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// Copyright 2019 Google LLC.
#ifndef Run_DEFINED
#define Run_DEFINED
#include "include/core/SkFont.h"
#include "include/core/SkFontMetrics.h"
#include "include/core/SkPoint.h"
#include "include/core/SkRect.h"
#include "include/core/SkScalar.h"
#include "include/core/SkSpan.h"
#include "include/core/SkTypes.h"
#include "include/private/SkTArray.h"
#include "modules/skparagraph/include/DartTypes.h"
#include "modules/skparagraph/include/TextStyle.h"
#include "modules/skshaper/include/SkShaper.h"
#include <math.h>
#include <algorithm>
#include <functional>
#include <limits>
#include <tuple>
class SkTextBlobBuilder;
namespace skia {
namespace textlayout {
class Cluster;
class InternalLineMetrics;
class ParagraphImpl;
typedef size_t RunIndex;
const size_t EMPTY_RUN = EMPTY_INDEX;
typedef size_t ClusterIndex;
typedef SkRange<size_t> ClusterRange;
const size_t EMPTY_CLUSTER = EMPTY_INDEX;
const SkRange<size_t> EMPTY_CLUSTERS = EMPTY_RANGE;
typedef size_t GraphemeIndex;
typedef SkRange<GraphemeIndex> GraphemeRange;
typedef size_t GlyphIndex;
typedef SkRange<GlyphIndex> GlyphRange;
// LTR: [start: end) where start <= end
// RTL: [end: start) where start >= end
class DirText {
DirText(bool dir, size_t s, size_t e) : start(s), end(e) { }
bool isLeftToRight() const { return start <= end; }
size_t start;
size_t end;
};
class Run {
public:
Run(ParagraphImpl* owner,
const SkShaper::RunHandler::RunInfo& info,
size_t firstChar,
SkScalar heightMultiplier,
bool useHalfLeading,
SkScalar baselineShift,
size_t index,
SkScalar shiftX);
Run(const Run&) = default;
Run& operator=(const Run&) = delete;
Run(Run&&) = default;
Run& operator=(Run&&) = delete;
~Run() = default;
void setOwner(ParagraphImpl* owner) { fOwner = owner; }
SkShaper::RunHandler::Buffer newRunBuffer();
SkScalar posX(size_t index) const { return fPositions[index].fX; }
void addX(size_t index, SkScalar shift) { fPositions[index].fX += shift; }
SkScalar posY(size_t index) const { return fPositions[index].fY; }
size_t size() const { return fGlyphs.size(); }
void setWidth(SkScalar width) { fAdvance.fX = width; }
void setHeight(SkScalar height) { fAdvance.fY = height; }
void shift(SkScalar shiftX, SkScalar shiftY) {
fOffset.fX += shiftX;
fOffset.fY += shiftY;
}
SkVector advance() const {
return SkVector::Make(fAdvance.fX, fFontMetrics.fDescent - fFontMetrics.fAscent + fFontMetrics.fLeading);
}
SkVector offset() const { return fOffset; }
SkScalar ascent() const { return fFontMetrics.fAscent + fBaselineShift; }
SkScalar descent() const { return fFontMetrics.fDescent + fBaselineShift; }
SkScalar leading() const { return fFontMetrics.fLeading; }
SkScalar correctAscent() const { return fCorrectAscent + fBaselineShift; }
SkScalar correctDescent() const { return fCorrectDescent + fBaselineShift; }
SkScalar correctLeading() const { return fCorrectLeading; }
const SkFont& font() const { return fFont; }
bool leftToRight() const { return fBidiLevel % 2 == 0; }
TextDirection getTextDirection() const { return leftToRight() ? TextDirection::kLtr : TextDirection::kRtl; }
size_t index() const { return fIndex; }
SkScalar heightMultiplier() const { return fHeightMultiplier; }
bool useHalfLeading() const { return fUseHalfLeading; }
SkScalar baselineShift() const { return fBaselineShift; }
PlaceholderStyle* placeholderStyle() const;
bool isPlaceholder() const { return fPlaceholderIndex != std::numeric_limits<size_t>::max(); }
size_t clusterIndex(size_t pos) const { return fClusterIndexes[pos]; }
size_t globalClusterIndex(size_t pos) const { return fClusterStart + fClusterIndexes[pos]; }
SkScalar positionX(size_t pos) const;
TextRange textRange() const { return fTextRange; }
ClusterRange clusterRange() const { return fClusterRange; }
ParagraphImpl* owner() const { return fOwner; }
bool isEllipsis() const { return fEllipsis; }
void calculateMetrics();
void updateMetrics(InternalLineMetrics* endlineMetrics);
void setClusterRange(size_t from, size_t to) { fClusterRange = ClusterRange(from, to); }
SkRect clip() const {
return SkRect::MakeXYWH(fOffset.fX, fOffset.fY, fAdvance.fX, fAdvance.fY);
}
SkScalar addSpacesAtTheEnd(SkScalar space, Cluster* cluster);
SkScalar addSpacesEvenly(SkScalar space, Cluster* cluster);
SkScalar addSpacesEvenly(SkScalar space);
void shift(const Cluster* cluster, SkScalar offset);
SkScalar calculateHeight(LineMetricStyle ascentStyle, LineMetricStyle descentStyle) const {
auto ascent = ascentStyle == LineMetricStyle::Typographic ? this->ascent()
: this->correctAscent();
auto descent = descentStyle == LineMetricStyle::Typographic ? this->descent()
: this->correctDescent();
return descent - ascent;
}
SkScalar calculateWidth(size_t start, size_t end, bool clip) const;
void copyTo(SkTextBlobBuilder& builder, size_t pos, size_t size) const;
template<typename Visitor>
void iterateThroughClustersInTextOrder(Visitor visitor);
using ClusterVisitor = std::function<void(Cluster* cluster)>;
void iterateThroughClusters(const ClusterVisitor& visitor);
std::tuple<bool, ClusterIndex, ClusterIndex> findLimitingClusters(TextRange text) const;
std::tuple<bool, TextIndex, TextIndex> findLimitingGraphemes(TextRange text) const;
SkSpan<const SkGlyphID> glyphs() const {
return SkSpan<const SkGlyphID>(fGlyphs.begin(), fGlyphs.size());
}
SkSpan<const SkPoint> positions() const {
return SkSpan<const SkPoint>(fPositions.begin(), fPositions.size());
}
SkSpan<const uint32_t> clusterIndexes() const {
return SkSpan<const uint32_t>(fClusterIndexes.begin(), fClusterIndexes.size());
}
void commit() { }
void resetJustificationShifts() {
fJustificationShifts.reset();
}
private:
friend class ParagraphImpl;
friend class TextLine;
friend class InternalLineMetrics;
friend class ParagraphCache;
friend class OneLineShaper;
ParagraphImpl* fOwner;
TextRange fTextRange;
ClusterRange fClusterRange;
SkFont fFont;
size_t fPlaceholderIndex;
size_t fIndex;
SkVector fAdvance;
SkVector fOffset;
TextIndex fClusterStart;
SkShaper::RunHandler::Range fUtf8Range;
// These fields are not modified after shaping completes and can safely be
// shared among copies of the run that are held by different paragraphs.
struct GlyphData {
SkSTArray<64, SkGlyphID, true> glyphs;
SkSTArray<64, SkPoint, true> positions;
SkSTArray<64, uint32_t, true> clusterIndexes;
};
std::shared_ptr<GlyphData> fGlyphData;
SkSTArray<64, SkGlyphID, true>& fGlyphs;
SkSTArray<64, SkPoint, true>& fPositions;
SkSTArray<64, uint32_t, true>& fClusterIndexes;
SkSTArray<64, SkPoint, true> fJustificationShifts; // For justification (current and prev shifts)
SkFontMetrics fFontMetrics;
const SkScalar fHeightMultiplier;
const bool fUseHalfLeading;
const SkScalar fBaselineShift;
SkScalar fCorrectAscent;
SkScalar fCorrectDescent;
SkScalar fCorrectLeading;
bool fEllipsis;
uint8_t fBidiLevel;
};
template<typename Visitor>
void Run::iterateThroughClustersInTextOrder(Visitor visitor) {
// Can't figure out how to do it with one code for both cases without 100 ifs
// Can't go through clusters because there are no cluster table yet
if (leftToRight()) {
size_t start = 0;
size_t cluster = this->clusterIndex(start);
for (size_t glyph = 1; glyph <= this->size(); ++glyph) {
auto nextCluster = this->clusterIndex(glyph);
if (nextCluster <= cluster) {
continue;
}
visitor(start,
glyph,
fClusterStart + cluster,
fClusterStart + nextCluster,
this->calculateWidth(start, glyph, glyph == size()),
this->calculateHeight(LineMetricStyle::CSS, LineMetricStyle::CSS));
start = glyph;
cluster = nextCluster;
}
} else {
size_t glyph = this->size();
size_t cluster = this->fUtf8Range.begin();
for (int32_t start = this->size() - 1; start >= 0; --start) {
size_t nextCluster =
start == 0 ? this->fUtf8Range.end() : this->clusterIndex(start - 1);
if (nextCluster <= cluster) {
continue;
}
visitor(start,
glyph,
fClusterStart + cluster,
fClusterStart + nextCluster,
this->calculateWidth(start, glyph, glyph == 0),
this->calculateHeight(LineMetricStyle::CSS, LineMetricStyle::CSS));
glyph = start;
cluster = nextCluster;
}
}
}
class Cluster {
public:
enum BreakType {
None,
GraphemeBreak, // calculated for all clusters (UBRK_CHARACTER)
SoftLineBreak, // calculated for all clusters (UBRK_LINE & UBRK_CHARACTER)
HardLineBreak, // calculated for all clusters (UBRK_LINE)
};
Cluster()
: fOwner(nullptr)
, fRunIndex(EMPTY_RUN)
, fTextRange(EMPTY_TEXT)
, fGraphemeRange(EMPTY_RANGE)
, fStart(0)
, fEnd()
, fWidth()
, fHeight()
, fHalfLetterSpacing(0.0) {}
Cluster(ParagraphImpl* owner,
RunIndex runIndex,
size_t start,
size_t end,
SkSpan<const char> text,
SkScalar width,
SkScalar height);
Cluster(TextRange textRange) : fTextRange(textRange), fGraphemeRange(EMPTY_RANGE) { }
Cluster(const Cluster&) = default;
~Cluster() = default;
SkScalar sizeToChar(TextIndex ch) const;
SkScalar sizeFromChar(TextIndex ch) const;
size_t roundPos(SkScalar s) const;
void space(SkScalar shift, SkScalar space) {
fWidth += shift;
}
ParagraphImpl* getOwner() const { return fOwner; }
void setOwner(ParagraphImpl* owner) { fOwner = owner; }
bool isWhitespaceBreak() const { return fIsWhiteSpaceBreak; }
bool isIntraWordBreak() const { return fIsIntraWordBreak; }
bool isHardBreak() const { return fIsHardBreak; }
bool isSoftBreak() const;
bool isGraphemeBreak() const;
bool canBreakLineAfter() const { return isHardBreak() || isSoftBreak(); }
size_t startPos() const { return fStart; }
size_t endPos() const { return fEnd; }
SkScalar width() const { return fWidth; }
SkScalar height() const { return fHeight; }
size_t size() const { return fEnd - fStart; }
void setHalfLetterSpacing(SkScalar halfLetterSpacing) { fHalfLetterSpacing = halfLetterSpacing; }
SkScalar getHalfLetterSpacing() const { return fHalfLetterSpacing; }
TextRange textRange() const { return fTextRange; }
RunIndex runIndex() const { return fRunIndex; }
ParagraphImpl* owner() const { return fOwner; }
Run* runOrNull() const;
Run& run() const;
SkFont font() const;
SkScalar trimmedWidth(size_t pos) const;
bool contains(TextIndex ch) const { return ch >= fTextRange.start && ch < fTextRange.end; }
bool belongs(TextRange text) const {
return fTextRange.start >= text.start && fTextRange.end <= text.end;
}
bool startsIn(TextRange text) const {
return fTextRange.start >= text.start && fTextRange.start < text.end;
}
private:
friend ParagraphImpl;
ParagraphImpl* fOwner;
RunIndex fRunIndex;
TextRange fTextRange;
GraphemeRange fGraphemeRange;
size_t fStart;
size_t fEnd;
SkScalar fWidth;
SkScalar fHeight;
SkScalar fHalfLetterSpacing;
bool fIsWhiteSpaceBreak;
bool fIsIntraWordBreak;
bool fIsHardBreak;
};
class InternalLineMetrics {
public:
InternalLineMetrics() {
clean();
fForceStrut = false;
}
InternalLineMetrics(bool forceStrut) {
clean();
fForceStrut = forceStrut;
}
InternalLineMetrics(SkScalar a, SkScalar d, SkScalar l) {
fAscent = a;
fDescent = d;
fLeading = l;
fRawAscent = a;
fRawDescent = d;
fRawLeading = l;
fForceStrut = false;
}
InternalLineMetrics(SkScalar a, SkScalar d, SkScalar l, SkScalar ra, SkScalar rd, SkScalar rl) {
fAscent = a;
fDescent = d;
fLeading = l;
fRawAscent = ra;
fRawDescent = rd;
fRawLeading = rl;
fForceStrut = false;
}
InternalLineMetrics(const SkFont& font, bool forceStrut) {
SkFontMetrics metrics;
font.getMetrics(&metrics);
fAscent = metrics.fAscent;
fDescent = metrics.fDescent;
fLeading = metrics.fLeading;
fRawAscent = metrics.fAscent;
fRawDescent = metrics.fDescent;
fRawLeading = metrics.fLeading;
fForceStrut = forceStrut;
}
void add(Run* run) {
if (fForceStrut) {
return;
}
fAscent = std::min(fAscent, run->correctAscent());
fDescent = std::max(fDescent, run->correctDescent());
fLeading = std::max(fLeading, run->correctLeading());
fRawAscent = std::min(fRawAscent, run->ascent());
fRawDescent = std::max(fRawDescent, run->descent());
fRawLeading = std::max(fRawLeading, run->leading());
}
void add(InternalLineMetrics other) {
fAscent = std::min(fAscent, other.fAscent);
fDescent = std::max(fDescent, other.fDescent);
fLeading = std::max(fLeading, other.fLeading);
fRawAscent = std::min(fRawAscent, other.fRawAscent);
fRawDescent = std::max(fRawDescent, other.fRawDescent);
fRawLeading = std::max(fRawLeading, other.fRawLeading);
}
void clean() {
fAscent = SK_ScalarMax;
fDescent = SK_ScalarMin;
fLeading = 0;
fRawAscent = SK_ScalarMax;
fRawDescent = SK_ScalarMin;
fRawLeading = 0;
}
SkScalar delta() const { return height() - ideographicBaseline(); }
void updateLineMetrics(InternalLineMetrics& metrics) {
if (metrics.fForceStrut) {
metrics.fAscent = fAscent;
metrics.fDescent = fDescent;
metrics.fLeading = fLeading;
metrics.fRawAscent = fRawAscent;
metrics.fRawDescent = fRawDescent;
metrics.fRawLeading = fRawLeading;
} else {
// This is another of those flutter changes. To be removed...
metrics.fAscent = std::min(metrics.fAscent, fAscent - fLeading / 2.0f);
metrics.fDescent = std::max(metrics.fDescent, fDescent + fLeading / 2.0f);
metrics.fRawAscent = std::min(metrics.fRawAscent, fRawAscent - fRawLeading / 2.0f);
metrics.fRawDescent = std::max(metrics.fRawDescent, fRawDescent + fRawLeading / 2.0f);
}
}
SkScalar runTop(const Run* run, LineMetricStyle ascentStyle) const {
return fLeading / 2 - fAscent +
(ascentStyle == LineMetricStyle::Typographic ? run->ascent() : run->correctAscent()) + delta();
}
SkScalar height() const {
return ::round((double)fDescent - fAscent + fLeading);
}
void update(SkScalar a, SkScalar d, SkScalar l) {
fAscent = a;
fDescent = d;
fLeading = l;
}
void updateRawData(SkScalar ra, SkScalar rd) {
fRawAscent = ra;
fRawDescent = rd;
}
SkScalar alphabeticBaseline() const { return fLeading / 2 - fAscent; }
SkScalar ideographicBaseline() const { return fDescent - fAscent + fLeading; }
SkScalar deltaBaselines() const { return fLeading / 2 + fDescent; }
SkScalar baseline() const { return fLeading / 2 - fAscent; }
SkScalar ascent() const { return fAscent; }
SkScalar descent() const { return fDescent; }
SkScalar leading() const { return fLeading; }
SkScalar rawAscent() const { return fRawAscent; }
SkScalar rawDescent() const { return fRawDescent; }
void setForceStrut(bool value) { fForceStrut = value; }
bool getForceStrut() const { return fForceStrut; }
private:
friend class ParagraphImpl;
friend class TextWrapper;
friend class TextLine;
SkScalar fAscent;
SkScalar fDescent;
SkScalar fLeading;
SkScalar fRawAscent;
SkScalar fRawDescent;
SkScalar fRawLeading;
bool fForceStrut;
};
} // namespace textlayout
} // namespace skia
#endif // Run_DEFINED