1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
|
/*
* Copyright (C) 2003-2023 Apple Inc. All rights reserved.
* Copyright (C) 2008 Holger Hans Peter Freyther
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#ifndef WidthIterator_h
#define WidthIterator_h
#include "GlyphBuffer.h"
#include "WritingMode.h"
#include <unicode/umachine.h>
#include <wtf/HashSet.h>
#include <wtf/TZoneMalloc.h>
#include <wtf/Vector.h>
namespace WebCore {
class FontCascade;
class FontCascadeDescription;
class Font;
class TextRun;
struct GlyphData;
struct GlyphIndexRange;
struct OriginalAdvancesForCharacterTreatedAsSpace;
struct AdvanceInternalState;
struct SmallCapsState;
using CharactersTreatedAsSpace = Vector<OriginalAdvancesForCharacterTreatedAsSpace, 64>;
struct WidthIterator {
WTF_MAKE_TZONE_ALLOCATED(WidthIterator);
public:
WidthIterator(const FontCascade&, const TextRun&, SingleThreadWeakHashSet<const Font>* fallbackFonts = 0, bool accountForGlyphBounds = false, bool forTextEmphasis = false);
void advance(unsigned to, GlyphBuffer&);
bool advanceOneCharacter(float& width, GlyphBuffer&);
void finalize(GlyphBuffer&);
float maxGlyphBoundingBoxY() const { ASSERT(m_accountForGlyphBounds); return m_maxGlyphBoundingBoxY; }
float minGlyphBoundingBoxY() const { ASSERT(m_accountForGlyphBounds); return m_minGlyphBoundingBoxY; }
float firstGlyphOverflow() const { ASSERT(m_accountForGlyphBounds); return m_firstGlyphOverflow; }
float lastGlyphOverflow() const { ASSERT(m_accountForGlyphBounds); return m_lastGlyphOverflow; }
const TextRun& run() const { return m_run; }
float runWidthSoFar() const { return m_runWidthSoFar; }
unsigned currentCharacterIndex() const { return m_currentCharacterIndex; }
WEBCORE_EXPORT static bool characterCanUseSimplifiedTextMeasuring(char32_t, bool whitespaceIsCollapsed);
private:
GlyphData glyphDataForCharacter(char32_t, bool mirror);
template <typename TextIterator>
inline void advanceInternal(TextIterator&, GlyphBuffer&);
enum class TransformsType { None, Forced, NotForced };
TransformsType shouldApplyFontTransforms(const GlyphBuffer&, unsigned lastGlyphCount, unsigned currentCharacterIndex) const;
struct ApplyFontTransformsResult {
float additionalAdvance;
GlyphBufferAdvance initialAdvance;
};
ApplyFontTransformsResult applyFontTransforms(GlyphBuffer&, unsigned lastGlyphCount, const Font&, CharactersTreatedAsSpace&);
void commitCurrentFontRange(AdvanceInternalState&);
void startNewFontRangeIfNeeded(AdvanceInternalState&, SmallCapsState&, const FontCascadeDescription&);
void applyInitialAdvance(GlyphBuffer&, GlyphBufferAdvance initialAdvance, unsigned lastGlyphCount);
bool hasExtraSpacing() const;
void applyExtraSpacingAfterShaping(GlyphBuffer&, unsigned characterStartIndex, unsigned glyphBufferStartIndex, unsigned characterDestinationIndex, float startingRunWidth);
void applyCSSVisibilityRules(GlyphBuffer&, unsigned glyphBufferStartIndex);
struct AdditionalWidth {
float left;
float right;
float leftExpansion;
float rightExpansion;
};
AdditionalWidth calculateAdditionalWidth(GlyphBuffer&, GlyphBufferStringOffset currentCharacterIndex, unsigned leadingGlyphIndex, unsigned trailingGlyphIndex, float position) const;
void applyAdditionalWidth(GlyphBuffer&, GlyphIndexRange, float leftAdditionalWidth, float rightAdditionalWidth, float leftExpansionAdditionalWidth, float rightExpansionAdditionalWidth);
TextDirection direction() const { return m_direction; }
bool rtl() const { return m_direction == TextDirection::RTL; }
bool ltr() const { return m_direction == TextDirection::LTR; }
CheckedRef<const FontCascade> m_font;
CheckedRef<const TextRun> m_run;
SingleThreadWeakHashSet<const Font>* m_fallbackFonts { nullptr };
std::optional<unsigned> m_lastCharacterIndex;
GlyphBufferAdvance m_leftoverInitialAdvance { makeGlyphBufferAdvance() };
unsigned m_currentCharacterIndex { 0 };
float m_leftoverJustificationWidth { 0 };
float m_runWidthSoFar { 0 };
float m_expansion { 0 };
float m_expansionPerOpportunity { 0 };
float m_maxGlyphBoundingBoxY { std::numeric_limits<float>::lowest() };
float m_minGlyphBoundingBoxY { std::numeric_limits<float>::max() };
float m_firstGlyphOverflow { 0 };
float m_lastGlyphOverflow { 0 };
TextDirection m_direction { TextDirection::LTR };
bool m_containsTabs { false };
bool m_isAfterExpansion { false };
bool m_accountForGlyphBounds { false };
bool m_enableKerning { false };
bool m_requiresShaping { false };
bool m_forTextEmphasis { false };
};
} // namespace WebCore
#endif
|
