icuSources/layout/StateTables.h

   1 /*
   2  *
   3  * (C) Copyright IBM Corp. and others 1998-2016 - 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 #include "LETableReference.h"
  18
  19 U_NAMESPACE_BEGIN
  20
  21
  22
  23
  24 /*
  25  * State table loop detection.
  26  * Detects if too many ( LE_STATE_PATIENCE_COUNT ) state changes occur without moving the glyph index 'g'.
  27  *
  28  * Usage (pseudocode):
  29  *
  30  * {
  31  *   LE_STATE_PATIENCE_INIT();
  32  *
  33  *   int g=0; // the glyph index - expect it to be moving
  34  *
  35  *   for(;;) {
  36  *     if(LE_STATE_PATIENCE_DECR()) { // decrements the patience counter
  37  *        // ran out of patience, get out.
  38  *        break;
  39  *     }
  40  *
  41  *     LE_STATE_PATIENCE_CURR(int, g); // store the 'current'
  42  *     state = newState(state,g);
  43  *     g+= <something, could be zero>;
  44  *     LE_STATE_PATIENCE_INCR(g);  // if g has moved, increment the patience counter. Otherwise leave it.
  45  *   }
  46  *
  47  */
  48
  49 #define LE_STATE_PATIENCE_COUNT 4096 /**< give up if a state table doesn't move the glyph after this many iterations */
  50 #define LE_STATE_PATIENCE_INIT()  le_uint32 le_patience_count = LE_STATE_PATIENCE_COUNT
  51 #define LE_STATE_PATIENCE_DECR()  --le_patience_count==0
  52 #define LE_STATE_PATIENCE_CURR(type,x)  type le_patience_curr=(x)
  53 #define LE_STATE_PATIENCE_INCR(x)    if((x)!=le_patience_curr) ++le_patience_count;
  54
  55
  56 struct StateTableHeader
  57 {
  58     le_int16 stateSize;
  59     ByteOffset classTableOffset;
  60     ByteOffset stateArrayOffset;
  61     ByteOffset entryTableOffset;
  62 };
  63
  64 struct StateTableHeader2
  65 {
  66     le_uint32 nClasses;
  67     le_uint32 classTableOffset;
  68     le_uint32 stateArrayOffset;
  69     le_uint32 entryTableOffset;
  70 };
  71
  72 enum ClassCodes
  73 {
  74     classCodeEOT = 0,
  75     classCodeOOB = 1,
  76     classCodeDEL = 2,
  77     classCodeEOL = 3,
  78     classCodeFirstFree = 4,
  79     classCodeMAX = 0xFF
  80 };
  81
  82 typedef le_uint8 ClassCode;
  83
  84 struct ClassTable
  85 {
  86     TTGlyphID firstGlyph;
  87     le_uint16 nGlyphs;
  88     ClassCode classArray[ANY_NUMBER];
  89 };
  90 LE_VAR_ARRAY(ClassTable, classArray)
  91
  92 enum StateNumber
  93 {
  94     stateSOT        = 0,
  95     stateSOL        = 1,
  96     stateFirstFree  = 2,
  97     stateMAX        = 0xFF
  98 };
  99
 100 typedef le_uint8 EntryTableIndex;
 101
 102 struct StateEntry
 103 {
 104     ByteOffset  newStateOffset;
 105     le_int16    flags;
 106 };
 107
 108 typedef le_uint16 EntryTableIndex2;
 109
 110 struct StateEntry2 // same struct different interpretation
 111 {
 112     le_uint16    newStateIndex;
 113     le_uint16    flags;
 114 };
 115
 116 U_NAMESPACE_END
 117 #endif
 118