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


/*
 *
 * (C) Copyright IBM Corp. 1998-2004 - 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 ScriptAndLangaugeTags.h for script and language codes
     *
     * @internal
     */
    ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
                            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 ScriptAndLangaugeTags.h for script and language codes
     *
     * @internal
     */
    ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode);

    /**
     * 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);

    /**
     * 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	*
374ca955	4	* (C) Copyright IBM Corp. 1998-2004 - 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
	47	* @see ScriptAndLangaugeTags.h for script and language codes
	48	*
	49	* @internal
	50	*/
	51	ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode,
	52	const GlyphSubstitutionTableHeader *gsubTable);
	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
	63	* @see ScriptAndLangaugeTags.h for script and language codes
	64	*
	65	* @internal
	66	*/
	67	ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode);
	68
69	/**
70	* The destructor, virtual for correct polymorphic invocation.
71	*
72	* @internal
73	*/
74	virtual ~ArabicOpenTypeLayoutEngine();
75
76	/**
77	* ICU "poor man's RTTI", returns a UClassID for the actual class.
78	*
374ca955	79	* @stable ICU 2.8
b75a7d8f	80	*/
374ca955	81	virtual UClassID getDynamicClassID() const;
b75a7d8f A	82
	83	/**
	84	* ICU "poor man's RTTI", returns a UClassID for this class.
	85	*
374ca955	86	* @stable ICU 2.8
b75a7d8f	87	*/
374ca955	88	static UClassID getStaticClassID();
b75a7d8f A	89
	90	protected:
	91
	92	/**
	93	* This method does Arabic OpenType character processing. It assigns the OpenType feature
	94	* tags to the characters to generate the correct contextual forms and ligatures.
	95	*
	96	* Input parameters:
	97	* @param chars - the input character context
	98	* @param offset - the index of the first character to process
	99	* @param count - the number of characters to process
	100	* @param max - the number of characters in the input context
374ca955	101	* @param rightToLeft - <code>TRUE</code> if the characters are in a right to left directional run
b75a7d8f A	102	*
	103	* Output parameters:
	104	* @param outChars - the output character arrayt
	105	* @param charIndices - the output character index array
	106	* @param featureTags - the output feature tag array
	107	* @param success - set to an error code if the operation fails
	108	*
	109	* @return the output character count
	110	*
	111	* @internal
	112	*/
	113	virtual le_int32 characterProcessing(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
374ca955	114	LEUnicode *&outChars, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f A	115
	116	/**
	117	* This method applies the GPOS table if it is present, otherwise it ensures that all vowel
	118	* and accent glyphs have a zero advance width by calling the adjustMarkGlyphs method.
	119	* If the font contains a GDEF table, that is used to identify voewls and accents. Otherwise
	120	* the character codes are used.
	121	*
	122	* @param chars - the input character context
	123	* @param offset - the offset of the first character to process
	124	* @param count - the number of characters to process
374ca955	125	* @param reverse - <code>TRUE</code> if the glyphs in the glyph array have been reordered
b75a7d8f A	126	* @param glyphs - the input glyph array
	127	* @param glyphCount - the number of glyphs
	128	* @param positions - the position array, will be updated as needed
	129	* @param success - output parameter set to an error code if the operation fails
	130	*
	131	* @internal
	132	*/
374ca955	133	virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f	134
374ca955	135	// static void adjustMarkGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool rightToLeft, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f	136
b75a7d8f A	137	};
	138
	139	/**
	140	* The class implements OpenType layout for Arabic fonts which don't
	141	* contain a GSUB table, using a canned GSUB table based on Unicode
	142	* Arabic Presentation Forms. It overrides the mapCharsToGlyphs method
	143	* to use the Presentation Forms as logical glyph indices. It overrides the
	144	* glyphPostProcessing method to convert the Presentation Forms to actual
	145	* glyph indices.
	146	*
	147	* @see ArabicOpenTypeLayoutEngine
	148	*
	149	* @internal
	150	*/
	151	class UnicodeArabicOpenTypeLayoutEngine : public ArabicOpenTypeLayoutEngine
	152	{
	153	public:
	154	/**
	155	* This constructs an instance of UnicodeArabicOpenTypeLayoutEngine for a specific font,
	156	* script and language.
	157	*
	158	* @param fontInstance - the font
	159	* @param scriptCode - the script
	160	* @param languageCode - the language
	161	*
	162	* @see LEFontInstance
	163	* @see ScriptAndLanguageTags.h for script and language codes
	164	*
	165	* @internal
	166	*/
	167	UnicodeArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode);
	168
	169	/**
	170	* The destructor, virtual for correct polymorphic invocation.
	171	*
	172	* @internal
	173	*/
	174	virtual ~UnicodeArabicOpenTypeLayoutEngine();
	175
	176	protected:
	177
	178	/**
	179	* This method converts the Arabic Presentation Forms in the temp glyph array
	180	* into actual glyph indices using ArabicOpenTypeLayoutEngine::mapCharsToGlyps.
	181	*
	182	* Input paramters:
	183	* @param tempGlyphs - the input presentation forms
	184	* @param tempCharIndices - the input character index array
	185	* @param tempGlyphCount - the number of Presentation Froms
	186	*
	187	* Output parameters:
	188	* @param glyphs - the output glyph index array
	189	* @param charIndices - the output character index array
	190	* @param success - set to an error code if the operation fails
	191	*
	192	* @return the number of glyph indices in the output glyph index array
	193	*
	194	* @internal
	195	*/
374ca955	196	virtual le_int32 glyphPostProcessing(LEGlyphStorage &tempGlyphStorage, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f A	197
	198	/**
	199	* This method copies the input characters into the output glyph index array,
	200	* for use by the canned GSUB table. It also generates the character index array.
	201	*
	202	* Input parameters:
	203	* @param chars - the input character context
	204	* @param offset - the offset of the first character to be mapped
	205	* @param count - the number of characters to be mapped
374ca955 A	206	* @param reverse - if <code>TRUE</code>, the output will be in reverse order
	207	* @param mirror - if <code>TRUE</code>, do character mirroring
	208	* @param glyphStorage - the glyph storage object. Glyph and char index arrays will be updated.
b75a7d8f	209	*
b75a7d8f A	210	* @param success - set to an error code if the operation fails
	211	*
	212	* @internal
	213	*/
	214	virtual void mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, le_bool mirror,
374ca955	215	LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f A	216
	217	/**
	218	* This method ensures that all vowel and accent glyphs have a zero advance width by calling
	219	* the adjustMarkGlyphs method. The character codes are used to identify the vowel and mark
	220	* glyphs.
	221	*
	222	* @param chars - the input character context
	223	* @param offset - the offset of the first character to process
	224	* @param count - the number of characters to process
374ca955 A	225	* @param reverse - <code>TRUE</code> if the glyphs in the glyph array have been reordered
374ca955 A	226	* @param glyphStorage - the glyph storage object. The glyph positions will be updated as needed.
b75a7d8f A	227	* @param success - output parameter set to an error code if the operation fails
	228	*
	229	* @internal
	230	*/
374ca955	231	virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse, LEGlyphStorage &glyphStorage, LEErrorCode &success);
b75a7d8f A	232	};
	233
	234	U_NAMESPACE_END
	235	#endif
	236