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#include <wtf/unicode/Unicode.h>
36
37typedef unsigned short CGGlyph;
38
39typedef const struct __CTRun * CTRunRef;
40typedef const struct __CTLine * CTLineRef;
41
42namespace WebCore {
43
44class Font;
45class SimpleFontData;
46class TextRun;
47
48enum GlyphIterationStyle { IncludePartialGlyphs, ByWholeGlyphs };
49
50// ComplexTextController is responsible for rendering and measuring glyphs for
51// complex scripts on OS X.
52class ComplexTextController {
53public:
54    ComplexTextController(const Font*, const TextRun&, bool mayUseNaturalWritingDirection = false, HashSet<const SimpleFontData*>* fallbackFonts = 0, bool forTextEmphasis = false);
55
56    // Advance and emit glyphs up to the specified character.
57    void advance(unsigned to, GlyphBuffer* = 0, GlyphIterationStyle = IncludePartialGlyphs, HashSet<const SimpleFontData*>* fallbackFonts = 0);
58
59    // Compute the character offset for a given x coordinate.
60    int offsetForPosition(float x, bool includePartialGlyphs);
61
62    // Returns the width of everything we've consumed so far.
63    float runWidthSoFar() const { return m_runWidthSoFar; }
64
65    float totalWidth() const { return m_totalWidth; }
66
67    float finalRoundingWidth() const { return m_finalRoundingWidth; }
68
69    float minGlyphBoundingBoxX() const { return m_minGlyphBoundingBoxX; }
70    float maxGlyphBoundingBoxX() const { return m_maxGlyphBoundingBoxX; }
71    float minGlyphBoundingBoxY() const { return m_minGlyphBoundingBoxY; }
72    float maxGlyphBoundingBoxY() const { return m_maxGlyphBoundingBoxY; }
73
74private:
75    class ComplexTextRun : public RefCounted<ComplexTextRun> {
76    public:
77        static PassRefPtr<ComplexTextRun> create(CTRunRef ctRun, const SimpleFontData* fontData, const UChar* characters, unsigned stringLocation, size_t stringLength, CFRange runRange)
78        {
79            return adoptRef(new ComplexTextRun(ctRun, fontData, characters, stringLocation, stringLength, runRange));
80        }
81
82        static PassRefPtr<ComplexTextRun> create(const SimpleFontData* fontData, const UChar* characters, unsigned stringLocation, size_t stringLength, bool ltr)
83        {
84            return adoptRef(new ComplexTextRun(fontData, characters, stringLocation, stringLength, ltr));
85        }
86
87        unsigned glyphCount() const { return m_glyphCount; }
88        const SimpleFontData* fontData() const { return m_fontData; }
89        const UChar* characters() const { return m_characters; }
90        unsigned stringLocation() const { return m_stringLocation; }
91        size_t stringLength() const { return m_stringLength; }
92        ALWAYS_INLINE CFIndex indexAt(size_t i) const;
93        CFIndex indexBegin() const { return m_indexBegin; }
94        CFIndex indexEnd() const { return m_indexEnd; }
95        CFIndex endOffsetAt(size_t i) const { ASSERT(!m_isMonotonic); return m_glyphEndOffsets[i]; }
96        const CGGlyph* glyphs() const { return m_glyphs; }
97        CGSize initialAdvance() const { return m_initialAdvance; }
98        const CGSize* advances() const { return m_advances; }
99        bool isLTR() const { return m_isLTR; }
100        bool isMonotonic() const { return m_isMonotonic; }
101        void setIsNonMonotonic();
102
103    private:
104        ComplexTextRun(CTRunRef, const SimpleFontData*, const UChar* characters, unsigned stringLocation, size_t stringLength, CFRange runRange);
105        ComplexTextRun(const SimpleFontData*, const UChar* characters, unsigned stringLocation, size_t stringLength, bool ltr);
106
107        unsigned m_glyphCount;
108        const SimpleFontData* m_fontData;
109        const UChar* m_characters;
110        unsigned m_stringLocation;
111        size_t m_stringLength;
112        Vector<CFIndex, 64> m_coreTextIndicesVector;
113        const CFIndex* m_coreTextIndices;
114        CFIndex m_indexBegin;
115        CFIndex m_indexEnd;
116        Vector<CFIndex, 64> m_glyphEndOffsets;
117        Vector<CGGlyph, 64> m_glyphsVector;
118        const CGGlyph* m_glyphs;
119        CGSize m_initialAdvance;
120        Vector<CGSize, 64> m_advancesVector;
121        const CGSize* m_advances;
122        bool m_isLTR;
123        bool m_isMonotonic;
124    };
125
126    static unsigned stringBegin(const ComplexTextRun& run) { return run.stringLocation() + run.indexBegin(); }
127    static unsigned stringEnd(const ComplexTextRun& run) { return run.stringLocation() + run.indexEnd(); }
128
129    void collectComplexTextRuns();
130
131    void collectComplexTextRunsForCharacters(const UChar*, unsigned length, unsigned stringLocation, const SimpleFontData*);
132    void adjustGlyphsAndAdvances();
133
134    unsigned indexOfCurrentRun(unsigned& leftmostGlyph);
135    unsigned incrementCurrentRun(unsigned& leftmostGlyph);
136
137    // The initial capacity of these vectors was selected as being the smallest power of two greater than
138    // the average (3.5) plus one standard deviation (7.5) of nonzero sizes used on Arabic Wikipedia.
139    Vector<unsigned, 16> m_runIndices;
140    Vector<unsigned, 16> m_glyphCountFromStartToIndex;
141
142    const Font& m_font;
143    const TextRun& m_run;
144    bool m_isLTROnly;
145    bool m_mayUseNaturalWritingDirection;
146    bool m_forTextEmphasis;
147
148    Vector<String> m_stringsFor8BitRuns;
149    Vector<UChar, 256> m_smallCapsBuffer;
150
151    // Retain lines rather than their runs for better performance.
152    Vector<RetainPtr<CTLineRef> > m_coreTextLines;
153    Vector<RefPtr<ComplexTextRun>, 16> m_complexTextRuns;
154    Vector<CGSize, 256> m_adjustedAdvances;
155    Vector<CGGlyph, 256> m_adjustedGlyphs;
156
157    unsigned m_currentCharacter;
158    int m_end;
159
160    CGFloat m_totalWidth;
161
162    float m_runWidthSoFar;
163    unsigned m_numGlyphsSoFar;
164    size_t m_currentRun;
165    unsigned m_glyphInCurrentRun;
166    unsigned m_characterInCurrentGlyph;
167    float m_finalRoundingWidth;
168    float m_expansion;
169    float m_expansionPerOpportunity;
170    float m_leadingExpansion;
171    bool m_afterExpansion;
172
173    HashSet<const SimpleFontData*>* m_fallbackFonts;
174
175    float m_minGlyphBoundingBoxX;
176    float m_maxGlyphBoundingBoxX;
177    float m_minGlyphBoundingBoxY;
178    float m_maxGlyphBoundingBoxY;
179
180    unsigned m_lastRoundingGlyph;
181};
182
183} // namespace WebCore
184
185#endif // ComplexTextController_h
186