| /* |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| /* |
| * |
| * (C) Copyright IBM Corp. 1998-2004 - All Rights Reserved |
| * |
| */ |
| |
| #include "LETypes.h" |
| #include "LayoutTables.h" |
| #include "LookupTables.h" |
| #include "LESwaps.h" |
| |
| U_NAMESPACE_BEGIN |
| |
| /* |
| These are the rolled-up versions of the uniform binary search. |
| Someday, if we need more performance, we can un-roll them. |
| |
| Note: I put these in the base class, so they only have to |
| be written once. Since the base class doesn't define the |
| segment table, these routines assume that it's right after |
| the binary search header. |
| |
| Another way to do this is to put each of these routines in one |
| of the derived classes, and implement it in the others by casting |
| the "this" pointer to the type that has the implementation. |
| */ |
| const LookupSegment *BinarySearchLookupTable::lookupSegment(const LETableReference &base, const LookupSegment *segments, LEGlyphID glyph, LEErrorCode &success) const |
| { |
| |
| le_int16 unity = SWAPW(unitSize); |
| le_int16 probe = SWAPW(searchRange); |
| le_int16 extra = SWAPW(rangeShift); |
| TTGlyphID ttGlyph = (TTGlyphID) LE_GET_GLYPH(glyph); |
| LEReferenceTo<LookupSegment> entry(base, success, segments); |
| LEReferenceTo<LookupSegment> trial(entry, success, extra); |
| |
| if(LE_FAILURE(success)) return NULL; |
| |
| if (SWAPW(trial->lastGlyph) <= ttGlyph) { |
| entry = trial; |
| } |
| |
| while (probe > unity && LE_SUCCESS(success)) { |
| probe >>= 1; |
| trial = entry; // copy |
| trial.addOffset(probe, success); |
| |
| if (SWAPW(trial->lastGlyph) <= ttGlyph) { |
| entry = trial; |
| } |
| } |
| |
| if (SWAPW(entry->firstGlyph) <= ttGlyph) { |
| return entry.getAlias(); |
| } |
| |
| return NULL; |
| } |
| |
| const LookupSingle *BinarySearchLookupTable::lookupSingle(const LETableReference &base, const LookupSingle *entries, LEGlyphID glyph, LEErrorCode &success) const |
| { |
| le_int16 unity = SWAPW(unitSize); |
| le_int16 probe = SWAPW(searchRange); |
| le_int16 extra = SWAPW(rangeShift); |
| TTGlyphID ttGlyph = (TTGlyphID) LE_GET_GLYPH(glyph); |
| LEReferenceTo<LookupSingle> entry(base, success, entries); |
| LEReferenceTo<LookupSingle> trial(entry, success, extra); |
| |
| if (!LE_SUCCESS(success)) { |
| return NULL; |
| } |
| |
| if (SWAPW(trial->glyph) <= ttGlyph) { |
| entry = trial; |
| } |
| |
| while (probe > unity && LE_SUCCESS(success)) { |
| probe >>= 1; |
| trial = entry; |
| trial.addOffset(probe, success); |
| |
| if (SWAPW(trial->glyph) <= ttGlyph) { |
| entry = trial; |
| } |
| } |
| |
| if (SWAPW(entry->glyph) == ttGlyph) { |
| return entry.getAlias(); |
| } |
| |
| return NULL; |
| } |
| |
| U_NAMESPACE_END |