LookupProcessor.cpp revision b0ac937921a2c196d8b9da665135bf6ba01a1ccf 
1/*
2 *
3 * (C) Copyright IBM Corp. 1998-2008 - All Rights Reserved
4 *
5 */
6
7#include "LETypes.h"
8#include "OpenTypeUtilities.h"
9#include "LEFontInstance.h"
10#include "OpenTypeTables.h"
11#include "Features.h"
12#include "Lookups.h"
13#include "ScriptAndLanguage.h"
14#include "GlyphDefinitionTables.h"
15#include "GlyphIterator.h"
16#include "LookupProcessor.h"
17#include "LEGlyphStorage.h"
18#include "LESwaps.h"
19
20U_NAMESPACE_BEGIN
21
22le_uint32 LookupProcessor::applyLookupTable(const LookupTable *lookupTable, GlyphIterator *glyphIterator,
23                                         const LEFontInstance *fontInstance, LEErrorCode& success) const
24{
25    if (LE_FAILURE(success)) {
26        return 0;
27    }
28
29    le_uint16 lookupType = SWAPW(lookupTable->lookupType);
30    le_uint16 subtableCount = SWAPW(lookupTable->subTableCount);
31    le_int32 startPosition = glyphIterator->getCurrStreamPosition();
32    le_uint32 delta;
33
34    for (le_uint16 subtable = 0; subtable < subtableCount; subtable += 1) {
35        const LookupSubtable *lookupSubtable = lookupTable->getLookupSubtable(subtable);
36
37        delta = applySubtable(lookupSubtable, lookupType, glyphIterator, fontInstance, success);
38
39        if (delta > 0 && LE_FAILURE(success)) {
40            return 1;
41        }
42
43        glyphIterator->setCurrStreamPosition(startPosition);
44    }
45
46    return 1;
47}
48
49le_int32 LookupProcessor::process(LEGlyphStorage &glyphStorage, GlyphPositionAdjustments *glyphPositionAdjustments,
50                              le_bool rightToLeft, const GlyphDefinitionTableHeader *glyphDefinitionTableHeader,
51                              const LEFontInstance *fontInstance, LEErrorCode& success) const
52{
53    if (LE_FAILURE(success)) {
54        return 0;
55    }
56
57    le_int32 glyphCount = glyphStorage.getGlyphCount();
58
59    if (lookupSelectArray == NULL) {
60        return glyphCount;
61    }
62
63    GlyphIterator glyphIterator(glyphStorage, glyphPositionAdjustments,
64                                rightToLeft, 0, 0, glyphDefinitionTableHeader);
65    le_int32 newGlyphCount = glyphCount;
66
67    for (le_uint16 order = 0; order < lookupOrderCount; order += 1) {
68        le_uint16 lookup = lookupOrderArray[order];
69        FeatureMask selectMask = lookupSelectArray[lookup];
70
71        if (selectMask != 0) {
72            const LookupTable *lookupTable = lookupListTable->getLookupTable(lookup);
73            le_uint16 lookupFlags = SWAPW(lookupTable->lookupFlags);
74
75            glyphIterator.reset(lookupFlags, selectMask);
76
77            while (glyphIterator.findFeatureTag()) {
78                applyLookupTable(lookupTable, &glyphIterator, fontInstance, success);
79                if (LE_FAILURE(success)) {
80                    return 0;
81                }
82            }
83
84            newGlyphCount = glyphIterator.applyInsertions();
85        }
86    }
87
88    return newGlyphCount;
89}
90
91le_uint32 LookupProcessor::applySingleLookup(le_uint16 lookupTableIndex, GlyphIterator *glyphIterator,
92                                          const LEFontInstance *fontInstance, LEErrorCode& success) const
93{
94    if (LE_FAILURE(success)) {
95        return 0;
96    }
97
98    const LookupTable *lookupTable = lookupListTable->getLookupTable(lookupTableIndex);
99    le_uint16 lookupFlags = SWAPW(lookupTable->lookupFlags);
100    GlyphIterator tempIterator(*glyphIterator, lookupFlags);
101    le_uint32 delta = applyLookupTable(lookupTable, &tempIterator, fontInstance, success);
102
103    return delta;
104}
105
106le_int32 LookupProcessor::selectLookups(const FeatureTable *featureTable, FeatureMask featureMask, le_int32 order)
107{
108    le_uint16 lookupCount = featureTable? SWAPW(featureTable->lookupCount) : 0;
109    le_int32  store = order;
110
111    for (le_uint16 lookup = 0; lookup < lookupCount; lookup += 1) {
112        le_uint16 lookupListIndex = SWAPW(featureTable->lookupListIndexArray[lookup]);
113
114        lookupSelectArray[lookupListIndex] |= featureMask;
115        lookupOrderArray[store++] = lookupListIndex;
116    }
117
118    return store - order;
119}
120
121LookupProcessor::LookupProcessor(const char *baseAddress,
122        Offset scriptListOffset, Offset featureListOffset, Offset lookupListOffset,
123        LETag scriptTag, LETag languageTag, const FeatureMap *featureMap, le_int32 featureMapCount, le_bool orderFeatures,
124        LEErrorCode& success)
125    : lookupListTable(NULL), featureListTable(NULL), lookupSelectArray(NULL),
126      lookupOrderArray(NULL), lookupOrderCount(0)
127{
128    const ScriptListTable *scriptListTable = NULL;
129    const LangSysTable *langSysTable = NULL;
130    le_uint16 featureCount = 0;
131    le_uint16 lookupListCount = 0;
132    le_uint16 requiredFeatureIndex;
133
134    if (LE_FAILURE(success)) {
135        return;
136    }
137
138    if (scriptListOffset != 0) {
139        scriptListTable = (const ScriptListTable *) (baseAddress + scriptListOffset);
140        langSysTable = scriptListTable->findLanguage(scriptTag, languageTag);
141
142        if (langSysTable != 0) {
143            featureCount = SWAPW(langSysTable->featureCount);
144        }
145    }
146
147    if (featureListOffset != 0) {
148        featureListTable = (const FeatureListTable *) (baseAddress + featureListOffset);
149    }
150
151    if (lookupListOffset != 0) {
152        lookupListTable = (const LookupListTable *) (baseAddress + lookupListOffset);
153        lookupListCount = SWAPW(lookupListTable->lookupCount);
154    }
155
156    if (langSysTable == NULL || featureListTable == NULL || lookupListTable == NULL ||
157        featureCount == 0 || lookupListCount == 0) {
158        return;
159    }
160
161    requiredFeatureIndex = SWAPW(langSysTable->reqFeatureIndex);
162
163    lookupSelectArray = LE_NEW_ARRAY(FeatureMask, lookupListCount);
164    if (lookupSelectArray == NULL) {
165        success = LE_MEMORY_ALLOCATION_ERROR;
166        return;
167    }
168
169    for (int i = 0; i < lookupListCount; i += 1) {
170        lookupSelectArray[i] = 0;
171    }
172
173    le_int32 count, order = 0;
174    le_int32 featureReferences = 0;
175    const FeatureTable *featureTable = NULL;
176    LETag featureTag;
177
178    const FeatureTable *requiredFeatureTable = NULL;
179    LETag requiredFeatureTag = 0x00000000U;
180
181    // Count the total number of lookups referenced by all features. This will
182    // be the maximum number of entries in the lookupOrderArray. We can't use
183    // lookupListCount because some lookups might be referenced by more than
184    // one feature.
185    for (le_int32 feature = 0; feature < featureCount; feature += 1) {
186        le_uint16 featureIndex = SWAPW(langSysTable->featureIndexArray[feature]);
187
188        featureTable = featureListTable->getFeatureTable(featureIndex, &featureTag);
189        featureReferences += SWAPW(featureTable->lookupCount);
190    }
191
192    if (requiredFeatureIndex != 0xFFFF) {
193        requiredFeatureTable = featureListTable->getFeatureTable(requiredFeatureIndex, &requiredFeatureTag);
194        featureReferences += SWAPW(featureTable->lookupCount);
195    }
196
197    lookupOrderArray = LE_NEW_ARRAY(le_uint16, featureReferences);
198    if (lookupOrderArray == NULL) {
199        success = LE_MEMORY_ALLOCATION_ERROR;
200        return;
201    }
202
203    for (le_int32 f = 0; f < featureMapCount; f += 1) {
204        FeatureMap fm = featureMap[f];
205        count = 0;
206
207        // If this is the required feature, add its lookups
208        if (requiredFeatureTag == fm.tag) {
209            count += selectLookups(requiredFeatureTable, fm.mask, order);
210        }
211
212        if (orderFeatures) {
213            // If we added lookups from the required feature, sort them
214            if (count > 1) {
215                OpenTypeUtilities::sort(lookupOrderArray, order);
216            }
217
218            for (le_uint16 feature = 0; feature < featureCount; feature += 1) {
219                le_uint16 featureIndex = SWAPW(langSysTable->featureIndexArray[feature]);
220
221                // don't add the required feature to the list more than once...
222                // TODO: Do we need this check? (Spec. says required feature won't be in feature list...)
223                if (featureIndex == requiredFeatureIndex) {
224                    continue;
225                }
226
227                featureTable = featureListTable->getFeatureTable(featureIndex, &featureTag);
228
229                if (featureTag == fm.tag) {
230                    count += selectLookups(featureTable, fm.mask, order + count);
231                }
232            }
233
234            if (count > 1) {
235                OpenTypeUtilities::sort(&lookupOrderArray[order], count);
236            }
237
238            order += count;
239        } else {
240            for (le_uint16 feature = 0; feature < featureCount; feature += 1) {
241                le_uint16 featureIndex = SWAPW(langSysTable->featureIndexArray[feature]);
242
243                // don't add the required feature to the list more than once...
244                // NOTE: This check is commented out because the spec. says that
245                // the required feature won't be in the feature list, and because
246                // any duplicate entries will be removed below.
247#if 0
248                if (featureIndex == requiredFeatureIndex) {
249                    continue;
250                }
251#endif
252
253                featureTable = featureListTable->getFeatureTable(featureIndex, &featureTag);
254
255                if (featureTag == fm.tag) {
256                    order += selectLookups(featureTable, fm.mask, order);
257                }
258            }
259        }
260    }
261
262    if (!orderFeatures && (order > 1)) {
263        OpenTypeUtilities::sort(lookupOrderArray, order);
264
265        // If there's no specified feature order,
266        // we will apply the lookups in the order
267        // that they're in the font. If a particular
268        // lookup may be referenced by more than one feature,
269        // it will apprear in the lookupOrderArray more than
270        // once, so remove any duplicate entries in the sorted array.
271        le_int32 out = 1;
272
273        for (le_int32 in = 1; in < order; in += 1) {
274            if (lookupOrderArray[out - 1] != lookupOrderArray[in]) {
275                if (out != in) {
276                    lookupOrderArray[out] = lookupOrderArray[in];
277                }
278
279                out += 1;
280            }
281        }
282
283        order = out;
284    }
285
286    lookupOrderCount = order;
287}
288
289LookupProcessor::LookupProcessor()
290{
291	lookupOrderArray = NULL;
292	lookupSelectArray = NULL;
293}
294
295LookupProcessor::~LookupProcessor()
296{
297    LE_DELETE_ARRAY(lookupOrderArray);
298    LE_DELETE_ARRAY(lookupSelectArray);
299}
300
301U_NAMESPACE_END
302