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Diffstat (limited to 'gcc-4.4.3/libjava/classpath/gnu/java/awt/font/opentype/truetype/GlyphLocator.java')
| -rw-r--r-- | gcc-4.4.3/libjava/classpath/gnu/java/awt/font/opentype/truetype/GlyphLocator.java | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/gcc-4.4.3/libjava/classpath/gnu/java/awt/font/opentype/truetype/GlyphLocator.java b/gcc-4.4.3/libjava/classpath/gnu/java/awt/font/opentype/truetype/GlyphLocator.java new file mode 100644 index 000000000..a2db8aca7 --- /dev/null +++ b/gcc-4.4.3/libjava/classpath/gnu/java/awt/font/opentype/truetype/GlyphLocator.java @@ -0,0 +1,187 @@ +/* GlyphLocator.java -- Locates outlines of TrueType glyphs. + Copyright (C) 2006 Free Software Foundation, Inc. + +This file is part of GNU Classpath. + +GNU Classpath is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +GNU Classpath 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 for more details. + +You should have received a copy of the GNU General Public License +along with GNU Classpath; see the file COPYING. If not, write to the +Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 USA. + +Linking this library statically or dynamically with other modules is +making a combined work based on this library. Thus, the terms and +conditions of the GNU General Public License cover the whole +combination. + +As a special exception, the copyright holders of this library give you +permission to link this library with independent modules to produce an +executable, regardless of the license terms of these independent +modules, and to copy and distribute the resulting executable under +terms of your choice, provided that you also meet, for each linked +independent module, the terms and conditions of the license of that +module. An independent module is a module which is not derived from +or based on this library. If you modify this library, you may extend +this exception to your version of the library, but you are not +obligated to do so. If you do not wish to do so, delete this +exception statement from your version. */ + +package gnu.java.awt.font.opentype.truetype; + +import java.awt.FontFormatException; +import java.nio.ByteBuffer; +import java.nio.CharBuffer; +import java.nio.IntBuffer; + + +/** + * Locates glyph outlines in a TrueType or OpenType <code>glyf</code> + * table. + * + * @see <a href= + * "http://partners.adobe.com/asn/tech/type/opentype/loca.html" + * >Adobe’s specification of the OpenType ‘loca’ + * table</a> + * + * @author Sascha Brawer (brawer@dandelis.ch) + */ +abstract class GlyphLocator +{ + /** + * The actual glyph data of the font, which is contained in the + * 'glyf' table. + */ + protected ByteBuffer glyfTable; + + + /** + * Creates a new GlyphLocator for a <code>loca</code> table. + * + * @param format the format of the <code>loca</code> table. The + * value must be 0 for two-byte offsets, or 1 for four-byte + * offsets. TrueType and OpenType fonts indicate the format in the + * <code>indexToLoc</code> field of the <a href= + * "http://partners.adobe.com/asn/tech/type/opentype/head.html" + * >font header</a>. + * + * @param loca the <code>loca</code> table of the font, which + * contains the position of each glyph in the <code>glyf</code> + * table. + * + * @param glyf the <code>glyf</code> table of the font, which + * contains the outline data of each glyph. + * + * @throws FontFormatException if <code>format</code> is neither 0 + * nor 1. + */ + public static GlyphLocator forTable(int format, ByteBuffer loca, + ByteBuffer glyf) + throws FontFormatException + { + switch (format) + { + case 0: + return new GlyphLocator.TwoByte(loca, glyf); + + case 1: + return new GlyphLocator.FourByte(loca, glyf); + + default: + throw new FontFormatException("unsupported loca format"); + } + } + + + /** + * Locates the outline data for a glyph. + * + * <p>For efficiency, the glyph locator does not create a new buffer + * for each invocation. Instead, this method always returns the same + * buffer object. Therefore, the data of a glyph must have been read + * completely before another glyph of the same font gets requested + * through this method. + * + * @param glyph the number of the glyph whose outlines are to be + * retrieved. + * + * @return a buffer whose position is set to the first byte of glyph + * data, and whose limit is set to disallow accessing any data that + * does not belong to the glyph. If there is no outline data for the + * requested glyph, as would be the case for the space glyph, the + * result will be <code>null</code>. + */ + public abstract ByteBuffer getGlyphData(int glyph); + + + /** + * A GlyphLocator that locates glyphs using two-byte offsets, + * interpreting <code>loca</code> tables of format 0. + * + * @author Sascha Brawer (brawer@dandelis.ch) + */ + private final static class TwoByte + extends GlyphLocator + { + final CharBuffer indexToLoc; + + TwoByte(ByteBuffer loca, ByteBuffer glyf) + { + this.glyfTable = glyf; + indexToLoc = loca.asCharBuffer(); + } + + + public ByteBuffer getGlyphData(int glyph) + { + int offset, limit; + offset = ((int) indexToLoc.get(glyph)) << 1; + limit = ((int) indexToLoc.get(glyph + 1)) << 1; + if (offset >= limit) + return null; + + glyfTable.limit(limit).position(offset); + return glyfTable; + } + } + + + /** + * A GlyphLocator that locates glyphs using four-byte offsets, + * interpreting <code>loca</code> tables of format 1. + * + * @author Sascha Brawer (brawer@dandelis.ch) + */ + private final static class FourByte + extends GlyphLocator + { + final IntBuffer indexToLoc; + + FourByte(ByteBuffer loca, ByteBuffer glyf) + { + this.glyfTable = glyf; + indexToLoc = loca.asIntBuffer(); + } + + + public ByteBuffer getGlyphData(int glyph) + { + int offset, limit; + offset = indexToLoc.get(glyph); + limit = indexToLoc.get(glyph + 1); + if (offset >= limit) + return null; + + glyfTable.limit(limit).position(offset); + return glyfTable; + } + } +} |