1 2 /* 3 * HanLayoutEngine.h: OpenType processing for Han fonts. 4 * 5 * (C) Copyright IBM Corp. 1998-2013 - All Rights Reserved. 6 */ 7 8 #ifndef __HANLAYOUTENGINE_H 9 #define __HANLAYOUTENGINE_H 10 11 #include "LETypes.h" 12 #include "LEFontInstance.h" 13 #include "LayoutEngine.h" 14 #include "OpenTypeLayoutEngine.h" 15 16 #include "GlyphSubstitutionTables.h" 17 18 U_NAMESPACE_BEGIN 19 20 class LEGlyphStorage; 21 22 /** 23 * This class implements OpenType layout for Han fonts. It overrides 24 * the characerProcessing method to assign the correct OpenType feature 25 * tags for the CJK language-specific forms. 26 * 27 * @internal 28 */ 29 class HanOpenTypeLayoutEngine : public OpenTypeLayoutEngine 30 { 31 public: 32 /** 33 * This is the main constructor. It constructs an instance of HanOpenTypeLayoutEngine for 34 * a particular font, script and language. It takes the GSUB table as a parameter since 35 * LayoutEngine::layoutEngineFactory has to read the GSUB table to know that it has a 36 * Han OpenType font. 37 * 38 * @param fontInstance - the font 39 * @param scriptCode - the script 40 * @param langaugeCode - the language 41 * @param gsubTable - the GSUB table 42 * @param success - set to an error code if the operation fails 43 * 44 * @see LayoutEngine::layoutEngineFactory 45 * @see OpenTypeLayoutEngine 46 * @see ScriptAndLangaugeTags.h for script and language codes 47 * 48 * @internal 49 */ 50 HanOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, 51 le_int32 typoFlags, const LEReferenceTo<GlyphSubstitutionTableHeader> &gsubTablem, LEErrorCode &success); 52 53 54 /** 55 * The destructor, virtual for correct polymorphic invocation. 56 * 57 * @internal 58 */ 59 virtual ~HanOpenTypeLayoutEngine(); 60 61 /** 62 * ICU "poor man's RTTI", returns a UClassID for the actual class. 63 * 64 * @stable ICU 2.8 65 */ 66 virtual UClassID getDynamicClassID() const; 67 68 /** 69 * ICU "poor man's RTTI", returns a UClassID for this class. 70 * 71 * @stable ICU 2.8 72 */ 73 static UClassID getStaticClassID(); 74 75 protected: 76 77 /** 78 * This method does Han OpenType character processing. It assigns the OpenType feature 79 * tags to the characters to generate the correct language-specific variants. 80 * 81 * Input parameters: 82 * @param chars - the input character context 83 * @param offset - the index of the first character to process 84 * @param count - the number of characters to process 85 * @param max - the number of characters in the input context 86 * @param rightToLeft - <code>TRUE</code> if the characters are in a right to left directional run 87 * @param glyphStorage - the object holding the glyph storage. The char index and auxillary data arrays will be set. 88 * 89 * Output parameters: 90 * @param outChars - the output character arrayt 91 * @param charIndices - the output character index array 92 * @param featureTags - the output feature tag array 93 * @param success - set to an error code if the operation fails 94 * 95 * @return the output character count 96 * 97 * @internal 98 */ 99 virtual le_int32 characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft, 100 LEUnicode *&outChars, LEGlyphStorage &glyphStorage, LEErrorCode &success); 101 102 }; 103 104 U_NAMESPACE_END 105 #endif 106
