1   /*
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3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
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7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  package sun.font;
27  
28  /* remember that the API requires a Font use a
29   * consistent glyph id. for a code point, and this is a
30   * problem if a particular strike uses native scaler sometimes
31   * and T2K others. That needs to be dealt with somewhere, but
32   * here we can just always get the same glyph code without
33   * needing a strike.
34   *
35   * The C implementation would cache the results of anything up
36   * to the maximum surrogate pair code point.
37   * This implementation will not cache as much, since the storage
38   * requirements are not justifiable. Even so it still can use up
39   * to 216*256*4 bytes of storage per composite font. If an app
40   * calls canDisplay on this range for all 20 composite fonts that's
41   * over 1Mb of cached data. May need to employ WeakReferences if
42   * this appears to cause problems.
43   */
44  
45  public final class CompositeGlyphMapper extends CharToGlyphMapper {
46  
47      public static final int SLOTMASK =  0xff000000;
48      public static final int GLYPHMASK = 0x00ffffff;
49  
50      public static final int NBLOCKS = 216;
51      public static final int BLOCKSZ = 256;
52      public static final int MAXUNICODE = NBLOCKS*BLOCKSZ;
53  
54  
55      CompositeFont font;
56      CharToGlyphMapper slotMappers[];
57      int[][] glyphMaps;
58      private boolean hasExcludes;
59  
60      public CompositeGlyphMapper(CompositeFont compFont) {
61          font = compFont;
62          initMapper();
63          /* This is often false which saves the overhead of a
64           * per-mapped char method call.
65           */
66          hasExcludes = compFont.exclusionRanges != null &&
67                        compFont.maxIndices != null;
68      }
69  
70      public final int compositeGlyphCode(int slot, int glyphCode) {
71          return (slot << 24 | (glyphCode & GLYPHMASK));
72      }
73  
74      private final void initMapper() {
75          if (missingGlyph == CharToGlyphMapper.UNINITIALIZED_GLYPH) {
76              if (glyphMaps == null) {
77                  glyphMaps = new int[NBLOCKS][];
78              }
79              slotMappers = new CharToGlyphMapper[font.numSlots];
80              /* This requires that slot 0 is never empty. */
81              missingGlyph = font.getSlotFont(0).getMissingGlyphCode();
82              missingGlyph = compositeGlyphCode(0, missingGlyph);
83          }
84      }
85  
86      private int getCachedGlyphCode(int unicode) {
87          if (unicode >= MAXUNICODE) {
88              return UNINITIALIZED_GLYPH; // don't cache surrogates
89          }
90          int[] gmap;
91          if ((gmap = glyphMaps[unicode >> 8]) == null) {
92              return UNINITIALIZED_GLYPH;
93          }
94          return gmap[unicode & 0xff];
95      }
96  
97      private void setCachedGlyphCode(int unicode, int glyphCode) {
98          if (unicode >= MAXUNICODE) {
99              return;     // don't cache surrogates
100         }
101         int index0 = unicode >> 8;
102         if (glyphMaps[index0] == null) {
103             glyphMaps[index0] = new int[BLOCKSZ];
104             for (int i=0;i<BLOCKSZ;i++) {
105                 glyphMaps[index0][i] = UNINITIALIZED_GLYPH;
106             }
107         }
108         glyphMaps[index0][unicode & 0xff] = glyphCode;
109     }
110 
111     private final CharToGlyphMapper getSlotMapper(int slot) {
112         CharToGlyphMapper mapper = slotMappers[slot];
113         if (mapper == null) {
114             mapper = font.getSlotFont(slot).getMapper();
115             slotMappers[slot] = mapper;
116         }
117         return mapper;
118     }
119 
120     private final int convertToGlyph(int unicode) {
121 
122         for (int slot = 0; slot < font.numSlots; slot++) {
123             if (!hasExcludes || !font.isExcludedChar(slot, unicode)) {
124                 CharToGlyphMapper mapper = getSlotMapper(slot);
125                 int glyphCode = mapper.charToGlyph(unicode);
126                 if (glyphCode != mapper.getMissingGlyphCode()) {
127                     glyphCode = compositeGlyphCode(slot, glyphCode);
128                     setCachedGlyphCode(unicode, glyphCode);
129                     return glyphCode;
130                 }
131             }
132         }
133         return missingGlyph;
134     }
135 
136     public int getNumGlyphs() {
137         int numGlyphs = 0;
138         /* The number of glyphs in a composite is affected by
139          * exclusion ranges and duplicates (ie the same code point is
140          * mapped by two different fonts) and also whether or not to
141          * count fallback fonts. A nearly correct answer would be very
142          * expensive to generate. A rough ballpark answer would
143          * just count the glyphs in all the slots. However this would
144          * initialize mappers for all slots when they aren't necessarily
145          * needed. For now just use the first slot as JDK 1.4 did.
146          */
147         for (int slot=0; slot<1 /*font.numSlots*/; slot++) {
148            CharToGlyphMapper mapper = slotMappers[slot];
149            if (mapper == null) {
150                mapper = font.getSlotFont(slot).getMapper();
151                slotMappers[slot] = mapper;
152            }
153            numGlyphs += mapper.getNumGlyphs();
154         }
155         return numGlyphs;
156     }
157 
158     public int charToGlyph(int unicode) {
159 
160         int glyphCode = getCachedGlyphCode(unicode);
161         if (glyphCode == UNINITIALIZED_GLYPH) {
162             glyphCode = convertToGlyph(unicode);
163         }
164         return glyphCode;
165     }
166 
167     public int charToGlyph(int unicode, int prefSlot) {
168         if (prefSlot >= 0) {
169             CharToGlyphMapper mapper = getSlotMapper(prefSlot);
170             int glyphCode = mapper.charToGlyph(unicode);
171             if (glyphCode != mapper.getMissingGlyphCode()) {
172                 return compositeGlyphCode(prefSlot, glyphCode);
173             }
174         }
175         return charToGlyph(unicode);
176     }
177 
178     public int charToGlyph(char unicode) {
179 
180         int glyphCode  = getCachedGlyphCode(unicode);
181         if (glyphCode == UNINITIALIZED_GLYPH) {
182             glyphCode = convertToGlyph(unicode);
183         }
184         return glyphCode;
185     }
186 
187     /* This variant checks if shaping is needed and immediately
188      * returns true if it does. A caller of this method should be expecting
189      * to check the return type because it needs to know how to handle
190      * the character data for display.
191      */
192     public boolean charsToGlyphsNS(int count, char[] unicodes, int[] glyphs) {
193 
194         for (int i=0; i<count; i++) {
195             int code = unicodes[i]; // char is unsigned.
196 
197             if (code >= HI_SURROGATE_START &&
198                 code <= HI_SURROGATE_END && i < count - 1) {
199                 char low = unicodes[i + 1];
200 
201                 if (low >= LO_SURROGATE_START &&
202                     low <= LO_SURROGATE_END) {
203                     code = (code - HI_SURROGATE_START) *
204                         0x400 + low - LO_SURROGATE_START + 0x10000;
205                     glyphs[i + 1] = INVISIBLE_GLYPH_ID;
206                 }
207             }
208 
209             int gc = glyphs[i] = getCachedGlyphCode(code);
210             if (gc == UNINITIALIZED_GLYPH) {
211                 glyphs[i] = convertToGlyph(code);
212             }
213 
214             if (code < FontUtilities.MIN_LAYOUT_CHARCODE) {
215                 continue;
216             }
217             else if (FontUtilities.isComplexCharCode(code)) {
218                 return true;
219             }
220             else if (code >= 0x10000) {
221                 i += 1; // Empty glyph slot after surrogate
222                 continue;
223             }
224         }
225 
226         return false;
227     }
228 
229     /* The conversion is not very efficient - looping as it does, converting
230      * one char at a time. However the cache should fill very rapidly.
231      */
232     public void charsToGlyphs(int count, char[] unicodes, int[] glyphs) {
233         for (int i=0; i<count; i++) {
234             int code = unicodes[i]; // char is unsigned.
235 
236             if (code >= HI_SURROGATE_START &&
237                 code <= HI_SURROGATE_END && i < count - 1) {
238                 char low = unicodes[i + 1];
239 
240                 if (low >= LO_SURROGATE_START &&
241                     low <= LO_SURROGATE_END) {
242                     code = (code - HI_SURROGATE_START) *
243                         0x400 + low - LO_SURROGATE_START + 0x10000;
244 
245                     int gc = glyphs[i] = getCachedGlyphCode(code);
246                     if (gc == UNINITIALIZED_GLYPH) {
247                         glyphs[i] = convertToGlyph(code);
248                     }
249                     i += 1; // Empty glyph slot after surrogate
250                     glyphs[i] = INVISIBLE_GLYPH_ID;
251                     continue;
252                 }
253             }
254 
255             int gc = glyphs[i] = getCachedGlyphCode(code);
256             if (gc == UNINITIALIZED_GLYPH) {
257                 glyphs[i] = convertToGlyph(code);
258             }
259         }
260     }
261 
262     public void charsToGlyphs(int count, int[] unicodes, int[] glyphs) {
263         for (int i=0; i<count; i++) {
264             int code = unicodes[i];
265 
266             glyphs[i] = getCachedGlyphCode(code);
267             if (glyphs[i] == UNINITIALIZED_GLYPH) {
268                 glyphs[i] = convertToGlyph(code);
269             }
270         }
271     }
272 
273 }