icuSources/layout/StateTables.h

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. and others 1998-2013 - All Rights Reserved
   4  *
   5  */
   6
   7 #ifndef __STATETABLES_H
   8 #define __STATETABLES_H
   9
  10 /**
  11  * \file
  12  * \internal
  13  */
  14
  15 #include "LETypes.h"
  16 #include "LayoutTables.h"
  17
  18 U_NAMESPACE_BEGIN
  19
  20
  21
  22
  23 /*
  24  * State table loop detection.
  25  * Detects if too many ( LE_STATE_PATIENCE_COUNT ) state changes occur without moving the glyph index 'g'.
  26  *
  27  * Usage (pseudocode):
  28  *
  29  * {
  30  *   LE_STATE_PATIENCE_INIT();
  31  *
  32  *   int g=0; // the glyph index - expect it to be moving
  33  *
  34  *   for(;;) {
  35  *     if(LE_STATE_PATIENCE_DECR()) { // decrements the patience counter
  36  *        // ran out of patience, get out.
  37  *        break;
  38  *     }
  39  *
  40  *     LE_STATE_PATIENCE_CURR(int, g); // store the 'current'
  41  *     state = newState(state,g);
  42  *     g+= <something, could be zero>;
  43  *     LE_STATE_PATIENCE_INCR(g);  // if g has moved, increment the patience counter. Otherwise leave it.
  44  *   }
  45  *
  46  */
  47
  48 #define LE_STATE_PATIENCE_COUNT 4096 /**< give up if a state table doesn't move the glyph after this many iterations */
  49 #define LE_STATE_PATIENCE_INIT()  le_uint32 le_patience_count = LE_STATE_PATIENCE_COUNT
  50 #define LE_STATE_PATIENCE_DECR()  --le_patience_count==0
  51 #define LE_STATE_PATIENCE_CURR(type,x)  type le_patience_curr=(x)
  52 #define LE_STATE_PATIENCE_INCR(x)    if((x)!=le_patience_curr) ++le_patience_count;
  53
  54
  55 struct StateTableHeader
  56 {
  57     le_int16 stateSize;
  58     ByteOffset classTableOffset;
  59     ByteOffset stateArrayOffset;
  60     ByteOffset entryTableOffset;
  61 };
  62
  63 struct StateTableHeader2
  64 {
  65     le_uint32 nClasses;
  66     le_uint32 classTableOffset;
  67     le_uint32 stateArrayOffset;
  68     le_uint32 entryTableOffset;
  69 };
  70
  71 enum ClassCodes
  72 {
  73     classCodeEOT = 0,
  74     classCodeOOB = 1,
  75     classCodeDEL = 2,
  76     classCodeEOL = 3,
  77     classCodeFirstFree = 4,
  78     classCodeMAX = 0xFF
  79 };
  80
  81 typedef le_uint8 ClassCode;
  82
  83 struct ClassTable
  84 {
  85     TTGlyphID firstGlyph;
  86     le_uint16 nGlyphs;
  87     ClassCode classArray[ANY_NUMBER];
  88 };
  89 LE_VAR_ARRAY(ClassTable, classArray)
  90
  91 enum StateNumber
  92 {
  93     stateSOT        = 0,
  94     stateSOL        = 1,
  95     stateFirstFree  = 2,
  96     stateMAX        = 0xFF
  97 };
  98
  99 typedef le_uint8 EntryTableIndex;
 100
 101 struct StateEntry
 102 {
 103     ByteOffset  newStateOffset;
 104     le_int16    flags;
 105 };
 106
 107 typedef le_uint16 EntryTableIndex2;
 108
 109 struct StateEntry2 // same struct different interpretation
 110 {
 111     le_uint16    newStateIndex;
 112     le_uint16    flags;
 113 };
 114
 115 U_NAMESPACE_END
 116 #endif
 117