1/*
2 * Copyright (C) 2007, 2008, 2009, 2011 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 *    notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 *    notice, this list of conditions and the following disclaimer in the
11 *    documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 */
24
25#ifndef ComplexTextController_h
26#define ComplexTextController_h
27
28#include "GlyphBuffer.h"
29#include <wtf/HashSet.h>
30#include <wtf/PassRefPtr.h>
31#include <wtf/RefCounted.h>
32#include <wtf/RetainPtr.h>
33#include <wtf/Vector.h>
34#include <wtf/text/WTFString.h>
35
36typedef unsigned short CGGlyph;
37
38typedef const struct __CTRun * CTRunRef;
39typedef const struct __CTLine * CTLineRef;
40
41namespace WebCore {
42
43class Font;
44class SimpleFontData;
45class TextRun;
46
47enum GlyphIterationStyle { IncludePartialGlyphs, ByWholeGlyphs };
48
49// ComplexTextController is responsible for rendering and measuring glyphs for
50// complex scripts on OS X.
51class ComplexTextController {
52public:
53    ComplexTextController(const Font*, const TextRun&, bool mayUseNaturalWritingDirection = false, HashSet<const SimpleFontData*>* fallbackFonts = 0, bool forTextEmphasis = false);
54
55    // Advance and emit glyphs up to the specified character.
56    void advance(unsigned to, GlyphBuffer* = 0, GlyphIterationStyle = IncludePartialGlyphs, HashSet<const SimpleFontData*>* fallbackFonts = 0);
57
58    // Compute the character offset for a given x coordinate.
59    int offsetForPosition(float x, bool includePartialGlyphs);
60
61    // Returns the width of everything we've consumed so far.
62    float runWidthSoFar() const { return m_runWidthSoFar; }
63
64    float totalWidth() const { return m_totalWidth; }
65
66    float finalRoundingWidth() const { return m_finalRoundingWidth; }
67
68    float minGlyphBoundingBoxX() const { return m_minGlyphBoundingBoxX; }
69    float maxGlyphBoundingBoxX() const { return m_maxGlyphBoundingBoxX; }
70    float minGlyphBoundingBoxY() const { return m_minGlyphBoundingBoxY; }
71    float maxGlyphBoundingBoxY() const { return m_maxGlyphBoundingBoxY; }
72
73private:
74    class ComplexTextRun : public RefCounted<ComplexTextRun> {
75    public:
76        static PassRefPtr<ComplexTextRun> create(CTRunRef ctRun, const SimpleFontData* fontData, const UChar* characters, unsigned stringLocation, size_t stringLength, CFRange runRange)
77        {
78            return adoptRef(new ComplexTextRun(ctRun, fontData, characters, stringLocation, stringLength, runRange));
79        }
80
81        static PassRefPtr<ComplexTextRun> create(const SimpleFontData* fontData, const UChar* characters, unsigned stringLocation, size_t stringLength, bool ltr)
82        {
83            return adoptRef(new ComplexTextRun(fontData, characters, stringLocation, stringLength, ltr));
84        }
85
86        unsigned glyphCount() const { return m_glyphCount; }
87        const SimpleFontData* fontData() const { return m_fontData; }
88        const UChar* characters() const { return m_characters; }
89        unsigned stringLocation() const { return m_stringLocation; }
90        size_t stringLength() const { return m_stringLength; }
91        ALWAYS_INLINE CFIndex indexAt(size_t i) const;
92        CFIndex indexBegin() const { return m_indexBegin; }
93        CFIndex indexEnd() const { return m_indexEnd; }
94        CFIndex endOffsetAt(size_t i) const { ASSERT(!m_isMonotonic); return m_glyphEndOffsets[i]; }
95        const CGGlyph* glyphs() const { return m_glyphs; }
96        CGSize initialAdvance() const { return m_initialAdvance; }
97        const CGSize* advances() const { return m_advances; }
98        bool isLTR() const { return m_isLTR; }
99        bool isMonotonic() const { return m_isMonotonic; }
100        void setIsNonMonotonic();
101
102    private:
103        ComplexTextRun(CTRunRef, const SimpleFontData*, const UChar* characters, unsigned stringLocation, size_t stringLength, CFRange runRange);
104        ComplexTextRun(const SimpleFontData*, const UChar* characters, unsigned stringLocation, size_t stringLength, bool ltr);
105
106        unsigned m_glyphCount;
107        const SimpleFontData* m_fontData;
108        const UChar* m_characters;
109        unsigned m_stringLocation;
110        size_t m_stringLength;
111        Vector<CFIndex, 64> m_coreTextIndicesVector;
112        const CFIndex* m_coreTextIndices;
113        CFIndex m_indexBegin;
114        CFIndex m_indexEnd;
115        Vector<CFIndex, 64> m_glyphEndOffsets;
116        Vector<CGGlyph, 64> m_glyphsVector;
117        const CGGlyph* m_glyphs;
118        CGSize m_initialAdvance;
119        Vector<CGSize, 64> m_advancesVector;
120        const CGSize* m_advances;
121        bool m_isLTR;
122        bool m_isMonotonic;
123    };
124
125    static unsigned stringBegin(const ComplexTextRun& run) { return run.stringLocation() + run.indexBegin(); }
126    static unsigned stringEnd(const ComplexTextRun& run) { return run.stringLocation() + run.indexEnd(); }
127
128    void collectComplexTextRuns();
129
130    void collectComplexTextRunsForCharacters(const UChar*, unsigned length, unsigned stringLocation, const SimpleFontData*);
131    void adjustGlyphsAndAdvances();
132
133    unsigned indexOfCurrentRun(unsigned& leftmostGlyph);
134    unsigned incrementCurrentRun(unsigned& leftmostGlyph);
135
136    // The initial capacity of these vectors was selected as being the smallest power of two greater than
137    // the average (3.5) plus one standard deviation (7.5) of nonzero sizes used on Arabic Wikipedia.
138    Vector<unsigned, 16> m_runIndices;
139    Vector<unsigned, 16> m_glyphCountFromStartToIndex;
140
141    const Font& m_font;
142    const TextRun& m_run;
143    bool m_isLTROnly;
144    bool m_mayUseNaturalWritingDirection;
145    bool m_forTextEmphasis;
146
147    Vector<String> m_stringsFor8BitRuns;
148    Vector<UChar, 256> m_smallCapsBuffer;
149
150    // Retain lines rather than their runs for better performance.
151    Vector<RetainPtr<CTLineRef>> m_coreTextLines;
152    Vector<RefPtr<ComplexTextRun>, 16> m_complexTextRuns;
153    Vector<CGSize, 256> m_adjustedAdvances;
154    Vector<CGGlyph, 256> m_adjustedGlyphs;
155
156    unsigned m_currentCharacter;
157    int m_end;
158
159    CGFloat m_totalWidth;
160
161    float m_runWidthSoFar;
162    unsigned m_numGlyphsSoFar;
163    size_t m_currentRun;
164    unsigned m_glyphInCurrentRun;
165    unsigned m_characterInCurrentGlyph;
166    float m_finalRoundingWidth;
167    float m_expansion;
168    float m_expansionPerOpportunity;
169    float m_leadingExpansion;
170    bool m_afterExpansion;
171
172    HashSet<const SimpleFontData*>* m_fallbackFonts;
173
174    float m_minGlyphBoundingBoxX;
175    float m_maxGlyphBoundingBoxX;
176    float m_minGlyphBoundingBoxY;
177    float m_maxGlyphBoundingBoxY;
178
179    unsigned m_lastRoundingGlyph;
180};
181
182} // namespace WebCore
183
184#endif // ComplexTextController_h
185