[apple/icu.git] / icuSources / layout / ArabicLayoutEngine.h


/*
 *
 * (C) Copyright IBM Corp. 1998-2008 - All Rights Reserved
 *
 */

#ifndef __ARABICLAYOUTENGINE_H
#define __ARABICLAYOUTENGINE_H

#include "LETypes.h"
#include "LEFontInstance.h"
#include "LEGlyphFilter.h"
#include "LayoutEngine.h"
#include "OpenTypeLayoutEngine.h"

#include "GlyphSubstitutionTables.h"
#include "GlyphDefinitionTables.h"
#include "GlyphPositioningTables.h"

U_NAMESPACE_BEGIN

/**
 * This class implements OpenType layout for Arabic fonts. It overrides
 * the characerProcessing method to assign the correct OpenType feature
 * tags for the Arabic contextual forms. It also overrides the adjustGlyphPositions
 * method to guarantee that all vowel and accent glyphs have zero advance width.
 *
 * @internal
 */
class ArabicOpenTypeLayoutEngine : public OpenTypeLayoutEngine
{
public:
    /**
     * This is the main constructor. It constructs an instance of ArabicOpenTypeLayoutEngine 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 an
     * Indic 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 ScriptAndLanguageTags.h for script and language codes
     *
     * @internal
     */
    ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
                            le_int32 typoFlags, const GlyphSubstitutionTableHeader *gsubTable, LEErrorCode &success);

    /**
     * This constructor is used when the font requires a "canned" GSUB table which can't be known
     * until after this constructor has been invoked.
     *
     * @param fontInstance - the font
     * @param scriptCode - the script
     * @param langaugeCode - the language
     * @param success - set to an error code if the operation fails
     *
     * @see OpenTypeLayoutEngine
     * @see ScriptAndLanguageTags.h for script and language codes
     *
     * @internal
     */
    ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
			       le_int32 typoFlags, LEErrorCode &success);

    /**
     * The destructor, virtual for correct polymorphic invocation.
     *
     * @internal
     */
    virtual ~ArabicOpenTypeLayoutEngine();

    /**
     * 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 Arabic OpenType character processing. It assigns the OpenType feature
     * tags to the characters to generate the correct contextual forms and ligatures.
     *
     * 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
     *
     * 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);

    /**
     * This method applies the GPOS table if it is present, otherwise it ensures that all vowel
     * and accent glyphs have a zero advance width by calling the adjustMarkGlyphs method.
     * If the font contains a GDEF table, that is used to identify voewls and accents. Otherwise
     * the character codes are used.
     *
     * @param chars - the input character context
     * @param offset - the offset of the first character to process
     * @param count - the number of characters to process
     * @param reverse - <code>TRUE</code> if the glyphs in the glyph array have been reordered
     * @param glyphs - the input glyph array
     * @param glyphCount - the number of glyphs
     * @param positions - the position array, will be updated as needed
     * @param success - output parameter set to an error code if the operation fails
     *
     * @internal
     */
    virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, LEGlyphStorage &glyphStorage, LEErrorCode &success);

    // static void adjustMarkGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool rightToLeft, LEGlyphStorage &glyphStorage, LEErrorCode &success);

};

/**
 * The class implements OpenType layout for Arabic fonts which don't
 * contain a GSUB table, using a canned GSUB table based on Unicode
 * Arabic Presentation Forms. It overrides the mapCharsToGlyphs method
 * to use the Presentation Forms as logical glyph indices. It overrides the
 * glyphPostProcessing method to convert the Presentation Forms to actual
 * glyph indices.
 *
 * @see ArabicOpenTypeLayoutEngine
 *
 * @internal
 */
class UnicodeArabicOpenTypeLayoutEngine : public ArabicOpenTypeLayoutEngine
{
public:
    /**
     * This constructs an instance of UnicodeArabicOpenTypeLayoutEngine for a specific font,
     * script and language.
     *
     * @param fontInstance - the font
     * @param scriptCode - the script
     * @param languageCode - the language
     * @param success - set to an error code if the operation fails
     *
     * @see LEFontInstance
     * @see ScriptAndLanguageTags.h for script and language codes
     *
     * @internal
     */
    UnicodeArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
		le_int32 typoFlags, LEErrorCode &success);

    /**
     * The destructor, virtual for correct polymorphic invocation.
     *
     * @internal
     */
    virtual ~UnicodeArabicOpenTypeLayoutEngine();

protected:

    /**
     * This method converts the Arabic Presentation Forms in the temp glyph array
     * into actual glyph indices using ArabicOpenTypeLayoutEngine::mapCharsToGlyps.
     *
     * Input paramters:
     * @param tempGlyphs - the input presentation forms
     * @param tempCharIndices - the input character index array
     * @param tempGlyphCount - the number of Presentation Froms
     *
     * Output parameters:
     * @param glyphs - the output glyph index array
     * @param charIndices - the output character index array
     * @param success - set to an error code if the operation fails
     *
     * @return the number of glyph indices in the output glyph index array
     *
     * @internal
     */
    virtual le_int32 glyphPostProcessing(LEGlyphStorage &tempGlyphStorage, LEGlyphStorage &glyphStorage, LEErrorCode &success);

    /**
     * This method copies the input characters into the output glyph index array,
     * for use by the canned GSUB table. It also generates the character index array.
     *
     * Input parameters:
     * @param chars - the input character context
     * @param offset - the offset of the first character to be mapped
     * @param count - the number of characters to be mapped
     * @param reverse - if <code>TRUE</code>, the output will be in reverse order
     * @param mirror - if <code>TRUE</code>, do character mirroring
     * @param glyphStorage - the glyph storage object. Glyph and char index arrays will be updated.
     *
     * @param success - set to an error code if the operation fails
     *
     * @internal
     */
    virtual void mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, le_bool mirror,
        LEGlyphStorage &glyphStorage, LEErrorCode &success);

    /**
     * This method ensures that all vowel and accent glyphs have a zero advance width by calling
     * the adjustMarkGlyphs method. The character codes are used to identify the vowel and mark
     * glyphs.
     *
     * @param chars - the input character context
     * @param offset - the offset of the first character to process
     * @param count - the number of characters to process
     * @param reverse - <code>TRUE</code> if the glyphs in the glyph array have been reordered
     * @param glyphStorage - the glyph storage object. The glyph positions will be updated as needed.
     * @param success - output parameter set to an error code if the operation fails
     *
     * @internal
     */
    virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, LEGlyphStorage &glyphStorage, LEErrorCode &success);
};

U_NAMESPACE_END
#endif
Commit	Line	Data
b75a7d8f A	1
b75a7d8f A	2	/*
b75a7d8f	3	*
729e4ab9	4	* (C) Copyright IBM Corp. 1998-2008 - All Rights Reserved
b75a7d8f A	5	*
	6	*/
	7
	8	#ifndef __ARABICLAYOUTENGINE_H
	9	#define __ARABICLAYOUTENGINE_H
	10
	11	#include "LETypes.h"
	12	#include "LEFontInstance.h"
	13	#include "LEGlyphFilter.h"
	14	#include "LayoutEngine.h"
	15	#include "OpenTypeLayoutEngine.h"
	16
	17	#include "GlyphSubstitutionTables.h"
	18	#include "GlyphDefinitionTables.h"
	19	#include "GlyphPositioningTables.h"
	20
	21	U_NAMESPACE_BEGIN
	22
	23	/**
	24	* This class implements OpenType layout for Arabic fonts. It overrides
	25	* the characerProcessing method to assign the correct OpenType feature
	26	* tags for the Arabic contextual forms. It also overrides the adjustGlyphPositions
	27	* method to guarantee that all vowel and accent glyphs have zero advance width.
	28	*
	29	* @internal
	30	*/
	31	class ArabicOpenTypeLayoutEngine : public OpenTypeLayoutEngine
	32	{
	33	public:
	34	/**
	35	* This is the main constructor. It constructs an instance of ArabicOpenTypeLayoutEngine for
	36	* a particular font, script and language. It takes the GSUB table as a parameter since
	37	* LayoutEngine::layoutEngineFactory has to read the GSUB table to know that it has an
	38	* Indic OpenType font.
	39	*
	40	* @param fontInstance - the font
	41	* @param scriptCode - the script
	42	* @param langaugeCode - the language
	43	* @param gsubTable - the GSUB table
729e4ab9	44	* @param success - set to an error code if the operation fails
b75a7d8f A	45	*
	46	* @see LayoutEngine::layoutEngineFactory
	47	* @see OpenTypeLayoutEngine
73c04bcf	48	* @see ScriptAndLanguageTags.h for script and language codes
b75a7d8f A	49	*
	50	* @internal
	51	*/
	52	ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
729e4ab9	53	le_int32 typoFlags, const GlyphSubstitutionTableHeader *gsubTable, LEErrorCode &success);
b75a7d8f A	54
	55	/**
	56	* This constructor is used when the font requires a "canned" GSUB table which can't be known
	57	* until after this constructor has been invoked.
	58	*
	59	* @param fontInstance - the font
	60	* @param scriptCode - the script
	61	* @param langaugeCode - the language
729e4ab9	62	* @param success - set to an error code if the operation fails
b75a7d8f A	63	*
b75a7d8f A	64	* @see OpenTypeLayoutEngine
73c04bcf	65	* @see ScriptAndLanguageTags.h for script and language codes
b75a7d8f A	66	*
	67	* @internal
	68	*/
73c04bcf	69	ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
729e4ab9	70	le_int32 typoFlags, LEErrorCode &success);
b75a7d8f A	71
	72	/**
	73	* The destructor, virtual for correct polymorphic invocation.
	74	*
	75	* @internal
	76	*/
	77	virtual ~ArabicOpenTypeLayoutEngine();
	78
	79	/**
	80	* ICU "poor man's RTTI", returns a UClassID for the actual class.
	81	*
374ca955	82	* @stable ICU 2.8
b75a7d8f	83	*/
374ca955	84	virtual UClassID getDynamicClassID() const;
b75a7d8f A	85
	86	/**
	87	* ICU "poor man's RTTI", returns a UClassID for this class.
	88	*
374ca955	89	* @stable ICU 2.8
b75a7d8f	90	*/
374ca955	91	static UClassID getStaticClassID();
b75a7d8f A	92
	93	protected:
	94
	95	/**
	96	* This method does Arabic OpenType character processing. It assigns the OpenType feature
	97	* tags to the characters to generate the correct contextual forms and ligatures.
	98	*
	99	* Input parameters:
	100	* @param chars - the input character context
	101	* @param offset - the index of the first character to process
	102	* @param count - the number of characters to process
	103	* @param max - the number of characters in the input context
374ca955	104	* @param rightToLeft - <code>TRUE</code> if the characters are in a right to left directional run
b75a7d8f A	105	*
	106	* Output parameters:
	107	* @param outChars - the output character arrayt
	108	* @param charIndices - the output character index array
	109	* @param featureTags - the output feature tag array
	110	* @param success - set to an error code if the operation fails
	111	*
	112	* @return the output character count
	113	*
	114	* @internal
	115	*/
	116	virtual le_int32 characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
374ca955	117	LEUnicode *&outChars, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f A	118
	119	/**
	120	* This method applies the GPOS table if it is present, otherwise it ensures that all vowel
	121	* and accent glyphs have a zero advance width by calling the adjustMarkGlyphs method.
	122	* If the font contains a GDEF table, that is used to identify voewls and accents. Otherwise
	123	* the character codes are used.
	124	*
	125	* @param chars - the input character context
	126	* @param offset - the offset of the first character to process
	127	* @param count - the number of characters to process
374ca955	128	* @param reverse - <code>TRUE</code> if the glyphs in the glyph array have been reordered
b75a7d8f A	129	* @param glyphs - the input glyph array
	130	* @param glyphCount - the number of glyphs
	131	* @param positions - the position array, will be updated as needed
	132	* @param success - output parameter set to an error code if the operation fails
	133	*
	134	* @internal
	135	*/
374ca955	136	virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f	137
374ca955	138	// static void adjustMarkGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool rightToLeft, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f	139
b75a7d8f A	140	};
	141
	142	/**
	143	* The class implements OpenType layout for Arabic fonts which don't
	144	* contain a GSUB table, using a canned GSUB table based on Unicode
	145	* Arabic Presentation Forms. It overrides the mapCharsToGlyphs method
	146	* to use the Presentation Forms as logical glyph indices. It overrides the
	147	* glyphPostProcessing method to convert the Presentation Forms to actual
	148	* glyph indices.
	149	*
	150	* @see ArabicOpenTypeLayoutEngine
	151	*
	152	* @internal
	153	*/
	154	class UnicodeArabicOpenTypeLayoutEngine : public ArabicOpenTypeLayoutEngine
	155	{
	156	public:
	157	/**
	158	* This constructs an instance of UnicodeArabicOpenTypeLayoutEngine for a specific font,
	159	* script and language.
	160	*
	161	* @param fontInstance - the font
	162	* @param scriptCode - the script
	163	* @param languageCode - the language
729e4ab9	164	* @param success - set to an error code if the operation fails
b75a7d8f A	165	*
	166	* @see LEFontInstance
	167	* @see ScriptAndLanguageTags.h for script and language codes
	168	*
	169	* @internal
	170	*/
73c04bcf	171	UnicodeArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
729e4ab9	172	le_int32 typoFlags, LEErrorCode &success);
b75a7d8f A	173
	174	/**
	175	* The destructor, virtual for correct polymorphic invocation.
	176	*
	177	* @internal
	178	*/
	179	virtual ~UnicodeArabicOpenTypeLayoutEngine();
	180
	181	protected:
	182
	183	/**
	184	* This method converts the Arabic Presentation Forms in the temp glyph array
	185	* into actual glyph indices using ArabicOpenTypeLayoutEngine::mapCharsToGlyps.
	186	*
	187	* Input paramters:
	188	* @param tempGlyphs - the input presentation forms
	189	* @param tempCharIndices - the input character index array
	190	* @param tempGlyphCount - the number of Presentation Froms
	191	*
	192	* Output parameters:
	193	* @param glyphs - the output glyph index array
	194	* @param charIndices - the output character index array
	195	* @param success - set to an error code if the operation fails
	196	*
	197	* @return the number of glyph indices in the output glyph index array
	198	*
	199	* @internal
	200	*/
374ca955	201	virtual le_int32 glyphPostProcessing(LEGlyphStorage &tempGlyphStorage, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f A	202
	203	/**
	204	* This method copies the input characters into the output glyph index array,
	205	* for use by the canned GSUB table. It also generates the character index array.
	206	*
	207	* Input parameters:
	208	* @param chars - the input character context
	209	* @param offset - the offset of the first character to be mapped
	210	* @param count - the number of characters to be mapped
374ca955 A	211	* @param reverse - if <code>TRUE</code>, the output will be in reverse order
	212	* @param mirror - if <code>TRUE</code>, do character mirroring
	213	* @param glyphStorage - the glyph storage object. Glyph and char index arrays will be updated.
b75a7d8f	214	*
b75a7d8f A	215	* @param success - set to an error code if the operation fails
	216	*
	217	* @internal
	218	*/
46f4442e	219	virtual void mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, le_bool mirror,
374ca955	220	LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f A	221
	222	/**
	223	* This method ensures that all vowel and accent glyphs have a zero advance width by calling
	224	* the adjustMarkGlyphs method. The character codes are used to identify the vowel and mark
	225	* glyphs.
	226	*
	227	* @param chars - the input character context
	228	* @param offset - the offset of the first character to process
	229	* @param count - the number of characters to process
374ca955 A	230	* @param reverse - <code>TRUE</code> if the glyphs in the glyph array have been reordered
374ca955 A	231	* @param glyphStorage - the glyph storage object. The glyph positions will be updated as needed.
b75a7d8f A	232	* @param success - output parameter set to an error code if the operation fails
	233	*
	234	* @internal
	235	*/
374ca955	236	virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f A	237	};
	238
	239	U_NAMESPACE_END
	240	#endif
	241