/* * * (C) Copyright IBM Corp. 1998-2014 - All Rights Reserved * */ #ifndef __ARABICLAYOUTENGINE_H #define __ARABICLAYOUTENGINE_H #include "LETypes.h" #include "LEFontInstance.h" #include "LEGlyphFilter.h" #include "LayoutEngine.h" #include "OpenTypeLayoutEngine.h" #include "GlyphSubstitutionTables.h" #include "GlyphDefinitionTables.h" #include "GlyphPositioningTables.h" U_NAMESPACE_BEGIN /** * This class implements OpenType layout for Arabic fonts. It overrides * the characerProcessing method to assign the correct OpenType feature * tags for the Arabic contextual forms. It also overrides the adjustGlyphPositions * method to guarantee that all vowel and accent glyphs have zero advance width. * * @internal */ class ArabicOpenTypeLayoutEngine : public OpenTypeLayoutEngine { public: /** * This is the main constructor. It constructs an instance of ArabicOpenTypeLayoutEngine for * a particular font, script and language. It takes the GSUB table as a parameter since * LayoutEngine::layoutEngineFactory has to read the GSUB table to know that it has an * Indic OpenType font. * * @param fontInstance - the font * @param scriptCode - the script * @param langaugeCode - the language * @param gsubTable - the GSUB table * @param success - set to an error code if the operation fails * * @see LayoutEngine::layoutEngineFactory * @see OpenTypeLayoutEngine * @see ScriptAndLanguageTags.h for script and language codes * * @internal */ ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, le_int32 typoFlags, const LEReferenceTo<GlyphSubstitutionTableHeader> &gsubTable, LEErrorCode &success); /** * This constructor is used when the font requires a "canned" GSUB table which can't be known * until after this constructor has been invoked. * * @param fontInstance - the font * @param scriptCode - the script * @param langaugeCode - the language * @param success - set to an error code if the operation fails * * @see OpenTypeLayoutEngine * @see ScriptAndLanguageTags.h for script and language codes * * @internal */ ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, le_int32 typoFlags, LEErrorCode &success); /** * The destructor, virtual for correct polymorphic invocation. * * @internal */ virtual ~ArabicOpenTypeLayoutEngine(); /** * ICU "poor man's RTTI", returns a UClassID for the actual class. * * @deprecated ICU 54. See {@link icu::LayoutEngine} */ virtual UClassID getDynamicClassID() const; /** * ICU "poor man's RTTI", returns a UClassID for this class. * * @deprecated ICU 54. See {@link icu::LayoutEngine} */ static UClassID getStaticClassID(); protected: /** * This method does Arabic OpenType character processing. It assigns the OpenType feature * tags to the characters to generate the correct contextual forms and ligatures. * * Input parameters: * @param chars - the input character context * @param offset - the index of the first character to process * @param count - the number of characters to process * @param max - the number of characters in the input context * @param rightToLeft - <code>TRUE</code> if the characters are in a right to left directional run * * Output parameters: * @param outChars - the output character arrayt * @param charIndices - the output character index array * @param featureTags - the output feature tag array * @param success - set to an error code if the operation fails * * @return the output character count * * @internal */ virtual le_int32 characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft, LEUnicode *&outChars, LEGlyphStorage &glyphStorage, LEErrorCode &success); /** * This method applies the GPOS table if it is present, otherwise it ensures that all vowel * and accent glyphs have a zero advance width by calling the adjustMarkGlyphs method. * If the font contains a GDEF table, that is used to identify voewls and accents. Otherwise * the character codes are used. * * @param chars - the input character context * @param offset - the offset of the first character to process * @param count - the number of characters to process * @param reverse - <code>TRUE</code> if the glyphs in the glyph array have been reordered * @param glyphs - the input glyph array * @param glyphCount - the number of glyphs * @param positions - the position array, will be updated as needed * @param success - output parameter set to an error code if the operation fails * * @internal */ virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, LEGlyphStorage &glyphStorage, LEErrorCode &success); // static void adjustMarkGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool rightToLeft, LEGlyphStorage &glyphStorage, LEErrorCode &success); }; /** * The class implements OpenType layout for Arabic fonts which don't * contain a GSUB table, using a canned GSUB table based on Unicode * Arabic Presentation Forms. It overrides the mapCharsToGlyphs method * to use the Presentation Forms as logical glyph indices. It overrides the * glyphPostProcessing method to convert the Presentation Forms to actual * glyph indices. * * @see ArabicOpenTypeLayoutEngine * * @internal */ class UnicodeArabicOpenTypeLayoutEngine : public ArabicOpenTypeLayoutEngine { public: /** * This constructs an instance of UnicodeArabicOpenTypeLayoutEngine for a specific font, * script and language. * * @param fontInstance - the font * @param scriptCode - the script * @param languageCode - the language * @param success - set to an error code if the operation fails * * @see LEFontInstance * @see ScriptAndLanguageTags.h for script and language codes * * @internal */ UnicodeArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, le_int32 typoFlags, LEErrorCode &success); /** * The destructor, virtual for correct polymorphic invocation. * * @internal */ virtual ~UnicodeArabicOpenTypeLayoutEngine(); protected: /** * This method converts the Arabic Presentation Forms in the temp glyph array * into actual glyph indices using ArabicOpenTypeLayoutEngine::mapCharsToGlyps. * * Input paramters: * @param tempGlyphs - the input presentation forms * @param tempCharIndices - the input character index array * @param tempGlyphCount - the number of Presentation Froms * * Output parameters: * @param glyphs - the output glyph index array * @param charIndices - the output character index array * @param success - set to an error code if the operation fails * * @return the number of glyph indices in the output glyph index array * * @internal */ virtual le_int32 glyphPostProcessing(LEGlyphStorage &tempGlyphStorage, LEGlyphStorage &glyphStorage, LEErrorCode &success); /** * This method copies the input characters into the output glyph index array, * for use by the canned GSUB table. It also generates the character index array. * * Input parameters: * @param chars - the input character context * @param offset - the offset of the first character to be mapped * @param count - the number of characters to be mapped * @param reverse - if <code>TRUE</code>, the output will be in reverse order * @param mirror - if <code>TRUE</code>, do character mirroring * @param glyphStorage - the glyph storage object. Glyph and char index arrays will be updated. * * @param success - set to an error code if the operation fails * * @internal */ virtual void mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, le_bool mirror, LEGlyphStorage &glyphStorage, LEErrorCode &success); /** * This method ensures that all vowel and accent glyphs have a zero advance width by calling * the adjustMarkGlyphs method. The character codes are used to identify the vowel and mark * glyphs. * * @param chars - the input character context * @param offset - the offset of the first character to process * @param count - the number of characters to process * @param reverse - <code>TRUE</code> if the glyphs in the glyph array have been reordered * @param glyphStorage - the glyph storage object. The glyph positions will be updated as needed. * @param success - output parameter set to an error code if the operation fails * * @internal */ virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, LEGlyphStorage &glyphStorage, LEErrorCode &success); }; U_NAMESPACE_END #endif