4 * (C) Copyright IBM Corp. 1998-2005 - All Rights Reserved
6 * This file is a modification of the ICU file IndicLayoutEngine.h
7 * by Jens Herden and Javier Sola for Khmer language
11 #ifndef __KHMERLAYOUTENGINE_H
12 #define __KHMERLAYOUTENGINE_H
14 // #include "LETypes.h"
15 // #include "LEFontInstance.h"
16 // #include "LEGlyphFilter.h"
17 // #include "LayoutEngine.h"
18 // #include "OpenTypeLayoutEngine.h"
20 // #include "GlyphSubstitutionTables.h"
21 // #include "GlyphDefinitionTables.h"
22 // #include "GlyphPositioningTables.h"
27 // class LEGlyphStorage;
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
34 * This class overrides the characterProcessing method to do Khmer character processing
35 * and reordering (See the MS spec. for more details)
39 class KhmerOpenTypeLayoutEngine : public OpenTypeLayoutEngine
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.
48 * @param fontInstance - the font
49 * @param scriptCode - the script
50 * @param langaugeCode - the language
51 * @param gsubTable - the GSUB table
53 * @see LayoutEngine::layoutEngineFactory
54 * @see OpenTypeLayoutEngine
55 * @see ScriptAndLangaugeTags.h for script and language codes
59 KhmerOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
60 le_int32 typoFlags, const GlyphSubstitutionTableHeader *gsubTable);
63 * This constructor is used when the font requires a "canned" GSUB table which can't be known
64 * until after this constructor has been invoked.
66 * @param fontInstance - the font
67 * @param scriptCode - the script
68 * @param langaugeCode - the language
70 * @see OpenTypeLayoutEngine
71 * @see ScriptAndLangaugeTags.h for script and language codes
75 KhmerOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
79 * The destructor, virtual for correct polymorphic invocation.
83 virtual ~KhmerOpenTypeLayoutEngine();
86 * ICU "poor man's RTTI", returns a UClassID for the actual class.
90 virtual UClassID getDynamicClassID() const;
93 * ICU "poor man's RTTI", returns a UClassID for this class.
97 static UClassID getStaticClassID();
102 * This method does Khmer OpenType character processing. It assigns the OpenType feature
103 * tags to the characters, and may generate output characters which have been reordered.
104 * It may also split some vowels, resulting in more output characters than input characters.
107 * @param chars - the input character context
108 * @param offset - the index of the first character to process
109 * @param count - the number of characters to process
110 * @param max - the number of characters in the input context
111 * @param rightToLeft - <code>TRUE</code> if the characters are in a right to left directional run
112 * @param glyphStorage - the glyph storage object. The glyph and character index arrays will be set.
113 * the auxillary data array will be set to the feature tags.
116 * @param success - set to an error code if the operation fails
118 * @return the output character count
122 virtual le_int32 characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
123 LEUnicode *&outChars, LEGlyphStorage &glyphStorage, LEErrorCode &success);