostly those with cursive connection) from having letterspacing
470 * applied. See https://github.com/behdad/harfbuzz/issues/64 for more details.
471 */
472static bool isScriptOkForLetterspacing(hb_script_t script) {
473    return !(
474            script == HB_SCRIPT_ARABIC ||
475            script == HB_SCRIPT_NKO ||
476            script == HB_SCRIPT_PSALTER_PAHLAVI ||
477            script == HB_SCRIPT_MANDAIC ||
478            script == HB_SCRIPT_MONGOLIAN ||
479            script == HB_SCRIPT_PHAGS_PA ||
480            script == HB_SCRIPT_DEVANAGARI ||
481            script == HB_SCRIPT_BENGALI ||
482            script == HB_SCRIPT_GURMUKHI ||
483            script == HB_SCRIPT_MODI ||
484            script == HB_SCRIPT_SHARADA ||
485            script == HB_SCRIPT_SYLOTI_NAGRI ||
486            script == HB_SCRIPT_TIRHUTA ||
487            script == HB_SCRIPT_OGHAM
488            );
489}
490
491void Layout::doLayout(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
492        int bidiFlags, const FontStyle &style, const MinikinPaint &paint) {
493    AutoMutex _l(gMinikinLock);
494
495    LayoutContext ctx;
496    ctx.style = style;
497    ctx.paint = paint;
498
499    bool isRtl = (bidiFlags & kDirection_Mask) != 0;
500    bool doSingleRun = true;
501
502    reset();
503    mAdvances.resize(count, 0);
504
505    if (!(bidiFlags == kBidi_Force_LTR || bidiFlags == kBidi_Force_RTL)) {
506        UBiDi* bidi = ubidi_open();
507        if (bidi) {
508            UErrorCode status = U_ZERO_ERROR;
509            UBiDiLevel bidiReq = bidiFlags;
510            if (bidiFlags == kBidi_Default_LTR) {
511                bidiReq = UBIDI_DEFAULT_LTR;
512            } else if (bidiFlags == kBidi_Default_RTL) {
513                bidiReq = UBIDI_DEFAULT_RTL;
514            }
515            ubidi_setPara(bidi, buf, bufSize, bidiReq, NULL, &status);
516            if (U_SUCCESS(status)) {
517                int paraDir = ubidi_getParaLevel(bidi) & kDirection_Mask;
518                ssize_t rc = ubidi_countRuns(bidi, &status);
519                if (!U_SUCCESS(status) || rc < 0) {
520                    ALOGW("error counting bidi runs, status = %d", status);
521                }
522                if (!U_SUCCESS(status) || rc <= 1) {
523                    isRtl = (paraDir == kBidi_RTL);
524                } else {
525                    doSingleRun = false;
526                    // iterate through runs
527                    for (ssize_t i = 0; i < (ssize_t)rc; i++) {
528                        int32_t startRun = -1;
529                        int32_t lengthRun = -1;
530                        UBiDiDirection runDir = ubidi_getVisualRun(bidi, i, &startRun, &lengthRun);
531                        if (startRun == -1 || lengthRun == -1) {
532                            ALOGE("invalid visual run");
533                            // skip the invalid run
534                            continue;
535                        }
536                        int32_t endRun = std::min(startRun + lengthRun, int32_t(start + count));
537                        startRun = std::max(startRun, int32_t(start));
538                        lengthRun = endRun - startRun;
539                        if (lengthRun > 0) {
540                            isRtl = (runDir == UBIDI_RTL);
541                            doLayoutRunCached(buf, startRun, lengthRun, bufSize, isRtl, &ctx,
542                                start);
543                        }
544                    }
545                }
546            } else {
547                ALOGE("error calling ubidi_setPara, status = %d", status);
548            }
549            ubidi_close(bidi);
550        } else {
551            ALOGE("error creating bidi object");
552        }
553    }
554    if (doSingleRun) {
555        doLayoutRunCached(buf, start, count, bufSize, isRtl, &ctx, start);
556    }
557    ctx.clearHbFonts();
558}
559
560void Layout::doLayoutRunCached(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
561        bool isRtl, LayoutContext* ctx, size_t dstStart) {
562    HyphenEdit hyphen = ctx->paint.hyphenEdit;
563    if (!isRtl) {
564        // left to right
565        size_t wordstart =
566                start == bufSize ? start : getPrevWordBreakForCache(buf, start + 1, bufSize);
567        size_t wordend;
568        for (size_t iter = start; iter < start + count; iter = wordend) {
569            wordend = getNextWordBreakForCache(buf, iter, bufSize);
570            // Only apply hyphen to the last word in the string.
571            ctx->paint.hyphenEdit = wordend >= start + count ? hyphen : HyphenEdit();
572            size_t wordcount = std::min(start + count, wordend) - iter;
573            doLayoutWord(buf + wordstart, iter - wordstart, wordcount, wordend - wordstart,
574                    isRtl, ctx, iter - dstStart);
575            wordstart = wordend;
576        }
577    } else {
578        // right to left
579        size_t wordstart;
580        size_t end = start + count;
581        size_t wordend = end == 0 ? 0 : getNextWordBreakForCache(buf, end - 1, bufSize);
582        for (size_t iter = end; iter > start; iter = wordstart) {
583            wordstart = getPrevWordBreakForCache(buf, iter, bufSize);
584            // Only apply hyphen to the last (leftmost) word in the string.
585            ctx->paint.hyphenEdit = iter == end ? hyphen : HyphenEdit();
586            size_t bufStart = std::max(start, wordstart);
587            doLayoutWord(buf + wordstart, bufStart - wordstart, iter - bufStart,
588                    wordend - wordstart, isRtl, ctx, bufStart - dstStart);
589            wordend = wordstart;
590        }
591    }
592}
593
594void Layout::doLayoutWord(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
595        bool isRtl, LayoutContext* ctx, size_t bufStart) {
596    LayoutCache& cache = LayoutEngine::getInstance().layoutCache;
597    LayoutCacheKey key(mCollection, ctx->paint, ctx->style, buf, start, count, bufSize, isRtl);
598    bool skipCache = ctx->paint.skipCache();
599    if (skipCache) {
600        Layout layout;
601        key.doLayout(&layout, ctx, mCollection);
602        appendLayout(&layout, bufStart);
603    } else {
604        Layout* layout = cache.get(key, ctx, mCollection);
605        appendLayout(layout, bufStart);
606    }
607}
608
609static void addFeatures(const string &str, vector<hb_feature_t>* features) {
610    if (!str.size())
611        return;
612
613    const char* start = str.c_str();
614    const char* end = start + str.size();
615
616    while (start < end) {
617        static hb_feature_t feature;
618        const char* p = strchr(start, ',');
619        if (!p)
620            p = end;
621        /* We do not allow setting features on ranges.  As such, reject any
622         * setting that has non-universal range. */
623        if (hb_feature_from_string (start, p - start, &feature)
624                && feature.start == 0 && feature.end == (unsigned int) -1)
625            features->push_back(feature);
626        start = p + 1;
627    }
628}
629
630void Layout::doLayoutRun(const uint16_t* buf, size_t start, size_t count, size_t bufSize,
631        bool isRtl, LayoutContext* ctx) {
632    hb_buffer_t* buffer = LayoutEngine::getInstance().hbBuffer;
633    vector<FontCollection::Run> items;
634    mCollection->itemize(buf + start, count, ctx->style, &items);
635    if (isRtl) {
636        std::reverse(items.begin(), items.end());
637    }
638
639    vector<hb_feature_t> features;
640    // Disable default-on non-required ligature features if letter-spacing
641    // See http://dev.w3.org/csswg/css-text-3/#letter-spacing-property
642    // "When the effective spacing between two characters is not zero (due to
643    // either justification or a non-zero value of letter-spacing), user agents
644    // should not apply optional ligatures."
645    if (fabs(ctx->paint.letterSpacing) > 0.03)
646    {
647        static const hb_feature_t no_liga = { HB_TAG('l', 'i', 'g', 'a'), 0, 0, ~0u };
648        static const hb_feature_t no_clig = { HB_TAG('c', 'l', 'i', 'g'), 0, 0, ~0u };
649        features.push_back(no_liga);
650        features.push_back(no_clig);
651    }
652    addFeatures(ctx->paint.fontFeatureSettings, &features);
653
654    double size = ctx->paint.size;
655    double scaleX = ctx->paint.scaleX;
656
657    float x = mAdvance;
658    float y = 0;
659    for (size_t run_ix = 0; run_ix < items.size(); run_ix++) {
660        FontCollection::Run &run = items[run_ix];
661        if (run.fakedFont.font == NULL) {
662            ALOGE("no font for run starting u+%04x length %d", buf[run.start], run.end - run.start);
663            continue;
664        }
665        int font_ix = findFace(run.fakedFont, ctx);
666        ctx->paint.font = mFaces[font_ix].font;
667        ctx->paint.fakery = mFaces[font_ix].fakery;
668        hb_font_t* hbFont = ctx->hbFonts[font_ix];
669#ifdef VERBOSE_DEBUG
670        ALOGD("Run %u, font %d [%d:%d]", run_ix, font_ix, run.start, run.end);
671#endif
672
673        hb_font_set_ppem(hbFont, size * scaleX, size);
674        hb_font_set_scale(hbFont, HBFloatToFixed(size * scaleX), HBFloatToFixed(size));
675
676        // TODO: if there are multiple scripts within a font in an RTL run,
677        // we need to reorder those runs. This is unlikely with our current
678        // font stack, but should be done for correctness.
679        ssize_t srunend;
680        for (ssize_t srunstart = run.start; srunstart < run.end; srunstart = srunend) {
681            srunend = srunstart;
682            hb_script_t script = getScriptRun(buf + start, run.end, &srunend);
683
684            double letterSpace = 0.0;
685            double letterSpaceHalfLeft = 0.0;
686            double letterSpaceHalfRight = 0.0;
687
688            if (ctx->paint.letterSpacing != 0.0 && isScriptOkForLetterspacing(script)) {
689                letterSpace = ctx->paint.letterSpacing * size * scaleX;
690                if ((ctx->paint.paintFlags & LinearTextFlag) == 0) {
691                    letterSpace = round(letterSpace);
692                    letterSpaceHalfLeft = floor(letterSpace * 0.5);
693                } else {
694                    letterSpaceHalfLeft = letterSpace * 0.5;
695                }
696                letterSpaceHalfRight = letterSpace - letterSpaceHalfLeft;
697            }
698
699            hb_buffer_clear_contents(buffer);
700            hb_buffer_set_script(buffer, script);
701            hb_buffer_set_direction(buffer, isRtl? HB_DIRECTION_RTL : HB_DIRECTION_LTR);
702            FontLanguage language = ctx->style.getLanguage();
703            if (language) {
704                string lang = language.getString();
705                hb_buffer_set_language(buffer, hb_language_from_string(lang.c_str(), -1));
706            }
707            hb_buffer_add_utf16(buffer, buf, bufSize, srunstart + start, srunend - srunstart);
708            if (ctx->paint.hyphenEdit.hasHyphen() && srunend > srunstart) {
709                // TODO: check whether this is really the desired semantics. It could have the
710                // effect of assigning the hyphen width to a nonspacing mark
711                unsigned int lastCluster = start + srunend - 1;
712
713                hb_codepoint_t hyphenChar = 0x2010; // HYPHEN
714                hb_codepoint_t glyph;
715                // Fallback to ASCII HYPHEN-MINUS if the font didn't have a glyph for HYPHEN. Note
716                // that we intentionally don't do anything special if the font doesn't have a
717                // HYPHEN-MINUS either, so a tofu could be shown, hinting towards something
718                // missing.
719                if (!hb_font_get_glyph(hbFont, hyphenChar, 0, &glyph)) {
720                    hyphenChar = 0x002D; // HYPHEN-MINUS
721                }
722                hb_buffer_add(buffer, hyphenChar, lastCluster);
723            }
724            hb_shape(hbFont, buffer, features.empty() ? NULL : &features[0], features.size());
725            unsigned int numGlyphs;
726            hb_glyph_info_t* info = hb_buffer_get_glyph_infos(buffer, &numGlyphs);
727            hb_glyph_position_t* positions = hb_buffer_get_glyph_positions(buffer, NULL);
728            if (numGlyphs)
729            {
730                mAdvances[info[0].cluster - start] += letterSpaceHalfLeft;
731                x += letterSpaceHalfLeft;
732            }
733            for (unsigned int i = 0; i < numGlyphs; i++) {
734#ifdef VERBOSE_DEBUG
735                ALOGD("%d %d %d %d",
736                        positions[i].x_advance, positions[i].y_advance,
737                        positions[i].x_offset, positions[i].y_offset);
738                ALOGD("DoLayout %u: %f; %d, %d",
739                        info[i].codepoint, HBFixedToFloat(positions[i].x_advance),
740                        positions[i].x_offset, positions[i].y_offset);
741#endif
742                if (i > 0 && info[i - 1].cluster != info[i].cluster) {
743                    mAdvances[info[i - 1].cluster - start] += letterSpaceHalfRight;
744                    mAdvances[info[i].cluster - start] += letterSpaceHalfLeft;
745                    x += letterSpace;
746                }
747
748                hb_codepoint_t glyph_ix = info[i].codepoint;
749                float xoff = HBFixedToFloat(positions[i].x_offset);
750                float yoff = -HBFixedToFloat(positions[i].y_offset);
751                xoff += yoff * ctx->paint.skewX;
752                LayoutGlyph glyph = {font_ix, glyph_ix, x + xoff, y + yoff};
753                mGlyphs.push_back(glyph);
754                float xAdvance = HBFixedToFloat(positions[i].x_advance);
755                if ((ctx->paint.paintFlags & LinearTextFlag) == 0) {
756                    xAdvance = roundf(xAdvance);
757                }
758                MinikinRect glyphBounds;
759                ctx->paint.font->GetBounds(&glyphBounds, glyph_ix, ctx->paint);
760                glyphBounds.offset(x + xoff, y + yoff);
761                mBounds.join(glyphBounds);
762                if (info[i].cluster - start < count) {
763                    mAdvances[info[i].cluster - start] += xAdvance;
764                } else {
765                    ALOGE("cluster %d (start %d) out of bounds of count %d",
766                        info[i].cluster - start, start, count);
767                }
768                x += xAdvance;
769            }
770            if (numGlyphs)
771            {
772                mAdvances[info[numGlyphs - 1].cluster - start] += letterSpaceHalfRight;
773                x += letterSpaceHalfRight;
774            }
775        }
776    }
777    mAdvance = x;
778}
779
780void Layout::appendLayout(Layout* src, size_t start) {
781    int fontMapStack[16];
782    int* fontMap;
783    if (src->mFaces.size() < sizeof(fontMapStack) / sizeof(fontMapStack[0])) {
784        fontMap = fontMapStack;
785    } else {
786        fontMap = new int[src->mFaces.size()];
787    }
788    for (size_t i = 0; i < src->mFaces.size(); i++) {
789        int font_ix = findFace(src->mFaces[i], NULL);
790        fontMap[i] = font_ix;
791    }
792    int x0 = mAdvance;
793    for (size_t i = 0; i < src->mGlyphs.size(); i++) {
794        LayoutGlyph& srcGlyph = src->mGlyphs[i];
795        int font_ix = fontMap[srcGlyph.font_ix];
796        unsigned int glyph_id = srcGlyph.glyph_id;
797        float x = x0 + srcGlyph.x;
798        float y = srcGlyph.y;
799        LayoutGlyph glyph = {font_ix, glyph_id, x, y};
800        mGlyphs.push_back(glyph);
801    }
802    for (size_t i = 0; i < src->mAdvances.size(); i++) {
803        mAdvances[i + start] = src->mAdvances[i];
804    }
805    MinikinRect srcBounds(src->mBounds);
806    srcBounds.offset(x0, 0);
807    mBounds.join(srcBounds);
808    mAdvance += src->mAdvance;
809
810    if (fontMap != fontMapStack) {
811        delete[] fontMap;
812    }
813}
814
815void Layout::draw(minikin::Bitmap* surface, int x0, int y0, float size) const {
816    /*
817    TODO: redo as MinikinPaint settings
818    if (mProps.hasTag(minikinHinting)) {
819        int hintflags = mProps.value(minikinHinting).getIntValue();
820        if (hintflags & 1) load_flags |= FT_LOAD_NO_HINTING;
821        if (hintflags & 2) load_flags |= FT_LOAD_NO_AUTOHINT;
822    }
823    */
824    for (size_t i = 0; i < mGlyphs.size(); i++) {
825        const LayoutGlyph& glyph = mGlyphs[i];
826        MinikinFont* mf = mFaces[glyph.font_ix].font;
827        MinikinFontFreeType* face = static_cast<MinikinFontFreeType*>(mf);
828        GlyphBitmap glyphBitmap;
829        MinikinPaint paint;
830        paint.size = size;
831        bool ok = face->Render(glyph.glyph_id, paint, &glyphBitmap);
832#ifdef VERBOSE_DEBUG
833        ALOGD("glyphBitmap.width=%d, glyphBitmap.height=%d (%d, %d) x=%f, y=%f, ok=%d",
834            glyphBitmap.width, glyphBitmap.height, glyphBitmap.left, glyphBitmap.top, glyph.x, glyph.y, ok);
835#endif
836        if (ok) {
837            surface->drawGlyph(glyphBitmap,
838                x0 + int(floor(glyph.x + 0.5)), y0 + int(floor(glyph.y + 0.5)));
839        }
840    }
841}
842
843size_t Layout::nGlyphs() const {
844    return mGlyphs.size();
845}
846
847MinikinFont* Layout::getFont(int i) const {
848    const LayoutGlyph& glyph = mGlyphs[i];
849    return mFaces[glyph.font_ix].font;
850}
851
852FontFakery Layout::getFakery(int i) const {
853    const LayoutGlyph& glyph = mGlyphs[i];
854    return mFaces[glyph.font_ix].fakery;
855}
856
857unsigned int Layout::getGlyphId(int i) const {
858    const LayoutGlyph& glyph = mGlyphs[i];
859    return glyph.glyph_id;
860}
861
862float Layout::getX(int i) const {
863    const LayoutGlyph& glyph = mGlyphs[i];
864    return glyph.x;
865}
866
867float Layout::getY(int i) const {
868    const LayoutGlyph& glyph = mGlyphs[i];
869    return glyph.y;
870}
871
872float Layout::getAdvance() const {
873    return mAdvance;
874}
875
876void Layout::getAdvances(float* advances) {
877    memcpy(advances, &mAdvances[0], mAdvances.size() * sizeof(float));
878}
879
880void Layout::getBounds(MinikinRect* bounds) {
881    bounds->set(mBounds);
882}
883
884void Layout::purgeCaches() {
885    AutoMutex _l(gMinikinLock);
886    LayoutCache& layoutCache = LayoutEngine::getInstance().layoutCache;
887    layoutCache.clear();
888    HbFaceCache& hbCache = LayoutEngine::getInstance().hbFaceCache;
889    hbCache.mCache.clear();
890}
891
892}  // namespace android
893