/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.pdfbox.pdmodel.font;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

import junit.framework.TestCase;
import org.apache.fontbox.ttf.CmapLookup;

import org.apache.fontbox.ttf.OS2WindowsMetricsTable;
import org.apache.fontbox.ttf.TTFParser;
import org.apache.fontbox.ttf.TrueTypeFont;
import org.apache.pdfbox.cos.COSArray;
import org.apache.pdfbox.cos.COSDictionary;
import org.apache.pdfbox.cos.COSName;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.pdmodel.PDPageContentStream;
import org.apache.pdfbox.pdmodel.PDPageContentStream.AppendMode;
import org.apache.pdfbox.pdmodel.PDResources;
import org.apache.pdfbox.rendering.TestPDFToImage;
import org.apache.pdfbox.text.PDFTextStripper;

import static org.mockito.BDDMockito.given;
import org.mockito.Mockito;

/**
 * Tests font embedding.
 *
 * @author John Hewson
 * @author Tilman Hausherr
 */
public class TestFontEmbedding extends TestCase
{
    private static final File OUT_DIR = new File("target/test-output");

    @Override
    protected void setUp() throws Exception
    {
        OUT_DIR.mkdirs();
    }

    /**
     * Embed a TTF as CIDFontType2.
     */
    public void testCIDFontType2() throws Exception
    {
        validateCIDFontType2(false);
    }

    /**
     * Embed a TTF as CIDFontType2 with subsetting.
     */
    public void testCIDFontType2Subset() throws Exception
    {
        validateCIDFontType2(true);
    }

    /**
     * Embed a monospace TTF as vertical CIDFontType2 with subsetting.
     *
     * @throws IOException
     */
    public void testCIDFontType2VerticalSubsetMonospace() throws IOException
    {
        String text = "「ABC」";
        String expectedExtractedtext = "「\nA\nB\nC\n」";
        File pdf = new File(OUT_DIR, "CIDFontType2VM.pdf");

        PDDocument document = new PDDocument();
        PDPage page = new PDPage(PDRectangle.A4);
        document.addPage(page);
        
        File ipafont = new File("target/fonts/ipag00303", "ipag.ttf");
        PDType0Font vfont = PDType0Font.loadVertical(document, ipafont);

        PDPageContentStream contentStream = new PDPageContentStream(document, page);
        contentStream.beginText();
        contentStream.setFont(vfont, 20);
        contentStream.newLineAtOffset(50, 700);
        contentStream.showText(text);
        contentStream.endText();
        contentStream.close();

        // Check the font substitution
        byte[] encode = vfont.encode(text);
        int cid = ((encode[0] & 0xFF) << 8) + (encode[1] & 0xFF);
        assertEquals(7392, cid); // it's 441 without substitution

        // Check the dictionaries
        COSDictionary fontDict = vfont.getCOSObject();
        assertEquals(COSName.IDENTITY_V, fontDict.getDictionaryObject(COSName.ENCODING));

        document.save(pdf);

        // Vertical metrics are fixed during subsetting, so do this after calling save()
        COSDictionary descFontDict = vfont.getDescendantFont().getCOSObject();
        COSArray dw2 = (COSArray) descFontDict.getDictionaryObject(COSName.DW2);
        assertNull(dw2); // This font uses default values for DW2
        COSArray w2 = (COSArray) descFontDict.getDictionaryObject(COSName.W2);
        assertEquals(0, w2.size()); // Monospaced font has no entries

        document.close();

        // Check text extraction
        String extracted = getUnicodeText(pdf);        
        assertEquals(expectedExtractedtext, extracted.replaceAll("\r", "").trim());
    }

    /**
     * Embed a proportional TTF as vertical CIDFontType2 with subsetting.
     *
     * @throws IOException
     */
    public void testCIDFontType2VerticalSubsetProportional() throws IOException
    {
        String text = "「ABC」";
        String expectedExtractedtext = "「\nA\nB\nC\n」";
        File pdf = new File(OUT_DIR, "CIDFontType2VP.pdf");

        PDDocument document = new PDDocument();
        
        PDPage page = new PDPage(PDRectangle.A4);
        document.addPage(page);
        File ipafont = new File("target/fonts/ipagp00303", "ipagp.ttf");
        PDType0Font vfont = PDType0Font.loadVertical(document, ipafont);
        PDPageContentStream contentStream = new PDPageContentStream(document, page);

        contentStream.beginText();
        contentStream.setFont(vfont, 20);
        contentStream.newLineAtOffset(50, 700);
        contentStream.showText(text);
        contentStream.endText();
        contentStream.close();

        // Check the font substitution
        byte[] encode = vfont.encode(text);
        int cid = ((encode[0] & 0xFF) << 8) + (encode[1] & 0xFF);
        assertEquals(12607, cid); // it's 12461 without substitution
        // Check the dictionaries
        COSDictionary fontDict = vfont.getCOSObject();
        assertEquals(COSName.IDENTITY_V, fontDict.getDictionaryObject(COSName.ENCODING));

        document.save(pdf);

        // Vertical metrics are fixed during subsetting, so do this after calling save()
        COSDictionary descFontDict = vfont.getDescendantFont().getCOSObject();
        COSArray dw2 = (COSArray) descFontDict.getDictionaryObject(COSName.DW2);
        assertNull(dw2); // This font uses default values for DW2
        // c [ w1_1y v_1x v_1y ... w1_ny v_nx v_ny ]
        COSArray w2 = (COSArray) descFontDict.getDictionaryObject(COSName.W2);
        assertEquals(2, w2.size());
        assertEquals(12607, w2.getInt(0)); // Start CID
        COSArray metrics = (COSArray) w2.getObject(1);
        int i = 0;
        for (int n : new int[] {-570, 500, 450, -570, 500, 880})
        {
            assertEquals(n, metrics.getInt(i++));
        }
        document.close();

        // Check text extraction
        String extracted = getUnicodeText(pdf);
        assertEquals(expectedExtractedtext, extracted.replaceAll("\r", "").trim());
    }

    /**
     * Test corner case of PDFBOX-4302.
     *
     * @throws java.io.IOException
     */
    public void testMaxEntries() throws IOException
    {
        File file;
        String text;
        text = "あいうえおかきくけこさしすせそたちつてとなにぬねのはひふへほまみむめもやゆよらりるれろわをん" +
                "アイウエオカキクケコサシスセソタチツテトナニヌネノハヒフヘホマミムメモヤユヨラリルレロワヲン" +
                "１２３４５６７８";

        // The test must have MAX_ENTRIES_PER_OPERATOR unique characters
        Set<Character> set = new HashSet<Character>(ToUnicodeWriter.MAX_ENTRIES_PER_OPERATOR);
        for (int i = 0; i < text.length(); ++i)
        {
            set.add(text.charAt(i));
        }
        assertEquals(ToUnicodeWriter.MAX_ENTRIES_PER_OPERATOR, set.size());

        PDDocument document = new PDDocument();
        PDPage page = new PDPage(PDRectangle.A0);
        document.addPage(page);
        File ipafont = new File("target/fonts/ipag00303", "ipag.ttf");
        PDType0Font font = PDType0Font.load(document, ipafont);
        PDPageContentStream contentStream = new PDPageContentStream(document, page);
        contentStream.beginText();
        contentStream.setFont(font, 20);
        contentStream.newLineAtOffset(50, 3000);
        contentStream.showText(text);
        contentStream.endText();
        contentStream.close();
        file = new File(OUT_DIR, "PDFBOX-4302-test.pdf");
        document.save(file);
        document.close();

        // check that the extracted text matches what we wrote
        String extracted = getUnicodeText(file);
        assertEquals(text, extracted.trim());
    }

    /**
     * When several code points map to one glyph, the ToUnicode CMap must reflect the code point
     * actually used, not the lowest one sharing the glyph. Finds such an ambiguous glyph in the
     * test font and verifies that each code point sharing it round-trips as itself.
     *
     * @throws IOException
     */
    public void testToUnicodePrefersUsedCodePoint() throws IOException
    {
        // Find a glyph reachable from two distinct printable code points, preferring a CJK
        // radical/ideograph pair (e.g. 食 U+98DF and its radical look-alike ⻝ U+2EDD). lowCp is
        // what the old reverse mapping always picked; highCp used to be mis-extracted as lowCp.
        int lowCp = -1;
        int highCp = -1;
        TrueTypeFont ttf = new TTFParser().parse(getNotoCjk());
        CmapLookup cmap = ttf.getUnicodeCmapLookup();
        int numGlyphs = ttf.getMaximumProfile().getNumGlyphs();
        boolean cjkPair = false;
        for (int gid = 1; gid <= numGlyphs && !cjkPair; gid++)
        {
            List<Integer> codes = cmap.getCharCodes(gid); // sorted ascending
            if (codes == null || codes.size() < 2)
            {
                continue;
            }
            int lo = -1;
            int hi = -1;
            for (int cp : codes)
            {
                if (cp <= 0xFFFF && !Character.isWhitespace(cp) && !Character.isISOControl(cp))
                {
                    if (lo == -1)
                    {
                        lo = cp;
                    }
                    else
                    {
                        hi = cp;
                        break;
                    }
                }
            }
            // lo >= 0x2E80 == CJK Radicals Supplement and above: a CJK demonstration
            if (hi != -1 && (lowCp == -1 || lo >= 0x2E80))
            {
                lowCp = lo;
                highCp = hi;
                cjkPair = lo >= 0x2E80;
            }
        }
        ttf.close();
        assertTrue("test font has no glyph shared between two printable code points", highCp != -1);

        // Each code point must round-trip as itself. Without the fix, highCp was extracted as lowCp.
        assertEquals(new String(Character.toChars(highCp)), renderAndExtract(1, highCp).trim());
        assertEquals(new String(Character.toChars(lowCp)), renderAndExtract(2, lowCp).trim());
    }

    /**
     * Explicit case: a CJK Unified Ideograph and its radical look-alike that share one glyph. The
     * ideograph must extract as itself (not the radical), and an intentionally typed radical must
     * be preserved.
     *
     * @throws IOException
     */
    public void testToUnicodeCjkAndRadicalLookAlike() throws IOException
    {
        final int ideograph = 0x98DF; // 食 CJK Unified Ideograph
        final int radical = 0x2EDD;   // ⻝ CJK RADICAL EAT ONE, shares the glyph

        // precondition: both code points map to the same glyph and the radical is the lower one,
        // i.e. the entry the old reverse mapping wrongly picked for both
        TrueTypeFont ttf = new TTFParser().parse(getNotoCjk());
        CmapLookup cmap = ttf.getUnicodeCmapLookup();
        int gid = cmap.getGlyphId(ideograph);
        assertTrue("test font must map both code points to the same glyph", gid > 0 && gid == cmap.getGlyphId(radical));
        assertEquals(radical, (int) cmap.getCharCodes(gid).get(0));
        ttf.close();

        assertEquals(new String(Character.toChars(ideograph)), renderAndExtract(3, ideograph).trim());
        assertEquals(new String(Character.toChars(radical)), renderAndExtract(4, radical).trim());
    }

    private static InputStream getNotoCjk() throws IOException
    {
        return new FileInputStream("target/fonts/NotoSansCJKkr-VF.ttf");
    }

    // num parameter needed because two tests produce the same files
    private String renderAndExtract(int num, int codePoint) throws IOException
    {
        File file = new File(OUT_DIR, "ToUnicode-" + num + "-U+" + Integer.toHexString(codePoint) + ".pdf");
        PDDocument document = new PDDocument();
        PDPage page = new PDPage(PDRectangle.A4);
        document.addPage(page);
        PDType0Font font = PDType0Font.load(document, getNotoCjk());
        PDPageContentStream stream = new PDPageContentStream(document, page);
        stream.beginText();
        stream.setFont(font, 20);
        stream.newLineAtOffset(50, 700);
        stream.showText(new String(Character.toChars(codePoint)));
        stream.endText();
        stream.close();
        document.save(file);
        document.close();
        return getUnicodeText(file);
    }

    private void validateCIDFontType2(boolean useSubset) throws Exception
    {
        PDDocument document = new PDDocument();
        PDPage page = new PDPage(PDRectangle.A4);
        document.addPage(page);

        InputStream input = PDFont.class.getResourceAsStream(
                "/org/apache/pdfbox/resources/ttf/LiberationSans-Regular.ttf");
        PDType0Font font = PDType0Font.load(document, input, useSubset);

        PDPageContentStream stream = new PDPageContentStream(document, page);

        stream.beginText();
        stream.setFont(font, 12);

        String text = "Unicode русский язык Tiếng Việt";
        stream.newLineAtOffset(50, 600);
        stream.showText(text);

        stream.endText();
        stream.close();
        
        File file = new File(OUT_DIR, "CIDFontType2.pdf");
        document.save(file);
        document.close();

        // check that the extracted text matches what we wrote
        String extracted = getUnicodeText(file);
        assertEquals(text, extracted.trim());
    }

    private String getUnicodeText(File file) throws IOException
    {
        PDDocument document = PDDocument.load(file);
        PDFTextStripper stripper = new PDFTextStripper();
        String text = stripper.getText(document);
        document.close();
        return text;
    }

    /**
     * Test that an embedded and subsetted font can be reused.
     * 
     * @throws IOException 
     */
    public void testReuseEmbeddedSubsettedFont() throws IOException
    {
        String text1 = "The quick brown fox";
        String text2 = "xof nworb kciuq ehT";
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        PDDocument document = new PDDocument();
        PDPage page = new PDPage();
        document.addPage(page);
        InputStream input = PDFont.class.getResourceAsStream(
                "/org/apache/pdfbox/resources/ttf/LiberationSans-Regular.ttf");
        PDType0Font font = PDType0Font.load(document, input);
        PDPageContentStream stream = new PDPageContentStream(document, page);
        stream.beginText();
        stream.setFont(font, 20);
        stream.newLineAtOffset(50, 600);
        stream.showText(text1);
        stream.endText();
        stream.close();
        document.save(baos);
        document.close();
        // Append, while reusing the font subset
        document = PDDocument.load(baos.toByteArray());
        page = document.getPage(0);
        font = (PDType0Font) page.getResources().getFont(COSName.getPDFName("F1"));
        stream = new PDPageContentStream(document, page, AppendMode.APPEND, true);
        stream.beginText();
        stream.setFont(font, 20);
        stream.newLineAtOffset(250, 600);
        stream.showText(text2);
        stream.endText();
        stream.close();
        baos.reset();
        document.save(baos);
        document.close();
        // Test that both texts are there
        document = PDDocument.load(baos.toByteArray());
        PDFTextStripper stripper = new PDFTextStripper();
        String extractedText = stripper.getText(document);
        assertEquals(text1 + " " + text2, extractedText.trim());
        document.close();
    }

    private class TrueTypeEmbedderTester extends TrueTypeEmbedder
    {

        /**
         * Common functionality for testing the TrueTypeFontEmbedder
         *
         */
        TrueTypeEmbedderTester(PDDocument document, COSDictionary dict, TrueTypeFont ttf, boolean embedSubset)
                throws IOException
        {
            super(document, dict, ttf, embedSubset);
        }

        @Override
        protected void buildSubset(InputStream ttfSubset, String tag, Map<Integer, Integer> gidToCid)
                throws IOException
        {
            // no-op.  Need to define method to extend abstract class, but
            // this method is not currently needed for testing
        }
    }

    /**
     * Test that we validate embedding permissions properly for all legal permissions combinations
     *
     * @throws IOException
     */
    public void testIsEmbeddingPermittedMultipleVersions() throws IOException
    {
        // SETUP
        PDDocument doc = new PDDocument();
        COSDictionary cosDictionary = new COSDictionary();
        InputStream input = PDFont.class.getResourceAsStream("/org/apache/pdfbox/resources/ttf/LiberationSans-Regular.ttf");
        TrueTypeFont ttf = new TTFParser().parseEmbedded(input);
        TrueTypeEmbedderTester tester = new TrueTypeEmbedderTester(doc, cosDictionary, ttf, true);
        TrueTypeFont mockTtf = Mockito.mock(TrueTypeFont.class);
        OS2WindowsMetricsTable mockOS2 = Mockito.mock(OS2WindowsMetricsTable.class);
        given(mockTtf.getOS2Windows()).willReturn(mockOS2);
        Boolean embeddingIsPermitted;

        // TEST 1: 0000 -- Installable embedding versions 0-3+
        given(mockTtf.getOS2Windows().getFsType()).willReturn((short) 0x0000);
        embeddingIsPermitted = tester.isEmbeddingPermitted(mockTtf);

        // VERIFY
        assertTrue(embeddingIsPermitted);

        // no test for 0001, since bit 0 is permanently reserved, and its use is deprecated
        // TEST 2: 0010 -- Restricted License embedding versions 0-3+
        given(mockTtf.getOS2Windows().getFsType()).willReturn((short) 0x0002);
        embeddingIsPermitted = tester.isEmbeddingPermitted(mockTtf);

        // VERIFY
        assertFalse(embeddingIsPermitted);

        // no test for 0011
        // TEST 3: 0100 -- Preview & Print embedding versions 0-3+
        given(mockTtf.getOS2Windows().getFsType()).willReturn((short) 0x0004);
        embeddingIsPermitted = tester.isEmbeddingPermitted(mockTtf);

        // VERIFY
        assertTrue(embeddingIsPermitted);

        // no test for 0101
        // TEST 4: 0110 -- Restricted License embedding AND Preview & Print embedding versions 0-2
        //              -- illegal permissions combination for versions 3+
        given(mockTtf.getOS2Windows().getFsType()).willReturn((short) 0x0006);
        embeddingIsPermitted = tester.isEmbeddingPermitted(mockTtf);

        // VERIFY
        assertTrue(embeddingIsPermitted);

        // no test for 0111
        // TEST 5: 1000 -- Editable embedding versions 0-3+
        given(mockTtf.getOS2Windows().getFsType()).willReturn((short) 0x0008);
        embeddingIsPermitted = tester.isEmbeddingPermitted(mockTtf);

        // VERIFY
        assertTrue(embeddingIsPermitted);

        // no test for 1001
        // TEST 6: 1010 -- Restricted License embedding AND Editable embedding versions 0-2
        //              -- illegal permissions combination for versions 3+
        given(mockTtf.getOS2Windows().getFsType()).willReturn((short) 0x000A);
        embeddingIsPermitted = tester.isEmbeddingPermitted(mockTtf);

        // VERIFY
        assertTrue(embeddingIsPermitted);

        // no test for 1011
        // TEST 7: 1100 -- Editable embedding AND Preview & Print embedding versions 0-2
        //              -- illegal permissions combination for versions 3+
        given(mockTtf.getOS2Windows().getFsType()).willReturn((short) 0x000C);
        embeddingIsPermitted = tester.isEmbeddingPermitted(mockTtf);

        // VERIFY
        assertTrue(embeddingIsPermitted);

        // no test for 1101
        // TEST 8: 1110 Editable embedding AND Preview & Print embedding AND Restricted License embedding versions 0-2
        //              -- illegal permissions combination for versions 3+
        given(mockTtf.getOS2Windows().getFsType()).willReturn((short) 0x000E);
        embeddingIsPermitted = tester.isEmbeddingPermitted(mockTtf);

        // VERIFY
        assertTrue(embeddingIsPermitted);

        // no test for 1111
        
        doc.close();
    }

    /**
     * PDFBOX-5812: Atka Mackerel in Japanese kanji. (surrogate pair)
     */
    public void testSurrogatePairCharacter() throws IOException
    {
        final String message = "𩸽\uD867\uDE3D";
        File pdf = new File(OUT_DIR, "PDFBOX-5812.pdf");
        File IN_DIR = new File("src/test/resources/org/apache/pdfbox/ttf");

        PDDocument doc = new PDDocument();
        PDPage page = new PDPage();
        doc.addPage(page);
        File ipafont = new File("target/fonts/ipag00303", "ipag.ttf");
        PDFont font = PDType0Font.load(doc, ipafont);
        PDPageContentStream contents = new PDPageContentStream(doc, page);
        contents.beginText();
        contents.setFont(font, 64);
        contents.newLineAtOffset(100, 700);
        contents.showText(message);
        contents.endText();
        contents.close();

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        doc.save(baos);
        doc.save(pdf);
        doc.close();

        doc = PDDocument.load(baos.toByteArray());
        PDFTextStripper stripper = new PDFTextStripper();
        String text = stripper.getText(doc).trim();
        assertEquals(message, text);
        doc.close();

        // compare rendering
        TestPDFToImage testPDFToImage = new TestPDFToImage(TestPDFToImage.class.getName());
        if (!testPDFToImage.doTestFile(pdf, IN_DIR.getAbsolutePath(), OUT_DIR.getAbsolutePath()))
        {
            // don't fail, rendering is different on different systems, result must be viewed manually
            System.err.println("Rendering of " + pdf + " failed or is not identical to expected rendering in " + IN_DIR + " directory");
        }
    }

    /**
     * PDFBOX-5230: Zero-width characters should be invisible.
     *
     * @throws IOException
     */
    public void testEmbeddedFontWithZeroWidthChars() throws IOException
    {
        String text = "AAA\u200CBBB";
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        PDDocument document = new PDDocument();
        PDPage page = new PDPage();
        document.addPage(page);
        InputStream input = PDFont.class.getResourceAsStream(
                "/org/apache/pdfbox/resources/ttf/LiberationSans-Regular.ttf");
        PDType0Font font = PDType0Font.load(document, input);
        PDPageContentStream stream = new PDPageContentStream(document, page);
        stream.beginText();
        stream.setFont(font, 20);
        stream.newLineAtOffset(50, 600);
        stream.showText(text);
        stream.endText();
        stream.close();
        document.save(baos);
        document.close();
        document = PDDocument.load(baos.toByteArray());
        // verify that the text still contains zero-width characters
        PDFTextStripper stripper = new PDFTextStripper();
        String extractedText = stripper.getText(document).trim();
        assertEquals(text, extractedText);
        assertEquals(7, extractedText.length());
        assertEquals('\u200C', extractedText.charAt(3));

        // verify that the zero-width characters are invisible
        page = document.getPage(0);
        PDResources resources = page.getResources();
        Iterable< COSName> fontNames = resources.getFontNames();
        COSName fontName = fontNames.iterator().next();
        font = (PDType0Font) resources.getFont(fontName);
        byte[] encoded = font.encode('\u200C');
        int code = ((encoded[0] & 0xFF) << 8) | (encoded[1] & 0xFF);
        assertEquals(0f, font.getWidth(code));
        assertEquals(0f, font.getWidthFromFont(code));
        assertTrue(font.getPath(code).getBounds2D().isEmpty());
        assertFalse(font.isDamaged());
        document.close();
    }

    /**
     * PDFBOX-6085: test with the Noto font, this one has a zero width GID between other GIDs and
     * failed in the past. This "fails before the fix" only with the version 2.004,
     * size 204336 bytes.
     *
     * @throws IOException
     */
    public void testDevanagari2() throws IOException
    {
        File IN_DIR = new File("src/test/resources/org/apache/pdfbox/ttf");
        File pdf = new File(OUT_DIR, "Devanagari2.pdf");
        PDDocument doc = new PDDocument();
        PDPage page = new PDPage(PDRectangle.A4);
        doc.addPage(page);
        int[] codepoints = new int[]
        {
            'A', 8204
        };
        PDPageContentStream cs = new PDPageContentStream(doc, page);
        InputStream is = TestFontEmbedding.class.getResourceAsStream(
                "/org/apache/pdfbox/ttf/NotoSansDevanagari-Regular.ttf");
        PDType0Font font = PDType0Font.load(doc, is);

        // check that we're using the correct font version. The newer font has a different glyph ordering.
        byte[] encoded = font.encode("A\u200c");
        int val1 = (encoded[0] << 8) + (encoded[1] & 0xff);
        int val2 = (encoded[2] << 8) + (encoded[3] & 0xff);
        assertEquals(960, val1);
        assertEquals(132, val2);

        String s = new String(codepoints, 0, codepoints.length);
        cs.beginText();
        cs.newLineAtOffset(20, 800);
        cs.setFont(font, 18);
        cs.showText(s);
        cs.endText();
        cs.close();
        doc.save(pdf);
        doc.close();

        // compare rendering
        TestPDFToImage testPDFToImage = new TestPDFToImage(TestPDFToImage.class.getName());
        if (!testPDFToImage.doTestFile(pdf, IN_DIR.getAbsolutePath(), OUT_DIR.getAbsolutePath()))
        {
            // don't fail, rendering is different on different systems, result must be viewed manually
            System.err.println("Rendering of " + pdf + " failed or is not identical to expected rendering in " + IN_DIR + " directory");
        }
    }

}
