1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation. Oracle designates this
7 * particular file as subject to the "Classpath" exception as provided
8 * by Oracle in the LICENSE file that accompanied this code.
9 *
10 * This code is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
13 * version 2 for more details (a copy is included in the LICENSE file that
14 * accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License version
17 * 2 along with this work; if not, write to the Free Software Foundation,
18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
19 *
20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
21 * or visit www.oracle.com if you need additional information or have any
22 * questions.
23 *
24 */
25
26 /*
27 *
28 * (C) Copyright IBM Corp. 1998-2013 - All Rights Reserved
29 *
30 */
31
32 #include "LETypes.h"
33 #include "MorphTables.h"
34 #include "StateTables.h"
35 #include "MorphStateTables.h"
36 #include "SubtableProcessor.h"
37 #include "StateTableProcessor.h"
38 #include "LigatureSubstProc.h"
39 #include "LEGlyphStorage.h"
40 #include "LESwaps.h"
41
42 U_NAMESPACE_BEGIN
43
44 #define ExtendedComplement(m) ((le_int32) (~((le_uint32) (m))))
45 #define SignBit(m) ((ExtendedComplement(m) >> 1) & (le_int32)(m))
46 #define SignExtend(v,m) (((v) & SignBit(m))? ((v) | ExtendedComplement(m)): (v))
47
48 UOBJECT_DEFINE_RTTI_IMPLEMENTATION(LigatureSubstitutionProcessor)
49
50 LigatureSubstitutionProcessor::LigatureSubstitutionProcessor(const LEReferenceTo<MorphSubtableHeader> &morphSubtableHeader, LEErrorCode &success)
51 : StateTableProcessor(morphSubtableHeader, success), ligatureSubstitutionHeader(morphSubtableHeader, success)
52 {
53 if(LE_FAILURE(success)) return;
54 ligatureActionTableOffset = SWAPW(ligatureSubstitutionHeader->ligatureActionTableOffset);
55 componentTableOffset = SWAPW(ligatureSubstitutionHeader->componentTableOffset);
56 ligatureTableOffset = SWAPW(ligatureSubstitutionHeader->ligatureTableOffset);
57
58 entryTable = LEReferenceToArrayOf<LigatureSubstitutionStateEntry>(stHeader, success, entryTableOffset, LE_UNBOUNDED_ARRAY);
59 }
60
61 LigatureSubstitutionProcessor::~LigatureSubstitutionProcessor()
62 {
63 }
64
65 void LigatureSubstitutionProcessor::beginStateTable()
66 {
67 m = -1;
68 }
69
70 ByteOffset LigatureSubstitutionProcessor::processStateEntry(LEGlyphStorage &glyphStorage, le_int32 &currGlyph, EntryTableIndex index)
71 {
72 LEErrorCode success = LE_NO_ERROR;
73 const LigatureSubstitutionStateEntry *entry = entryTable.getAlias(index, success);
74 if (LE_FAILURE(success)) {
75 currGlyph++;
76 return 0;
77 }
78
79 ByteOffset newState = SWAPW(entry->newStateOffset);
80 le_uint16 flags = SWAPW(entry->flags);
81
82 if (flags & lsfSetComponent) {
83 if (++m >= nComponents) {
84 m = 0;
85 }
86
87 componentStack[m] = currGlyph;
88 } else if ( m == -1) {
89 // bad font- skip this glyph.
90 currGlyph++;
91 return newState;
92 }
93
94 ByteOffset actionOffset = flags & lsfActionOffsetMask;
95
96 if (actionOffset != 0) {
97 LEReferenceTo<LigatureActionEntry> ap(stHeader, success, actionOffset);
98 if (LE_FAILURE(success)) {
99 currGlyph++;
100 return newState;
101 }
102 LigatureActionEntry action;
103 le_int32 offset, i = 0, j = 0;
104 le_int32 stack[nComponents];
105 le_int16 mm = -1;
106
107 do {
108 le_uint32 componentGlyph = componentStack[m--];
109
110 if (j++ > 0) {
111 ap.addObject(success);
112 if (LE_FAILURE(success)) {
113 currGlyph++;
114 return newState;
115 }
116 }
117
118 action = SWAPL(*ap.getAlias());
119
120 if (m < 0) {
121 m = nComponents - 1;
122 }
123
124 offset = action & lafComponentOffsetMask;
125 if (offset != 0) {
126 LEReferenceToArrayOf<le_int16> offsetTable(stHeader, success, 2 * SignExtend(offset, lafComponentOffsetMask), LE_UNBOUNDED_ARRAY);
127
128 if(LE_FAILURE(success)) {
129 currGlyph++;
130 LE_DEBUG_BAD_FONT("off end of ligature substitution header");
131 return newState; // get out! bad font
132 }
133 if(componentGlyph >= glyphStorage.getGlyphCount()) {
134 LE_DEBUG_BAD_FONT("preposterous componentGlyph");
135 currGlyph++;
136 return newState; // get out! bad font
137 }
138 i += SWAPW(offsetTable.getObject(LE_GET_GLYPH(glyphStorage[componentGlyph]), success));
139 if (LE_FAILURE(success)) {
140 currGlyph++;
141 return newState;
142 }
143
144 if (action & (lafLast | lafStore)) {
145 LEReferenceTo<TTGlyphID> ligatureOffset(stHeader, success, i);
146 if (LE_FAILURE(success)) {
147 currGlyph++;
148 return newState;
149 }
150 TTGlyphID ligatureGlyph = SWAPW(*ligatureOffset.getAlias());
151
152 glyphStorage[componentGlyph] = LE_SET_GLYPH(glyphStorage[componentGlyph], ligatureGlyph);
153 ++mm;
154 if (mm == nComponents) {
155 LE_DEBUG_BAD_FONT("exceeded nComponents");
156 mm--; // don't overrun the stack.
157 }
158 stack[mm] = componentGlyph;
159 i = 0;
160 } else {
161 glyphStorage[componentGlyph] = LE_SET_GLYPH(glyphStorage[componentGlyph], 0xFFFF);
162 }
163 }
164 #if LE_ASSERT_BAD_FONT
165 if(m<0) {
166 LE_DEBUG_BAD_FONT("m<0")
167 }
168 #endif
169 } while (!(action & lafLast) && (m>=0) ); // stop if last bit is set, or if run out of items
170
171 while (mm >= 0) {
172 if (++m >= nComponents) {
173 m = 0;
174 }
175
176 componentStack[m] = stack[mm--];
177 }
178 }
179
180 if (!(flags & lsfDontAdvance)) {
181 // should handle reverse too!
182 currGlyph += 1;
183 }
184
185 return newState;
186 }
187
188 void LigatureSubstitutionProcessor::endStateTable()
189 {
190 }
191
192 U_NAMESPACE_END