1 2 /* 3 * 4 * (C) Copyright IBM Corp. 1998-2008 - All Rights Reserved 5 * 6 * This file is a modification of the ICU file IndicLayoutEngine.h 7 * by Jens Herden and Javier Sola for Khmer language 8 * 9 */ 10 11 #ifndef __KHMERLAYOUTENGINE_H 12 #define __KHMERLAYOUTENGINE_H 13 14 // #include "LETypes.h" 15 // #include "LEFontInstance.h" 16 // #include "LEGlyphFilter.h" 17 // #include "LayoutEngine.h" 18 // #include "OpenTypeLayoutEngine.h" 19 20 // #include "GlyphSubstitutionTables.h" 21 // #include "GlyphDefinitionTables.h" 22 // #include "GlyphPositioningTables.h" 23 24 U_NAMESPACE_BEGIN 25 26 // class MPreFixups; 27 // class LEGlyphStorage; 28 29 /** 30 * This class implements OpenType layout for Khmer OpenType fonts, as 31 * specified by Microsoft in "Creating and Supporting OpenType Fonts for 32 * Khmer Scripts" (http://www.microsoft.com/typography/otspec/indicot/default.htm) TODO: change url 33 * 34 * This class overrides the characterProcessing method to do Khmer character processing 35 * and reordering (See the MS spec. for more details) 36 * 37 * @internal 38 */ 39 class KhmerOpenTypeLayoutEngine : public OpenTypeLayoutEngine 40 { 41 public: 42 /** 43 * This is the main constructor. It constructs an instance of KhmerOpenTypeLayoutEngine for 44 * a particular font, script and language. It takes the GSUB table as a parameter since 45 * LayoutEngine::layoutEngineFactory has to read the GSUB table to know that it has an 46 * Khmer OpenType font. 47 * 48 * @param fontInstance - the font 49 * @param scriptCode - the script 50 * @param langaugeCode - the language 51 * @param gsubTable - the GSUB table 52 * @param success - set to an error code if the operation fails 53 * 54 * @see LayoutEngine::layoutEngineFactory 55 * @see OpenTypeLayoutEngine 56 * @see ScriptAndLangaugeTags.h for script and language codes 57 * 58 * @internal 59 */ 60 KhmerOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, 61 le_int32 typoFlags, const GlyphSubstitutionTableHeader *gsubTable, LEErrorCode &success); 62 63 /** 64 * This constructor is used when the font requires a "canned" GSUB table which can't be known 65 * until after this constructor has been invoked. 66 * 67 * @param fontInstance - the font 68 * @param scriptCode - the script 69 * @param langaugeCode - the language 70 * @param success - set to an error code if the operation fails 71 * 72 * @see OpenTypeLayoutEngine 73 * @see ScriptAndLangaugeTags.h for script and language codes 74 * 75 * @internal 76 */ 77 KhmerOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, 78 le_int32 typoFlags, LEErrorCode &success); 79 80 /** 81 * The destructor, virtual for correct polymorphic invocation. 82 * 83 * @internal 84 */ 85 virtual ~KhmerOpenTypeLayoutEngine(); 86 87 /** 88 * ICU "poor man's RTTI", returns a UClassID for the actual class. 89 * 90 * @stable ICU 2.8 91 */ 92 virtual UClassID getDynamicClassID() const; 93 94 /** 95 * ICU "poor man's RTTI", returns a UClassID for this class. 96 * 97 * @stable ICU 2.8 98 */ 99 static UClassID getStaticClassID(); 100 101 protected: 102 103 /** 104 * This method does Khmer OpenType character processing. It assigns the OpenType feature 105 * tags to the characters, and may generate output characters which have been reordered. 106 * It may also split some vowels, resulting in more output characters than input characters. 107 * 108 * Input parameters: 109 * @param chars - the input character context 110 * @param offset - the index of the first character to process 111 * @param count - the number of characters to process 112 * @param max - the number of characters in the input context 113 * @param rightToLeft - <code>TRUE</code> if the characters are in a right to left directional run 114 * @param glyphStorage - the glyph storage object. The glyph and character index arrays will be set. 115 * the auxillary data array will be set to the feature tags. 116 * 117 * Output parameters: 118 * @param success - set to an error code if the operation fails 119 * 120 * @return the output character count 121 * 122 * @internal 123 */ 124 virtual le_int32 characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft, 125 LEUnicode *&outChars, LEGlyphStorage &glyphStorage, LEErrorCode &success); 126 127 }; 128 129 U_NAMESPACE_END 130 #endif 131 132