// Initialize GcPdfDocument.
GcPdfDocument doc = new GcPdfDocument();

// Open PDF document in the file stream.
FileStream fs = File.OpenRead("Invoice.pdf");

// Load the PDF document.
doc.Load(fs);

// Remove duplicate images.
doc.RemoveDuplicateImages();

// Save PDF document.
doc.Save("RemovedDuplicateImages.pdf");

static void Main(string[] args)
{
    // Create a 5 page non-optimal PDF.
    var tmpInput = MakeInputFile("CompleteJavaScriptBook.pdf");
    var fiInput = new FileInfo(tmpInput);

    // Create a new PDF, load the source PDF into it, and optimize it.
    var tmpOutput = Path.GetTempFileName();
    var tmpDoc = new GcPdfDocument();
    using (var fs = File.OpenRead(tmpInput))
    {
        tmpDoc.Load(fs);

        // By default GcPdfDocument uses CompressionLevel.Fastest when saving a PDF.
        // Set CompressionLevel to Optimal to reduce the size of the PDF.
        tmpDoc.CompressionLevel = CompressionLevel.Optimal;

        // Optimize the font usage.
        tmpDoc.OptimizeFonts();
        tmpDoc.Save(tmpOutput);
    }
    var fiOutput = new FileInfo(tmpOutput);

    // Record the input and output file sizes in the resultant PDF.
    var doc = new GcPdfDocument();
    Common.Util.AddNote(String.Format(
        "Using the GcPdfDocument.OptimizeFonts() method reduced the size of a 5-page PDF from {0:N0} to {1:N0} bytes " +
        "by merging duplicate and removing unused font data.\n" +
        "To reproduce these results locally, download and run this sample. You may also modify the sample code to keep the temporary " +
        "input and output files and compare their sizes using a file manager.", fiInput.Length, fiOutput.Length),
        doc.NewPage());
    doc.Save("OptimizeFonts.Pdf");

    // Delete the temp files.
    File.Delete(tmpInput);
    File.Delete(tmpOutput);
}

// Create a method to make input file.
static string MakeInputFile(string inFn)
{
    // Initialize GcPdfDocument.
    var indoc = new GcPdfDocument();

    // Load the PDF document.
    using var fs = File.OpenRead(inFn);
    indoc.Load(fs);

    // Create 5 PDFs from the first 5 pages of the source document.
    var pageCount = 5;
    var docs = new List<GcPdfDocument>(pageCount);
    for (int i = 0; i < pageCount; ++i)
    {
        var outdoc = new GcPdfDocument();
        outdoc.MergeWithDocument(indoc, new MergeDocumentOptions() { PagesRange = new OutputRange(i + 1, i + 1) });
        docs.Add(outdoc);
    }

    // Merge the PDFs into a single document.
    var doc = new GcPdfDocument();
    foreach (var d in docs)
        doc.MergeWithDocument(d);

    // Save the resultant PDF in a temp file.
    var outFn = Path.GetTempFileName();
    doc.Save(outFn);
    return outFn;
}

// Load the font from file.
var gabriola = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "Gabriola.ttf"));
if (gabriola == null)
    throw new Exception("Could not load font Gabriola");

// Render the text using the font.
var tf = new TextFormat() { Font = gabriola, FontSize = 16 };

// Initialize GcPdfDocument.
var doc = new GcPdfDocument();
var g = doc.NewPage().Graphics;

// Set PdfFontFormat to Type0IdentityEncoding.
doc.PdfFontFormat = PdfFontFormat.Type0IdentityEncoding;

// Draw the string.
g.DrawString($"Sample text drawn with font {gabriola.FontFamilyName}.", tf, new PointF(72, 72));
            
// Change the font size.
tf.FontSize += 4;
            
// Draw the string.
g.DrawString("The quick brown fox jumps over the lazy dog.", tf, new PointF(72, 72 * 2));

// Emulate bold or italic style with a non-bold (non-italic) font.
tf.FontStyle = GCTEXT.FontStyle.Bold;

// Draw the string.
g.DrawString("This line prints with the same font, using emulated bold style.", tf, new PointF(72, 72 * 3));

// Set bold italic font and print a line with it.
var timesbi = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "timesbi.ttf"));
tf.Font = timesbi ?? throw new Exception("Could not load font timesbi");
tf.FontStyle = GCTEXT.FontStyle.Regular;

// Draw the string.
g.DrawString($"This line prints with {timesbi.FullFontName}.", tf, new PointF(72, 72 * 4));
            
// Save the PDF document.
doc.Save("OptimizeFontFormat.pdf");

static void Main(string[] args)
{
    // Create a 5 page non-optimal PDF.
    var tmpInput = MakeInputFile();
    var fiInput = new FileInfo(tmpInput);

    // Create a new PDF, load the source PDF into it, and optimize it.
    var tmpOutput = Path.GetTempFileName();
    var tmpDoc = new GcPdfDocument();
    using (var fs = File.OpenRead(tmpInput))
    {
        tmpDoc.Load(fs);

        // By default GcPdfDocument uses CompressionLevel.Fastest when saving a PDF.
        // Set CompressionLevel to Optimal.
        tmpDoc.CompressionLevel = CompressionLevel.Optimal;

        // Minimize stream sizes using object streams.
        tmpDoc.Save(tmpOutput, new SavePdfOptions(SaveMode.Default, PdfStreamHandling.MinimizeSize, UseObjectStreams.Multiple));
    }
    var fiOutput = new FileInfo(tmpOutput);

    // Record the input and output file sizes in the resultant PDF.
    var doc = new GcPdfDocument();
    Common.Util.AddNote(String.Format(
        "Using the UseObjectStreams.Multiple option when saving a PDF will in most cases reduce the resulting file size, " +
        "sometimes significantly. In this case the size of the PDF generated by the 'Large Document' sample decreased " +
        "from {0:N0} to {1:N0} bytes, without any loss in fidelity or PDF opening speed.\n" +
        "Using the UseObjectStreams.Single option yields an even slightly smaller PDF size at the cost of slower opening in PDF viewers.\n" +
        "To reproduce these results locally, download and run this sample, specifying a valid license key " +
        "(otherwise loading is limited to 5 pages, and the size reduction may be too small). " +
        "You may also modify the sample code to keep the temporary " +
        "input and output files, and compare their sizes using a file manager.", fiInput.Length, fiOutput.Length),
        doc.NewPage());

    // Save the resultant PDF document.
    doc.Save("ObjectStreams.pdf");

    // Delete the temp files.
    File.Delete(tmpInput);
    File.Delete(tmpOutput);
}

// Create method to make input file.
static string MakeInputFile()
{
    // Set number of pages to generate.
    const int N = Common.Util.LargeDocumentIterations;
    var start = Common.Util.TimeNow();
    var doc = new GcPdfDocument();

    // Create a TextLayout to hold/format the text.
    var tl = new TextLayout(72)
    {
        MaxWidth = doc.PageSize.Width,
        MaxHeight = doc.PageSize.Height,
        MarginAll = 72,
        FirstLineIndent = 36,
    };
    tl.DefaultFormat.Font = StandardFonts.Times;
    tl.DefaultFormat.FontSize = 12;

    // Generate the PDF document.
    for (int pageIdx = 0; pageIdx < N; ++pageIdx)
    {
        tl.Append(Common.Util.LoremIpsum(1));
        tl.PerformLayout(true);
        doc.NewPage().Graphics.DrawTextLayout(tl, PointF.Empty);
        tl.Clear();
    }

    // Insert a title page (cannot be done if using StartDoc/EndDoc).
    tl.FirstLineIndent = 0;
    var fnt = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "yumin.ttf"));
    var tf0 = new TextFormat() { Font = fnt, FontSize = 24, FontBold = true };
    tl.Append(string.Format("Large Document\n{0} Pages of Lorem Ipsum\n\n", N), tf0);
    var tf1 = new TextFormat(tf0) { FontSize = 14, FontItalic = true };
    tl.Append(string.Format("Generated on {0} in {1:m\\m\\ s\\s\\ fff\\m\\s}.", Common.Util.TimeNow().ToString("R"), Common.Util.TimeNow() - start), tf1);
    tl.TextAlignment = TextAlignment.Center;
    tl.PerformLayout(true);
    doc.Pages.Insert(0).Graphics.DrawTextLayout(tl, PointF.Empty);

    // Save the resultant PDF in a temp file with UseObjectStreams.None (it is the default).
    var outFn = Path.GetTempFileName();
    doc.Save(outFn, new SavePdfOptions(SaveMode.Default, PdfStreamHandling.Copy, UseObjectStreams.None));
    return outFn;
}