1 2 /* 3 * Copyright 2011 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 10 #ifndef SkPDFFont_DEFINED 11 #define SkPDFFont_DEFINED 12 13 #include "SkAdvancedTypefaceMetrics.h" 14 #include "SkBitSet.h" 15 #include "SkPDFTypes.h" 16 #include "SkTDArray.h" 17 #include "SkTypeface.h" 18 19 class SkPaint; 20 class SkPDFCanon; 21 class SkPDFObjNumMap; 22 class SkPDFFont; 23 24 class SkPDFGlyphSet : SkNoncopyable { 25 public: 26 SkPDFGlyphSet(); 27 28 void set(const uint16_t* glyphIDs, int numGlyphs); 29 bool has(uint16_t glyphID) const; 30 void merge(const SkPDFGlyphSet& usage); 31 void exportTo(SkTDArray<uint32_t>* glyphIDs) const; 32 33 private: 34 SkBitSet fBitSet; 35 }; 36 37 class SkPDFGlyphSetMap : SkNoncopyable { 38 public: 39 struct FontGlyphSetPair { 40 FontGlyphSetPair(SkPDFFont* font, SkPDFGlyphSet* glyphSet); 41 42 SkPDFFont* fFont; 43 SkPDFGlyphSet* fGlyphSet; 44 }; 45 46 SkPDFGlyphSetMap(); 47 ~SkPDFGlyphSetMap(); 48 49 class F2BIter { 50 public: 51 explicit F2BIter(const SkPDFGlyphSetMap& map); 52 const FontGlyphSetPair* next() const; 53 void reset(const SkPDFGlyphSetMap& map); 54 55 private: 56 const SkTDArray<FontGlyphSetPair>* fMap; 57 mutable int fIndex; 58 }; 59 60 void merge(const SkPDFGlyphSetMap& usage); 61 void reset(); 62 63 void noteGlyphUsage(SkPDFFont* font, const uint16_t* glyphIDs, 64 int numGlyphs); 65 66 private: 67 SkPDFGlyphSet* getGlyphSetForFont(SkPDFFont* font); 68 69 SkTDArray<FontGlyphSetPair> fMap; 70 }; 71 72 73 /** \class SkPDFFont 74 A PDF Object class representing a font. The font may have resources 75 attached to it in order to embed the font. SkPDFFonts are canonicalized 76 so that resource deduplication will only include one copy of a font. 77 This class uses the same pattern as SkPDFGraphicState, a static weak 78 reference to each instantiated class. 79 */ 80 class SkPDFFont : public SkPDFDict { 81 82 public: 83 virtual ~SkPDFFont(); 84 85 /** Returns the typeface represented by this class. Returns nullptr for the 86 * default typeface. 87 */ 88 SkTypeface* typeface(); 89 90 /** Returns the font type represented in this font. For Type0 fonts, 91 * returns the type of the decendant font. 92 */ 93 virtual SkAdvancedTypefaceMetrics::FontType getType(); 94 95 /** Returns true if this font encoding supports glyph IDs above 255. 96 */ 97 virtual bool multiByteGlyphs() const = 0; 98 99 /** Returns true if the machine readable licensing bits allow embedding. 100 */ 101 bool canEmbed() const; 102 103 /** Returns true if the machine readable licensing bits allow subsetting. 104 */ 105 bool canSubset() const; 106 107 /** Return true if this font has an encoding for the passed glyph id. 108 */ 109 bool hasGlyph(uint16_t glyphID); 110 111 /** Convert (in place) the input glyph IDs into the font encoding. If the 112 * font has more glyphs than can be encoded (like a type 1 font with more 113 * than 255 glyphs) this method only converts up to the first out of range 114 * glyph ID. 115 * @param glyphIDs The input text as glyph IDs. 116 * @param numGlyphs The number of input glyphs. 117 * @return Returns the number of glyphs consumed. 118 */ 119 int glyphsToPDFFontEncoding(uint16_t* glyphIDs, int numGlyphs); 120 121 /** Get the font resource for the passed typeface and glyphID. The 122 * reference count of the object is incremented and it is the caller's 123 * responsibility to unreference it when done. This is needed to 124 * accommodate the weak reference pattern used when the returned object 125 * is new and has no other references. 126 * @param typeface The typeface to find. 127 * @param glyphID Specify which section of a large font is of interest. 128 */ 129 static SkPDFFont* GetFontResource(SkPDFCanon* canon, 130 SkTypeface* typeface, 131 uint16_t glyphID); 132 133 /** Subset the font based on usage set. Returns a SkPDFFont instance with 134 * subset. 135 * @param usage Glyph subset requested. 136 * @return nullptr if font does not support subsetting, a new instance 137 * of SkPDFFont otherwise. 138 */ 139 virtual SkPDFFont* getFontSubset(const SkPDFGlyphSet* usage); 140 141 enum Match { 142 kExact_Match, 143 kRelated_Match, 144 kNot_Match, 145 }; 146 static Match IsMatch(SkPDFFont* existingFont, 147 uint32_t existingFontID, 148 uint16_t existingGlyphID, 149 uint32_t searchFontID, 150 uint16_t searchGlyphID); 151 152 /** 153 * Return false iff the typeface has its NotEmbeddable flag set. 154 * If typeface is NULL, the default typeface is checked. 155 */ 156 static bool CanEmbedTypeface(SkTypeface*, SkPDFCanon*); 157 158 protected: 159 // Common constructor to handle common members. 160 SkPDFFont(const SkAdvancedTypefaceMetrics* fontInfo, 161 SkTypeface* typeface, 162 SkPDFDict* relatedFontDescriptor); 163 164 // Accessors for subclass. 165 const SkAdvancedTypefaceMetrics* fontInfo(); 166 void setFontInfo(const SkAdvancedTypefaceMetrics* info); 167 uint16_t firstGlyphID() const; 168 uint16_t lastGlyphID() const; 169 void setLastGlyphID(uint16_t glyphID); 170 171 // Accessors for FontDescriptor associated with this object. 172 SkPDFDict* getFontDescriptor(); 173 void setFontDescriptor(SkPDFDict* descriptor); 174 175 // Add common entries to FontDescriptor. 176 bool addCommonFontDescriptorEntries(int16_t defaultWidth); 177 178 /** Set fFirstGlyphID and fLastGlyphID to span at most 255 glyphs, 179 * including the passed glyphID. 180 */ 181 void adjustGlyphRangeForSingleByteEncoding(uint16_t glyphID); 182 183 // Generate ToUnicode table according to glyph usage subset. 184 // If subset is nullptr, all available glyph ids will be used. 185 void populateToUnicodeTable(const SkPDFGlyphSet* subset); 186 187 // Create instances of derived types based on fontInfo. 188 static SkPDFFont* Create(SkPDFCanon* canon, 189 const SkAdvancedTypefaceMetrics* fontInfo, 190 SkTypeface* typeface, 191 uint16_t glyphID, 192 SkPDFDict* relatedFontDescriptor); 193 194 static bool Find(uint32_t fontID, uint16_t glyphID, int* index); 195 196 private: 197 SkAutoTUnref<SkTypeface> fTypeface; 198 199 // The glyph IDs accessible with this font. For Type1 (non CID) fonts, 200 // this will be a subset if the font has more than 255 glyphs. 201 uint16_t fFirstGlyphID; 202 uint16_t fLastGlyphID; 203 SkAutoTUnref<const SkAdvancedTypefaceMetrics> fFontInfo; 204 SkAutoTUnref<SkPDFDict> fDescriptor; 205 206 SkAdvancedTypefaceMetrics::FontType fFontType; 207 208 typedef SkPDFDict INHERITED; 209 }; 210 211 #endif 212
