blob: 8f09de1527bd3bfa29c4a05c844cfc1120393f6d [file] [log] [blame]
/*
* Copyright 2016 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "include/core/SkFont.h"
#include "include/core/SkFontArguments.h"
#include "include/core/SkFontMetrics.h"
#include "include/core/SkFontMgr.h"
#include "include/core/SkFontTypes.h"
#include "include/core/SkPaint.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/core/SkScalar.h"
#include "include/core/SkSpan.h"
#include "include/core/SkStream.h"
#include "include/core/SkTypeface.h"
#include "include/core/SkTypes.h"
#include "include/private/SkBitmaskEnum.h"
#include "include/private/base/SkTArray.h"
#include "include/private/base/SkTypeTraits.h"
#include "include/private/base/SkMalloc.h"
#include "include/private/base/SkMutex.h"
#include "include/private/base/SkTFitsIn.h"
#include "include/private/base/SkTo.h"
#include "modules/skshaper/include/SkShaper.h"
#include "modules/skunicode/include/SkUnicode.h"
#include "src/base/SkTDPQueue.h"
#include "src/base/SkUTF.h"
#include "src/core/SkLRUCache.h"
#include <hb.h>
#include <hb-ot.h>
#include <cstring>
#include <locale>
#include <memory>
#include <type_traits>
#include <utility>
using namespace skia_private;
// HB_FEATURE_GLOBAL_START and HB_FEATURE_GLOBAL_END were not added until HarfBuzz 2.0
// They would have always worked, they just hadn't been named yet.
#if !defined(HB_FEATURE_GLOBAL_START)
# define HB_FEATURE_GLOBAL_START 0
#endif
#if !defined(HB_FEATURE_GLOBAL_END)
# define HB_FEATURE_GLOBAL_END ((unsigned int) -1)
#endif
namespace sknonstd {
template <> struct is_bitmask_enum<hb_buffer_flags_t> : std::true_type {};
} // namespace sknonstd
namespace {
using HBBlob = std::unique_ptr<hb_blob_t , SkFunctionObject<hb_blob_destroy> >;
using HBFace = std::unique_ptr<hb_face_t , SkFunctionObject<hb_face_destroy> >;
using HBFont = std::unique_ptr<hb_font_t , SkFunctionObject<hb_font_destroy> >;
using HBBuffer = std::unique_ptr<hb_buffer_t, SkFunctionObject<hb_buffer_destroy>>;
using SkUnicodeBidi = std::unique_ptr<SkBidiIterator>;
using SkUnicodeBreak = std::unique_ptr<SkBreakIterator>;
hb_position_t skhb_position(SkScalar value) {
// Treat HarfBuzz hb_position_t as 16.16 fixed-point.
constexpr int kHbPosition1 = 1 << 16;
return SkScalarRoundToInt(value * kHbPosition1);
}
hb_bool_t skhb_glyph(hb_font_t* hb_font,
void* font_data,
hb_codepoint_t unicode,
hb_codepoint_t variation_selector,
hb_codepoint_t* glyph,
void* user_data) {
SkFont& font = *reinterpret_cast<SkFont*>(font_data);
*glyph = font.unicharToGlyph(unicode);
return *glyph != 0;
}
hb_bool_t skhb_nominal_glyph(hb_font_t* hb_font,
void* font_data,
hb_codepoint_t unicode,
hb_codepoint_t* glyph,
void* user_data) {
return skhb_glyph(hb_font, font_data, unicode, 0, glyph, user_data);
}
unsigned skhb_nominal_glyphs(hb_font_t *hb_font, void *font_data,
unsigned int count,
const hb_codepoint_t *unicodes,
unsigned int unicode_stride,
hb_codepoint_t *glyphs,
unsigned int glyph_stride,
void *user_data) {
SkFont& font = *reinterpret_cast<SkFont*>(font_data);
// Batch call textToGlyphs since entry cost is not cheap.
// Copy requred because textToGlyphs is dense and hb is strided.
AutoSTMalloc<256, SkUnichar> unicode(count);
for (unsigned i = 0; i < count; i++) {
unicode[i] = *unicodes;
unicodes = SkTAddOffset<const hb_codepoint_t>(unicodes, unicode_stride);
}
AutoSTMalloc<256, SkGlyphID> glyph(count);
font.textToGlyphs(unicode.get(), count * sizeof(SkUnichar), SkTextEncoding::kUTF32,
glyph.get(), count);
// Copy the results back to the sparse array.
unsigned int done;
for (done = 0; done < count && glyph[done] != 0; done++) {
*glyphs = glyph[done];
glyphs = SkTAddOffset<hb_codepoint_t>(glyphs, glyph_stride);
}
// return 'done' to allow HarfBuzz to synthesize with NFC and spaces, return 'count' to avoid
return done;
}
hb_position_t skhb_glyph_h_advance(hb_font_t* hb_font,
void* font_data,
hb_codepoint_t hbGlyph,
void* user_data) {
SkFont& font = *reinterpret_cast<SkFont*>(font_data);
SkScalar advance;
SkGlyphID skGlyph = SkTo<SkGlyphID>(hbGlyph);
font.getWidths(&skGlyph, 1, &advance);
if (!font.isSubpixel()) {
advance = SkScalarRoundToInt(advance);
}
return skhb_position(advance);
}
void skhb_glyph_h_advances(hb_font_t* hb_font,
void* font_data,
unsigned count,
const hb_codepoint_t* glyphs,
unsigned int glyph_stride,
hb_position_t* advances,
unsigned int advance_stride,
void* user_data) {
SkFont& font = *reinterpret_cast<SkFont*>(font_data);
// Batch call getWidths since entry cost is not cheap.
// Copy requred because getWidths is dense and hb is strided.
AutoSTMalloc<256, SkGlyphID> glyph(count);
for (unsigned i = 0; i < count; i++) {
glyph[i] = *glyphs;
glyphs = SkTAddOffset<const hb_codepoint_t>(glyphs, glyph_stride);
}
AutoSTMalloc<256, SkScalar> advance(count);
font.getWidths(glyph.get(), count, advance.get());
if (!font.isSubpixel()) {
for (unsigned i = 0; i < count; i++) {
advance[i] = SkScalarRoundToInt(advance[i]);
}
}
// Copy the results back to the sparse array.
for (unsigned i = 0; i < count; i++) {
*advances = skhb_position(advance[i]);
advances = SkTAddOffset<hb_position_t>(advances, advance_stride);
}
}
// HarfBuzz callback to retrieve glyph extents, mainly used by HarfBuzz for
// fallback mark positioning, i.e. the situation when the font does not have
// mark anchors or other mark positioning rules, but instead HarfBuzz is
// supposed to heuristically place combining marks around base glyphs. HarfBuzz
// does this by measuring "ink boxes" of glyphs, and placing them according to
// Unicode mark classes. Above, below, centered or left or right, etc.
hb_bool_t skhb_glyph_extents(hb_font_t* hb_font,
void* font_data,
hb_codepoint_t hbGlyph,
hb_glyph_extents_t* extents,
void* user_data) {
SkFont& font = *reinterpret_cast<SkFont*>(font_data);
SkASSERT(extents);
SkRect sk_bounds;
SkGlyphID skGlyph = SkTo<SkGlyphID>(hbGlyph);
font.getWidths(&skGlyph, 1, nullptr, &sk_bounds);
if (!font.isSubpixel()) {
sk_bounds.set(sk_bounds.roundOut());
}
// Skia is y-down but HarfBuzz is y-up.
extents->x_bearing = skhb_position(sk_bounds.fLeft);
extents->y_bearing = skhb_position(-sk_bounds.fTop);
extents->width = skhb_position(sk_bounds.width());
extents->height = skhb_position(-sk_bounds.height());
return true;
}
#define SK_HB_VERSION_CHECK(x, y, z) \
(HB_VERSION_MAJOR > (x)) || \
(HB_VERSION_MAJOR == (x) && HB_VERSION_MINOR > (y)) || \
(HB_VERSION_MAJOR == (x) && HB_VERSION_MINOR == (y) && HB_VERSION_MICRO >= (z))
hb_font_funcs_t* skhb_get_font_funcs() {
static hb_font_funcs_t* const funcs = []{
// HarfBuzz will use the default (parent) implementation if they aren't set.
hb_font_funcs_t* const funcs = hb_font_funcs_create();
hb_font_funcs_set_variation_glyph_func(funcs, skhb_glyph, nullptr, nullptr);
hb_font_funcs_set_nominal_glyph_func(funcs, skhb_nominal_glyph, nullptr, nullptr);
#if SK_HB_VERSION_CHECK(2, 0, 0)
hb_font_funcs_set_nominal_glyphs_func(funcs, skhb_nominal_glyphs, nullptr, nullptr);
#else
sk_ignore_unused_variable(skhb_nominal_glyphs);
#endif
hb_font_funcs_set_glyph_h_advance_func(funcs, skhb_glyph_h_advance, nullptr, nullptr);
#if SK_HB_VERSION_CHECK(1, 8, 6)
hb_font_funcs_set_glyph_h_advances_func(funcs, skhb_glyph_h_advances, nullptr, nullptr);
#else
sk_ignore_unused_variable(skhb_glyph_h_advances);
#endif
hb_font_funcs_set_glyph_extents_func(funcs, skhb_glyph_extents, nullptr, nullptr);
hb_font_funcs_make_immutable(funcs);
return funcs;
}();
SkASSERT(funcs);
return funcs;
}
hb_blob_t* skhb_get_table(hb_face_t* face, hb_tag_t tag, void* user_data) {
SkTypeface& typeface = *reinterpret_cast<SkTypeface*>(user_data);
auto data = typeface.copyTableData(tag);
if (!data) {
return nullptr;
}
SkData* rawData = data.release();
return hb_blob_create(reinterpret_cast<char*>(rawData->writable_data()), rawData->size(),
HB_MEMORY_MODE_READONLY, rawData, [](void* ctx) {
SkSafeUnref(((SkData*)ctx));
});
}
HBBlob stream_to_blob(std::unique_ptr<SkStreamAsset> asset) {
size_t size = asset->getLength();
HBBlob blob;
if (const void* base = asset->getMemoryBase()) {
blob.reset(hb_blob_create((char*)base, SkToUInt(size),
HB_MEMORY_MODE_READONLY, asset.release(),
[](void* p) { delete (SkStreamAsset*)p; }));
} else {
// SkDebugf("Extra SkStreamAsset copy\n");
void* ptr = size ? sk_malloc_throw(size) : nullptr;
asset->read(ptr, size);
blob.reset(hb_blob_create((char*)ptr, SkToUInt(size),
HB_MEMORY_MODE_READONLY, ptr, sk_free));
}
SkASSERT(blob);
hb_blob_make_immutable(blob.get());
return blob;
}
SkDEBUGCODE(static hb_user_data_key_t gDataIdKey;)
HBFace create_hb_face(const SkTypeface& typeface) {
int index = 0;
std::unique_ptr<SkStreamAsset> typefaceAsset = typeface.openExistingStream(&index);
HBFace face;
if (typefaceAsset && typefaceAsset->getMemoryBase()) {
HBBlob blob(stream_to_blob(std::move(typefaceAsset)));
// hb_face_create always succeeds. Check that the format is minimally recognized first.
// hb_face_create_for_tables may still create a working hb_face.
// See https://github.com/harfbuzz/harfbuzz/issues/248 .
unsigned int num_hb_faces = hb_face_count(blob.get());
if (0 < num_hb_faces && (unsigned)index < num_hb_faces) {
face.reset(hb_face_create(blob.get(), (unsigned)index));
// Check the number of glyphs as a basic sanitization step.
if (face && hb_face_get_glyph_count(face.get()) == 0) {
face.reset();
}
}
}
if (!face) {
face.reset(hb_face_create_for_tables(
skhb_get_table,
const_cast<SkTypeface*>(SkRef(&typeface)),
[](void* user_data){ SkSafeUnref(reinterpret_cast<SkTypeface*>(user_data)); }));
hb_face_set_index(face.get(), (unsigned)index);
}
SkASSERT(face);
if (!face) {
return nullptr;
}
hb_face_set_upem(face.get(), typeface.getUnitsPerEm());
SkDEBUGCODE(
hb_face_set_user_data(face.get(), &gDataIdKey, const_cast<SkTypeface*>(&typeface),
nullptr, false);
)
return face;
}
HBFont create_typeface_hb_font(const SkTypeface& typeface) {
HBFace face(create_hb_face(typeface));
if (!face) {
return nullptr;
}
HBFont otFont(hb_font_create(face.get()));
SkASSERT(otFont);
if (!otFont) {
return nullptr;
}
hb_ot_font_set_funcs(otFont.get());
int axis_count = typeface.getVariationDesignPosition(nullptr, 0);
if (axis_count > 0) {
AutoSTMalloc<4, SkFontArguments::VariationPosition::Coordinate> axis_values(axis_count);
if (typeface.getVariationDesignPosition(axis_values, axis_count) == axis_count) {
hb_font_set_variations(otFont.get(),
reinterpret_cast<hb_variation_t*>(axis_values.get()),
axis_count);
}
}
return otFont;
}
HBFont create_sub_hb_font(const SkFont& font, const HBFont& typefaceFont) {
SkDEBUGCODE(
hb_face_t* face = hb_font_get_face(typefaceFont.get());
void* dataId = hb_face_get_user_data(face, &gDataIdKey);
SkASSERT(dataId == font.getTypeface());
)
// Creating a sub font means that non-available functions
// are found from the parent.
HBFont skFont(hb_font_create_sub_font(typefaceFont.get()));
hb_font_set_funcs(skFont.get(), skhb_get_font_funcs(),
reinterpret_cast<void *>(new SkFont(font)),
[](void* user_data){ delete reinterpret_cast<SkFont*>(user_data); });
int scale = skhb_position(font.getSize());
hb_font_set_scale(skFont.get(), scale, scale);
return skFont;
}
/** Replaces invalid utf-8 sequences with REPLACEMENT CHARACTER U+FFFD. */
static inline SkUnichar utf8_next(const char** ptr, const char* end) {
SkUnichar val = SkUTF::NextUTF8(ptr, end);
return val < 0 ? 0xFFFD : val;
}
class SkUnicodeBidiRunIterator final : public SkShaper::BiDiRunIterator {
public:
SkUnicodeBidiRunIterator(const char* utf8, const char* end, SkUnicodeBidi bidi)
: fBidi(std::move(bidi))
, fEndOfCurrentRun(utf8)
, fBegin(utf8)
, fEnd(end)
, fUTF16LogicalPosition(0)
, fLevel(SkBidiIterator::kLTR)
{}
void consume() override {
SkASSERT(fUTF16LogicalPosition < fBidi->getLength());
int32_t endPosition = fBidi->getLength();
fLevel = fBidi->getLevelAt(fUTF16LogicalPosition);
SkUnichar u = utf8_next(&fEndOfCurrentRun, fEnd);
fUTF16LogicalPosition += SkUTF::ToUTF16(u);
SkBidiIterator::Level level;
while (fUTF16LogicalPosition < endPosition) {
level = fBidi->getLevelAt(fUTF16LogicalPosition);
if (level != fLevel) {
break;
}
u = utf8_next(&fEndOfCurrentRun, fEnd);
fUTF16LogicalPosition += SkUTF::ToUTF16(u);
}
}
size_t endOfCurrentRun() const override {
return fEndOfCurrentRun - fBegin;
}
bool atEnd() const override {
return fUTF16LogicalPosition == fBidi->getLength();
}
SkBidiIterator::Level currentLevel() const override {
return fLevel;
}
private:
SkUnicodeBidi fBidi;
char const * fEndOfCurrentRun;
char const * const fBegin;
char const * const fEnd;
int32_t fUTF16LogicalPosition;
SkBidiIterator::Level fLevel;
};
class SkUnicodeHbScriptRunIterator final: public SkShaper::ScriptRunIterator {
public:
SkUnicodeHbScriptRunIterator(const char* utf8,
size_t utf8Bytes,
hb_script_t defaultScript)
: fCurrent(utf8)
, fBegin(utf8)
, fEnd(fCurrent + utf8Bytes)
, fCurrentScript(defaultScript) {}
hb_script_t hb_script_for_unichar(SkUnichar u) {
return hb_unicode_script(hb_unicode_funcs_get_default(), u);
}
void consume() override {
SkASSERT(fCurrent < fEnd);
SkUnichar u = utf8_next(&fCurrent, fEnd);
fCurrentScript = hb_script_for_unichar(u);
while (fCurrent < fEnd) {
const char* prev = fCurrent;
u = utf8_next(&fCurrent, fEnd);
const hb_script_t script = hb_script_for_unichar(u);
if (script != fCurrentScript) {
if (fCurrentScript == HB_SCRIPT_INHERITED || fCurrentScript == HB_SCRIPT_COMMON) {
fCurrentScript = script;
} else if (script == HB_SCRIPT_INHERITED || script == HB_SCRIPT_COMMON) {
continue;
} else {
fCurrent = prev;
break;
}
}
}
if (fCurrentScript == HB_SCRIPT_INHERITED) {
fCurrentScript = HB_SCRIPT_COMMON;
}
}
size_t endOfCurrentRun() const override {
return fCurrent - fBegin;
}
bool atEnd() const override {
return fCurrent == fEnd;
}
SkFourByteTag currentScript() const override {
return SkSetFourByteTag(HB_UNTAG(fCurrentScript));
}
private:
char const * fCurrent;
char const * const fBegin;
char const * const fEnd;
hb_script_t fCurrentScript;
};
class RunIteratorQueue {
public:
void insert(SkShaper::RunIterator* runIterator, int priority) {
fEntries.insert({runIterator, priority});
}
bool advanceRuns() {
const SkShaper::RunIterator* leastRun = fEntries.peek().runIterator;
if (leastRun->atEnd()) {
SkASSERT(this->allRunsAreAtEnd());
return false;
}
const size_t leastEnd = leastRun->endOfCurrentRun();
SkShaper::RunIterator* currentRun = nullptr;
SkDEBUGCODE(size_t previousEndOfCurrentRun);
while ((currentRun = fEntries.peek().runIterator)->endOfCurrentRun() <= leastEnd) {
int priority = fEntries.peek().priority;
fEntries.pop();
SkDEBUGCODE(previousEndOfCurrentRun = currentRun->endOfCurrentRun());
currentRun->consume();
SkASSERT(previousEndOfCurrentRun < currentRun->endOfCurrentRun());
fEntries.insert({currentRun, priority});
}
return true;
}
size_t endOfCurrentRun() const {
return fEntries.peek().runIterator->endOfCurrentRun();
}
private:
bool allRunsAreAtEnd() const {
for (int i = 0; i < fEntries.count(); ++i) {
if (!fEntries.at(i).runIterator->atEnd()) {
return false;
}
}
return true;
}
struct Entry {
SkShaper::RunIterator* runIterator;
int priority;
};
static bool CompareEntry(Entry const& a, Entry const& b) {
size_t aEnd = a.runIterator->endOfCurrentRun();
size_t bEnd = b.runIterator->endOfCurrentRun();
return aEnd < bEnd || (aEnd == bEnd && a.priority < b.priority);
}
SkTDPQueue<Entry, CompareEntry> fEntries;
};
struct ShapedGlyph {
SkGlyphID fID;
uint32_t fCluster;
SkPoint fOffset;
SkVector fAdvance;
bool fMayLineBreakBefore;
bool fMustLineBreakBefore;
bool fHasVisual;
bool fGraphemeBreakBefore;
bool fUnsafeToBreak;
};
struct ShapedRun {
ShapedRun(SkShaper::RunHandler::Range utf8Range, const SkFont& font, SkBidiIterator::Level level,
std::unique_ptr<ShapedGlyph[]> glyphs, size_t numGlyphs, SkVector advance = {0, 0})
: fUtf8Range(utf8Range), fFont(font), fLevel(level)
, fGlyphs(std::move(glyphs)), fNumGlyphs(numGlyphs), fAdvance(advance)
{}
SkShaper::RunHandler::Range fUtf8Range;
SkFont fFont;
SkBidiIterator::Level fLevel;
std::unique_ptr<ShapedGlyph[]> fGlyphs;
size_t fNumGlyphs;
SkVector fAdvance;
static_assert(::sk_is_trivially_relocatable<decltype(fUtf8Range)>::value);
static_assert(::sk_is_trivially_relocatable<decltype(fFont)>::value);
static_assert(::sk_is_trivially_relocatable<decltype(fLevel)>::value);
static_assert(::sk_is_trivially_relocatable<decltype(fGlyphs)>::value);
static_assert(::sk_is_trivially_relocatable<decltype(fAdvance)>::value);
using sk_is_trivially_relocatable = std::true_type;
};
struct ShapedLine {
SkTArray<ShapedRun> runs;
SkVector fAdvance = { 0, 0 };
};
constexpr bool is_LTR(SkBidiIterator::Level level) {
return (level & 1) == 0;
}
void append(SkShaper::RunHandler* handler, const SkShaper::RunHandler::RunInfo& runInfo,
const ShapedRun& run, size_t startGlyphIndex, size_t endGlyphIndex) {
SkASSERT(startGlyphIndex <= endGlyphIndex);
const size_t glyphLen = endGlyphIndex - startGlyphIndex;
const auto buffer = handler->runBuffer(runInfo);
SkASSERT(buffer.glyphs);
SkASSERT(buffer.positions);
SkVector advance = {0,0};
for (size_t i = 0; i < glyphLen; i++) {
// Glyphs are in logical order, but output ltr since PDF readers seem to expect that.
const ShapedGlyph& glyph = run.fGlyphs[is_LTR(run.fLevel) ? startGlyphIndex + i
: endGlyphIndex - 1 - i];
buffer.glyphs[i] = glyph.fID;
if (buffer.offsets) {
buffer.positions[i] = advance + buffer.point;
buffer.offsets[i] = glyph.fOffset;
} else {
buffer.positions[i] = advance + buffer.point + glyph.fOffset;
}
if (buffer.clusters) {
buffer.clusters[i] = glyph.fCluster;
}
advance += glyph.fAdvance;
}
handler->commitRunBuffer(runInfo);
}
void emit(SkUnicode* unicode, const ShapedLine& line, SkShaper::RunHandler* handler) {
// Reorder the runs and glyphs per line and write them out.
handler->beginLine();
int numRuns = line.runs.size();
AutoSTMalloc<4, SkBidiIterator::Level> runLevels(numRuns);
for (int i = 0; i < numRuns; ++i) {
runLevels[i] = line.runs[i].fLevel;
}
AutoSTMalloc<4, int32_t> logicalFromVisual(numRuns);
unicode->reorderVisual(runLevels, numRuns, logicalFromVisual);
for (int i = 0; i < numRuns; ++i) {
int logicalIndex = logicalFromVisual[i];
const auto& run = line.runs[logicalIndex];
const SkShaper::RunHandler::RunInfo info = {
run.fFont,
run.fLevel,
run.fAdvance,
run.fNumGlyphs,
run.fUtf8Range
};
handler->runInfo(info);
}
handler->commitRunInfo();
for (int i = 0; i < numRuns; ++i) {
int logicalIndex = logicalFromVisual[i];
const auto& run = line.runs[logicalIndex];
const SkShaper::RunHandler::RunInfo info = {
run.fFont,
run.fLevel,
run.fAdvance,
run.fNumGlyphs,
run.fUtf8Range
};
append(handler, info, run, 0, run.fNumGlyphs);
}
handler->commitLine();
}
struct ShapedRunGlyphIterator {
ShapedRunGlyphIterator(const SkTArray<ShapedRun>& origRuns)
: fRuns(&origRuns), fRunIndex(0), fGlyphIndex(0)
{ }
ShapedRunGlyphIterator(const ShapedRunGlyphIterator& that) = default;
ShapedRunGlyphIterator& operator=(const ShapedRunGlyphIterator& that) = default;
bool operator==(const ShapedRunGlyphIterator& that) const {
return fRuns == that.fRuns &&
fRunIndex == that.fRunIndex &&
fGlyphIndex == that.fGlyphIndex;
}
bool operator!=(const ShapedRunGlyphIterator& that) const {
return fRuns != that.fRuns ||
fRunIndex != that.fRunIndex ||
fGlyphIndex != that.fGlyphIndex;
}
ShapedGlyph* next() {
const SkTArray<ShapedRun>& runs = *fRuns;
SkASSERT(fRunIndex < runs.size());
SkASSERT(fGlyphIndex < runs[fRunIndex].fNumGlyphs);
++fGlyphIndex;
if (fGlyphIndex == runs[fRunIndex].fNumGlyphs) {
fGlyphIndex = 0;
++fRunIndex;
if (fRunIndex >= runs.size()) {
return nullptr;
}
}
return &runs[fRunIndex].fGlyphs[fGlyphIndex];
}
ShapedGlyph* current() {
const SkTArray<ShapedRun>& runs = *fRuns;
if (fRunIndex >= runs.size()) {
return nullptr;
}
return &runs[fRunIndex].fGlyphs[fGlyphIndex];
}
const SkTArray<ShapedRun>* fRuns;
int fRunIndex;
size_t fGlyphIndex;
};
class ShaperHarfBuzz : public SkShaper {
public:
ShaperHarfBuzz(std::unique_ptr<SkUnicode>,
SkUnicodeBreak line,
SkUnicodeBreak grapheme,
HBBuffer,
sk_sp<SkFontMgr>);
protected:
std::unique_ptr<SkUnicode> fUnicode;
SkUnicodeBreak fLineBreakIterator;
SkUnicodeBreak fGraphemeBreakIterator;
ShapedRun shape(const char* utf8, size_t utf8Bytes,
const char* utf8Start,
const char* utf8End,
const BiDiRunIterator&,
const LanguageRunIterator&,
const ScriptRunIterator&,
const FontRunIterator&,
const Feature*, size_t featuresSize) const;
private:
const sk_sp<SkFontMgr> fFontMgr;
HBBuffer fBuffer;
hb_language_t fUndefinedLanguage;
void shape(const char* utf8, size_t utf8Bytes,
const SkFont&,
bool leftToRight,
SkScalar width,
RunHandler*) const override;
void shape(const char* utf8Text, size_t textBytes,
FontRunIterator&,
BiDiRunIterator&,
ScriptRunIterator&,
LanguageRunIterator&,
SkScalar width,
RunHandler*) const override;
void shape(const char* utf8Text, size_t textBytes,
FontRunIterator&,
BiDiRunIterator&,
ScriptRunIterator&,
LanguageRunIterator&,
const Feature*, size_t featuresSize,
SkScalar width,
RunHandler*) const override;
virtual void wrap(char const * const utf8, size_t utf8Bytes,
const BiDiRunIterator&,
const LanguageRunIterator&,
const ScriptRunIterator&,
const FontRunIterator&,
RunIteratorQueue& runSegmenter,
const Feature*, size_t featuresSize,
SkScalar width,
RunHandler*) const = 0;
};
class ShaperDrivenWrapper : public ShaperHarfBuzz {
public:
using ShaperHarfBuzz::ShaperHarfBuzz;
private:
void wrap(char const * const utf8, size_t utf8Bytes,
const BiDiRunIterator&,
const LanguageRunIterator&,
const ScriptRunIterator&,
const FontRunIterator&,
RunIteratorQueue& runSegmenter,
const Feature*, size_t featuresSize,
SkScalar width,
RunHandler*) const override;
};
class ShapeThenWrap : public ShaperHarfBuzz {
public:
using ShaperHarfBuzz::ShaperHarfBuzz;
private:
void wrap(char const * const utf8, size_t utf8Bytes,
const BiDiRunIterator&,
const LanguageRunIterator&,
const ScriptRunIterator&,
const FontRunIterator&,
RunIteratorQueue& runSegmenter,
const Feature*, size_t featuresSize,
SkScalar width,
RunHandler*) const override;
};
class ShapeDontWrapOrReorder : public ShaperHarfBuzz {
public:
using ShaperHarfBuzz::ShaperHarfBuzz;
private:
void wrap(char const * const utf8, size_t utf8Bytes,
const BiDiRunIterator&,
const LanguageRunIterator&,
const ScriptRunIterator&,
const FontRunIterator&,
RunIteratorQueue& runSegmenter,
const Feature*, size_t featuresSize,
SkScalar width,
RunHandler*) const override;
};
static std::unique_ptr<SkShaper> MakeHarfBuzz(sk_sp<SkFontMgr> fontmgr, bool correct) {
HBBuffer buffer(hb_buffer_create());
if (!buffer) {
SkDEBUGF("Could not create hb_buffer");
return nullptr;
}
auto unicode = SkUnicode::Make();
if (!unicode) {
return nullptr;
}
const auto lname = std::locale().name();
auto lineIter = unicode->makeBreakIterator(lname.c_str(), SkUnicode::BreakType::kLines);
if (!lineIter) {
return nullptr;
}
auto graphIter = unicode->makeBreakIterator(lname.c_str(), SkUnicode::BreakType::kGraphemes);
if (!graphIter) {
return nullptr;
}
if (correct) {
return std::make_unique<ShaperDrivenWrapper>(std::move(unicode),
std::move(lineIter), std::move(graphIter), std::move(buffer), std::move(fontmgr));
} else {
return std::make_unique<ShapeThenWrap>(std::move(unicode),
std::move(lineIter), std::move(graphIter), std::move(buffer), std::move(fontmgr));
}
}
ShaperHarfBuzz::ShaperHarfBuzz(std::unique_ptr<SkUnicode> unicode,
SkUnicodeBreak lineIter, SkUnicodeBreak graphIter, HBBuffer buffer, sk_sp<SkFontMgr> fontmgr)
: fUnicode(std::move(unicode))
, fLineBreakIterator(std::move(lineIter))
, fGraphemeBreakIterator(std::move(graphIter))
, fFontMgr(std::move(fontmgr))
, fBuffer(std::move(buffer))
, fUndefinedLanguage(hb_language_from_string("und", -1))
{ }
void ShaperHarfBuzz::shape(const char* utf8, size_t utf8Bytes,
const SkFont& srcFont,
bool leftToRight,
SkScalar width,
RunHandler* handler) const
{
SkBidiIterator::Level defaultLevel = leftToRight ? SkBidiIterator::kLTR : SkBidiIterator::kRTL;
std::unique_ptr<BiDiRunIterator> bidi(MakeSkUnicodeBidiRunIterator(fUnicode.get(),
utf8,
utf8Bytes,
defaultLevel));
if (!bidi) {
return;
}
std::unique_ptr<LanguageRunIterator> language(MakeStdLanguageRunIterator(utf8, utf8Bytes));
if (!language) {
return;
}
std::unique_ptr<ScriptRunIterator> script(MakeSkUnicodeHbScriptRunIterator(utf8, utf8Bytes));
if (!script) {
return;
}
std::unique_ptr<FontRunIterator> font(
MakeFontMgrRunIterator(utf8, utf8Bytes, srcFont,
fFontMgr ? fFontMgr : SkFontMgr::RefDefault()));
if (!font) {
return;
}
this->shape(utf8, utf8Bytes, *font, *bidi, *script, *language, width, handler);
}
void ShaperHarfBuzz::shape(const char* utf8, size_t utf8Bytes,
FontRunIterator& font,
BiDiRunIterator& bidi,
ScriptRunIterator& script,
LanguageRunIterator& language,
SkScalar width,
RunHandler* handler) const
{
this->shape(utf8, utf8Bytes, font, bidi, script, language, nullptr, 0, width, handler);
}
void ShaperHarfBuzz::shape(const char* utf8, size_t utf8Bytes,
FontRunIterator& font,
BiDiRunIterator& bidi,
ScriptRunIterator& script,
LanguageRunIterator& language,
const Feature* features, size_t featuresSize,
SkScalar width,
RunHandler* handler) const
{
SkASSERT(handler);
RunIteratorQueue runSegmenter;
runSegmenter.insert(&font, 3); // The font iterator is always run last in case of tie.
runSegmenter.insert(&bidi, 2);
runSegmenter.insert(&script, 1);
runSegmenter.insert(&language, 0);
this->wrap(utf8, utf8Bytes, bidi, language, script, font, runSegmenter,
features, featuresSize, width, handler);
}
void ShaperDrivenWrapper::wrap(char const * const utf8, size_t utf8Bytes,
const BiDiRunIterator& bidi,
const LanguageRunIterator& language,
const ScriptRunIterator& script,
const FontRunIterator& font,
RunIteratorQueue& runSegmenter,
const Feature* features, size_t featuresSize,
SkScalar width,
RunHandler* handler) const
{
ShapedLine line;
const char* utf8Start = nullptr;
const char* utf8End = utf8;
while (runSegmenter.advanceRuns()) { // For each item
utf8Start = utf8End;
utf8End = utf8 + runSegmenter.endOfCurrentRun();
ShapedRun model(RunHandler::Range(), SkFont(), 0, nullptr, 0);
bool modelNeedsRegenerated = true;
int modelGlyphOffset = 0;
struct TextProps {
int glyphLen = 0;
SkVector advance = {0, 0};
};
// map from character position to [safe to break, glyph position, advance]
std::unique_ptr<TextProps[]> modelText;
int modelTextOffset = 0;
SkVector modelAdvanceOffset = {0, 0};
while (utf8Start < utf8End) { // While there are still code points left in this item
size_t utf8runLength = utf8End - utf8Start;
if (modelNeedsRegenerated) {
model = shape(utf8, utf8Bytes,
utf8Start, utf8End,
bidi, language, script, font,
features, featuresSize);
modelGlyphOffset = 0;
SkVector advance = {0, 0};
modelText = std::make_unique<TextProps[]>(utf8runLength + 1);
size_t modelStartCluster = utf8Start - utf8;
size_t previousCluster = 0;
for (size_t i = 0; i < model.fNumGlyphs; ++i) {
SkASSERT(modelStartCluster <= model.fGlyphs[i].fCluster);
SkASSERT( model.fGlyphs[i].fCluster < (size_t)(utf8End - utf8));
if (!model.fGlyphs[i].fUnsafeToBreak) {
// Store up to the first glyph in the cluster.
size_t currentCluster = model.fGlyphs[i].fCluster - modelStartCluster;
if (previousCluster != currentCluster) {
previousCluster = currentCluster;
modelText[currentCluster].glyphLen = i;
modelText[currentCluster].advance = advance;
}
}
advance += model.fGlyphs[i].fAdvance;
}
// Assume it is always safe to break after the end of an item
modelText[utf8runLength].glyphLen = model.fNumGlyphs;
modelText[utf8runLength].advance = model.fAdvance;
modelTextOffset = 0;
modelAdvanceOffset = {0, 0};
modelNeedsRegenerated = false;
}
// TODO: break iterator per item, but just reset position if needed?
// Maybe break iterator with model?
if (!fLineBreakIterator->setText(utf8Start, utf8runLength)) {
return;
}
SkBreakIterator& breakIterator = *fLineBreakIterator;
ShapedRun best(RunHandler::Range(), SkFont(), 0, nullptr, 0,
{ SK_ScalarNegativeInfinity, SK_ScalarNegativeInfinity });
bool bestIsInvalid = true;
bool bestUsesModelForGlyphs = false;
SkScalar widthLeft = width - line.fAdvance.fX;
for (int32_t breakIteratorCurrent = breakIterator.next();
!breakIterator.isDone();
breakIteratorCurrent = breakIterator.next())
{
// TODO: if past a safe to break, future safe to break will be at least as long
// TODO: adjust breakIteratorCurrent by ignorable whitespace
bool candidateUsesModelForGlyphs = false;
ShapedRun candidate = [&](const TextProps& props){
if (props.glyphLen) {
candidateUsesModelForGlyphs = true;
return ShapedRun(RunHandler::Range(utf8Start - utf8, breakIteratorCurrent),
font.currentFont(), bidi.currentLevel(),
std::unique_ptr<ShapedGlyph[]>(),
props.glyphLen - modelGlyphOffset,
props.advance - modelAdvanceOffset);
} else {
return shape(utf8, utf8Bytes,
utf8Start, utf8Start + breakIteratorCurrent,
bidi, language, script, font,
features, featuresSize);
}
}(modelText[breakIteratorCurrent + modelTextOffset]);
auto score = [widthLeft](const ShapedRun& run) -> SkScalar {
if (run.fAdvance.fX < widthLeft) {
return run.fUtf8Range.size();
} else {
return widthLeft - run.fAdvance.fX;
}
};
if (bestIsInvalid || score(best) < score(candidate)) {
best = std::move(candidate);
bestIsInvalid = false;
bestUsesModelForGlyphs = candidateUsesModelForGlyphs;
}
}
// If nothing fit (best score is negative) and the line is not empty
if (width < line.fAdvance.fX + best.fAdvance.fX && !line.runs.empty()) {
emit(fUnicode.get(), line, handler);
line.runs.clear();
line.fAdvance = {0, 0};
} else {
if (bestUsesModelForGlyphs) {
best.fGlyphs = std::make_unique<ShapedGlyph[]>(best.fNumGlyphs);
memcpy(best.fGlyphs.get(), model.fGlyphs.get() + modelGlyphOffset,
best.fNumGlyphs * sizeof(ShapedGlyph));
modelGlyphOffset += best.fNumGlyphs;
modelTextOffset += best.fUtf8Range.size();
modelAdvanceOffset += best.fAdvance;
} else {
modelNeedsRegenerated = true;
}
utf8Start += best.fUtf8Range.size();
line.fAdvance += best.fAdvance;
line.runs.emplace_back(std::move(best));
// If item broken, emit line (prevent remainder from accidentally fitting)
if (utf8Start != utf8End) {
emit(fUnicode.get(), line, handler);
line.runs.clear();
line.fAdvance = {0, 0};
}
}
}
}
emit(fUnicode.get(), line, handler);
}
void ShapeThenWrap::wrap(char const * const utf8, size_t utf8Bytes,
const BiDiRunIterator& bidi,
const LanguageRunIterator& language,
const ScriptRunIterator& script,
const FontRunIterator& font,
RunIteratorQueue& runSegmenter,
const Feature* features, size_t featuresSize,
SkScalar width,
RunHandler* handler) const
{
SkTArray<ShapedRun> runs;
{
if (!fLineBreakIterator->setText(utf8, utf8Bytes)) {
return;
}
if (!fGraphemeBreakIterator->setText(utf8, utf8Bytes)) {
return;
}
SkBreakIterator& lineBreakIterator = *fLineBreakIterator;
SkBreakIterator& graphemeBreakIterator = *fGraphemeBreakIterator;
const char* utf8Start = nullptr;
const char* utf8End = utf8;
while (runSegmenter.advanceRuns()) {
utf8Start = utf8End;
utf8End = utf8 + runSegmenter.endOfCurrentRun();
runs.emplace_back(shape(utf8, utf8Bytes,
utf8Start, utf8End,
bidi, language, script, font,
features, featuresSize));
ShapedRun& run = runs.back();
uint32_t previousCluster = 0xFFFFFFFF;
for (size_t i = 0; i < run.fNumGlyphs; ++i) {
ShapedGlyph& glyph = run.fGlyphs[i];
int32_t glyphCluster = glyph.fCluster;
int32_t lineBreakIteratorCurrent = lineBreakIterator.current();
while (!lineBreakIterator.isDone() && lineBreakIteratorCurrent < glyphCluster)
{
lineBreakIteratorCurrent = lineBreakIterator.next();
}
glyph.fMayLineBreakBefore = glyph.fCluster != previousCluster &&
lineBreakIteratorCurrent == glyphCluster;
int32_t graphemeBreakIteratorCurrent = graphemeBreakIterator.current();
while (!graphemeBreakIterator.isDone() && graphemeBreakIteratorCurrent < glyphCluster)
{
graphemeBreakIteratorCurrent = graphemeBreakIterator.next();
}
glyph.fGraphemeBreakBefore = glyph.fCluster != previousCluster &&
graphemeBreakIteratorCurrent == glyphCluster;
previousCluster = glyph.fCluster;
}
}
}
// Iterate over the glyphs in logical order to find potential line lengths.
{
/** The position of the beginning of the line. */
ShapedRunGlyphIterator beginning(runs);
/** The position of the candidate line break. */
ShapedRunGlyphIterator candidateLineBreak(runs);
SkScalar candidateLineBreakWidth = 0;
/** The position of the candidate grapheme break. */
ShapedRunGlyphIterator candidateGraphemeBreak(runs);
SkScalar candidateGraphemeBreakWidth = 0;
/** The position of the current location. */
ShapedRunGlyphIterator current(runs);
SkScalar currentWidth = 0;
while (ShapedGlyph* glyph = current.current()) {
// 'Break' at graphemes until a line boundary, then only at line boundaries.
// Only break at graphemes if no line boundary is valid.
if (current != beginning) {
if (glyph->fGraphemeBreakBefore || glyph->fMayLineBreakBefore) {
// TODO: preserve line breaks <= grapheme breaks
// and prevent line breaks inside graphemes
candidateGraphemeBreak = current;
candidateGraphemeBreakWidth = currentWidth;
if (glyph->fMayLineBreakBefore) {
candidateLineBreak = current;
candidateLineBreakWidth = currentWidth;
}
}
}
SkScalar glyphWidth = glyph->fAdvance.fX;
// Break when overwidth, the glyph has a visual representation, and some space is used.
if (width < currentWidth + glyphWidth && glyph->fHasVisual && candidateGraphemeBreakWidth > 0){
if (candidateLineBreak != beginning) {
beginning = candidateLineBreak;
currentWidth -= candidateLineBreakWidth;
candidateGraphemeBreakWidth -= candidateLineBreakWidth;
candidateLineBreakWidth = 0;
} else if (candidateGraphemeBreak != beginning) {
beginning = candidateGraphemeBreak;
candidateLineBreak = beginning;
currentWidth -= candidateGraphemeBreakWidth;
candidateGraphemeBreakWidth = 0;
candidateLineBreakWidth = 0;
} else {
SK_ABORT("");
}
if (width < currentWidth) {
if (width < candidateGraphemeBreakWidth) {
candidateGraphemeBreak = candidateLineBreak;
candidateGraphemeBreakWidth = candidateLineBreakWidth;
}
current = candidateGraphemeBreak;
currentWidth = candidateGraphemeBreakWidth;
}
glyph = beginning.current();
if (glyph) {
glyph->fMustLineBreakBefore = true;
}
} else {
current.next();
currentWidth += glyphWidth;
}
}
}
// Reorder the runs and glyphs per line and write them out.
{
ShapedRunGlyphIterator previousBreak(runs);
ShapedRunGlyphIterator glyphIterator(runs);
int previousRunIndex = -1;
while (glyphIterator.current()) {
const ShapedRunGlyphIterator current = glyphIterator;
ShapedGlyph* nextGlyph = glyphIterator.next();
if (previousRunIndex != current.fRunIndex) {
SkFontMetrics metrics;
runs[current.fRunIndex].fFont.getMetrics(&metrics);
previousRunIndex = current.fRunIndex;
}
// Nothing can be written until the baseline is known.
if (!(nextGlyph == nullptr || nextGlyph->fMustLineBreakBefore)) {
continue;
}
int numRuns = current.fRunIndex - previousBreak.fRunIndex + 1;
AutoSTMalloc<4, SkBidiIterator::Level> runLevels(numRuns);
for (int i = 0; i < numRuns; ++i) {
runLevels[i] = runs[previousBreak.fRunIndex + i].fLevel;
}
AutoSTMalloc<4, int32_t> logicalFromVisual(numRuns);
fUnicode->reorderVisual(runLevels, numRuns, logicalFromVisual);
// step through the runs in reverse visual order and the glyphs in reverse logical order
// until a visible glyph is found and force them to the end of the visual line.
handler->beginLine();
struct SubRun { const ShapedRun& run; size_t startGlyphIndex; size_t endGlyphIndex; };
auto makeSubRun = [&runs, &previousBreak, &current, &logicalFromVisual](size_t visualIndex){
int logicalIndex = previousBreak.fRunIndex + logicalFromVisual[visualIndex];
const auto& run = runs[logicalIndex];
size_t startGlyphIndex = (logicalIndex == previousBreak.fRunIndex)
? previousBreak.fGlyphIndex
: 0;
size_t endGlyphIndex = (logicalIndex == current.fRunIndex)
? current.fGlyphIndex + 1
: run.fNumGlyphs;
return SubRun{ run, startGlyphIndex, endGlyphIndex };
};
auto makeRunInfo = [](const SubRun& sub) {
uint32_t startUtf8 = sub.run.fGlyphs[sub.startGlyphIndex].fCluster;
uint32_t endUtf8 = (sub.endGlyphIndex < sub.run.fNumGlyphs)
? sub.run.fGlyphs[sub.endGlyphIndex].fCluster
: sub.run.fUtf8Range.end();
SkVector advance = SkVector::Make(0, 0);
for (size_t i = sub.startGlyphIndex; i < sub.endGlyphIndex; ++i) {
advance += sub.run.fGlyphs[i].fAdvance;
}
return RunHandler::RunInfo{
sub.run.fFont,
sub.run.fLevel,
advance,
sub.endGlyphIndex - sub.startGlyphIndex,
RunHandler::Range(startUtf8, endUtf8 - startUtf8)
};
};
for (int i = 0; i < numRuns; ++i) {
handler->runInfo(makeRunInfo(makeSubRun(i)));
}
handler->commitRunInfo();
for (int i = 0; i < numRuns; ++i) {
SubRun sub = makeSubRun(i);
append(handler, makeRunInfo(sub), sub.run, sub.startGlyphIndex, sub.endGlyphIndex);
}
handler->commitLine();
previousRunIndex = -1;
previousBreak = glyphIterator;
}
}
}
void ShapeDontWrapOrReorder::wrap(char const * const utf8, size_t utf8Bytes,
const BiDiRunIterator& bidi,
const LanguageRunIterator& language,
const ScriptRunIterator& script,
const FontRunIterator& font,
RunIteratorQueue& runSegmenter,
const Feature* features, size_t featuresSize,
SkScalar width,
RunHandler* handler) const
{
sk_ignore_unused_variable(width);
SkTArray<ShapedRun> runs;
const char* utf8Start = nullptr;
const char* utf8End = utf8;
while (runSegmenter.advanceRuns()) {
utf8Start = utf8End;
utf8End = utf8 + runSegmenter.endOfCurrentRun();
runs.emplace_back(shape(utf8, utf8Bytes,
utf8Start, utf8End,
bidi, language, script, font,
features, featuresSize));
}
handler->beginLine();
for (const auto& run : runs) {
const RunHandler::RunInfo info = {
run.fFont,
run.fLevel,
run.fAdvance,
run.fNumGlyphs,
run.fUtf8Range
};
handler->runInfo(info);
}
handler->commitRunInfo();
for (const auto& run : runs) {
const RunHandler::RunInfo info = {
run.fFont,
run.fLevel,
run.fAdvance,
run.fNumGlyphs,
run.fUtf8Range
};
append(handler, info, run, 0, run.fNumGlyphs);
}
handler->commitLine();
}
class HBLockedFaceCache {
public:
HBLockedFaceCache(SkLRUCache<SkTypefaceID, HBFont>& lruCache, SkMutex& mutex)
: fLRUCache(lruCache), fMutex(mutex)
{
fMutex.acquire();
}
HBLockedFaceCache(const HBLockedFaceCache&) = delete;
HBLockedFaceCache& operator=(const HBLockedFaceCache&) = delete;
HBLockedFaceCache& operator=(HBLockedFaceCache&&) = delete;
~HBLockedFaceCache() {
fMutex.release();
}
HBFont* find(SkTypefaceID fontId) {
return fLRUCache.find(fontId);
}
HBFont* insert(SkTypefaceID fontId, HBFont hbFont) {
return fLRUCache.insert(fontId, std::move(hbFont));
}
void reset() {
fLRUCache.reset();
}
private:
SkLRUCache<SkTypefaceID, HBFont>& fLRUCache;
SkMutex& fMutex;
};
static HBLockedFaceCache get_hbFace_cache() {
static SkMutex gHBFaceCacheMutex;
static SkLRUCache<SkTypefaceID, HBFont> gHBFaceCache(100);
return HBLockedFaceCache(gHBFaceCache, gHBFaceCacheMutex);
}
ShapedRun ShaperHarfBuzz::shape(char const * const utf8,
size_t const utf8Bytes,
char const * const utf8Start,
char const * const utf8End,
const BiDiRunIterator& bidi,
const LanguageRunIterator& language,
const ScriptRunIterator& script,
const FontRunIterator& font,
Feature const * const features, size_t const featuresSize) const
{
size_t utf8runLength = utf8End - utf8Start;
ShapedRun run(RunHandler::Range(utf8Start - utf8, utf8runLength),
font.currentFont(), bidi.currentLevel(), nullptr, 0);
hb_buffer_t* buffer = fBuffer.get();
SkAutoTCallVProc<hb_buffer_t, hb_buffer_clear_contents> autoClearBuffer(buffer);
hb_buffer_set_content_type(buffer, HB_BUFFER_CONTENT_TYPE_UNICODE);
hb_buffer_set_cluster_level(buffer, HB_BUFFER_CLUSTER_LEVEL_MONOTONE_CHARACTERS);
// Documentation for HB_BUFFER_FLAG_BOT/EOT at 763e5466c0a03a7c27020e1e2598e488612529a7.
// Currently BOT forces a dotted circle when first codepoint is a mark; EOT has no effect.
// Avoid adding dotted circle, re-evaluate if BOT/EOT change. See https://skbug.com/9618.
// hb_buffer_set_flags(buffer, HB_BUFFER_FLAG_BOT | HB_BUFFER_FLAG_EOT);
// Add precontext.
hb_buffer_add_utf8(buffer, utf8, utf8Start - utf8, utf8Start - utf8, 0);
// Populate the hb_buffer directly with utf8 cluster indexes.
const char* utf8Current = utf8Start;
while (utf8Current < utf8End) {
unsigned int cluster = utf8Current - utf8;
hb_codepoint_t u = utf8_next(&utf8Current, utf8End);
hb_buffer_add(buffer, u, cluster);
}
// Add postcontext.
hb_buffer_add_utf8(buffer, utf8Current, utf8 + utf8Bytes - utf8Current, 0, 0);
hb_direction_t direction = is_LTR(bidi.currentLevel()) ? HB_DIRECTION_LTR:HB_DIRECTION_RTL;
hb_buffer_set_direction(buffer, direction);
hb_buffer_set_script(buffer, hb_script_from_iso15924_tag((hb_tag_t)script.currentScript()));
// Buffers with HB_LANGUAGE_INVALID race since hb_language_get_default is not thread safe.
// The user must provide a language, but may provide data hb_language_from_string cannot use.
// Use "und" for the undefined language in this case (RFC5646 4.1 5).
hb_language_t hbLanguage = hb_language_from_string(language.currentLanguage(), -1);
if (hbLanguage == HB_LANGUAGE_INVALID) {
hbLanguage = fUndefinedLanguage;
}
hb_buffer_set_language(buffer, hbLanguage);
hb_buffer_guess_segment_properties(buffer);
// TODO: better cache HBFace (data) / hbfont (typeface)
// An HBFace is expensive (it sanitizes the bits).
// An HBFont is fairly inexpensive.
// An HBFace is actually tied to the data, not the typeface.
// The size of 100 here is completely arbitrary and used to match libtxt.
HBFont hbFont;
{
HBLockedFaceCache cache = get_hbFace_cache();
SkTypefaceID dataId = font.currentFont().getTypeface()->uniqueID();
HBFont* typefaceFontCached = cache.find(dataId);
if (!typefaceFontCached) {
HBFont typefaceFont(create_typeface_hb_font(*font.currentFont().getTypeface()));
typefaceFontCached = cache.insert(dataId, std::move(typefaceFont));
}
hbFont = create_sub_hb_font(font.currentFont(), *typefaceFontCached);
}
if (!hbFont) {
return run;
}
SkSTArray<32, hb_feature_t> hbFeatures;
for (const auto& feature : SkSpan(features, featuresSize)) {
if (feature.end < SkTo<size_t>(utf8Start - utf8) ||
SkTo<size_t>(utf8End - utf8) <= feature.start)
{
continue;
}
if (feature.start <= SkTo<size_t>(utf8Start - utf8) &&
SkTo<size_t>(utf8End - utf8) <= feature.end)
{
hbFeatures.push_back({ (hb_tag_t)feature.tag, feature.value,
HB_FEATURE_GLOBAL_START, HB_FEATURE_GLOBAL_END});
} else {
hbFeatures.push_back({ (hb_tag_t)feature.tag, feature.value,
SkTo<unsigned>(feature.start), SkTo<unsigned>(feature.end)});
}
}
hb_shape(hbFont.get(), buffer, hbFeatures.data(), hbFeatures.size());
unsigned len = hb_buffer_get_length(buffer);
if (len == 0) {
return run;
}
if (direction == HB_DIRECTION_RTL) {
// Put the clusters back in logical order.
// Note that the advances remain ltr.
hb_buffer_reverse(buffer);
}
hb_glyph_info_t* info = hb_buffer_get_glyph_infos(buffer, nullptr);
hb_glyph_position_t* pos = hb_buffer_get_glyph_positions(buffer, nullptr);
run = ShapedRun(RunHandler::Range(utf8Start - utf8, utf8runLength),
font.currentFont(), bidi.currentLevel(),
std::unique_ptr<ShapedGlyph[]>(new ShapedGlyph[len]), len);
// Undo skhb_position with (1.0/(1<<16)) and scale as needed.
AutoSTArray<32, SkGlyphID> glyphIDs(len);
for (unsigned i = 0; i < len; i++) {
glyphIDs[i] = info[i].codepoint;
}
AutoSTArray<32, SkRect> glyphBounds(len);
SkPaint p;
run.fFont.getBounds(glyphIDs.get(), len, glyphBounds.get(), &p);
double SkScalarFromHBPosX = +(1.52587890625e-5) * run.fFont.getScaleX();
double SkScalarFromHBPosY = -(1.52587890625e-5); // HarfBuzz y-up, Skia y-down
SkVector runAdvance = { 0, 0 };
for (unsigned i = 0; i < len; i++) {
ShapedGlyph& glyph = run.fGlyphs[i];
glyph.fID = info[i].codepoint;
glyph.fCluster = info[i].cluster;
glyph.fOffset.fX = pos[i].x_offset * SkScalarFromHBPosX;
glyph.fOffset.fY = pos[i].y_offset * SkScalarFromHBPosY;
glyph.fAdvance.fX = pos[i].x_advance * SkScalarFromHBPosX;
glyph.fAdvance.fY = pos[i].y_advance * SkScalarFromHBPosY;
glyph.fHasVisual = !glyphBounds[i].isEmpty(); //!font->currentTypeface()->glyphBoundsAreZero(glyph.fID);
#if SK_HB_VERSION_CHECK(1, 5, 0)
glyph.fUnsafeToBreak = info[i].mask & HB_GLYPH_FLAG_UNSAFE_TO_BREAK;
#else
glyph.fUnsafeToBreak = false;
#endif
glyph.fMustLineBreakBefore = false;
runAdvance += glyph.fAdvance;
}
run.fAdvance = runAdvance;
return run;
}
} // namespace
std::unique_ptr<SkShaper::BiDiRunIterator>
SkShaper::MakeIcuBiDiRunIterator(const char* utf8, size_t utf8Bytes, uint8_t bidiLevel) {
auto unicode = SkUnicode::Make();
if (!unicode) {
return nullptr;
}
return SkShaper::MakeSkUnicodeBidiRunIterator(unicode.get(),
utf8,
utf8Bytes,
bidiLevel);
}
std::unique_ptr<SkShaper::BiDiRunIterator>
SkShaper::MakeSkUnicodeBidiRunIterator(SkUnicode* unicode, const char* utf8, size_t utf8Bytes, uint8_t bidiLevel) {
// ubidi only accepts utf16 (though internally it basically works on utf32 chars).
// We want an ubidi_setPara(UBiDi*, UText*, UBiDiLevel, UBiDiLevel*, UErrorCode*);
if (!SkTFitsIn<int32_t>(utf8Bytes)) {
SkDEBUGF("Bidi error: text too long");
return nullptr;
}
int32_t utf16Units = SkUTF::UTF8ToUTF16(nullptr, 0, utf8, utf8Bytes);
if (utf16Units < 0) {
SkDEBUGF("Invalid utf8 input\n");
return nullptr;
}
std::unique_ptr<uint16_t[]> utf16(new uint16_t[utf16Units]);
(void)SkUTF::UTF8ToUTF16(utf16.get(), utf16Units, utf8, utf8Bytes);
auto bidiDir = (bidiLevel % 2 == 0) ? SkBidiIterator::kLTR : SkBidiIterator::kRTL;
SkUnicodeBidi bidi = unicode->makeBidiIterator(utf16.get(), utf16Units, bidiDir);
if (!bidi) {
SkDEBUGF("Bidi error\n");
return nullptr;
}
return std::make_unique<SkUnicodeBidiRunIterator>(utf8, utf8 + utf8Bytes, std::move(bidi));
}
std::unique_ptr<SkShaper::ScriptRunIterator>
SkShaper::MakeHbIcuScriptRunIterator(const char* utf8, size_t utf8Bytes) {
return SkShaper::MakeSkUnicodeHbScriptRunIterator(utf8, utf8Bytes);
}
std::unique_ptr<SkShaper::ScriptRunIterator>
SkShaper::MakeSkUnicodeHbScriptRunIterator(const char* utf8, size_t utf8Bytes) {
return std::make_unique<SkUnicodeHbScriptRunIterator>(utf8, utf8Bytes, HB_SCRIPT_UNKNOWN);
}
std::unique_ptr<SkShaper::ScriptRunIterator> SkShaper::MakeSkUnicodeHbScriptRunIterator(
const char* utf8, size_t utf8Bytes, SkFourByteTag script) {
return std::make_unique<SkUnicodeHbScriptRunIterator>(
utf8, utf8Bytes, hb_script_from_iso15924_tag((hb_tag_t)script));
}
std::unique_ptr<SkShaper> SkShaper::MakeShaperDrivenWrapper(sk_sp<SkFontMgr> fontmgr) {
return MakeHarfBuzz(std::move(fontmgr), true);
}
std::unique_ptr<SkShaper> SkShaper::MakeShapeThenWrap(sk_sp<SkFontMgr> fontmgr) {
return MakeHarfBuzz(std::move(fontmgr), false);
}
std::unique_ptr<SkShaper> SkShaper::MakeShapeDontWrapOrReorder(std::unique_ptr<SkUnicode> unicode,
sk_sp<SkFontMgr> fontmgr) {
HBBuffer buffer(hb_buffer_create());
if (!buffer) {
SkDEBUGF("Could not create hb_buffer");
return nullptr;
}
if (!unicode) {
return nullptr;
}
return std::make_unique<ShapeDontWrapOrReorder>
(std::move(unicode), nullptr, nullptr, std::move(buffer), std::move(fontmgr));
}
void SkShaper::PurgeHarfBuzzCache() {
HBLockedFaceCache cache = get_hbFace_cache();
cache.reset();
}