J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 3 | * |
| 4 | * This code is free software; you can redistribute it and/or modify it |
| 5 | * under the terms of the GNU General Public License version 2 only, as |
| 6 | * published by the Free Software Foundation. Sun designates this |
| 7 | * particular file as subject to the "Classpath" exception as provided |
| 8 | * by Sun in the LICENSE file that accompanied this code. |
| 9 | * |
| 10 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 11 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 12 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 13 | * version 2 for more details (a copy is included in the LICENSE file that |
| 14 | * accompanied this code). |
| 15 | * |
| 16 | * You should have received a copy of the GNU General Public License version |
| 17 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 18 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 19 | * |
| 20 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 21 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 22 | * have any questions. |
| 23 | * |
| 24 | */ |
| 25 | |
| 26 | |
| 27 | /* |
| 28 | * |
| 29 | * (C) Copyright IBM Corp. 1998-2005 - All Rights Reserved |
| 30 | * |
| 31 | */ |
| 32 | |
| 33 | #ifndef __ARABICLAYOUTENGINE_H |
| 34 | #define __ARABICLAYOUTENGINE_H |
| 35 | |
| 36 | #include "LETypes.h" |
| 37 | #include "LEFontInstance.h" |
| 38 | #include "LEGlyphFilter.h" |
| 39 | #include "LayoutEngine.h" |
| 40 | #include "OpenTypeLayoutEngine.h" |
| 41 | |
| 42 | #include "GlyphSubstitutionTables.h" |
| 43 | #include "GlyphDefinitionTables.h" |
| 44 | #include "GlyphPositioningTables.h" |
| 45 | |
| 46 | /** |
| 47 | * This class implements OpenType layout for Arabic fonts. It overrides |
| 48 | * the characerProcessing method to assign the correct OpenType feature |
| 49 | * tags for the Arabic contextual forms. It also overrides the adjustGlyphPositions |
| 50 | * method to guarantee that all vowel and accent glyphs have zero advance width. |
| 51 | * |
| 52 | * @internal |
| 53 | */ |
| 54 | class ArabicOpenTypeLayoutEngine : public OpenTypeLayoutEngine |
| 55 | { |
| 56 | public: |
| 57 | /** |
| 58 | * This is the main constructor. It constructs an instance of ArabicOpenTypeLayoutEngine for |
| 59 | * a particular font, script and language. It takes the GSUB table as a parameter since |
| 60 | * LayoutEngine::layoutEngineFactory has to read the GSUB table to know that it has an |
| 61 | * Indic OpenType font. |
| 62 | * |
| 63 | * @param fontInstance - the font |
| 64 | * @param scriptCode - the script |
| 65 | * @param langaugeCode - the language |
| 66 | * @param gsubTable - the GSUB table |
| 67 | * |
| 68 | * @see LayoutEngine::layoutEngineFactory |
| 69 | * @see OpenTypeLayoutEngine |
| 70 | * @see ScriptAndLanguageTags.h for script and language codes |
| 71 | * |
| 72 | * @internal |
| 73 | */ |
| 74 | ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, |
| 75 | le_int32 languageCode, le_int32 typoFlags, const GlyphSubstitutionTableHeader *gsubTable); |
| 76 | |
| 77 | /** |
| 78 | * This constructor is used when the font requires a "canned" GSUB table which can't be known |
| 79 | * until after this constructor has been invoked. |
| 80 | * |
| 81 | * @param fontInstance - the font |
| 82 | * @param scriptCode - the script |
| 83 | * @param langaugeCode - the language |
| 84 | * |
| 85 | * @see OpenTypeLayoutEngine |
| 86 | * @see ScriptAndLanguageTags.h for script and language codes |
| 87 | * |
| 88 | * @internal |
| 89 | */ |
| 90 | ArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, le_int32 scriptCode, |
| 91 | le_int32 languageCode, le_int32 typoFlags); |
| 92 | |
| 93 | /** |
| 94 | * The destructor, virtual for correct polymorphic invocation. |
| 95 | * |
| 96 | * @internal |
| 97 | */ |
| 98 | virtual ~ArabicOpenTypeLayoutEngine(); |
| 99 | |
| 100 | protected: |
| 101 | |
| 102 | /** |
| 103 | * This method does Arabic OpenType character processing. It assigns the OpenType feature |
| 104 | * tags to the characters to generate the correct contextual forms and ligatures. |
| 105 | * |
| 106 | * Input parameters: |
| 107 | * @param chars - the input character context |
| 108 | * @param offset - the index of the first character to process |
| 109 | * @param count - the number of characters to process |
| 110 | * @param max - the number of characters in the input context |
| 111 | * @param rightToLeft - <code>TRUE</code> if the characters are in a |
| 112 | * right to left directional run |
| 113 | * |
| 114 | * Output parameters: |
| 115 | * @param outChars - the output character arrayt |
| 116 | * @param charIndices - the output character index array |
| 117 | * @param featureTags - the output feature tag array |
| 118 | * @param success - set to an error code if the operation fails |
| 119 | * |
| 120 | * @return the output character count |
| 121 | * |
| 122 | * @internal |
| 123 | */ |
| 124 | virtual le_int32 characterProcessing(const LEUnicode chars[], le_int32 offset, |
| 125 | le_int32 count, le_int32 max, le_bool rightToLeft, |
| 126 | LEUnicode *&outChars, LEGlyphStorage &glyphStorage, LEErrorCode &success); |
| 127 | |
| 128 | /** |
| 129 | * This method applies the GPOS table if it is present, otherwise it ensures that all vowel |
| 130 | * and accent glyphs have a zero advance width by calling the adjustMarkGlyphs method. |
| 131 | * If the font contains a GDEF table, that is used to identify voewls and accents. Otherwise |
| 132 | * the character codes are used. |
| 133 | * |
| 134 | * @param chars - the input character context |
| 135 | * @param offset - the offset of the first character to process |
| 136 | * @param count - the number of characters to process |
| 137 | * @param reverse - <code>TRUE</code> if the glyphs in the glyph array have been reordered |
| 138 | * @param glyphs - the input glyph array |
| 139 | * @param glyphCount - the number of glyphs |
| 140 | * @param positions - the position array, will be updated as needed |
| 141 | * @param success - output parameter set to an error code if the operation fails |
| 142 | * |
| 143 | * @internal |
| 144 | */ |
| 145 | virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, |
| 146 | le_int32 count, le_bool reverse, LEGlyphStorage &glyphStorage, LEErrorCode &success); |
| 147 | |
| 148 | // static void adjustMarkGlyphs(const LEUnicode chars[], le_int32 offset, le_int32 count, |
| 149 | // le_bool rightToLeft, LEGlyphStorage &glyphStorage, LEErrorCode &success); |
| 150 | |
| 151 | }; |
| 152 | |
| 153 | /** |
| 154 | * The class implements OpenType layout for Arabic fonts which don't |
| 155 | * contain a GSUB table, using a canned GSUB table based on Unicode |
| 156 | * Arabic Presentation Forms. It overrides the mapCharsToGlyphs method |
| 157 | * to use the Presentation Forms as logical glyph indices. It overrides the |
| 158 | * glyphPostProcessing method to convert the Presentation Forms to actual |
| 159 | * glyph indices. |
| 160 | * |
| 161 | * @see ArabicOpenTypeLayoutEngine |
| 162 | * |
| 163 | * @internal |
| 164 | */ |
| 165 | class UnicodeArabicOpenTypeLayoutEngine : public ArabicOpenTypeLayoutEngine |
| 166 | { |
| 167 | public: |
| 168 | /** |
| 169 | * This constructs an instance of UnicodeArabicOpenTypeLayoutEngine for a specific font, |
| 170 | * script and language. |
| 171 | * |
| 172 | * @param fontInstance - the font |
| 173 | * @param scriptCode - the script |
| 174 | * @param languageCode - the language |
| 175 | * |
| 176 | * @see LEFontInstance |
| 177 | * @see ScriptAndLanguageTags.h for script and language codes |
| 178 | * |
| 179 | * @internal |
| 180 | */ |
| 181 | UnicodeArabicOpenTypeLayoutEngine(const LEFontInstance *fontInstance, |
| 182 | le_int32 scriptCode, le_int32 languageCode, le_int32 typoFlags); |
| 183 | |
| 184 | /** |
| 185 | * The destructor, virtual for correct polymorphic invocation. |
| 186 | * |
| 187 | * @internal |
| 188 | */ |
| 189 | virtual ~UnicodeArabicOpenTypeLayoutEngine(); |
| 190 | |
| 191 | protected: |
| 192 | |
| 193 | /** |
| 194 | * This method converts the Arabic Presentation Forms in the temp glyph array |
| 195 | * into actual glyph indices using ArabicOpenTypeLayoutEngine::mapCharsToGlyps. |
| 196 | * |
| 197 | * Input paramters: |
| 198 | * @param tempGlyphs - the input presentation forms |
| 199 | * @param tempCharIndices - the input character index array |
| 200 | * @param tempGlyphCount - the number of Presentation Froms |
| 201 | * |
| 202 | * Output parameters: |
| 203 | * @param glyphs - the output glyph index array |
| 204 | * @param charIndices - the output character index array |
| 205 | * @param success - set to an error code if the operation fails |
| 206 | * |
| 207 | * @return the number of glyph indices in the output glyph index array |
| 208 | * |
| 209 | * @internal |
| 210 | */ |
| 211 | virtual le_int32 glyphPostProcessing(LEGlyphStorage &tempGlyphStorage, |
| 212 | LEGlyphStorage &glyphStorage, LEErrorCode &success); |
| 213 | |
| 214 | /** |
| 215 | * This method copies the input characters into the output glyph index array, |
| 216 | * for use by the canned GSUB table. It also generates the character index array. |
| 217 | * |
| 218 | * Input parameters: |
| 219 | * @param chars - the input character context |
| 220 | * @param offset - the offset of the first character to be mapped |
| 221 | * @param count - the number of characters to be mapped |
| 222 | * @param reverse - if <code>TRUE</code>, the output will be in reverse order |
| 223 | * @param mirror - if <code>TRUE</code>, do character mirroring |
| 224 | * @param glyphStorage - the glyph storage object. Glyph and char index arrays will be updated. |
| 225 | * |
| 226 | * @param success - set to an error code if the operation fails |
| 227 | * |
| 228 | * @internal |
| 229 | */ |
| 230 | virtual void mapCharsToGlyphs(const LEUnicode chars[], le_int32 offset, |
| 231 | le_int32 count, le_bool reverse, le_bool mirror, |
| 232 | LEGlyphStorage &glyphStorage, LEErrorCode &success); |
| 233 | |
| 234 | /** |
| 235 | * This method ensures that all vowel and accent glyphs have a zero advance width by calling |
| 236 | * the adjustMarkGlyphs method. The character codes are used to identify the vowel and mark |
| 237 | * glyphs. |
| 238 | * |
| 239 | * @param chars - the input character context |
| 240 | * @param offset - the offset of the first character to process |
| 241 | * @param count - the number of characters to process |
| 242 | * @param reverse - <code>TRUE</code> if the glyphs in the glyph array have been reordered |
| 243 | * @param glyphStorage - the glyph storage object. The glyph positions will be updated as needed. |
| 244 | * @param success - output parameter set to an error code if the operation fails |
| 245 | * |
| 246 | * @internal |
| 247 | */ |
| 248 | virtual void adjustGlyphPositions(const LEUnicode chars[], le_int32 offset, |
| 249 | le_int32 count, le_bool reverse, LEGlyphStorage &glyphStorage, LEErrorCode &success); |
| 250 | }; |
| 251 | |
| 252 | #endif |