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Support TrueType font merging
DEVSIX-5179
1 parent 6467b68 commit 7f5a018

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-591
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29 files changed

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‎io/src/main/java/com/itextpdf/io/exceptions/IoExceptionMessageConstant.java‎

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@@ -109,6 +109,8 @@ public final class IoExceptionMessageConstant {
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public static final String IMAGE_MAGICK_OUTPUT_IS_NULL = "ImageMagick process output is null.";
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public static final String IMAGE_MAGICK_PROCESS_EXECUTION_FAILED = "ImageMagick process execution finished with errors: ";
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public static final String IMAGE_MASK_CANNOT_CONTAIN_ANOTHER_IMAGE_MASK = "Image mask cannot contain another image mask.";
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public static final String INCOMPATIBLE_GLYPH_DATA_DURING_FONT_MERGING =
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"Incompatibility of glyph data/metrics between merged fonts";
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public static final String INCOMPLETE_PALETTE = "Incomplete palette.";
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public static final String INCORRECT_SIGNATURE = "Incorrect woff2 signature";
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public static final String INVALID_BMP_FILE_COMPRESSION = "Invalid BMP file compression.";

‎io/src/main/java/com/itextpdf/io/font/AbstractTrueTypeFontModifier.java‎

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/*
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This file is part of the iText (R) project.
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Copyright (c) 1998-2025 Apryse Group NV
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Authors: Apryse Software.
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This program is offered under a commercial and under the AGPL license.
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For commercial licensing, contact us at https://itextpdf.com/sales. For AGPL licensing, see below.
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AGPL licensing:
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU Affero General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU Affero General Public License for more details.
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You should have received a copy of the GNU Affero General Public License
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along with this program. If not, see <https://www.gnu.org/licenses/>.
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*/
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package com.itextpdf.io.font;
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import com.itextpdf.io.exceptions.IOException;
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import com.itextpdf.io.exceptions.IoExceptionMessageConstant;
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import com.itextpdf.io.source.RandomAccessFileOrArray;
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import java.util.Arrays;
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import java.util.HashMap;
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import java.util.Map;
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/**
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* The abstract class which provides a functionality to modify TrueType fonts with returning raw data of modified font.
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*/
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abstract class AbstractTrueTypeFontModifier {
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// If it's a regular font subset, we should not add `name` and `post`,
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// because information in these tables maybe irrelevant for a subset.
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private static final String[] TABLE_NAMES_SUBSET =
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{"cvt ", "fpgm", "glyf", "head", "hhea", "hmtx", "loca", "maxp", "prep", "cmap", "OS/2"};
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// In case ttc (true type collection) file with subset = false (#directoryOffset > 0)
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// `name` and `post` shall be included, because it's actually a full font.
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private static final String[] TABLE_NAMES =
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{"cvt ", "fpgm", "glyf", "head", "hhea", "hmtx", "loca", "maxp", "prep", "cmap", "OS/2", "name", "post"};
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private static final int[] ENTRY_SELECTORS = {0, 0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4};
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private static final int TABLE_CHECKSUM = 0;
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private static final int TABLE_OFFSET = 1;
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private static final int TABLE_LENGTH = 2;
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private static final int HEAD_LOCA_FORMAT_OFFSET = 51;
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/**
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* Contains the location of the several tables. The key is the name of the table and the
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* value is an {@code int[3]} where position 0 is the checksum, position 1 is the offset
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* from the start of the file and position 2 is the length of the table.
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*/
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protected Map<String, int[]> tableDirectory;
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/**
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* Contains glyph data from `glyf` table. The key is the GID (glyph ID) and the value is a raw data of glyph.
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*/
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protected Map<Integer, byte[]> glyphDataMap;
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/**
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* Contains font tables which have been changed during the modification. The key is the name of table which has
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* been changed and the value is raw data of the modified table.
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*/
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protected final Map<String, byte[]> modifiedTables = new HashMap<>();
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/**
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* Font raw data on which new modified font will be built.
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*/
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protected RandomAccessFileOrArray raf;
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/**
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* Table directory offset which corresponds to font's raw data from {@link #raf}.
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*/
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protected int directoryOffset;
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/**
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* the name of font which will be modified
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*/
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protected final String fontName;
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private FontRawData outFont;
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private final String[] tableNames;
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/**
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* Instantiates a new {@link AbstractTrueTypeFontModifier} instance.
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*
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* @param fontName the name of font which will be modified
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* @param subsetTables whether subset tables (remove `name` and `post` tables) or not. It's used in case of ttc
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* (true type collection) font where single "full" font is needed. Despite the value of that
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* flag, only used glyphs will be left in the font
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*/
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AbstractTrueTypeFontModifier(String fontName, boolean subsetTables) {
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// subset = false is possible with directoryOffset > 0, i.e. ttc font without subset.
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if (subsetTables) {
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tableNames = TABLE_NAMES_SUBSET;
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} else {
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tableNames = TABLE_NAMES;
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}
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this.fontName = fontName;
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}
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byte[] process() throws java.io.IOException {
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try {
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createTableDirectory();
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mergeTables();
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assembleFont();
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return outFont.getData();
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} finally {
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try {
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raf.close();
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} catch (Exception ignore) {
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}
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}
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}
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abstract void mergeTables() throws java.io.IOException;
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protected void createNewGlyfAndLocaTables() throws java.io.IOException {
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int[] activeGlyphs = new int[glyphDataMap.size()];
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int i = 0;
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int glyfSize = 0;
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for (Map.Entry<Integer, byte[]> entry : glyphDataMap.entrySet()) {
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activeGlyphs[i++] = entry.getKey();
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glyfSize += entry.getValue().length;
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}
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Arrays.sort(activeGlyphs);
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// If the biggest used GID is X, size of loca should be X + 1 (array index starts from 0),
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// plus one extra entry to get size of X element (loca[X + 1] - loca[X]), it's why 2 added
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int locaSize = activeGlyphs[activeGlyphs.length - 1] + 2;
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boolean isLocaShortTable = isLocaShortTable();
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int newLocaTableSize = isLocaShortTable ? locaSize * 2 : locaSize * 4;
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byte[] newLoca = new byte[newLocaTableSize + 3 & ~3];
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byte[] newGlyf = new byte[glyfSize + 3 & ~3];
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int glyfPtr = 0;
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int listGlyf = 0;
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for (int k = 0; k < locaSize; ++k) {
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writeToLoca(newLoca, k, glyfPtr, isLocaShortTable);
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if (listGlyf < activeGlyphs.length && activeGlyphs[listGlyf] == k) {
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++listGlyf;
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byte[] glyphData = glyphDataMap.get(k);
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System.arraycopy(glyphData, 0, newGlyf, glyfPtr, glyphData.length);
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glyfPtr += glyphData.length;
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}
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}
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modifiedTables.put("glyf", newGlyf);
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modifiedTables.put("loca", newLoca);
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}
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private void createTableDirectory() throws java.io.IOException {
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tableDirectory = new HashMap<>();
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raf.seek(directoryOffset);
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int id = raf.readInt();
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if (id != 0x00010000) {
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throw new IOException(IoExceptionMessageConstant.NOT_AT_TRUE_TYPE_FILE).setMessageParams(fontName);
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}
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int numTables = raf.readUnsignedShort();
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raf.skipBytes(6);
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for (int k = 0; k < numTables; ++k) {
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String tag = readTag();
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int[] tableLocation = new int[3];
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tableLocation[TABLE_CHECKSUM] = raf.readInt();
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tableLocation[TABLE_OFFSET] = raf.readInt();
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tableLocation[TABLE_LENGTH] = raf.readInt();
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tableDirectory.put(tag, tableLocation);
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}
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}
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private boolean isLocaShortTable() throws java.io.IOException {
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int[] tableLocation = tableDirectory.get("head");
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if (tableLocation == null) {
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throw new IOException(IoExceptionMessageConstant.TABLE_DOES_NOT_EXISTS_IN).setMessageParams("head",
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fontName);
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}
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raf.seek(tableLocation[TABLE_OFFSET] + HEAD_LOCA_FORMAT_OFFSET);
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return raf.readUnsignedShort() == 0;
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}
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private void assembleFont() throws java.io.IOException {
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int[] tableLocation;
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// Calculate size of the out font
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int fullFontSize = 0;
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int tablesUsed = modifiedTables.size();
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for (String name : tableNames) {
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if (modifiedTables.containsKey(name)) {
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continue;
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}
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tableLocation = tableDirectory.get(name);
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if (tableLocation == null) {
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continue;
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}
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tablesUsed++;
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fullFontSize += tableLocation[TABLE_LENGTH] + 3 & ~3;
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}
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for (byte[] table : modifiedTables.values()) {
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fullFontSize += table.length;
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}
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int reference = 16 * tablesUsed + 12;
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fullFontSize += reference;
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outFont = new FontRawData(fullFontSize);
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// Write font headers + tables directory
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outFont.writeFontInt(0x00010000);
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outFont.writeFontShort(tablesUsed);
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int selector = ENTRY_SELECTORS[tablesUsed];
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outFont.writeFontShort((1 << selector) * 16);
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outFont.writeFontShort(selector);
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outFont.writeFontShort((tablesUsed - (1 << selector)) * 16);
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for (String name : tableNames) {
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int len;
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tableLocation = tableDirectory.get(name);
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if (tableLocation == null) {
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continue;
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}
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outFont.writeFontString(name);
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if (modifiedTables.containsKey(name)) {
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byte[] table = modifiedTables.get(name);
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outFont.writeFontInt(calculateChecksum(table));
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len = table.length;
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} else {
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outFont.writeFontInt(tableLocation[TABLE_CHECKSUM]);
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len = tableLocation[TABLE_LENGTH];
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}
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outFont.writeFontInt(reference);
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outFont.writeFontInt(len);
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reference += len + 3 & ~3;
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}
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// Write tables data
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for (String name : tableNames) {
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tableLocation = tableDirectory.get(name);
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if (tableLocation == null) {
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continue;
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}
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if (modifiedTables.containsKey(name)) {
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byte[] table = modifiedTables.get(name);
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outFont.writeFontTable(table);
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} else {
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raf.seek(tableLocation[TABLE_OFFSET]);
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outFont.writeFontTable(raf, tableLocation[TABLE_LENGTH]);
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}
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}
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}
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private String readTag() throws java.io.IOException {
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byte[] buf = new byte[4];
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raf.readFully(buf);
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try {
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return new String(buf, PdfEncodings.WINANSI);
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} catch (Exception e) {
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throw new IOException("TrueType font", e);
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}
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}
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private static void writeToLoca(byte[] loca, int index, int location, boolean isLocaShortTable) {
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if (isLocaShortTable) {
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index *= 2;
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location /= 2;
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loca[index] = (byte) (location >> 8);
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loca[index + 1] = (byte) location;
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}
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else {
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index *= 4;
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loca[index] = (byte) (location >> 24);
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loca[index + 1] = (byte) (location >> 16);
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loca[index + 2] = (byte) (location >> 8);
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loca[index + 3] = (byte) location;
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}
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}
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private int calculateChecksum(byte[] b) {
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int len = b.length / 4;
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int v0 = 0;
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int v1 = 0;
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int v2 = 0;
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int v3 = 0;
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int ptr = 0;
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for (int k = 0; k < len; ++k) {
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v3 += b[ptr++] & 0xff;
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v2 += b[ptr++] & 0xff;
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v1 += b[ptr++] & 0xff;
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v0 += b[ptr++] & 0xff;
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}
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return v0 + (v1 << 8) + (v2 << 16) + (v3 << 24);
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}
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private static class FontRawData {
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private final byte[] data;
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private int ptr;
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FontRawData(int size) {
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this.data = new byte[size];
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this.ptr = 0;
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}
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public byte[] getData() {
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return data;
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}
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void writeFontTable(RandomAccessFileOrArray raf, int tableLength) throws java.io.IOException {
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raf.readFully(data, ptr, tableLength);
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ptr += tableLength + 3 & ~3;
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}
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void writeFontTable(byte[] tableData) {
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System.arraycopy(tableData, 0, data, ptr, tableData.length);
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ptr += tableData.length;
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}
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void writeFontShort(int n) {
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data[ptr++] = (byte) (n >> 8);
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data[ptr++] = (byte) n;
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}
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void writeFontInt(int n) {
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data[ptr++] = (byte) (n >> 24);
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data[ptr++] = (byte) (n >> 16);
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data[ptr++] = (byte) (n >> 8);
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data[ptr++] = (byte) n;
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}
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void writeFontString(String s) {
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byte[] b = PdfEncodings.convertToBytes(s, PdfEncodings.WINANSI);
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System.arraycopy(b, 0, data, ptr, b.length);
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ptr += b.length;
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}
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}
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}

‎io/src/main/java/com/itextpdf/io/font/FontCache.java‎

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*/
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package com.itextpdf.io.font;
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import com.itextpdf.io.font.cmap.CMapByteCid;
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import com.itextpdf.io.font.cmap.CMapCidToCodepoint;
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import com.itextpdf.io.font.cmap.CMapCidUni;
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import com.itextpdf.io.font.cmap.CMapCodepointToCid;
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import com.itextpdf.io.font.cmap.CMapUniCid;
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import java.util.Map;
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import java.util.Set;
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import java.util.concurrent.ConcurrentHashMap;
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public class FontCache {

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