icuSources/layout/ArabicShaping.h

   1 /*
   2  * @(#)ArabicShaping.h  1.6 00/03/15
   3  *
   4  * (C) Copyright IBM Corp. 1998-2003 - All Rights Reserved
   5  *
   6  */
   7
   8 #ifndef __ARABICSHAPING_H
   9 #define __ARABICSHAPING_H
  10
  11 /**
  12  * \file
  13  * \internal
  14  */
  15
  16 #include "LETypes.h"
  17 #include "OpenTypeTables.h"
  18
  19 U_NAMESPACE_BEGIN
  20
  21 class Shaper /* not : public UObject because this is an interface/mixin class */ {
  22 public:
  23     virtual inline ~Shaper() {};
  24     virtual void init(LEUnicode ch, le_int32 outIndex, le_bool isloate) = 0;
  25     virtual void shape(le_int32 outIndex, le_int32 shapeOffset) = 0;
  26 };
  27
  28 class ArabicShaping /* not : public UObject because all methods are static */ {
  29 public:
  30     // shaping bit masks
  31     enum ShapingBitMasks
  32     {
  33         MASK_SHAPE_RIGHT    = 1, // if this bit set, shapes to right
  34         MASK_SHAPE_LEFT     = 2, // if this bit set, shapes to left
  35         MASK_TRANSPARENT    = 4, // if this bit set, is transparent (ignore other bits)
  36         MASK_NOSHAPE        = 8  // if this bit set, don't shape this char, i.e. tatweel
  37     };
  38
  39     // shaping values
  40     enum ShapeTypeValues
  41     {
  42         ST_NONE         = 0,
  43         ST_RIGHT        = MASK_SHAPE_RIGHT,
  44         ST_LEFT         = MASK_SHAPE_LEFT,
  45         ST_DUAL         = MASK_SHAPE_RIGHT | MASK_SHAPE_LEFT,
  46         ST_TRANSPARENT  = MASK_TRANSPARENT,
  47         ST_NOSHAPE_DUAL = MASK_NOSHAPE | ST_DUAL,
  48         ST_NOSHAPE_NONE = MASK_NOSHAPE
  49     };
  50
  51     typedef le_int32 ShapeType;
  52
  53     static void shape(const LEUnicode *chars, le_int32 offset, le_int32 charCount, le_int32 charMax,
  54                       le_bool rightToLeft, Shaper &shaper);
  55
  56     static const LETag *getFeatureOrder();
  57
  58     static const le_uint8 glyphSubstitutionTable[];
  59   //static le_uint8 ligatureSubstitutionSubtable[];
  60     static const le_uint8 glyphDefinitionTable[];
  61
  62 private:
  63     // forbid instantiation
  64     ArabicShaping();
  65
  66     static ShapeType getShapeType(LEUnicode c);
  67
  68     static const ShapeType shapeTypes[];
  69 };
  70
  71 class GlyphShaper : public UMemory, public Shaper
  72 {
  73 public:
  74     virtual void init(LEUnicode ch, le_int32 outIndex, le_bool isolate);
  75     virtual void shape(le_int32 outIndex, le_int32 shapeOffset);
  76
  77     GlyphShaper(const LETag **outputTags);
  78     ~GlyphShaper();
  79
  80 private:
  81     const LETag **charTags;
  82
  83     static const LETag tagArray[];
  84
  85     GlyphShaper(const GlyphShaper &other); // forbid copying of this class
  86     GlyphShaper &operator=(const GlyphShaper &other); // forbid copying of this class
  87 };
  88
  89 class CharShaper : public UMemory, public Shaper
  90 {
  91 public:
  92     virtual void init(LEUnicode ch, le_int32 outIndex, le_bool isolate);
  93     virtual void shape(le_int32 outIndex, le_int32 shapeOffset);
  94
  95     CharShaper(LEUnicode *outputChars);
  96     ~CharShaper();
  97
  98 private:
  99     LEUnicode *chars;
 100
 101     static const LEUnicode isolateShapes[];
 102
 103     static LEUnicode getToIsolateShape(LEUnicode ch);
 104
 105     CharShaper(const CharShaper &other); // forbid copying of this class
 106     CharShaper &operator=(const CharShaper &other); // forbid copying of this class
 107 };
 108
 109 U_NAMESPACE_END
 110 #endif