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1 /*
2  *
3  * (C) Copyright IBM Corp.  and others 1998-2014 - All Rights Reserved
4  *
5  */
6 
7 #ifndef __GXLAYOUTENGINE2_H
8 #define __GXLAYOUTENGINE2_H
9 
10 #include "LETypes.h"
11 #include "LayoutEngine.h"
12 
13 #include "MorphTables.h"
14 
15 U_NAMESPACE_BEGIN
16 
17 class LEFontInstance;
18 class LEGlyphStorage;
19 
20 /**
21  * This class implements layout for QuickDraw GX or Apple Advanced Typograyph (AAT)
22  * fonts. A font is a GX or AAT font if it contains a 'mort' table. See Apple's
23  * TrueType Reference Manual (http://fonts.apple.com/TTRefMan/index.html) for details.
24  * Information about 'mort' tables is in the chapter titled "Font Files."
25  *
26  * @internal
27  */
28 class GXLayoutEngine2 : public LayoutEngine
29 {
30 public:
31     /**
32      * This is the main constructor. It constructs an instance of GXLayoutEngine for
33      * a particular font, script and language. It takes the 'mort' table as a parameter since
34      * LayoutEngine::layoutEngineFactory has to read the 'mort' table to know that it has a
35      * GX font.
36      *
37      * Note: GX and AAT fonts don't contain any script and language specific tables, so
38      * the script and language are ignored.
39      *
40      * @param fontInstance - the font
41      * @param scriptCode - the script
42      * @param langaugeCode - the language
43      * @param morphTable - the 'mort' table
44      * @param success - set to an error code if the operation fails
45      *
46      * @see LayoutEngine::layoutEngineFactory
47      * @see ScriptAndLangaugeTags.h for script and language codes
48      *
49      * @internal
50      */
51     GXLayoutEngine2(const LEFontInstance *fontInstance, le_int32 scriptCode, le_int32 languageCode, const LEReferenceTo<MorphTableHeader2> &morphTable, le_int32 typoFlags, LEErrorCode &success);
52 
53     /**
54      * The destructor, virtual for correct polymorphic invocation.
55      *
56      * @internal
57      */
58     virtual ~GXLayoutEngine2();
59 
60     /**
61      * ICU "poor man's RTTI", returns a UClassID for the actual class.
62      *
63      * @deprecated ICU 54. See {@link icu::LayoutEngine}
64      */
65     virtual UClassID getDynamicClassID() const;
66 
67     /**
68      * ICU "poor man's RTTI", returns a UClassID for this class.
69      *
70      * @deprecated ICU 54. See {@link icu::LayoutEngine}
71      */
72     static UClassID getStaticClassID();
73 
74 protected:
75 
76     /**
77      * The address of the 'mort' table
78      *
79      * @internal
80      */
81     const LEReferenceTo<MorphTableHeader2> fMorphTable;
82 
83     /**
84      * This method does GX layout using the font's 'mort' table. It converts the
85      * input character codes to glyph indices using mapCharsToGlyphs, and then
86      * applies the 'mort' table.
87      *
88      * Input parameters:
89      * @param chars - the input character context
90      * @param offset - the index of the first character to process
91      * @param count - the number of characters to process
92      * @param max - the number of characters in the input context
93      * @param rightToLeft - <code>TRUE</code> if the text is in a right to left directional run
94      * @param glyphStorage - the glyph storage object. The glyph and char index arrays will be set.
95      *
96      * Output parameters:
97      * @param success - set to an error code if the operation fails
98      *
99      * @return the number of glyphs in the glyph index array
100      *
101      * @internal
102      */
103     virtual le_int32 computeGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, le_int32 max, le_bool rightToLeft,
104         LEGlyphStorage &glyphStorage, LEErrorCode &success);
105 
106     /**
107      * This method adjusts the glyph positions using the font's
108      * 'kern', 'trak', 'bsln', 'opbd' and 'just' tables.
109      *
110      * Input parameters:
111      * @param glyphStorage - the object holding the glyph storage. The positions will be updated as needed.
112      *
113      * Output parameters:
114      * @param success - set to an error code if the operation fails
115      *
116      * @internal
117      */
118     virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, le_int32 count, le_bool reverse,
119                                       LEGlyphStorage &glyphStorage, LEErrorCode &success);
120 
121 };
122 
123 U_NAMESPACE_END
124 #endif
125 
126