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


/*
 *
 * (C) Copyright IBM Corp. 1998-2005 - 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
     *
     * @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);

    /**
     * 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
     *
     * @see OpenTypeLayoutEngine
     * @see ScriptAndLanguageTags.h for script and language codes
     *
     * @internal
     */
    ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
			       le_int32 typoFlags);

    /**
     * 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
     *
     * @see LEFontInstance
     * @see ScriptAndLanguageTags.h for script and language codes
     *
     * @internal
     */
    UnicodeArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
		le_int32 typoFlags);

    /**
     * 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 filterZeroWidth - if <code>TRUE</code> replace ZWJ / ZWNJ with a glyph with no contours.
     * @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, le_bool filterZeroWidth,
        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	*
73c04bcf	4	* (C) Copyright IBM Corp. 1998-2005 - 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
	44	*
	45	* @see LayoutEngine::layoutEngineFactory
	46	* @see OpenTypeLayoutEngine
73c04bcf	47	* @see ScriptAndLanguageTags.h for script and language codes
b75a7d8f A	48	*
	49	* @internal
	50	*/
	51	ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
73c04bcf	52	le_int32 typoFlags, const GlyphSubstitutionTableHeader *gsubTable);
b75a7d8f A	53
	54	/**
	55	* This constructor is used when the font requires a "canned" GSUB table which can't be known
	56	* until after this constructor has been invoked.
	57	*
	58	* @param fontInstance - the font
	59	* @param scriptCode - the script
	60	* @param langaugeCode - the language
	61	*
	62	* @see OpenTypeLayoutEngine
73c04bcf	63	* @see ScriptAndLanguageTags.h for script and language codes
b75a7d8f A	64	*
	65	* @internal
	66	*/
73c04bcf A	67	ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
73c04bcf A	68	le_int32 typoFlags);
b75a7d8f A	69
	70	/**
	71	* The destructor, virtual for correct polymorphic invocation.
	72	*
	73	* @internal
	74	*/
	75	virtual ~ArabicOpenTypeLayoutEngine();
	76
	77	/**
	78	* ICU "poor man's RTTI", returns a UClassID for the actual class.
	79	*
374ca955	80	* @stable ICU 2.8
b75a7d8f	81	*/
374ca955	82	virtual UClassID getDynamicClassID() const;
b75a7d8f A	83
	84	/**
	85	* ICU "poor man's RTTI", returns a UClassID for this class.
	86	*
374ca955	87	* @stable ICU 2.8
b75a7d8f	88	*/
374ca955	89	static UClassID getStaticClassID();
b75a7d8f A	90
	91	protected:
	92
	93	/**
	94	* This method does Arabic OpenType character processing. It assigns the OpenType feature
	95	* tags to the characters to generate the correct contextual forms and ligatures.
	96	*
	97	* Input parameters:
	98	* @param chars - the input character context
	99	* @param offset - the index of the first character to process
	100	* @param count - the number of characters to process
	101	* @param max - the number of characters in the input context
374ca955	102	* @param rightToLeft - <code>TRUE</code> if the characters are in a right to left directional run
b75a7d8f A	103	*
	104	* Output parameters:
	105	* @param outChars - the output character arrayt
	106	* @param charIndices - the output character index array
	107	* @param featureTags - the output feature tag array
	108	* @param success - set to an error code if the operation fails
	109	*
	110	* @return the output character count
	111	*
	112	* @internal
	113	*/
	114	virtual le_int32 characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
374ca955	115	LEUnicode *&outChars, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f A	116
	117	/**
	118	* This method applies the GPOS table if it is present, otherwise it ensures that all vowel
	119	* and accent glyphs have a zero advance width by calling the adjustMarkGlyphs method.
	120	* If the font contains a GDEF table, that is used to identify voewls and accents. Otherwise
	121	* the character codes are used.
	122	*
	123	* @param chars - the input character context
	124	* @param offset - the offset of the first character to process
	125	* @param count - the number of characters to process
374ca955	126	* @param reverse - <code>TRUE</code> if the glyphs in the glyph array have been reordered
b75a7d8f A	127	* @param glyphs - the input glyph array
	128	* @param glyphCount - the number of glyphs
	129	* @param positions - the position array, will be updated as needed
	130	* @param success - output parameter set to an error code if the operation fails
	131	*
	132	* @internal
	133	*/
374ca955	134	virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f	135
374ca955	136	// static void adjustMarkGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool rightToLeft, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f	137
b75a7d8f A	138	};
	139
	140	/**
	141	* The class implements OpenType layout for Arabic fonts which don't
	142	* contain a GSUB table, using a canned GSUB table based on Unicode
	143	* Arabic Presentation Forms. It overrides the mapCharsToGlyphs method
	144	* to use the Presentation Forms as logical glyph indices. It overrides the
	145	* glyphPostProcessing method to convert the Presentation Forms to actual
	146	* glyph indices.
	147	*
	148	* @see ArabicOpenTypeLayoutEngine
	149	*
	150	* @internal
	151	*/
	152	class UnicodeArabicOpenTypeLayoutEngine : public ArabicOpenTypeLayoutEngine
	153	{
	154	public:
	155	/**
	156	* This constructs an instance of UnicodeArabicOpenTypeLayoutEngine for a specific font,
	157	* script and language.
	158	*
	159	* @param fontInstance - the font
	160	* @param scriptCode - the script
	161	* @param languageCode - the language
	162	*
	163	* @see LEFontInstance
	164	* @see ScriptAndLanguageTags.h for script and language codes
	165	*
	166	* @internal
	167	*/
73c04bcf A	168	UnicodeArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
73c04bcf A	169	le_int32 typoFlags);
b75a7d8f A	170
	171	/**
	172	* The destructor, virtual for correct polymorphic invocation.
	173	*
	174	* @internal
	175	*/
	176	virtual ~UnicodeArabicOpenTypeLayoutEngine();
	177
	178	protected:
	179
	180	/**
	181	* This method converts the Arabic Presentation Forms in the temp glyph array
	182	* into actual glyph indices using ArabicOpenTypeLayoutEngine::mapCharsToGlyps.
	183	*
	184	* Input paramters:
	185	* @param tempGlyphs - the input presentation forms
	186	* @param tempCharIndices - the input character index array
	187	* @param tempGlyphCount - the number of Presentation Froms
	188	*
	189	* Output parameters:
	190	* @param glyphs - the output glyph index array
	191	* @param charIndices - the output character index array
	192	* @param success - set to an error code if the operation fails
	193	*
	194	* @return the number of glyph indices in the output glyph index array
	195	*
	196	* @internal
	197	*/
374ca955	198	virtual le_int32 glyphPostProcessing(LEGlyphStorage &tempGlyphStorage, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f A	199
	200	/**
	201	* This method copies the input characters into the output glyph index array,
	202	* for use by the canned GSUB table. It also generates the character index array.
	203	*
	204	* Input parameters:
	205	* @param chars - the input character context
	206	* @param offset - the offset of the first character to be mapped
	207	* @param count - the number of characters to be mapped
374ca955 A	208	* @param reverse - if <code>TRUE</code>, the output will be in reverse order
374ca955 A	209	* @param mirror - if <code>TRUE</code>, do character mirroring
73c04bcf	210	* @param filterZeroWidth - if <code>TRUE</code> replace ZWJ / ZWNJ with a glyph with no contours.
374ca955	211	* @param glyphStorage - the glyph storage object. Glyph and char index arrays will be updated.
b75a7d8f	212	*
b75a7d8f A	213	* @param success - set to an error code if the operation fails
	214	*
	215	* @internal
	216	*/
73c04bcf	217	virtual void mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, le_bool mirror, le_bool filterZeroWidth,
374ca955	218	LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f A	219
	220	/**
	221	* This method ensures that all vowel and accent glyphs have a zero advance width by calling
	222	* the adjustMarkGlyphs method. The character codes are used to identify the vowel and mark
	223	* glyphs.
	224	*
	225	* @param chars - the input character context
	226	* @param offset - the offset of the first character to process
	227	* @param count - the number of characters to process
374ca955 A	228	* @param reverse - <code>TRUE</code> if the glyphs in the glyph array have been reordered
374ca955 A	229	* @param glyphStorage - the glyph storage object. The glyph positions will be updated as needed.
b75a7d8f A	230	* @param success - output parameter set to an error code if the operation fails
	231	*
	232	* @internal
	233	*/
374ca955	234	virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f A	235	};
	236
	237	U_NAMESPACE_END
	238	#endif
	239