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1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 /***************************************************************************
4 *
5 *   Copyright (C) 1998-2014, International Business Machines
6 *   Corporation and others.  All Rights Reserved.
7 *
8 ************************************************************************/
9 
10 #include "layout/LETypes.h"
11 #include "layout/LESwaps.h"
12 
13 #include "sfnt.h"
14 #include "cmaps.h"
15 #include <stdio.h>
16 
17 #define SWAPU16(code) ((LEUnicode16) SWAPW(code))
18 #define SWAPU32(code) ((LEUnicode32) SWAPL(code))
19 
20 //
21 // Finds the high bit by binary searching
22 // through the bits in value.
23 //
highBit(le_uint32 value)24 le_int8 highBit(le_uint32 value)
25 {
26     le_uint8 bit = 0;
27 
28     if (value >= 1 << 16) {
29         value >>= 16;
30         bit += 16;
31     }
32 
33     if (value >= 1 << 8) {
34         value >>= 8;
35         bit += 8;
36     }
37 
38     if (value >= 1 << 4) {
39         value >>= 4;
40         bit += 4;
41     }
42 
43     if (value >= 1 << 2) {
44         value >>= 2;
45         bit += 2;
46     }
47 
48     if (value >= 1 << 1) {
49         value >>= 1;
50         bit += 1;
51     }
52 
53     return bit;
54 }
55 
createUnicodeMapper(const CMAPTable * cmap)56 CMAPMapper *CMAPMapper::createUnicodeMapper(const CMAPTable *cmap)
57 {
58     le_uint16 i;
59     le_uint16 nSubtables = SWAPW(cmap->numberSubtables);
60     const CMAPEncodingSubtable *subtable = NULL;
61     le_bool found = false;
62     le_uint16 foundPlatformID = 0xFFFF;
63     le_uint16 foundPlatformSpecificID = 0xFFFF;
64     le_uint32 foundOffset = 0;
65     le_uint16 foundTable = 0xFFFF;
66     // first pass, look for MS table. (preferred?)
67     for (i = 0; i < nSubtables && !found; i += 1) {
68         const CMAPEncodingSubtableHeader *esh = &cmap->encodingSubtableHeaders[i];
69 
70         le_uint16 platformID = SWAPW(esh->platformID);
71         le_uint16 platformSpecificID = SWAPW(esh->platformSpecificID);
72         if (platformID == 3) { // microsoft
73           switch (platformSpecificID) {
74             case 1: // Unicode BMP (UCS-2)
75             case 10: // Unicode UCS-4
76                 foundOffset = SWAPL(esh->encodingOffset);
77                 foundPlatformID = platformID;
78                 foundPlatformSpecificID = platformSpecificID;
79                 found = true;
80                 foundTable = i;
81                 break;
82 
83                 //default:
84               //              printf("%s:%d: microsoft (3) platform specific ID %d (wanted 1 or 10) for subtable %d/%d\n", __FILE__, __LINE__, (SWAPW(esh->platformSpecificID)), i, nSubtables);
85             }
86         } else {
87           //printf("%s:%d: platform  ID %d (wanted 3, microsoft) for subtable %d/%d\n", __FILE__, __LINE__, (SWAPW(esh->platformID)), i, nSubtables);
88         }
89     }
90 
91     // second pass, allow non MS table
92     // first pass, look for MS table. (preferred?)
93       for (i = 0; i < nSubtables && !found; i += 1) {
94         const CMAPEncodingSubtableHeader *esh = &cmap->encodingSubtableHeaders[i];
95         le_uint16 platformID = SWAPW(esh->platformID);
96         le_uint16 platformSpecificID = SWAPW(esh->platformSpecificID);
97         //printf("%s:%d: table %d/%d has platform:specific %d:%d\n", __FILE__, __LINE__, i, nSubtables, platformID, platformSpecificID);
98         switch(platformID) {
99         case 0: // Unicode platform
100           switch(platformSpecificID) {
101           case 0:
102           case 1:
103           case 2:
104           case 3:
105             foundOffset = SWAPL(esh->encodingOffset);
106             foundPlatformID = platformID;
107             foundPlatformSpecificID = platformSpecificID;
108             foundTable = i;
109             found = true;
110             break;
111 
112           default: printf("Error: table %d (psid %d) is unknown. Skipping.\n", i, platformSpecificID); break;
113           }
114           break;
115 
116           //default:
117           //printf("Skipping platform id %d\n", platformID);
118         }
119     }
120 
121 
122     if (found)
123     {
124       subtable = (const CMAPEncodingSubtable *) ((const char *) cmap + foundOffset);
125       //printf("%s:%d: using subtable #%d/%d type %d:%d\n", __FILE__, __LINE__, foundTable, nSubtables, foundPlatformID, foundPlatformSpecificID);
126       (void)foundPlatformID;   // Suppress unused variable compiler warnings.
127       (void)foundTable;
128       (void)foundPlatformSpecificID;
129     } else {
130       printf("%s:%d: could not find subtable.\n", __FILE__, __LINE__);
131       return NULL;
132     }
133 
134     le_uint16 tableFormat = SWAPW(subtable->format);
135     //printf("%s:%d: table format %d\n", __FILE__, __LINE__, tableFormat);
136 
137     switch (tableFormat) {
138     case 4:
139         return new CMAPFormat4Mapper(cmap, (const CMAPFormat4Encoding *) subtable);
140 
141     case 12:
142     {
143         const CMAPFormat12Encoding *encoding = (const CMAPFormat12Encoding *) subtable;
144 
145         return new CMAPGroupMapper(cmap, encoding->groups, SWAPL(encoding->nGroups));
146     }
147 
148     default:
149         break;
150     }
151 
152     printf("%s:%d: Unknown format %x.\n", __FILE__, __LINE__, (SWAPW(subtable->format)));
153     return NULL;
154 }
155 
CMAPFormat4Mapper(const CMAPTable * cmap,const CMAPFormat4Encoding * header)156 CMAPFormat4Mapper::CMAPFormat4Mapper(const CMAPTable *cmap, const CMAPFormat4Encoding *header)
157     : CMAPMapper(cmap)
158 {
159     le_uint16 segCount = SWAPW(header->segCountX2) / 2;
160 
161     fEntrySelector = SWAPW(header->entrySelector);
162     fRangeShift = SWAPW(header->rangeShift) / 2;
163     fEndCodes = &header->endCodes[0];
164     fStartCodes = &header->endCodes[segCount + 1]; // + 1 for reservedPad...
165     fIdDelta = &fStartCodes[segCount];
166     fIdRangeOffset = &fIdDelta[segCount];
167 }
168 
unicodeToGlyph(LEUnicode32 unicode32) const169 LEGlyphID CMAPFormat4Mapper::unicodeToGlyph(LEUnicode32 unicode32) const
170 {
171     if (unicode32 >= 0x10000) {
172         return 0;
173     }
174 
175     LEUnicode16 unicode = (LEUnicode16) unicode32;
176     le_uint16 index = 0;
177     le_uint16 probe = 1 << fEntrySelector;
178     TTGlyphID result = 0;
179 
180     if (SWAPU16(fStartCodes[fRangeShift]) <= unicode) {
181         index = fRangeShift;
182     }
183 
184     while (probe > (1 << 0)) {
185         probe >>= 1;
186 
187         if (SWAPU16(fStartCodes[index + probe]) <= unicode) {
188             index += probe;
189         }
190     }
191 
192     if (unicode >= SWAPU16(fStartCodes[index]) && unicode <= SWAPU16(fEndCodes[index])) {
193         if (fIdRangeOffset[index] == 0) {
194             result = (TTGlyphID) unicode;
195         } else {
196             le_uint16 offset = unicode - SWAPU16(fStartCodes[index]);
197             le_uint16 rangeOffset = SWAPW(fIdRangeOffset[index]);
198             le_uint16 *glyphIndexTable = (le_uint16 *) ((char *) &fIdRangeOffset[index] + rangeOffset);
199 
200             result = SWAPW(glyphIndexTable[offset]);
201         }
202 
203         result += SWAPW(fIdDelta[index]);
204     } else {
205         result = 0;
206     }
207 
208     return LE_SET_GLYPH(0, result);
209 }
210 
~CMAPFormat4Mapper()211 CMAPFormat4Mapper::~CMAPFormat4Mapper()
212 {
213     // parent destructor does it all
214 }
215 
CMAPGroupMapper(const CMAPTable * cmap,const CMAPGroup * groups,le_uint32 nGroups)216 CMAPGroupMapper::CMAPGroupMapper(const CMAPTable *cmap, const CMAPGroup *groups, le_uint32 nGroups)
217     : CMAPMapper(cmap), fGroups(groups)
218 {
219     le_uint8 bit = highBit(nGroups);
220     fPower = 1 << bit;
221     fRangeOffset = nGroups - fPower;
222 }
223 
unicodeToGlyph(LEUnicode32 unicode32) const224 LEGlyphID CMAPGroupMapper::unicodeToGlyph(LEUnicode32 unicode32) const
225 {
226     le_int32 probe = fPower;
227     le_int32 range = 0;
228 
229     if (SWAPU32(fGroups[fRangeOffset].startCharCode) <= unicode32) {
230         range = fRangeOffset;
231     }
232 
233     while (probe > (1 << 0)) {
234         probe >>= 1;
235 
236         if (SWAPU32(fGroups[range + probe].startCharCode) <= unicode32) {
237             range += probe;
238         }
239     }
240 
241     if (SWAPU32(fGroups[range].startCharCode) <= unicode32 && SWAPU32(fGroups[range].endCharCode) >= unicode32) {
242         return (LEGlyphID) (SWAPU32(fGroups[range].startGlyphCode) + unicode32 - SWAPU32(fGroups[range].startCharCode));
243     }
244 
245     return 0;
246 }
247 
~CMAPGroupMapper()248 CMAPGroupMapper::~CMAPGroupMapper()
249 {
250     // parent destructor does it all
251 }
252 
253