1 /*
2 *
3 * (C) Copyright IBM Corp. 1998-2013 - All Rights Reserved
4 *
5 */
6
7 #include "LETypes.h"
8 #include "MorphTables.h"
9 #include "StateTables.h"
10 #include "MorphStateTables.h"
11 #include "SubtableProcessor.h"
12 #include "StateTableProcessor.h"
13 #include "LigatureSubstProc.h"
14 #include "LEGlyphStorage.h"
15 #include "LESwaps.h"
16
17 U_NAMESPACE_BEGIN
18
19 #define ExtendedComplement(m) ((le_int32) (~((le_uint32) (m))))
20 #define SignBit(m) ((ExtendedComplement(m) >> 1) & (le_int32)(m))
21 #define SignExtend(v,m) (((v) & SignBit(m))? ((v) | ExtendedComplement(m)): (v))
22
UOBJECT_DEFINE_RTTI_IMPLEMENTATION(LigatureSubstitutionProcessor)23 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(LigatureSubstitutionProcessor)
24
25 LigatureSubstitutionProcessor::LigatureSubstitutionProcessor(const LEReferenceTo<MorphSubtableHeader> &morphSubtableHeader, LEErrorCode &success)
26 : StateTableProcessor(morphSubtableHeader, success), ligatureSubstitutionHeader(morphSubtableHeader, success)
27 {
28 if(LE_FAILURE(success)) return;
29 ligatureActionTableOffset = SWAPW(ligatureSubstitutionHeader->ligatureActionTableOffset);
30 componentTableOffset = SWAPW(ligatureSubstitutionHeader->componentTableOffset);
31 ligatureTableOffset = SWAPW(ligatureSubstitutionHeader->ligatureTableOffset);
32
33 entryTable = LEReferenceToArrayOf<LigatureSubstitutionStateEntry>(stHeader, success, entryTableOffset, LE_UNBOUNDED_ARRAY);
34 }
35
~LigatureSubstitutionProcessor()36 LigatureSubstitutionProcessor::~LigatureSubstitutionProcessor()
37 {
38 }
39
beginStateTable()40 void LigatureSubstitutionProcessor::beginStateTable()
41 {
42 m = -1;
43 }
44
processStateEntry(LEGlyphStorage & glyphStorage,le_int32 & currGlyph,EntryTableIndex index)45 ByteOffset LigatureSubstitutionProcessor::processStateEntry(LEGlyphStorage &glyphStorage, le_int32 &currGlyph, EntryTableIndex index)
46 {
47 LEErrorCode success = LE_NO_ERROR;
48 const LigatureSubstitutionStateEntry *entry = entryTable.getAlias(index, success);
49
50 ByteOffset newState = SWAPW(entry->newStateOffset);
51 le_int16 flags = SWAPW(entry->flags);
52
53 if (flags & lsfSetComponent) {
54 if (++m >= nComponents) {
55 m = 0;
56 }
57
58 componentStack[m] = currGlyph;
59 } else if ( m == -1) {
60 // bad font- skip this glyph.
61 currGlyph++;
62 return newState;
63 }
64
65 ByteOffset actionOffset = flags & lsfActionOffsetMask;
66
67 if (actionOffset != 0) {
68 LEReferenceTo<LigatureActionEntry> ap(stHeader, success, actionOffset);
69 LigatureActionEntry action;
70 le_int32 offset, i = 0;
71 le_int32 stack[nComponents];
72 le_int16 mm = -1;
73
74 do {
75 le_uint32 componentGlyph = componentStack[m--];
76
77 action = SWAPL(*ap.getAlias());
78 ap.addObject(success); // ap++
79
80 if (m < 0) {
81 m = nComponents - 1;
82 }
83
84 offset = action & lafComponentOffsetMask;
85 if (offset != 0) {
86 LEReferenceToArrayOf<le_int16> offsetTable(stHeader, success, 2 * SignExtend(offset, lafComponentOffsetMask), LE_UNBOUNDED_ARRAY);
87
88 if(LE_FAILURE(success)) {
89 currGlyph++;
90 LE_DEBUG_BAD_FONT("off end of ligature substitution header");
91 return newState; // get out! bad font
92 }
93 if(componentGlyph > (le_uint32)glyphStorage.getGlyphCount()) {
94 LE_DEBUG_BAD_FONT("preposterous componentGlyph");
95 currGlyph++;
96 return newState; // get out! bad font
97 }
98 i += SWAPW(offsetTable.getObject(LE_GET_GLYPH(glyphStorage[componentGlyph]), success));
99
100 if (action & (lafLast | lafStore)) {
101 LEReferenceTo<TTGlyphID> ligatureOffset(stHeader, success, i);
102 TTGlyphID ligatureGlyph = SWAPW(*ligatureOffset.getAlias());
103
104 glyphStorage[componentGlyph] = LE_SET_GLYPH(glyphStorage[componentGlyph], ligatureGlyph);
105 if(mm==nComponents) {
106 LE_DEBUG_BAD_FONT("exceeded nComponents");
107 mm--; // don't overrun the stack.
108 }
109 stack[++mm] = componentGlyph;
110 i = 0;
111 } else {
112 glyphStorage[componentGlyph] = LE_SET_GLYPH(glyphStorage[componentGlyph], 0xFFFF);
113 }
114 }
115 #if LE_ASSERT_BAD_FONT
116 if(m<0) {
117 LE_DEBUG_BAD_FONT("m<0")
118 }
119 #endif
120 } while (!(action & lafLast) && (m>=0) ); // stop if last bit is set, or if run out of items
121
122 while (mm >= 0) {
123 if (++m >= nComponents) {
124 m = 0;
125 }
126
127 componentStack[m] = stack[mm--];
128 }
129 }
130
131 if (!(flags & lsfDontAdvance)) {
132 // should handle reverse too!
133 currGlyph += 1;
134 }
135
136 return newState;
137 }
138
endStateTable()139 void LigatureSubstitutionProcessor::endStateTable()
140 {
141 }
142
143 U_NAMESPACE_END
144