/*

 * HanLayoutEngine.h: OpenType processing for Han fonts.

 *

 * (C) Copyright IBM Corp. 1998-2005 - 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

     *

     * @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 *gsubTable);

    /**

     * 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