Create Unicode text or embed composite fonts in PDF files using C#

//
// Copyright (c) 2001-2020 by PDFTron Systems Inc. All Rights Reserved.
//

using System;
using System.IO;
using System.Threading.Tasks;
using Windows.Foundation;

using pdftron.Filters;
using pdftron.PDF;
using pdftron.SDF;

using PDFNetUniversalSamples.ViewModels;
using Windows.UI.Xaml.Media;
using Windows.UI.Core;
using System.Text;

namespace PDFNetSamples
{
    // This example illustrates how to create Unicode text and how to embed composite fonts.
    // 
    // Note: This demo attempts to make use of 'arialuni.ttf' in the '/Samples/TestFiles' 
    // directory. Arial Unicode MS is about 24MB in size and used to come together with Windows and 
    // MS Office.
    // 
    // In case you don't have access to Arial Unicode MS you can use another wide coverage
    // font, like Google Noto, GNU UniFont, or cyberbit. Many of these are freely available,
    // and there is a list maintained at https://en.wikipedia.org/wiki/Unicode_font
    // 
    // If no specific font file can be loaded, the demo will fall back to system specific font
    // substitution routines, and the result will depend on which fonts are available.
    class UnicodeWriteTest : Sample
    {
        public UnicodeWriteTest() : 
            base ("UnicodeWrite", "This example illustrates how to create Unicode text and how to embed composite fonts.")
        {
        }

        public override IAsyncAction RunAsync()
        {
            pdftron.PDFNet.Initialize();

            

            return Task.Run(new System.Action(async () => 
            {
                try
                {
                    PDFDoc doc = new PDFDoc();

                    ElementBuilder eb = new ElementBuilder();	// ElementBuilder is used to build new Element objects
                    ElementWriter writer = new ElementWriter();	// ElementWriter is used to write Elements to the page	

                    Page page = doc.PageCreate(new pdftron.PDF.Rect(0, 0, 612, 794)); // Start a new page

                    writer.Begin(page);	// begin writing to this page

                    Font fnt = null;
                    try
                    {
                        fnt = Font.Create(doc, "Arial", "");
                    }
                    catch (Exception e)
                    {
                        WriteLine("Exception:" + e.Message);
                    }

                    if (fnt == null)
                    {
                        try
                        {
                            fnt = Font.CreateCIDTrueTypeFont(doc, "ARIALUNI.TTF", true, true);
                        }
                        catch (Exception e)
                        {
                            WriteLine("Exception:" + e.Message);
                        }
                    } else if (fnt == null)
                    {
                        try
                        {
                            fnt = Font.CreateCIDTrueTypeFont(doc, "C:/Windows/Fonts/ARIALUNI.TTF", true, true);
                        }
                        catch (Exception e)
                        {
                            WriteLine("Exception:" + e.Message);
                        }
                    } else if (fnt == null)
                    {
                        WriteLine("Note: using system font substitution for unshaped unicode text");
                        fnt = Font.Create(doc, "Helvetica", "");
                    }
                    else
                    {
                        WriteLine("Note: using Arial Unicode for unshaped unicode text");
                    }

                    Element element = eb.CreateTextBegin(fnt, 1);
                    element.SetTextMatrix(10, 0, 0, 10, 50, 600);
                    element.GetGState().SetLeading(2); // Set the spacing between lines
                    writer.WriteElement(element);

                    // Hello World!!!
                    string hello = "Hello World!";
                    writer.WriteElement(eb.CreateUnicodeTextRun(hello));
                    writer.WriteElement(eb.CreateTextNewLine());

                    // Latin
                    char[] latin = {
                                'a', 'A', 'b', 'B', 'c', 'C', 'd', 'D', '\x45', '\x0046', '\x00C0',
                                '\x00C1', '\x00C2', '\x0143', '\x0144', '\x0145', '\x0152', '1', '2' // etc.
					};
                    writer.WriteElement(eb.CreateUnicodeTextRun(new string(latin)));
                    writer.WriteElement(eb.CreateTextNewLine());

                    // Greek
                    char[] greek = {
                                (char)0x039E, (char)0x039F, (char)0x03A0, (char)0x03A1, (char)0x03A3,
                                (char)0x03A6, (char)0x03A8, (char)0x03A9  // etc.
							};
                    writer.WriteElement(eb.CreateUnicodeTextRun(new string(greek)));
                    writer.WriteElement(eb.CreateTextNewLine());

                    // Cyrillic
                    char[] cyrillic = {
                                (char)0x0409, (char)0x040A, (char)0x040B, (char)0x040C, (char)0x040E, (char)0x040F, (char)0x0410, (char)0x0411,
                                (char)0x0412, (char)0x0413, (char)0x0414, (char)0x0415, (char)0x0416, (char)0x0417, (char)0x0418, (char)0x0419 // etc.
							};
                    writer.WriteElement(eb.CreateUnicodeTextRun(new string(cyrillic)));
                    writer.WriteElement(eb.CreateTextNewLine());

                    // Hebrew
                    char[] hebrew = {
                                (char)0x05D0, (char)0x05D1, (char)0x05D3, (char)0x05D3, (char)0x05D4, (char)0x05D5, (char)0x05D6, (char)0x05D7, (char)0x05D8,
                                (char)0x05D9, (char)0x05DA, (char)0x05DB, (char)0x05DC, (char)0x05DD, (char)0x05DE, (char)0x05DF, (char)0x05E0, (char)0x05E1 // etc. 
							};
                    writer.WriteElement(eb.CreateUnicodeTextRun(new string(hebrew)));
                    writer.WriteElement(eb.CreateTextNewLine());

                    // Arabic
                    char[] arabic = {
                                (char)0x0624, (char)0x0625, (char)0x0626, (char)0x0627, (char)0x0628, (char)0x0629, (char)0x062A, (char)0x062B, (char)0x062C,
                                (char)0x062D, (char)0x062E, (char)0x062F, (char)0x0630, (char)0x0631, (char)0x0632, (char)0x0633, (char)0x0634, (char)0x0635 // etc. 
							};
                    writer.WriteElement(eb.CreateUnicodeTextRun(new string(arabic)));
                    writer.WriteElement(eb.CreateTextNewLine());

                    // Thai 
                    char[] thai = {
                                (char)0x0E01, (char)0x0E02, (char)0x0E03, (char)0x0E04, (char)0x0E05, (char)0x0E06, (char)0x0E07, (char)0x0E08, (char)0x0E09,
                                (char)0x0E0A, (char)0x0E0B, (char)0x0E0C, (char)0x0E0D, (char)0x0E0E, (char)0x0E0F, (char)0x0E10, (char)0x0E11, (char)0x0E12 // etc. 
							};
                    writer.WriteElement(eb.CreateUnicodeTextRun(new string(thai)));
                    writer.WriteElement(eb.CreateTextNewLine());

                    // Hiragana - Japanese 
                    char[] hiragana = {
                                (char)0x3041, (char)0x3042, (char)0x3043, (char)0x3044, (char)0x3045, (char)0x3046, (char)0x3047, (char)0x3048, (char)0x3049,
                                (char)0x304A, (char)0x304B, (char)0x304C, (char)0x304D, (char)0x304E, (char)0x304F, (char)0x3051, (char)0x3051, (char)0x3052 // etc. 
							};
                    writer.WriteElement(eb.CreateUnicodeTextRun(new string(hiragana)));
                    writer.WriteElement(eb.CreateTextNewLine());

                    // CJK Unified Ideographs
                    char[] cjk_uni = {
                                (char)0x5841, (char)0x5842, (char)0x5843, (char)0x5844, (char)0x5845, (char)0x5846, (char)0x5847, (char)0x5848, (char)0x5849,
                                (char)0x584A, (char)0x584B, (char)0x584C, (char)0x584D, (char)0x584E, (char)0x584F, (char)0x5850, (char)0x5851, (char)0x5852 // etc. 
							};
                    writer.WriteElement(eb.CreateUnicodeTextRun(new string(cjk_uni)));
                    writer.WriteElement(eb.CreateTextNewLine());

                    // Finish the block of text
                    writer.WriteElement(eb.CreateTextEnd());

                    WriteLine("Now using text shaping logic to place text");

                    // Create a font in indexed encoding mode 
                    // normally this would mean that we are required to provide glyph indices
                    // directly to CreateUnicodeTextRun, but instead, we will use the GetShapedText
                    // method to take care of this detail for us.
                    Font indexedFont = Font.CreateCIDTrueTypeFont(doc, Path.Combine(InputPath, "NotoSans_with_hindi.ttf"), true, true, FontEncoding.e_Indices);
                    element = eb.CreateTextBegin(indexedFont, 10.0);
                    writer.WriteElement(element);

                    double linePos = 350.0;
                    double lineSpace = 20.0;

                    // Transform unicode text into an abstract collection of glyph indices and positioning info 
                    ShapedText shapedText = indexedFont.GetShapedText("Shaped Hindi Text:");

                    // transform the shaped text info into a PDF element and write it to the page
                    element = eb.CreateShapedTextRun(shapedText);
                    element.SetTextMatrix(1.5, 0, 0, 1.5, 50, linePos);
                    linePos -= lineSpace;
                    writer.WriteElement(element);

                    // read in unicode text lines from a file 

                    string[] hindiTextLines = File.ReadAllLines(Path.Combine(InputPath, "hindi_sample_utf16le.txt"), new UnicodeEncoding());

                    WriteLine("Read in " + hindiTextLines.Length + " lines of Unicode text from file");
                    foreach (string textLine in hindiTextLines)
                    {
                        shapedText = indexedFont.GetShapedText(textLine);
                        element = eb.CreateShapedTextRun(shapedText);
                        element.SetTextMatrix(1.5, 0, 0, 1.5, 50, linePos);
                        linePos -= lineSpace;
                        writer.WriteElement(element);
                        WriteLine("Wrote shaped line to page");
                    }

                    // Finish the shaped block of text
                    writer.WriteElement(eb.CreateTextEnd());

                    writer.End();  // save changes to the current page
                    doc.PagePushBack(page);

                    await doc.SaveAsync(Path.Combine(OutputPath, "unicodewrite.pdf"), 
                        SDFDocSaveOptions.e_linearized | SDFDocSaveOptions.e_hex_strings);

                    await AddFileToOutputList(Path.Combine(OutputPath, "unicodewrite.pdf"));

                    WriteLine("Done. Result saved in unicodewrite.pdf...");
                }
                catch (Exception e)
                {
                    WriteLine(GetExceptionMessage(e));
                }

            })).AsAsyncAction();
        }
    }
}