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 | * (C) Copyright IBM Corp. 2003 - All Rights Reserved |
| 29 | */ |
| 30 | |
| 31 | package sun.font; |
| 32 | |
| 33 | import sun.font.GlyphLayout.*; |
| 34 | import java.awt.geom.Point2D; |
| 35 | import java.lang.ref.SoftReference; |
| 36 | import java.util.HashMap; |
| 37 | import java.util.Locale; |
| 38 | |
| 39 | /* |
| 40 | * different ways to do this |
| 41 | * 1) each physical font2d keeps a hashtable mapping scripts to layout |
| 42 | * engines, we query and fill this cache. |
| 43 | * 2) we keep a mapping independent of font using the key Most likely |
| 44 | * few fonts will be used, so option 2 seems better |
| 45 | * |
| 46 | * Once we know which engine to use for a font, we always know, so we |
| 47 | * shouldn't have to recheck each time we do layout. So the cache is |
| 48 | * ok. |
| 49 | * |
| 50 | * Should we reuse engines? We could instantiate an engine for each |
| 51 | * font/script pair. The engine would hold onto the table(s) from the |
| 52 | * font that it needs. If we have multiple threads using the same |
| 53 | * engine, we still need to keep the state separate, so the native |
| 54 | * engines would still need to be allocated for each call, since they |
| 55 | * keep their state in themselves. If they used the passed-in GVData |
| 56 | * arrays directly (with some checks for space) then since each GVData |
| 57 | * is different per thread, we could reuse the layout engines. This |
| 58 | * still requires a separate layout engine per font, because of the |
| 59 | * table state in the engine. If we pushed that out too and passed it |
| 60 | * in with the native call as well, we'd be ok if the layout engines |
| 61 | * keep all their process state on the stack, but I don't know if this |
| 62 | * is true. Then we'd basically just be down to an engine index which |
| 63 | * we pass into native and then invoke the engine code (now a |
| 64 | * procedure call, not an object invocation) based on a switch on the |
| 65 | * index. There would be only half a dozen engine objects then, not |
| 66 | * potentially half a dozen per font. But we'd have to stack-allocate |
| 67 | * some state that included the pointer to the required font tables. |
| 68 | * |
| 69 | * Seems for now that the way to do things is to come in with a |
| 70 | * selector and the font. The selector indicates which engine to use, |
| 71 | * the engine is stack allocated and initialized with the required |
| 72 | * font tables (the selector indicates which). Then layout is called, |
| 73 | * the contents are copied (or not), and the stack is destroyed on |
| 74 | * exit. So the association is between the font/script (layout engine |
| 75 | * desc) and and one of a few permanent engine objects, which are |
| 76 | * handed the key when they need to process something. In the native |
| 77 | * case, the engine holds an index, and just passes it together with |
| 78 | * the key info down to native. Some default cases are the 'default |
| 79 | * layout' case that just runs the c2gmapper, this stays in java and |
| 80 | * just uses the mapper from the font/strike. Another default case |
| 81 | * might be the unicode arabic shaper, since this doesn't care about |
| 82 | * the font (or script or lang?) it wouldn't need to extract this |
| 83 | * data. It could be (yikes) ported back to java even to avoid |
| 84 | * upcalls to check if the font supports a particular unicode |
| 85 | * character. |
| 86 | * |
| 87 | * I'd expect that the majority of scripts use the default mapper for |
| 88 | * a particular font. Loading the hastable with 40 or so keys 30+ of |
| 89 | * which all map to the same object is unfortunate. It might be worth |
| 90 | * instead having a per-font list of 'scripts with non-default |
| 91 | * engines', e.g. the factory has a hashtable mapping fonts to 'script |
| 92 | * lists' (the factory has this since the design potentially has other |
| 93 | * factories, though I admit there's no client for this yet and no |
| 94 | * public api) and then the script list is queried for the script in |
| 95 | * question. it can be preloaded at creation time with all the |
| 96 | * scripts that don't have default engines-- either a list or a hash |
| 97 | * table, so a null return from the table means 'default' and not 'i |
| 98 | * don't know yet'. |
| 99 | * |
| 100 | * On the other hand, in most all cases the number of unique |
| 101 | * script/font combinations will be small, so a flat hashtable should |
| 102 | * suffice. |
| 103 | * */ |
| 104 | public final class SunLayoutEngine implements LayoutEngine, LayoutEngineFactory { |
| 105 | private static native void initGVIDs(); |
| 106 | static { |
| 107 | FontManagerNativeLibrary.load(); |
| 108 | initGVIDs(); |
| 109 | } |
| 110 | |
| 111 | private LayoutEngineKey key; |
| 112 | |
| 113 | private static LayoutEngineFactory instance; |
| 114 | |
| 115 | public static LayoutEngineFactory instance() { |
| 116 | if (instance == null) { |
| 117 | instance = new SunLayoutEngine(); |
| 118 | } |
| 119 | return instance; |
| 120 | } |
| 121 | |
| 122 | private SunLayoutEngine() { |
| 123 | // actually a factory, key is null so layout cannot be called on it |
| 124 | } |
| 125 | |
| 126 | public LayoutEngine getEngine(Font2D font, int script, int lang) { |
| 127 | return getEngine(new LayoutEngineKey(font, script, lang)); |
| 128 | } |
| 129 | |
| 130 | // !!! don't need this unless we have more than one sun layout engine... |
| 131 | public LayoutEngine getEngine(LayoutEngineKey key) { |
| 132 | HashMap cache = (HashMap)cacheref.get(); |
| 133 | if (cache == null) { |
| 134 | cache = new HashMap(); |
| 135 | cacheref = new SoftReference(cache); |
| 136 | } |
| 137 | |
| 138 | LayoutEngine e = (LayoutEngine)cache.get(key); |
| 139 | if (e == null) { |
| 140 | e = new SunLayoutEngine(key.copy()); |
| 141 | cache.put(key, e); |
| 142 | } |
| 143 | return e; |
| 144 | } |
| 145 | private SoftReference cacheref = new SoftReference(null); |
| 146 | |
| 147 | private SunLayoutEngine(LayoutEngineKey key) { |
| 148 | this.key = key; |
| 149 | } |
| 150 | |
| 151 | public void layout(FontStrikeDesc desc, float[] mat, int gmask, |
| 152 | int baseIndex, TextRecord tr, int typo_flags, |
| 153 | Point2D.Float pt, GVData data) { |
| 154 | Font2D font = key.font(); |
| 155 | FontStrike strike = font.getStrike(desc); |
| 156 | long layoutTables = 0; |
| 157 | if (font instanceof TrueTypeFont) { |
| 158 | layoutTables = ((TrueTypeFont) font).getLayoutTableCache(); |
| 159 | } |
| 160 | nativeLayout(font, strike, mat, gmask, baseIndex, |
| 161 | tr.text, tr.start, tr.limit, tr.min, tr.max, |
| 162 | key.script(), key.lang(), typo_flags, pt, data, |
| 163 | font.getUnitsPerEm(), layoutTables); |
| 164 | } |
| 165 | |
| 166 | private static native void |
| 167 | nativeLayout(Font2D font, FontStrike strike, float[] mat, int gmask, |
| 168 | int baseIndex, char[] chars, int offset, int limit, |
| 169 | int min, int max, int script, int lang, int typo_flags, |
| 170 | Point2D.Float pt, GVData data, long upem, long layoutTables); |
| 171 | } |