PdfEncodingMap.h

// SPDX-FileCopyrightText: 2007 Dominik Seichter <domseichter@web.de>
// SPDX-FileCopyrightText: 2020 Francesco Pretto <ceztko@gmail.com>
// SPDX-License-Identifier: LGPL-2.0-or-later OR MPL-2.0
 
#ifndef PDF_ENCODING_MAP_H
#define PDF_ENCODING_MAP_H
 
#include "PdfDeclarations.h"
#include "PdfObject.h"
#include "PdfCharCodeMap.h"
#include "PdfCIDToGIDMap.h"
 
namespace PoDoFo {
 
class PdfIndirectObjectList;
class PdfFont;
class PdfFontMetrics;
class PdfEncodingFactory;
class PdfDifferenceMap;
 
class PODOFO_API PdfEncodingMap
{
    friend class PdfEncoding;
    friend class PdfEncodingMapBase;
    friend class PdfEncodingMapSimple;
    friend class PdfDifferenceEncoding;
    friend class PdfNullEncodingMap;
    friend class PdfIdentityEncoding;
    friend class PdfPredefinedToUnicodeCMap;
    friend class PdfStringScanContext;
    friend class PdfEncodingFactory;
    PODOFO_PRIVATE_FRIEND(class PdfEncodingTest);
 
private:
    PdfEncodingMap(PdfEncodingMapType type);
 
public:
    bool TryGetNextCharCode(std::string_view::iterator& it,
        const std::string_view::iterator& end, PdfCharCode& codeUnit) const;
 
    bool TryGetCharCode(char32_t codePoint, PdfCharCode& codeUnit) const;
 
    bool TryGetCharCode(const unicodeview& codePoints, PdfCharCode& codeUnit) const;
 
    bool TryGetCharCode(unsigned cid, PdfCharCode& codeUnit) const;
 
    bool TryGetNextCID(std::string_view::iterator& it,
        const std::string_view::iterator& end, PdfCID& cid) const;
 
    bool TryGetNextCodePoints(std::string_view::iterator& it,
        const std::string_view::iterator& end, CodePointSpan& codePoints) const;
 
    bool TryGetCodePoints(const PdfCharCode& codeUnit, CodePointSpan& codePoints) const;
 
    virtual const PdfEncodingLimits& GetLimits() const = 0;
 
    PdfEncodingMapType GetType() const { return m_Type; }
 
    virtual PdfPredefinedEncodingType GetPredefinedEncodingType() const;
 
    virtual bool HasLigaturesSupport() const;
 
public:
    virtual ~PdfEncodingMap();
 
protected:
    virtual bool tryGetNextCharCode(std::string_view::iterator& it,
        const std::string_view::iterator& end, PdfCharCode& codeUnit) const;
 
    virtual bool tryGetCharCodeSpan(const unicodeview& ligature, PdfCharCode& codeUnit) const;
 
    virtual bool tryGetCharCode(char32_t codePoint, PdfCharCode& codeUnit) const = 0;
 
    virtual bool tryGetCodePoints(const PdfCharCode& codeUnit, const unsigned* cidId, CodePointSpan& codePoints) const = 0;
 
    virtual void getExportObject(PdfIndirectObjectList& objects, PdfName& name, PdfObject*& obj) const;
 
    virtual int GetWModeRaw() const;
 
protected:
    virtual void AppendCodeSpaceRange(OutputStream& stream, charbuff& temp) const;
 
    virtual void AppendToUnicodeEntries(OutputStream& stream, const PdfFont& font, charbuff& temp) const = 0;
 
    virtual void AppendCIDMappingEntries(OutputStream& stream, const PdfFont& font, charbuff& temp) const = 0;
 
    virtual PdfCIDToGIDMapConstPtr GetIntrinsicCIDToGIDMap(const PdfDictionary& fontDict, const PdfFontMetrics& metrics) const;
 
private:
    bool TryGetExportObject(PdfIndirectObjectList& objects, PdfName& name, PdfObject*& obj) const;
 
    /* Overload of TryGetCodePoints that allows for a fast path to fetch code points from a full CID, if available
     *
     * To be called by PdfStringScanContext
     */
    bool TryGetCodePoints(const PdfCID& cid, CodePointSpan& codePoints) const;
 
    bool TryGetCIDId(const PdfCharCode& codeUnit, unsigned& id) const;
 
    bool tryGetNextCodePoints(std::string_view::iterator& it, const std::string_view::iterator& end,
        PdfCharCode& codeUnit, CodePointSpan& codePoints) const;
 
    PdfWModeKind GetWModeSafe() const;
 
private:
    PdfEncodingMapType m_Type;
};
 
class PODOFO_API PdfEncodingMapBase : public PdfEncodingMap
{
    friend class PdfCMapEncoding;
    PODOFO_PRIVATE_FRIEND(class PdfDynamicEncodingMap);
 
protected:
    bool tryGetNextCharCode(std::string_view::iterator& it,
        const std::string_view::iterator& end, PdfCharCode& codeUnit) const override;
 
    bool tryGetCharCodeSpan(const unicodeview& codePoints, PdfCharCode& codeUnit) const override;
 
    bool tryGetCharCode(char32_t codePoint, PdfCharCode& codeUnit) const override;
 
    bool tryGetCodePoints(const PdfCharCode& codeUnit, const unsigned* cidId, CodePointSpan& codePoints) const override;
 
    void AppendCodeSpaceRange(OutputStream& stream, charbuff& temp) const override;
 
    void AppendToUnicodeEntries(OutputStream& stream, const PdfFont& font, charbuff& temp) const override;
 
    void AppendCIDMappingEntries(OutputStream& stream, const PdfFont& font, charbuff& temp) const override;
 
public:
    inline const PdfCharCodeMap& GetCharMap() const { return *m_charMap; }
 
    const PdfEncodingLimits& GetLimits() const override;
 
private:
    PdfEncodingMapBase(PdfCharCodeMap&& map, PdfEncodingMapType type);
    PdfEncodingMapBase(std::shared_ptr<PdfCharCodeMap>&& map, PdfEncodingMapType type);
 
private:
    std::shared_ptr<PdfCharCodeMap> m_charMap;
};
 
class PODOFO_API PdfEncodingMapSimple : public PdfEncodingMap
{
    friend class PdfBuiltInEncoding;
    friend class PdfDifferenceEncoding;
    PODOFO_PRIVATE_FRIEND(class PdfFontBuiltinType1Encoding);
 
private:
    PdfEncodingMapSimple(const PdfEncodingLimits& limits);
 
protected:
    void AppendToUnicodeEntries(OutputStream& stream, const PdfFont& font, charbuff& temp) const override;
 
    void AppendCIDMappingEntries(OutputStream& stream, const PdfFont& font, charbuff& temp) const override;
 
    const PdfEncodingLimits& GetLimits() const override;
 
    PdfCIDToGIDMapConstPtr GetIntrinsicCIDToGIDMap(const PdfDictionary& fontDict, const PdfFontMetrics& metrics) const override;
 
    virtual void GetBaseEncoding(const PdfEncodingMap*& baseEncoding, const PdfDifferenceMap*& differences) const;
 
private:
    PdfEncodingLimits m_Limits;
};
 
class PODOFO_API PdfBuiltInEncoding : public PdfEncodingMapSimple
{
    friend class PdfFontMetricsFreetype;
    friend class PdfPredefinedEncoding;
    friend class PdfStandardEncoding;
    friend class PdfSymbolEncoding;
    friend class PdfZapfDingbatsEncoding;
    PODOFO_PRIVATE_FRIEND(class AppleLatin1Encoding);
 
private:
    PdfBuiltInEncoding(const PdfName& name);
 
public:
    inline const PdfName& GetName() const { return m_Name; }
 
protected:
    bool tryGetCharCode(char32_t codePoint, PdfCharCode& codeUnit) const override;
    bool tryGetCodePoints(const PdfCharCode& codeUnit, const unsigned* cidId, CodePointSpan& codePoints) const override;
 
    virtual const char32_t* GetToUnicodeTable() const = 0;
 
private:
    // To be called by PdfFontMetricsFreetype
    void CreateUnicodeToGIDMap(const std::unordered_map<unsigned, unsigned>& codeToGidMap,
        std::unordered_map<uint32_t, unsigned>& unicodeMap) const;
 
private:
    void initEncodingTable();
 
private:
    PdfName m_Name;         // The name of the encoding
    std::unordered_map<char32_t, char> m_EncodingTable; // The helper table for conversions into this encoding
};
 
class PODOFO_API PdfNullEncodingMap final : public PdfEncodingMap
{
    friend class PdfEncodingMapFactory;
 
private:
    PdfNullEncodingMap();
 
public:
    const PdfEncodingLimits& GetLimits() const override;
 
protected:
    bool tryGetCharCode(char32_t codePoint, PdfCharCode& codeUnit) const override;
 
    bool tryGetCodePoints(const PdfCharCode& codeUnit, const unsigned* cidId, CodePointSpan& codePoints) const override;
 
    void AppendToUnicodeEntries(OutputStream& stream, const PdfFont& font, charbuff& temp) const override;
 
    void AppendCIDMappingEntries(OutputStream& stream, const PdfFont& font, charbuff& temp) const override;
};
 
using PdfEncodingMapConstPtr = std::shared_ptr<const PdfEncodingMap>;
 
using PdfBuiltInEncodingConstPtr = std::shared_ptr<const PdfBuiltInEncoding>;
 
using PdfToUnicodeMapConstPtr = std::shared_ptr<const PdfEncodingMap>;
}
 
#endif // PDF_ENCODING_MAP_H