1 /*
2 *
3 * (C) Copyright IBM Corp. 1998-2008 - All Rights Reserved
4 *
5 */
6
7 #include "LETypes.h"
8 #include "OpenTypeTables.h"
9 #include "ArabicShaping.h"
10 #include "LEGlyphStorage.h"
11 #include "ClassDefinitionTables.h"
12
13 U_NAMESPACE_BEGIN
14
15 // This table maps Unicode joining types to
16 // ShapeTypes.
17 const ArabicShaping::ShapeType ArabicShaping::shapeTypes[] =
18 {
19 ArabicShaping::ST_NOSHAPE_NONE, // [U]
20 ArabicShaping::ST_NOSHAPE_DUAL, // [C]
21 ArabicShaping::ST_DUAL, // [D]
22 ArabicShaping::ST_LEFT, // [L]
23 ArabicShaping::ST_RIGHT, // [R]
24 ArabicShaping::ST_TRANSPARENT // [T]
25 };
26
27 /*
28 shaping array holds types for Arabic chars between 0610 and 0700
29 other values are either unshaped, or transparent if a mark or format
30 code, except for format codes 200c (zero-width non-joiner) and 200d
31 (dual-width joiner) which are both unshaped and non_joining or
32 dual-joining, respectively.
33 */
getShapeType(LEUnicode c)34 ArabicShaping::ShapeType ArabicShaping::getShapeType(LEUnicode c)
35 {
36 const ClassDefinitionTable *joiningTypes = (const ClassDefinitionTable *) ArabicShaping::shapingTypeTable;
37 le_int32 joiningType = joiningTypes->getGlyphClass(c);
38
39 if (joiningType >= 0 && joiningType < ArabicShaping::JT_COUNT) {
40 return ArabicShaping::shapeTypes[joiningType];
41 }
42
43 return ArabicShaping::ST_NOSHAPE_NONE;
44 }
45
46 #define isolFeatureTag LE_ISOL_FEATURE_TAG
47 #define initFeatureTag LE_INIT_FEATURE_TAG
48 #define mediFeatureTag LE_MEDI_FEATURE_TAG
49 #define finaFeatureTag LE_FINA_FEATURE_TAG
50 #define ligaFeatureTag LE_LIGA_FEATURE_TAG
51 #define msetFeatureTag LE_MSET_FEATURE_TAG
52 #define markFeatureTag LE_MARK_FEATURE_TAG
53 #define ccmpFeatureTag LE_CCMP_FEATURE_TAG
54 #define rligFeatureTag LE_RLIG_FEATURE_TAG
55 #define caltFeatureTag LE_CALT_FEATURE_TAG
56 #define dligFeatureTag LE_DLIG_FEATURE_TAG
57 #define cswhFeatureTag LE_CSWH_FEATURE_TAG
58 #define cursFeatureTag LE_CURS_FEATURE_TAG
59 #define kernFeatureTag LE_KERN_FEATURE_TAG
60 #define mkmkFeatureTag LE_MKMK_FEATURE_TAG
61
62 // NOTE:
63 // The isol, fina, init and medi features must be
64 // defined in the above order, and have masks that
65 // are all in the same nibble.
66 #define isolFeatureMask 0x80000000UL
67 #define finaFeatureMask 0x40000000UL
68 #define initFeatureMask 0x20000000UL
69 #define mediFeatureMask 0x10000000UL
70 #define ccmpFeatureMask 0x08000000UL
71 #define rligFeatureMask 0x04000000UL
72 #define caltFeatureMask 0x02000000UL
73 #define ligaFeatureMask 0x01000000UL
74 #define dligFeatureMask 0x00800000UL
75 #define cswhFeatureMask 0x00400000UL
76 #define msetFeatureMask 0x00200000UL
77 #define cursFeatureMask 0x00100000UL
78 #define kernFeatureMask 0x00080000UL
79 #define markFeatureMask 0x00040000UL
80 #define mkmkFeatureMask 0x00020000UL
81
82 #define NO_FEATURES 0
83 #define ISOL_FEATURES (isolFeatureMask | ligaFeatureMask | msetFeatureMask | markFeatureMask | ccmpFeatureMask | rligFeatureMask | caltFeatureMask | dligFeatureMask | cswhFeatureMask | cursFeatureMask | kernFeatureMask | mkmkFeatureMask)
84
85 #define SHAPE_MASK 0xF0000000UL
86
87 static const FeatureMap featureMap[] = {
88 {ccmpFeatureTag, ccmpFeatureMask},
89 {isolFeatureTag, isolFeatureMask},
90 {finaFeatureTag, finaFeatureMask},
91 {mediFeatureTag, mediFeatureMask},
92 {initFeatureTag, initFeatureMask},
93 {rligFeatureTag, rligFeatureMask},
94 {caltFeatureTag, caltFeatureMask},
95 {ligaFeatureTag, ligaFeatureMask},
96 {dligFeatureTag, dligFeatureMask},
97 {cswhFeatureTag, cswhFeatureMask},
98 {msetFeatureTag, msetFeatureMask},
99 {cursFeatureTag, cursFeatureMask},
100 {kernFeatureTag, kernFeatureMask},
101 {markFeatureTag, markFeatureMask},
102 {mkmkFeatureTag, mkmkFeatureMask}
103 };
104
getFeatureMap(le_int32 & count)105 const FeatureMap *ArabicShaping::getFeatureMap(le_int32 &count)
106 {
107 count = LE_ARRAY_SIZE(featureMap);
108
109 return featureMap;
110 }
111
adjustTags(le_int32 outIndex,le_int32 shapeOffset,LEGlyphStorage & glyphStorage)112 void ArabicShaping::adjustTags(le_int32 outIndex, le_int32 shapeOffset, LEGlyphStorage &glyphStorage)
113 {
114 LEErrorCode success = LE_NO_ERROR;
115 FeatureMask featureMask = (FeatureMask) glyphStorage.getAuxData(outIndex, success);
116 FeatureMask shape = featureMask & SHAPE_MASK;
117
118 shape >>= shapeOffset;
119
120 glyphStorage.setAuxData(outIndex, ((featureMask & ~SHAPE_MASK) | shape), success);
121 }
122
shape(const LEUnicode * chars,le_int32 offset,le_int32 charCount,le_int32 charMax,le_bool rightToLeft,LEGlyphStorage & glyphStorage)123 void ArabicShaping::shape(const LEUnicode *chars, le_int32 offset, le_int32 charCount, le_int32 charMax,
124 le_bool rightToLeft, LEGlyphStorage &glyphStorage)
125 {
126 // iterate in logical order, store tags in visible order
127 //
128 // the effective right char is the most recently encountered
129 // non-transparent char
130 //
131 // four boolean states:
132 // the effective right char shapes
133 // the effective right char causes left shaping
134 // the current char shapes
135 // the current char causes right shaping
136 //
137 // if both cause shaping, then
138 // shaper.shape(errout, 2) (isolate to initial, or final to medial)
139 // shaper.shape(out, 1) (isolate to final)
140
141 ShapeType rightType = ST_NOSHAPE_NONE, leftType = ST_NOSHAPE_NONE;
142 LEErrorCode success = LE_NO_ERROR;
143 le_int32 i;
144
145 for (i = offset - 1; i >= 0; i -= 1) {
146 rightType = getShapeType(chars[i]);
147
148 if (rightType != ST_TRANSPARENT) {
149 break;
150 }
151 }
152
153 for (i = offset + charCount; i < charMax; i += 1) {
154 leftType = getShapeType(chars[i]);
155
156 if (leftType != ST_TRANSPARENT) {
157 break;
158 }
159 }
160
161 // erout is effective right logical index
162 le_int32 erout = -1;
163 le_bool rightShapes = FALSE;
164 le_bool rightCauses = (rightType & MASK_SHAPE_LEFT) != 0;
165 le_int32 in, e, out = 0, dir = 1;
166
167 if (rightToLeft) {
168 out = charCount - 1;
169 erout = charCount;
170 dir = -1;
171 }
172
173 for (in = offset, e = offset + charCount; in < e; in += 1, out += dir) {
174 LEUnicode c = chars[in];
175 ShapeType t = getShapeType(c);
176
177 if (t == ST_NOSHAPE_NONE) {
178 glyphStorage.setAuxData(out, NO_FEATURES, success);
179 } else {
180 glyphStorage.setAuxData(out, ISOL_FEATURES, success);
181 }
182
183 if ((t & MASK_TRANSPARENT) != 0) {
184 continue;
185 }
186
187 le_bool curShapes = (t & MASK_NOSHAPE) == 0;
188 le_bool curCauses = (t & MASK_SHAPE_RIGHT) != 0;
189
190 if (rightCauses && curCauses) {
191 if (rightShapes) {
192 adjustTags(erout, 2, glyphStorage);
193 }
194
195 if (curShapes) {
196 adjustTags(out, 1, glyphStorage);
197 }
198 }
199
200 rightShapes = curShapes;
201 rightCauses = (t & MASK_SHAPE_LEFT) != 0;
202 erout = out;
203 }
204
205 if (rightShapes && rightCauses && (leftType & MASK_SHAPE_RIGHT) != 0) {
206 adjustTags(erout, 2, glyphStorage);
207 }
208 }
209
210 U_NAMESPACE_END
211