1 /* 2 * Copyright (C) 2011 Google Inc. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef SkPDFFont_DEFINED 18 #define SkPDFFont_DEFINED 19 20 #include "SkAdvancedTypefaceMetrics.h" 21 #include "SkPDFTypes.h" 22 #include "SkTDArray.h" 23 #include "SkThread.h" 24 25 class SkPaint; 26 27 /** \class SkPDFFont 28 A PDF Object class representing a font. The font may have resources 29 attached to it in order to embed the font. SkPDFFonts are canonicalized 30 so that resource deduplication will only include one copy of a font. 31 This class uses the same pattern as SkPDFGraphicState, a static weak 32 reference to each instantiated class. 33 */ 34 class SkPDFFont : public SkPDFDict { 35 public: 36 SK_API virtual ~SkPDFFont(); 37 38 SK_API virtual void getResources(SkTDArray<SkPDFObject*>* resourceList); 39 40 /** Returns the typeface represented by this class. Returns NULL for the 41 * default typeface. 42 */ 43 SK_API SkTypeface* typeface(); 44 45 /** Returns the font type represented in this font. For Type0 fonts, 46 * returns the type of the decendant font. 47 */ 48 SK_API SkAdvancedTypefaceMetrics::FontType getType(); 49 50 /** Return true if this font has an encoding for the passed glyph id. 51 */ 52 SK_API bool hasGlyph(uint16_t glyphID); 53 54 /** Returns true if this font encoding supports glyph IDs above 255. 55 */ 56 SK_API bool multiByteGlyphs(); 57 58 /** Convert (in place) the input glyph IDs into the font encoding. If the 59 * font has more glyphs than can be encoded (like a type 1 font with more 60 * than 255 glyphs) this method only converts up to the first out of range 61 * glyph ID. 62 * @param glyphIDs The input text as glyph IDs. 63 * @param numGlyphs The number of input glyphs. 64 * @return Returns the number of glyphs consumed. 65 */ 66 SK_API size_t glyphsToPDFFontEncoding(uint16_t* glyphIDs, size_t numGlyphs); 67 68 /** Get the font resource for the passed typeface and glyphID. The 69 * reference count of the object is incremented and it is the caller's 70 * responsibility to unreference it when done. This is needed to 71 * accommodate the weak reference pattern used when the returned object 72 * is new and has no other references. 73 * @param typeface The typeface to find. 74 * @param glyphID Specify which section of a large font is of interest. 75 */ 76 SK_API static SkPDFFont* getFontResource(SkTypeface* typeface, 77 uint16_t glyphID); 78 79 private: 80 SkRefPtr<SkTypeface> fTypeface; 81 SkAdvancedTypefaceMetrics::FontType fType; 82 #ifdef SK_DEBUG 83 bool fDescendant; 84 #endif 85 bool fMultiByteGlyphs; 86 87 // The glyph IDs accessible with this font. For Type1 (non CID) fonts, 88 // this will be a subset if the font has more than 255 glyphs. 89 uint16_t fFirstGlyphID; 90 uint16_t fLastGlyphID; 91 // The font info is only kept around after construction for large 92 // Type1 (non CID) fonts that need multiple "fonts" to access all glyphs. 93 SkRefPtr<SkAdvancedTypefaceMetrics> fFontInfo; 94 SkTDArray<SkPDFObject*> fResources; 95 SkRefPtr<SkPDFDict> fDescriptor; 96 97 class FontRec { 98 public: 99 SkPDFFont* fFont; 100 uint32_t fFontID; 101 uint16_t fGlyphID; 102 103 // A fGlyphID of 0 with no fFont always matches. 104 bool operator==(const FontRec& b) const; 105 FontRec(SkPDFFont* font, uint32_t fontID, uint16_t fGlyphID); 106 }; 107 108 // This should be made a hash table if performance is a problem. 109 static SkTDArray<FontRec>& canonicalFonts(); 110 static SkMutex& canonicalFontsMutex(); 111 112 /** Construct a new font dictionary and support objects. 113 * @param fontInfo Information about the to create. 114 * @param typeface The typeface for the font. 115 * @param glyphID The glyph ID the caller is interested in. This 116 * is important only for Type1 fonts, which have 117 * more than 255 glyphs. 118 * @param descendantFont If this is the descendant (true) or root 119 * (Type 0 font - false) font dictionary. Only True 120 * Type and CID encoded fonts will use a true value. 121 * @param fontDescriptor If the font descriptor has already have generated 122 * for this font, pass it in here, otherwise pass 123 * NULL. 124 */ 125 SkPDFFont(class SkAdvancedTypefaceMetrics* fontInfo, SkTypeface* typeface, 126 uint16_t glyphID, bool descendantFont, SkPDFDict* fontDescriptor); 127 128 void populateType0Font(); 129 void populateCIDFont(); 130 bool populateType1Font(int16_t glyphID); 131 132 /** Populate the PDF font dictionary as Type3 font which includes glyph 133 * descriptions with instructions for painting the glyphs. This function 134 * doesn't use any fields from SkAdvancedTypefaceMetrics (fFontInfo). Font 135 * information including glyph paths are queried from the platform 136 * dependent SkGlyphCache. 137 */ 138 void populateType3Font(int16_t glyphID); 139 bool addFontDescriptor(int16_t defaultWidth); 140 void populateToUnicodeTable(); 141 void addWidthInfoFromRange(int16_t defaultWidth, 142 const SkAdvancedTypefaceMetrics::WidthRange* widthRangeEntry); 143 /** Set fFirstGlyphID and fLastGlyphID to span at most 255 glyphs, 144 * including the passed glyphID. 145 */ 146 void adjustGlyphRangeForSingleByteEncoding(int16_t glyphID); 147 148 static bool find(uint32_t fontID, uint16_t glyphID, int* index); 149 }; 150 151 #endif 152