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/*
* HanLayoutEngine.h: OpenType processing for Han fonts.
*
* (C) Copyright IBM Corp. 1998-2008 - All Rights Reserved.
*/
#ifndef __HANLAYOUTENGINE_H
#define __HANLAYOUTENGINE_H
#include "LETypes.h"
#include "LEFontInstance.h"
#include "LayoutEngine.h"
#include "OpenTypeLayoutEngine.h"
#include "GlyphSubstitutionTables.h"
U_NAMESPACE_BEGIN
class LEGlyphStorage;
/**
* This class implements OpenType layout for Han fonts. It overrides
* the characerProcessing method to assign the correct OpenType feature
* tags for the CJK language-specific forms.
*
* @internal
*/
class HanOpenTypeLayoutEngine : public OpenTypeLayoutEngine
{
public:
/**
* This is the main constructor. It constructs an instance of HanOpenTypeLayoutEngine 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 a
* Han 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 ScriptAndLangaugeTags.h for script and language codes
*
* @internal
*/
HanOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
le_int32 typoFlags, const GlyphSubstitutionTableHeader *gsubTablem, LEErrorCode &success);
/**
* The destructor, virtual for correct polymorphic invocation.
*
* @internal
*/
virtual ~HanOpenTypeLayoutEngine();
/**
* ICU "poor man's RTTI", returns a UClassID for the actual class.
*
* @stable ICU 2.8
*/
virtual UClassID getDynamicClassID() const;
/**
* ICU "poor man's RTTI", returns a UClassID for this class.
*
* @stable ICU 2.8
*/
static UClassID getStaticClassID();
protected:
/**
* This method does Han OpenType character processing. It assigns the OpenType feature
* tags to the characters to generate the correct language-specific variants.
*
* 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
* @param glyphStorage - the object holding the glyph storage. The char index and auxillary data arrays will be set.
*
* 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);
};
U_NAMESPACE_END
#endif