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/*
* Copyright 2011 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkPDFFont_DEFINED
#define SkPDFFont_DEFINED
#include "SkAdvancedTypefaceMetrics.h"
#include "SkBitSet.h"
#include "SkPDFTypes.h"
#include "SkTDArray.h"
#include "SkTypeface.h"
class SkPDFCanon;
class SkPDFFont;
class SkPDFGlyphSet : SkNoncopyable {
public:
SkPDFGlyphSet();
SkPDFGlyphSet(SkPDFGlyphSet&& o) : fBitSet(std::move(o.fBitSet)) {}
void set(const uint16_t* glyphIDs, int numGlyphs);
bool has(uint16_t glyphID) const;
void exportTo(SkTDArray<uint32_t>* glyphIDs) const;
private:
SkBitSet fBitSet;
};
class SkPDFGlyphSetMap : SkNoncopyable {
public:
struct FontGlyphSetPair : SkNoncopyable {
FontGlyphSetPair() : fFont(nullptr) {}
FontGlyphSetPair(FontGlyphSetPair&& o)
: fFont(o.fFont)
, fGlyphSet(std::move(o.fGlyphSet)) {
o.fFont = nullptr;
}
SkPDFFont* fFont;
SkPDFGlyphSet fGlyphSet;
};
SkPDFGlyphSetMap();
~SkPDFGlyphSetMap();
const FontGlyphSetPair* begin() const { return fMap.begin(); }
const FontGlyphSetPair* end() const { return fMap.end(); }
void noteGlyphUsage(SkPDFFont* font, const uint16_t* glyphIDs,
int numGlyphs);
private:
SkPDFGlyphSet* getGlyphSetForFont(SkPDFFont* font);
SkTArray<FontGlyphSetPair> fMap;
};
/** \class SkPDFFont
A PDF Object class representing a font. The font may have resources
attached to it in order to embed the font. SkPDFFonts are canonicalized
so that resource deduplication will only include one copy of a font.
This class uses the same pattern as SkPDFGraphicState, a static weak
reference to each instantiated class.
*/
class SkPDFFont : public SkPDFDict {
public:
virtual ~SkPDFFont();
/** Returns the typeface represented by this class. Returns nullptr for the
* default typeface.
*/
SkTypeface* typeface();
/** Returns the font type represented in this font. For Type0 fonts,
* returns the type of the decendant font.
*/
virtual SkAdvancedTypefaceMetrics::FontType getType();
/** Returns true if this font encoding supports glyph IDs above 255.
*/
virtual bool multiByteGlyphs() const = 0;
/** Returns true if the machine readable licensing bits allow embedding.
*/
bool canEmbed() const;
/** Returns true if the machine readable licensing bits allow subsetting.
*/
bool canSubset() const;
/** Return true if this font has an encoding for the passed glyph id.
*/
bool hasGlyph(uint16_t glyphID);
/** Convert (in place) the input glyph IDs into the font encoding. If the
* font has more glyphs than can be encoded (like a type 1 font with more
* than 255 glyphs) this method only converts up to the first out of range
* glyph ID.
* @param glyphIDs The input text as glyph IDs.
* @param numGlyphs The number of input glyphs.
* @return Returns the number of glyphs consumed.
*/
int glyphsToPDFFontEncoding(uint16_t* glyphIDs, int numGlyphs);
/** Get the font resource for the passed typeface and glyphID. The
* reference count of the object is incremented and it is the caller's
* responsibility to unreference it when done. This is needed to
* accommodate the weak reference pattern used when the returned object
* is new and has no other references.
* @param typeface The typeface to find.
* @param glyphID Specify which section of a large font is of interest.
*/
static SkPDFFont* GetFontResource(SkPDFCanon* canon,
SkTypeface* typeface,
uint16_t glyphID);
/** Subset the font based on usage set. Returns a SkPDFFont instance with
* subset.
* @param usage Glyph subset requested.
* @return nullptr if font does not support subsetting, a new instance
* of SkPDFFont otherwise.
*/
virtual SkPDFFont* getFontSubset(const SkPDFGlyphSet* usage);
enum Match {
kExact_Match,
kRelated_Match,
kNot_Match,
};
static Match IsMatch(SkPDFFont* existingFont,
uint32_t existingFontID,
uint16_t existingGlyphID,
uint32_t searchFontID,
uint16_t searchGlyphID);
/**
* Return false iff the typeface has its NotEmbeddable flag set.
* If typeface is NULL, the default typeface is checked.
*/
static bool CanEmbedTypeface(SkTypeface*, SkPDFCanon*);
protected:
// Common constructor to handle common members.
SkPDFFont(const SkAdvancedTypefaceMetrics* fontInfo,
SkTypeface* typeface,
SkPDFDict* relatedFontDescriptor);
// Accessors for subclass.
const SkAdvancedTypefaceMetrics* fontInfo();
void setFontInfo(const SkAdvancedTypefaceMetrics* info);
uint16_t firstGlyphID() const;
uint16_t lastGlyphID() const;
void setLastGlyphID(uint16_t glyphID);
// Accessors for FontDescriptor associated with this object.
SkPDFDict* getFontDescriptor();
void setFontDescriptor(SkPDFDict* descriptor);
// Add common entries to FontDescriptor.
bool addCommonFontDescriptorEntries(int16_t defaultWidth);
/** Set fFirstGlyphID and fLastGlyphID to span at most 255 glyphs,
* including the passed glyphID.
*/
void adjustGlyphRangeForSingleByteEncoding(uint16_t glyphID);
// Generate ToUnicode table according to glyph usage subset.
// If subset is nullptr, all available glyph ids will be used.
void populateToUnicodeTable(const SkPDFGlyphSet* subset);
// Create instances of derived types based on fontInfo.
static SkPDFFont* Create(SkPDFCanon* canon,
const SkAdvancedTypefaceMetrics* fontInfo,
SkTypeface* typeface,
uint16_t glyphID,
SkPDFDict* relatedFontDescriptor);
static bool Find(uint32_t fontID, uint16_t glyphID, int* index);
void drop() override;
private:
sk_sp<SkTypeface> fTypeface;
// The glyph IDs accessible with this font. For Type1 (non CID) fonts,
// this will be a subset if the font has more than 255 glyphs.
uint16_t fFirstGlyphID;
uint16_t fLastGlyphID;
sk_sp<const SkAdvancedTypefaceMetrics> fFontInfo;
sk_sp<SkPDFDict> fDescriptor;
SkAdvancedTypefaceMetrics::FontType fFontType;
typedef SkPDFDict INHERITED;
};
#endif
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