1 /*
   2  * Copyright (c) 2003, 2006, Oracle and/or its affiliates. All rights reserved.
   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
   6  * under the terms of the GNU General Public License version 2 only, as
   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 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 int compositeGlyphCode(int slot, int glyphCode) {
  71         return (slot << 24 | (glyphCode & GLYPHMASK));
  72     }
  73 
  74     private 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 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 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     private int convertToGlyph(int unicode, int variationSelector) {
 137         if (variationSelector == 0) {
 138             return convertToGlyph(unicode);
 139         }
 140         for (int slot = 0; slot < font.numSlots; slot++) {
 141             if (!hasExcludes || !font.isExcludedChar(slot, unicode)) {
 142                 CharToGlyphMapper mapper = getSlotMapper(slot);
 143                 int glyphCode = missingGlyph;
 144                 if (mapper.hasVariationSelectorGlyph(unicode, 
 145                                                      variationSelector)) {
 146                     int glyphCodes[] = { 0, 0};
 147                     int codes[] = {unicode, variationSelector};
 148                     mapper.charsToGlyphs(2, codes, glyphCodes);
 149                     glyphCode = glyphCodes[0];
 150                     if (glyphCode != mapper.getMissingGlyphCode()) {
 151                         glyphCode = compositeGlyphCode(slot, glyphCode);
 152                         return glyphCode;
 153                     }
 154                 }
 155             }
 156         }
 157         return convertToGlyph(unicode); //retry without Variation Selector
 158     }
 159 
 160     public int getNumGlyphs() {
 161         int numGlyphs = 0;
 162         /* The number of glyphs in a composite is affected by
 163          * exclusion ranges and duplicates (ie the same code point is
 164          * mapped by two different fonts) and also whether or not to
 165          * count fallback fonts. A nearly correct answer would be very
 166          * expensive to generate. A rough ballpark answer would
 167          * just count the glyphs in all the slots. However this would
 168          * initialize mappers for all slots when they aren't necessarily
 169          * needed. For now just use the first slot as JDK 1.4 did.
 170          */
 171         for (int slot=0; slot<1 /*font.numSlots*/; slot++) {
 172            CharToGlyphMapper mapper = slotMappers[slot];
 173            if (mapper == null) {
 174                mapper = font.getSlotFont(slot).getMapper();
 175                slotMappers[slot] = mapper;
 176            }
 177            numGlyphs += mapper.getNumGlyphs();
 178         }
 179         return numGlyphs;
 180     }
 181 
 182     public int charToGlyph(int unicode) {
 183 
 184         int glyphCode = getCachedGlyphCode(unicode);
 185         if (glyphCode == UNINITIALIZED_GLYPH) {
 186             glyphCode = convertToGlyph(unicode);
 187         }
 188         return glyphCode;
 189     }
 190 
 191     public int charToGlyph(int unicode, int prefSlot) {
 192         if (prefSlot >= 0) {
 193             CharToGlyphMapper mapper = getSlotMapper(prefSlot);
 194             int glyphCode = mapper.charToGlyph(unicode);
 195             if (glyphCode != mapper.getMissingGlyphCode()) {
 196                 return compositeGlyphCode(prefSlot, glyphCode);
 197             }
 198         }
 199         return charToGlyph(unicode);
 200     }
 201 
 202     public int charToGlyph(char unicode) {
 203 
 204         int glyphCode  = getCachedGlyphCode(unicode);
 205         if (glyphCode == UNINITIALIZED_GLYPH) {
 206             glyphCode = convertToGlyph(unicode);
 207         }
 208         return glyphCode;
 209     }
 210 
 211     /* This variant checks if shaping is needed and immediately
 212      * returns true if it does. A caller of this method should be expecting
 213      * to check the return type because it needs to know how to handle
 214      * the character data for display.
 215      */
 216     public boolean charsToGlyphsNS(int count, char[] unicodes, int[] glyphs) {
 217 
 218         for (int i=0; i<count; i++) {
 219             int code = unicodes[i]; // char is unsigned.
 220             int step = 1;
 221             int variationSelector = 0;
 222 
 223             if (code >= HI_SURROGATE_START &&
 224                 code <= HI_SURROGATE_END && i < count - 1) {
 225                 char low = unicodes[i + 1];
 226 
 227                 if (low >= LO_SURROGATE_START &&
 228                     low <= LO_SURROGATE_END) {
 229                     code = (code - HI_SURROGATE_START) *
 230                         0x400 + low - LO_SURROGATE_START + 0x10000;
 231                     glyphs[i + 1] = INVISIBLE_GLYPH_ID;
 232                     step = 2;
 233                 }
 234             }
 235 
 236             if (i < count - step &&
 237                 isVariationSelector(unicodes[i+step]) &&
 238                 isBaseChar(code)) {
 239                 variationSelector = unicodes[i+step];
 240                 glyphs[i] = convertToGlyph(code, variationSelector);
 241                 glyphs[i+step] = INVISIBLE_GLYPH_ID;
 242                 i += 1;
 243             } else if (i < count - step -1 &&
 244                        isVariationSelector(unicodes[i+step],
 245                                            unicodes[i+step+1]) &&
 246                        isBaseChar(code)) {
 247                 variationSelector = (unicodes[i+step] 
 248                                      - HI_SURROGATE_START) * 0x400 
 249                                     + unicodes[i+step+1] - LO_SURROGATE_START
 250                                     + 0x10000;
 251                 glyphs[i] = convertToGlyph(code, variationSelector);
 252                 glyphs[i+step] = INVISIBLE_GLYPH_ID;
 253                 glyphs[i+step+1] = INVISIBLE_GLYPH_ID;
 254                 i += 2;
 255             }
 256             if (variationSelector == 0) {
 257                 int gc = glyphs[i] = getCachedGlyphCode(code);
 258                 if (gc == UNINITIALIZED_GLYPH) {
 259                     glyphs[i] = convertToGlyph(code);
 260                 }
 261             }
 262 
 263             if (code < FontUtilities.MIN_LAYOUT_CHARCODE) {
 264                 continue;
 265             }
 266             else if (FontUtilities.isComplexCharCode(code)) {
 267                 return true;
 268             }
 269             else if (code >= 0x10000) {
 270                 i += 1; // Empty glyph slot after surrogate
 271                 continue;
 272             }
 273         }
 274 
 275         return false;
 276     }
 277 
 278     /* The conversion is not very efficient - looping as it does, converting
 279      * one char at a time. However the cache should fill very rapidly.
 280      */
 281     public void charsToGlyphs(int count, char[] unicodes, int[] glyphs) {
 282         for (int i=0; i<count; i++) {
 283             int code = unicodes[i]; // char is unsigned.
 284             int variationSelector = 0;
 285             int step = 1;
 286 
 287             if (code >= HI_SURROGATE_START &&
 288                 code <= HI_SURROGATE_END && i < count - 1) {
 289                 char low = unicodes[i + 1];
 290 
 291                 if (low >= LO_SURROGATE_START &&
 292                     low <= LO_SURROGATE_END) {
 293                     code = (code - HI_SURROGATE_START) *
 294                         0x400 + low - LO_SURROGATE_START + 0x10000;
 295 
 296                     glyphs[i+1] = INVISIBLE_GLYPH_ID;
 297                     step = 2;





 298                 }
 299             }
 300 
 301             if (i < count - step &&
 302                 isVariationSelector(unicodes[i+step]) &&
 303                 isBaseChar(code)) {
 304                     variationSelector = unicodes[i+step];
 305                     glyphs[i] = convertToGlyph(code, variationSelector);
 306                     glyphs[i+step] = INVISIBLE_GLYPH_ID;
 307                     i += 1;
 308             } else if (i < count - step -1 &&
 309                        isVariationSelector(unicodes[i+step], 
 310                                            unicodes[i+step+1]) &&
 311                        isBaseChar(code)) {
 312                 variationSelector = (unicodes[i+step] 
 313                                      - HI_SURROGATE_START) * 0x400 
 314                                     + unicodes[i+step+1] - LO_SURROGATE_START
 315                                     + 0x10000;
 316                 glyphs[i] = convertToGlyph(code, variationSelector);
 317                 glyphs[i+step] = INVISIBLE_GLYPH_ID;
 318                 glyphs[i+step+1] = INVISIBLE_GLYPH_ID;
 319                 i += 2;
 320             }
 321             if (variationSelector == 0) {
 322                 int gc = glyphs[i] = getCachedGlyphCode(code);
 323                 if (gc == UNINITIALIZED_GLYPH) {
 324                     glyphs[i] = convertToGlyph(code);
 325                 }
 326             }
 327             if (code >= 0x10000) {
 328                 i++;
 329             }
 330         }
 331     }
 332 
 333     public void charsToGlyphs(int count, int[] unicodes, int[] glyphs) {
 334         for (int i=0; i<count; i++) {
 335             int code = unicodes[i];
 336 
 337             if (i < count-1
 338                 && isVariationSelector(unicodes[i+1])
 339                 && isBaseChar(code) ) {
 340                 glyphs[i] = convertToGlyph(code, unicodes[i+1]);
 341                 glyphs[i+1] = INVISIBLE_GLYPH_ID;
 342                 i++;
 343             } else {
 344                 glyphs[i] = getCachedGlyphCode(code);
 345                 if (glyphs[i] == UNINITIALIZED_GLYPH) {
 346                     glyphs[i] = convertToGlyph(code);
 347                 }
 348             }
 349         }
 350     }
 351 
 352 }
--- EOF ---