pdfio(3)

NAME
pdfio - pdf read/write library

Introduction

PDFio is a simple C library for reading and writing PDF files. The primary goals of pdfio are:

•

Read and write any version of PDF file

•

Provide access to pages, objects, and streams within a PDF file

•

Support reading and writing of encrypted PDF files

•

Extract or embed useful metadata (author, creator, page information, etc.)

•

"Filter" PDF files, for example to extract a range of pages or to embed fonts that are missing from a PDF

•

Provide access to objects used for each page

PDFio is not
 concerned with rendering or viewing a PDF file, although a PDF RIP or viewer could be written using it.

PDFio is Copyright © 2021-2024 by Michael R Sweet and is licensed under the Apache License Version 2.0 with an (optional) exception to allow linking against GPL2/LGPL2 software. See the files "LICENSE" and "NOTICE" for more information.

  Requirements

PDFio requires the following to build the software:

•

A C99 compiler such as Clang, GCC, or MS Visual C

•

A POSIX-compliant make program

•

A POSIX-compliant sh program

•

ZLIB (https://www.zlib.net) 1.0 or higher

IDE files for Xcode (macOS/iOS) and Visual Studio (Windows) are also provided.

  Installing pdfio

PDFio comes with a configure script that creates a portable makefile that will work on any POSIX-compliant system with ZLIB installed. To make it, run:
    ./configure
    make

To test it, run:
    make test

To install it, run:
    sudo make install

If you want a shared library, run:
    ./configure --enable-shared
    make
    sudo make install

The default installation location is "/usr/local". Pass the --prefix option to make to install it to another location:
    ./configure --prefix=/some/other/directory

Other configure options can be found using the --help option:
    ./configure --help

  Visual Studio Project

The Visual Studio solution ("pdfio.sln") is provided for Windows developers and generates both a static library and DLL.

  Xcode Project

There is also an Xcode project ("pdfio.xcodeproj") you can use on macOS which generates a static library that will be installed under "/usr/local" with:
    sudo xcodebuild install

  Detecting PDFio

PDFio can be detected using the pkg-config command, for example:
    if pkg-config --exists pdfio; then
        ...
    fi

In a makefile you can add the necessary compiler and linker options with:
    CFLAGS  +=      `pkg-config --cflags pdfio`
    LIBS    +=      `pkg-config --libs pdfio`

On Windows, you need to link to the PDFIO1.LIB (DLL) library and include the zlib_native NuGet package dependency. You can also use the published pdfio_native NuGet package.

  Header Files

PDFio provides a primary header file that is always used:
    #include <pdfio.h>

PDFio also provides PDF content helper functions for producing PDF content that are defined in a separate header file:
    #include <pdfio-content.h>

API Overview

PDFio exposes several types:

•

pdfio_file_t: A PDF file (for reading or writing)

•

pdfio_array_t: An array of values

•

pdfio_dict_t: A dictionary of key/value pairs in a PDF file, object, etc.

•

pdfio_obj_t: An object in a PDF file

•

pdfio_stream_t: An object stream

  Reading PDF Files

You open an existing PDF file using the pdfioFileOpen function:
    pdfio_file_t *pdf = pdfioFileOpen("myinputfile.pdf", password_cb, password_data,
                                      error_cb, error_data);

where the five arguments to the function are the filename ("myinputfile.pdf"), an optional password callback function (password_cb) and data pointer value (password_data), and an optional error callback function (error_cb) and data pointer value (error_data). The password callback is called for encrypted PDF files that are not using the default password, for example:
    const char *
    password_cb(void *data, const char *filename)
    {
      (void)data;     // This callback doesn't use the data pointer
      (void)filename; // This callback doesn't use the filename

      // Return a password string for the file...
      return ("Password42");
    }

The error callback is called for both errors and warnings and accepts the pdfio_file_t pointer, a message string, and the callback pointer value, for example:
    bool
    error_cb(pdfio_file_t *pdf, const char *message, void *data)
    {
      (void)data; // This callback does not use the data pointer

      fprintf(stderr, "%s: %s\n", pdfioFileGetName(pdf), message);

      // Return false to treat warnings as errors
      return (false);
    }

The default error callback (NULL) does the equivalent of the above.

Each PDF file contains one or more pages. The pdfioFileGetNumPages function returns the number of pages in the file while the pdfioFileGetPage function gets the specified page in the PDF file:
    pdfio_file_t *pdf;   // PDF file
    size_t       i;      // Looping var
    size_t       count;  // Number of pages
    pdfio_obj_t  *page;  // Current page

    // Iterate the pages in the PDF file
    for (i = 0, count = pdfioFileGetNumPages(pdf); i < count; i ++)
    {
      page = pdfioFileGetPage(pdf, i);
      // do something with page
    }

Each page is represented by a "page tree" object (what pdfioFileGetPage returns) that specifies information about the page and one or more "content" objects that contain the images, fonts, text, and graphics that appear on the page. Use the pdfioPageGetNumStreams and pdfioPageOpenStream functions to access the content streams for each page, and pdfioObjGetDict to get the associated page object dictionary. For example, if you want to display the media and crop boxes for a given page:
    pdfio_file_t  *pdf;             // PDF file
    size_t        i;                // Looping var
    size_t        count;            // Number of pages
    pdfio_obj_t   *page;            // Current page
    pdfio_dict_t  *dict;            // Current page dictionary
    pdfio_array_t *media_box;       // MediaBox array
    double        media_values[4];  // MediaBox values
    pdfio_array_t *crop_box;        // CropBox array
    double        crop_values[4];   // CropBox values

    // Iterate the pages in the PDF file
    for (i = 0, count = pdfioFileGetNumPages(pdf); i < count; i ++)
    {
      page = pdfioFileGetPage(pdf, i);
      dict = pdfioObjGetDict(page);

      media_box       = pdfioDictGetArray(dict, "MediaBox");
      media_values[0] = pdfioArrayGetNumber(media_box, 0);
      media_values[1] = pdfioArrayGetNumber(media_box, 1);
      media_values[2] = pdfioArrayGetNumber(media_box, 2);
      media_values[3] = pdfioArrayGetNumber(media_box, 3);

      crop_box       = pdfioDictGetArray(dict, "CropBox");
      crop_values[0] = pdfioArrayGetNumber(crop_box, 0);
      crop_values[1] = pdfioArrayGetNumber(crop_box, 1);
      crop_values[2] = pdfioArrayGetNumber(crop_box, 2);
      crop_values[3] = pdfioArrayGetNumber(crop_box, 3);

      printf("Page %u: MediaBox=[%g %g %g %g], CropBox=[%g %g %g %g]\n",
             (unsigned)(i + 1),
             media_values[0], media_values[1], media_values[2], media_values[3],
             crop_values[0], crop_values[1], crop_values[2], crop_values[3]);
    }

Page object dictionaries have several (mostly optional) key/value pairs, including:

•

"Annots": An array of annotation dictionaries for the page; use pdfioDictGetArray to get the array

•

"CropBox": The crop box as an array of four numbers for the left, bottom, right, and top coordinates of the target media; use pdfioDictGetArray to get a pointer to the array of numbers

•

"Dur": The number of seconds the page should be displayed; use pdfioDictGetNumber to get the page duration value

•

"Group": The dictionary of transparency group values for the page; use pdfioDictGetDict to get a pointer to the resources dictionary

•

"LastModified": The date and time when this page was last modified; use pdfioDictGetDate to get the Unix time_t value

•

"Parent": The parent page tree node object for this page; use pdfioDictGetObj to get a pointer to the object

•

"MediaBox": The media box as an array of four numbers for the left, bottom, right, and top coordinates of the target media; use pdfioDictGetArray to get a pointer to the array of numbers

•

"Resources": The dictionary of resources for the page; use pdfioDictGetDict to get a pointer to the resources dictionary

•

"Rotate": A number indicating the number of degrees of counter-clockwise rotation to apply to the page when viewing; use pdfioDictGetNumber to get the rotation angle

•

"Thumb": A thumbnail image object for the page; use pdfioDictGetObj to get a pointer to the thumbnail image object

•

"Trans": The page transition dictionary; use pdfioDictGetDict to get a pointer to the dictionary

The pdfioFileClose function closes a PDF file and frees all memory that was used for it:
    pdfioFileClose(pdf);

  Writing PDF Files

You create a new PDF file using the pdfioFileCreate function:
    pdfio_rect_t media_box = { 0.0, 0.0, 612.0, 792.0 };  // US Letter
    pdfio_rect_t crop_box = { 36.0, 36.0, 576.0, 756.0 }; // w/0.5" margins

    pdfio_file_t *pdf = pdfioFileCreate("myoutputfile.pdf", "2.0", &media_box, &crop_box, error_cb, error_data);

where the six arguments to the function are the filename ("myoutputfile.pdf"), PDF version ("2.0"), media box (media_box), crop box (crop_box), an optional error callback function (error_cb), and an optional pointer value for the error callback function (error_data). The units for the media and crop boxes are points (1/72nd of an inch).

Alternately you can stream a PDF file using the pdfioFileCreateOutput function:
    pdfio_rect_t media_box = { 0.0, 0.0, 612.0, 792.0 };  // US Letter
    pdfio_rect_t crop_box = { 36.0, 36.0, 576.0, 756.0 }; // w/0.5" margins

    pdfio_file_t *pdf = pdfioFileCreateOutput(output_cb, output_ctx, "2.0", &media_box, &crop_box, error_cb, error_data);

Once the file is created, use the pdfioFileCreateObj, pdfioFileCreatePage, and pdfioPageCopy functions to create objects and pages in the file.

Finally, the pdfioFileClose function writes the PDF cross-reference and "trailer" information, closes the file, and frees all memory that was used for it.

  PDF Objects

PDF objects are identified using two numbers - the object number (1 to N) and the object generation (0 to 65535) that specifies a particular version of an object. An object's numbers are returned by the pdfioObjGetNumber and pdfioObjGetGeneration functions. You can find a numbered object using the pdfioFileFindObj function.

Objects contain values (typically dictionaries) and usually an associated data stream containing images, fonts, ICC profiles, and page content. PDFio provides several accessor functions to get the value(s) associated with an object:

•

pdfioObjGetArray returns an object's array value, if any

•

pdfioObjGetDict returns an object's dictionary value, if any

•

pdfioObjGetLength returns the length of the data stream, if any

•

pdfioObjGetSubtype returns the sub-type name of the object, for example "Image" for an image object.

•

pdfioObjGetType returns the type name of the object, for example "XObject" for an image object.

  PDF Streams

Some PDF objects have an associated data stream, such as for pages, images, ICC color profiles, and fonts. You access the stream for an existing object using the pdfioObjOpenStream function:
    pdfio_file_t *pdf = pdfioFileOpen(...);
    pdfio_obj_t *obj = pdfioFileFindObj(pdf, number);
    pdfio_stream_t *st = pdfioObjOpenStream(obj, true);

The first argument is the object pointer. The second argument is a boolean value that specifies whether you want to decode (typically decompress) the stream data or return it as-is.

When reading a page stream you'll use the pdfioPageOpenStream function instead:
    pdfio_file_t *pdf = pdfioFileOpen(...);
    pdfio_obj_t *obj = pdfioFileGetPage(pdf, number);
    pdfio_stream_t *st = pdfioPageOpenStream(obj, 0, true);

Once you have the stream open, you can use one of several functions to read from it:

•

pdfioStreamConsume reads and discards a number of bytes in the stream

•

pdfioStreamGetToken reads a PDF token from the stream

•

pdfioStreamPeek peeks at the next stream data without advancing or "consuming" it

•

pdfioStreamRead reads a buffer of data

When you are done reading from the stream, call the pdfioStreamClose function:
    pdfioStreamClose(st);

To create a stream for a new object, call the pdfioObjCreateStream function:
    pdfio_file_t *pdf = pdfioFileCreate(...);
    pdfio_obj_t *obj = pdfioFileCreateObj(pdf, ...);
    pdfio_stream_t *st = pdfioObjCreateStream(obj, PDFIO_FILTER_FLATE);

The first argument is the newly created object. The second argument is either PDFIO_FILTER_NONE to specify that any encoding is done by your program or PDFIO_FILTER_FLATE to specify that PDFio should Flate compress the stream.

To create a page content stream call the pdfioFileCreatePage function:
    pdfio_file_t *pdf = pdfioFileCreate(...);
    pdfio_dict_t *dict = pdfioDictCreate(pdf);
    ... set page dictionary keys and values ...
    pdfio_stream_t *st = pdfioFileCreatePage(pdf, dict);

Once you have created the stream, use any of the following functions to write to the stream:

•

pdfioStreamPrintf writes a formatted string to the stream

•

pdfioStreamPutChar writes a single character to the stream

•

pdfioStreamPuts writes a C string to the stream

•

pdfioStreamWrite writes a buffer of data to the stream

The PDF content helper functions provide additional functions for writing specific PDF page stream commands.

When you are done writing the stream, call pdfioStreamClose to close both the stream and the object.

  PDF Content Helper Functions

PDFio includes many helper functions for embedding or writing specific kinds of content to a PDF file. These functions can be roughly grouped into five categories:

•

Color Space Functions

•

Font Object Functions

•

Image Object Functions

•

Page Stream Functions

•

Page Dictionary Functions

Color Space Functions

PDF color spaces are specified using well-known names like "DeviceCMYK", "DeviceGray", and "DeviceRGB" or using arrays that define so-called calibrated color spaces. PDFio provides several functions for embedding ICC profiles and creating color space arrays:

•

pdfioArrayCreateColorFromICCObj creates a color array for an ICC color profile object

•

pdfioArrayCreateColorFromMatrix creates a color array using a CIE XYZ color transform matrix, a gamma value, and a CIE XYZ white point

•

pdfioArrayCreateColorFromPalette creates an indexed color array from an array of sRGB values

•

pdfioArrayCreateColorFromPrimaries creates a color array using CIE XYZ primaries and a gamma value

•

pdfioArrayCreateColorFromStandard creates a color array for a standard color space

You can embed an ICC color profile using the pdfioFileCreateICCObjFromFile function:
    pdfio_file_t *pdf = pdfioFileCreate(...);
    pdfio_obj_t *icc = pdfioFileCreateICCObjFromFile(pdf, "filename.icc");

where the first argument is the PDF file and the second argument is the filename of the ICC color profile.

PDFio also includes predefined constants for creating a few standard color spaces:
    pdfio_file_t *pdf = pdfioFileCreate(...);

    // Create an AdobeRGB color array
    pdfio_array_t *adobe_rgb = pdfioArrayCreateColorFromStandard(pdf, 3, PDFIO_CS_ADOBE);

    // Create an Display P3 color array
    pdfio_array_t *display_p3 = pdfioArrayCreateColorFromStandard(pdf, 3, PDFIO_CS_P3_D65);

    // Create an sRGB color array
    pdfio_array_t *srgb = pdfioArrayCreateColorFromStandard(pdf, 3, PDFIO_CS_SRGB);

Font Object Functions

PDF supports many kinds of fonts, including PostScript Type1, PDF Type3, TrueType/OpenType, and CID. PDFio provides two functions for creating font objects. The first is pdfioFileCreateFontObjFromBase which creates a font object for one of the base PDF fonts:

•

"Courier"

•

"Courier-Bold"

•

"Courier-BoldItalic"

•

"Courier-Italic"

•

"Helvetica"

•

"Helvetica-Bold"

•

"Helvetica-BoldOblique"

•

"Helvetica-Oblique"

•

"Symbol"

•

"Times-Bold"

•

"Times-BoldItalic"

•

"Times-Italic"

•

"Times-Roman"

•

"ZapfDingbats"

PDFio always uses the Windows CP1252 subset of Unicode for these fonts.

The second function is pdfioFileCreateFontObjFromFile which creates a font object from a TrueType/OpenType font file, for example:
    pdfio_file_t *pdf = pdfioFileCreate(...);
    pdfio_obj_t *arial = pdfioFileCreateFontObjFromFile(pdf, "OpenSans-Regular.ttf", false);

will embed an OpenSans Regular TrueType font using the Windows CP1252 subset of Unicode. Pass true for the third argument to embed it as a Unicode CID font instead, for example:
    pdfio_file_t *pdf = pdfioFileCreate(...);
    pdfio_obj_t *arial = pdfioFileCreateFontObjFromFile(pdf, "NotoSansJP-Regular.otf", true);

will embed the NotoSansJP Regular OpenType font with full support for Unicode.

Note: Not all fonts support Unicode.

Image Object Functions

PDF supports images with many different color spaces and bit depths with optional transparency. PDFio provides two helper functions for creating image objects that can be referenced in page streams. The first function is pdfioFileCreateImageObjFromData which creates an image object from data in memory, for example:
    pdfio_file_t *pdf = pdfioFileCreate(...);
    unsigned char data[1024 * 1024 * 4]; // 1024x1024 RGBA image data
    pdfio_obj_t *img = pdfioFileCreateImageObjFromData(pdf, data, /*width*/1024, /*height*/1024, /*num_colors*/3, /*color_data*/NULL, /*alpha*/true, /*interpolate*/false);

will create an object for a 1024x1024 RGBA image in memory, using the default color space for 3 colors ("DeviceRGB"). We can use one of the color space functions to use a specific color space for this image, for example:
    pdfio_file_t *pdf = pdfioFileCreate(...);

    // Create an AdobeRGB color array
    pdfio_array_t *adobe_rgb = pdfioArrayCreateColorFromMatrix(pdf, 3, pdfioAdobeRGBGamma, pdfioAdobeRGBMatrix, pdfioAdobeRGBWhitePoint);

    // Create a 1024x1024 RGBA image using AdobeRGB
    unsigned char data[1024 * 1024 * 4]; // 1024x1024 RGBA image data
    pdfio_obj_t *img = pdfioFileCreateImageObjFromData(pdf, data, /*width*/1024, /*height*/1024, /*num_colors*/3, /*color_data*/adobe_rgb, /*alpha*/true, /*interpolate*/false);

The "interpolate" argument specifies whether the colors in the image should be smoothed/interpolated when scaling. This is most useful for photographs but should be false for screenshot and barcode images.

If you have a JPEG or PNG file, use the pdfioFileCreateImageObjFromFile function to copy the image into a PDF image object, for example:
    pdfio_file_t *pdf = pdfioFileCreate(...);
    pdfio_obj_t *img = pdfioFileCreateImageObjFromFile(pdf, "myphoto.jpg", /*interpolate*/true);

Page Dictionary Functions

PDF pages each have an associated dictionary to specify the images, fonts, and color spaces used by the page. PDFio provides functions to add these resources to the dictionary:

•

pdfioPageDictAddColorSpace adds a named color space to the page dictionary

•

pdfioPageDictAddFont adds a named font to the page dictionary

•

pdfioPageDictAddImage adds a named image to the page dictionary

Page Stream Functions

PDF page streams contain textual commands for drawing on the page. PDFio provides many functions for writing these commands with the correct format and escaping, as needed:

•

pdfioContentClip clips future drawing to the current path

•

pdfioContentDrawImage draws an image object

•

pdfioContentFill fills the current path

•

pdfioContentFillAndStroke fills and strokes the current path

•

pdfioContentMatrixConcat concatenates a matrix with the current transform matrix

•

pdfioContentMatrixRotate concatenates a rotation matrix with the current transform matrix

•

pdfioContentMatrixScale concatenates a scaling matrix with the current transform matrix

•

pdfioContentMatrixTranslate concatenates a translation matrix with the current transform matrix

•

pdfioContentPathClose closes the current path

•

pdfioContentPathCurve appends a Bezier curve to the current path

•

pdfioContentPathCurve13 appends a Bezier curve with 2 control points to the current path

•

pdfioContentPathCurve23 appends a Bezier curve with 2 control points to the current path

•

pdfioContentPathLineTo appends a line to the current path

•

pdfioContentPathMoveTo moves the current point in the current path

•

pdfioContentPathRect appends a rectangle to the current path

•

pdfioContentRestore restores a previous graphics state

•

pdfioContentSave saves the current graphics state

•

pdfioContentSetDashPattern sets the line dash pattern

•

pdfioContentSetFillColorDeviceCMYK sets the current fill color using a device CMYK color

•

pdfioContentSetFillColorDeviceGray sets the current fill color using a device gray color

•

pdfioContentSetFillColorDeviceRGB sets the current fill color using a device RGB color

•

pdfioContentSetFillColorGray sets the current fill color using a calibrated gray color

•

pdfioContentSetFillColorRGB sets the current fill color using a calibrated RGB color

•

pdfioContentSetFillColorSpace sets the current fill color space

•

pdfioContentSetFlatness sets the flatness for curves

•

pdfioContentSetLineCap sets how the ends of lines are stroked

•

pdfioContentSetLineJoin sets how connections between lines are stroked

•

pdfioContentSetLineWidth sets the width of stroked lines

•

pdfioContentSetMiterLimit sets the miter limit for stroked lines

•

pdfioContentSetStrokeColorDeviceCMYK sets the current stroke color using a device CMYK color

•

pdfioContentSetStrokeColorDeviceGray sets the current stroke color using a device gray color

•

pdfioContentSetStrokeColorDeviceRGB sets the current stroke color using a device RGB color

•

pdfioContentSetStrokeColorGray sets the current stroke color using a calibrated gray color

•

pdfioContentSetStrokeColorRGB sets the current stroke color using a calibrated RGB color

•

pdfioContentSetStrokeColorSpace sets the current stroke color space

•

pdfioContentSetTextCharacterSpacing sets the spacing between characters for text

•

pdfioContentSetTextFont sets the font and size for text

•

pdfioContentSetTextLeading sets the line height for text

•

pdfioContentSetTextMatrix concatenates a matrix with the current text matrix

•

pdfioContentSetTextRenderingMode sets the text rendering mode

•

pdfioContentSetTextRise adjusts the baseline for text

•

pdfioContentSetTextWordSpacing sets the spacing between words for text

•

pdfioContentSetTextXScaling sets the horizontal scaling for text

•

pdfioContentStroke strokes the current path

•

pdfioContentTextBegin begins a block of text

•

pdfioContentTextEnd ends a block of text

•

pdfioContentTextMoveLine moves to the next line with an offset in a text block

•

pdfioContentTextMoveTo moves within the current line in a text block

•

pdfioContentTextNewLine moves to the beginning of the next line in a text block

•

pdfioContentTextNewLineShow moves to the beginning of the next line in a text block and shows literal text with optional word and character spacing

•

pdfioContentTextNewLineShowf moves to the beginning of the next line in a text block and shows formatted text with optional word and character spacing

•

pdfioContentTextShow draws a literal string in a text block

•

pdfioContentTextShowf draws a formatted string in a text block

•

pdfioContentTextShowJustified draws an array of literal strings with offsets between them

Examples

  Read PDF Metadata

The following example function will open a PDF file and print the title, author, creation date, and number of pages:
    #include <pdfio.h>
    #include <time.h>

    void
    show_pdf_info(const char *filename)
    {
      pdfio_file_t *pdf;
      time_t       creation_date;
      struct tm    *creation_tm;
      char         creation_text[256];

      // Open the PDF file with the default callbacks...
      pdf = pdfioFileOpen(filename, /*password_cb*/NULL, /*password_cbdata*/NULL, /*error_cb*/NULL, /*error_cbdata*/NULL);
      if (pdf == NULL)
        return;

      // Get the creation date and convert to a string...
      creation_date = pdfioFileGetCreationDate(pdf);
      creation_tm   = localtime(&creation_date);
      strftime(creation_text, sizeof(creation_text), "%c", &creation_tm);

      // Print file information to stdout...
      printf("%s:\n", filename);
      printf("         Title: %s\n", pdfioFileGetTitle(pdf));
      printf("        Author: %s\n", pdfioFileGetAuthor(pdf));
      printf("    Created On: %s\n", creation_text);
      printf("  Number Pages: %u\n", (unsigned)pdfioFileGetNumPages(pdf));

      // Close the PDF file...
      pdfioFileClose(pdf);
    }

  Create PDF File With Text and Image

The following example function will create a PDF file, embed a base font and the named JPEG or PNG image file, and then creates a page with the image centered on the page with the text centered below:
    #include <pdfio.h>
    #include <pdfio-content.h>
    #include <string.h>

    void
    create_pdf_image_file(const char *pdfname, const char *imagename, const char *caption)
    {
      pdfio_file_t   *pdf;
      pdfio_obj_t    *font;
      pdfio_obj_t    *image;
      pdfio_dict_t   *dict;
      pdfio_stream_t *page;
      double         width, height;
      double         swidth, sheight;
      double         tx, ty;

      // Create the PDF file...
      pdf = pdfioFileCreate(pdfname, /*version*/NULL, /*media_box*/NULL, /*crop_box*/NULL, /*error_cb*/NULL, /*error_cbdata*/NULL);

      // Create a Courier base font for the caption
      font = pdfioFileCreateFontObjFromBase(pdf, "Courier");

      // Create an image object from the JPEG/PNG image file...
      image = pdfioFileCreateImageObjFromFile(pdf, imagename, true);

      // Create a page dictionary with the font and image...
      dict = pdfioDictCreate(pdf);
      pdfioPageDictAddFont(dict, "F1", font);
      pdfioPageDictAddImage(dict, "IM1", image);

      // Create the page and its content stream...
      page = pdfioFileCreatePage(pdf, dict);

      // Position and scale the image on the page...
      width  = pdfioImageGetWidth(image);
      height = pdfioImageGetHeight(image);

      // Default media_box is "universal" 595.28x792 points (8.27x11in or 210x279mm)
      // Use margins of 36 points (0.5in or 12.7mm) with another 36 points for the
      // caption underneath...
      swidth  = 595.28 - 72.0;
      sheight = swidth * height / width;
      if (sheight > (792.0 - 36.0 - 72.0))
      {
        sheight = 792.0 - 36.0 - 72.0;
        swidth  = sheight * width / height;
      }

      tx = 0.5 * (595.28 - swidth);
      ty = 0.5 * (792 - 36 - sheight);

      pdfioContentDrawImage(page, "IM1", tx, ty + 36.0, swidth, sheight);

      // Draw the caption in black...
      pdfioContentSetFillColorDeviceGray(page, 0.0);

      // Compute the starting point for the text - Courier is monospaced with a
      // nominal width of 0.6 times the text height...
      tx = 0.5 * (595.28 - 18.0 * 0.6 * strlen(caption));

      // Position and draw the caption underneath...
      pdfioContentTextBegin(page);
      pdfioContentSetTextFont(page, "F1", 18.0);
      pdfioContentTextMoveTo(page, tx, ty);
      pdfioContentTextShow(page, /*unicode*/false, caption);
      pdfioContentTextEnd(page);

      // Close the page stream and the PDF file...
      pdfioStreamClose(page);
      pdfioFileClose(pdf);
    }

ENUMERATIONS

  pdfio_cs_e
Standard color spaces

PDFIO_CS_ADOBE
    AdobeRGB 1998

PDFIO_CS_P3_D65
    Display P3

PDFIO_CS_SRGB
    sRGB

  pdfio_encryption_e
PDF encryption modes

PDFIO_ENCRYPTION_AES_128
    128-bit AES encryption (PDF 1.6)

PDFIO_ENCRYPTION_AES_256
    256-bit AES encryption (PDF 2.0)

PDFIO_ENCRYPTION_NONE
    No encryption

PDFIO_ENCRYPTION_RC4_128
    128-bit RC4 encryption (PDF 1.4)

PDFIO_ENCRYPTION_RC4_40
    40-bit RC4 encryption (PDF 1.3)

  pdfio_filter_e
Compression/decompression filters for streams

PDFIO_FILTER_ASCII85
    ASCII85Decode filter (reading only)

PDFIO_FILTER_ASCIIHEX
    ASCIIHexDecode filter (reading only)

PDFIO_FILTER_CCITTFAX
    CCITTFaxDecode filter

PDFIO_FILTER_CRYPT
    Encryption filter

PDFIO_FILTER_DCT
    DCTDecode (JPEG) filter

PDFIO_FILTER_FLATE
    FlateDecode filter

PDFIO_FILTER_JBIG2
    JBIG2Decode filter

PDFIO_FILTER_JPX
    JPXDecode filter (reading only)

PDFIO_FILTER_LZW
    LZWDecode filter (reading only)

PDFIO_FILTER_NONE
    No filter

PDFIO_FILTER_RUNLENGTH
    RunLengthDecode filter (reading only)

  pdfio_linecap_e
Line capping modes

PDFIO_LINECAP_BUTT
    Butt ends

PDFIO_LINECAP_ROUND
    Round ends

PDFIO_LINECAP_SQUARE
    Square ends

  pdfio_linejoin_e
Line joining modes

PDFIO_LINEJOIN_BEVEL
    Bevel joint

PDFIO_LINEJOIN_MITER
    Miter joint

PDFIO_LINEJOIN_ROUND
    Round joint

  pdfio_permission_e
PDF permission bits

PDFIO_PERMISSION_ALL

PDFIO_PERMISSION_ANNOTATE
    PDF allows annotation

PDFIO_PERMISSION_ASSEMBLE
    PDF allows assembly (insert, delete, or rotate pages, add document outlines and thumbnails)

PDFIO_PERMISSION_COPY
    PDF allows copying

PDFIO_PERMISSION_FORMS
    PDF allows filling in forms

PDFIO_PERMISSION_MODIFY
    PDF allows modification

PDFIO_PERMISSION_NONE
    No permissions

PDFIO_PERMISSION_PRINT
    PDF allows printing

PDFIO_PERMISSION_PRINT_HIGH
    PDF allows high quality printing

PDFIO_PERMISSION_READING
    PDF allows screen reading/accessibility (deprecated in PDF 2.0)

~0
    All permissions

  pdfio_textrendering_e
Text rendering modes

PDFIO_TEXTRENDERING_FILL
    Fill text

PDFIO_TEXTRENDERING_FILL_AND_STROKE
    Fill then stroke text

PDFIO_TEXTRENDERING_FILL_AND_STROKE_PATH
    Fill then stroke text and add to path

PDFIO_TEXTRENDERING_FILL_PATH
    Fill text and add to path

PDFIO_TEXTRENDERING_INVISIBLE
    Don't fill or stroke (invisible)

PDFIO_TEXTRENDERING_STROKE
    Stroke text

PDFIO_TEXTRENDERING_STROKE_PATH
    Stroke text and add to path

PDFIO_TEXTRENDERING_TEXT_PATH
    Add text to path (invisible)

  pdfio_valtype_e
PDF value types

PDFIO_VALTYPE_ARRAY
    Array

PDFIO_VALTYPE_BINARY
    Binary data

PDFIO_VALTYPE_BOOLEAN
    Boolean

PDFIO_VALTYPE_DATE
    Date/time

PDFIO_VALTYPE_DICT
    Dictionary

PDFIO_VALTYPE_INDIRECT
    Indirect object (N G obj)

PDFIO_VALTYPE_NAME
    Name

PDFIO_VALTYPE_NONE
    No value, not set

PDFIO_VALTYPE_NULL
    Null object

PDFIO_VALTYPE_NUMBER
    Number (integer or real)

PDFIO_VALTYPE_STRING
    String

FUNCTIONS

  pdfioArrayAppendArray
Add an array value to an array.

bool  pdfioArrayAppendArray (
    pdfio_array_t *a,
    pdfio_array_t *value
);

  pdfioArrayAppendBinary
Add a binary string value to an array.

bool  pdfioArrayAppendBinary (
    pdfio_array_t *a,
    const unsigned char *value,
    size_t valuelen
);

  pdfioArrayAppendBoolean
Add a boolean value to an array.

bool  pdfioArrayAppendBoolean (
    pdfio_array_t *a,
    bool value
);

  pdfioArrayAppendDate
Add a date value to an array.

bool  pdfioArrayAppendDate (
    pdfio_array_t *a,
    time_t value
);

  pdfioArrayAppendDict
Add a dictionary to an array.

bool  pdfioArrayAppendDict (
    pdfio_array_t *a,
    pdfio_dict_t *value
);

  pdfioArrayAppendName
Add a name to an array.

bool  pdfioArrayAppendName (
    pdfio_array_t *a,
    const char *value
);

  pdfioArrayAppendNumber
Add a number to an array.

bool  pdfioArrayAppendNumber (
    pdfio_array_t *a,
    double value
);

  pdfioArrayAppendObj
Add an indirect object reference to an array.

bool  pdfioArrayAppendObj (
    pdfio_array_t *a,
    pdfio_obj_t *value
);

  pdfioArrayAppendString
Add a string to an array.

bool  pdfioArrayAppendString (
    pdfio_array_t *a,
    const char *value
);

  pdfioArrayCopy
Copy an array.

pdfio_array_t * pdfioArrayCopy (
    pdfio_file_t *pdf,
    pdfio_array_t *a
);

  pdfioArrayCreate
Create an empty array.

pdfio_array_t * pdfioArrayCreate (
    pdfio_file_t *pdf
);

  pdfioArrayCreateColorFromICCObj
Create an ICC-based color space array.

pdfio_array_t * pdfioArrayCreateColorFromICCObj (
    pdfio_file_t *pdf,
    pdfio_obj_t *icc_object
);

  pdfioArrayCreateColorFromMatrix
Create a calibrated color space array using a CIE XYZ transform matrix.

pdfio_array_t * pdfioArrayCreateColorFromMatrix (
    pdfio_file_t *pdf,
    size_t num_colors,
    double gamma,
    const double matrix[3][3],
    const double white_point[3]
);

  pdfioArrayCreateColorFromPalette
Create an indexed color space array.

pdfio_array_t * pdfioArrayCreateColorFromPalette (
    pdfio_file_t *pdf,
    size_t num_colors,
    const unsigned char *colors
);

  pdfioArrayCreateColorFromPrimaries
Create a calibrated color sapce array using CIE xy primary chromacities.

pdfio_array_t * pdfioArrayCreateColorFromPrimaries (
    pdfio_file_t *pdf,
    size_t num_colors,
    double gamma,
    double wx,
    double wy,
    double rx,
    double ry,
    double gx,
    double gy,
    double bx,
    double by
);

  pdfioArrayCreateColorFromStandard
Create a color array for a standard color space.

pdfio_array_t * pdfioArrayCreateColorFromStandard (
    pdfio_file_t *pdf,
    size_t num_colors,
    pdfio_cs_t cs
);

This function creates a color array for a standard PDFIO_CS_ enumerated color space. The "num_colors" argument must be 1 for grayscale and 3 for RGB color.

  pdfioArrayGetArray
Get an array value from an array.

pdfio_array_t * pdfioArrayGetArray (
    pdfio_array_t *a,
    size_t n
);

  pdfioArrayGetBinary
Get a binary string value from an array.

unsigned char * pdfioArrayGetBinary (
    pdfio_array_t *a,
    size_t n,
    size_t *length
);

  pdfioArrayGetBoolean
Get a boolean value from an array.

bool  pdfioArrayGetBoolean (
    pdfio_array_t *a,
    size_t n
);

  pdfioArrayGetDate
Get a date value from an array.

time_t  pdfioArrayGetDate (
    pdfio_array_t *a,
    size_t n
);

  pdfioArrayGetDict
Get a dictionary value from an array.

pdfio_dict_t * pdfioArrayGetDict (
    pdfio_array_t *a,
    size_t n
);

  pdfioArrayGetName
Get a name value from an array.

const char * pdfioArrayGetName (
    pdfio_array_t *a,
    size_t n
);

  pdfioArrayGetNumber
Get a number from an array.

double  pdfioArrayGetNumber (
    pdfio_array_t *a,
    size_t n
);

  pdfioArrayGetObj
Get an indirect object reference from an array.

pdfio_obj_t * pdfioArrayGetObj (
    pdfio_array_t *a,
    size_t n
);

  pdfioArrayGetSize
Get the length of an array.

size_t  pdfioArrayGetSize (
    pdfio_array_t *a
);

  pdfioArrayGetString
Get a string value from an array.

const char * pdfioArrayGetString (
    pdfio_array_t *a,
    size_t n
);

  pdfioArrayGetType
Get a value type from an array.

pdfio_valtype_t  pdfioArrayGetType (
    pdfio_array_t *a,
    size_t n
);

  pdfioContentClip
Clip output to the current path.

bool  pdfioContentClip (
    pdfio_stream_t *st,
    bool even_odd
);

  pdfioContentDrawImage
Draw an image object.

bool  pdfioContentDrawImage (
    pdfio_stream_t *st,
    const char *name,
    double x,
    double y,
    double width,
    double height
);

The object name must be part of the page dictionary resources, typically using the pdfioPageDictAddImage function.

  pdfioContentFill
Fill the current path.

bool  pdfioContentFill (
    pdfio_stream_t *st,
    bool even_odd
);

  pdfioContentFillAndStroke
Fill and stroke the current path.

bool  pdfioContentFillAndStroke (
    pdfio_stream_t *st,
    bool even_odd
);

  pdfioContentMatrixConcat
Concatenate a matrix to the current graphics
                        state.

bool  pdfioContentMatrixConcat (
    pdfio_stream_t *st,
    pdfio_matrix_t m
);

  pdfioContentMatrixRotate
Rotate the current transform matrix.

bool  pdfioContentMatrixRotate (
    pdfio_stream_t *st,
    double degrees
);

  pdfioContentMatrixScale
Scale the current transform matrix.

bool  pdfioContentMatrixScale (
    pdfio_stream_t *st,
    double sx,
    double sy
);

  pdfioContentMatrixTranslate
Translate the current transform matrix.

bool  pdfioContentMatrixTranslate (
    pdfio_stream_t *st,
    double tx,
    double ty
);

  pdfioContentPathClose
Close the current path.

bool  pdfioContentPathClose (
    pdfio_stream_t *st
);

  pdfioContentPathCurve
Add a Bezier curve with two control points.

bool  pdfioContentPathCurve (
    pdfio_stream_t *st,
    double x1,
    double y1,
    double x2,
    double y2,
    double x3,
    double y3
);

  pdfioContentPathCurve13
Add a Bezier curve with an initial control point.

bool  pdfioContentPathCurve13 (
    pdfio_stream_t *st,
    double x1,
    double y1,
    double x3,
    double y3
);

  pdfioContentPathCurve23
Add a Bezier curve with a trailing control point.

bool  pdfioContentPathCurve23 (
    pdfio_stream_t *st,
    double x2,
    double y2,
    double x3,
    double y3
);

  pdfioContentPathEnd
Clear the current path.

bool  pdfioContentPathEnd (
    pdfio_stream_t *st
);

  pdfioContentPathLineTo
Add a straight line to the current path.

bool  pdfioContentPathLineTo (
    pdfio_stream_t *st,
    double x,
    double y
);

  pdfioContentPathMoveTo
Start a new subpath.

bool  pdfioContentPathMoveTo (
    pdfio_stream_t *st,
    double x,
    double y
);

  pdfioContentPathRect
Add a rectangle to the current path.

bool  pdfioContentPathRect (
    pdfio_stream_t *st,
    double x,
    double y,
    double width,
    double height
);

  pdfioContentRestore
Restore a previous graphics state.

bool  pdfioContentRestore (
    pdfio_stream_t *st
);

  pdfioContentSave
Save the current graphics state.

bool  pdfioContentSave (
    pdfio_stream_t *st
);

  pdfioContentSetDashPattern
Set the stroke pattern.

bool  pdfioContentSetDashPattern (
    pdfio_stream_t *st,
    double phase,
    double on,
    double off
);

This function sets the stroke pattern when drawing lines. If "on" and "off" are 0, a solid line is drawn.

  pdfioContentSetFillColorDeviceCMYK
Set device CMYK fill color.

bool  pdfioContentSetFillColorDeviceCMYK (
    pdfio_stream_t *st,
    double c,
    double m,
    double y,
    double k
);

  pdfioContentSetFillColorDeviceGray
Set the device gray fill color.

bool  pdfioContentSetFillColorDeviceGray (
    pdfio_stream_t *st,
    double g
);

  pdfioContentSetFillColorDeviceRGB
Set the device RGB fill color.

bool  pdfioContentSetFillColorDeviceRGB (
    pdfio_stream_t *st,
    double r,
    double g,
    double b
);

  pdfioContentSetFillColorGray
Set the calibrated gray fill color.

bool  pdfioContentSetFillColorGray (
    pdfio_stream_t *st,
    double g
);

  pdfioContentSetFillColorRGB
Set the calibrated RGB fill color.

bool  pdfioContentSetFillColorRGB (
    pdfio_stream_t *st,
    double r,
    double g,
    double b
);

  pdfioContentSetFillColorSpace
Set the fill colorspace.

bool  pdfioContentSetFillColorSpace (
    pdfio_stream_t *st,
    const char *name
);

  pdfioContentSetFlatness
Set the flatness tolerance.

bool  pdfioContentSetFlatness (
    pdfio_stream_t *st,
    double flatness
);

  pdfioContentSetLineCap
Set the line ends style.

bool  pdfioContentSetLineCap (
    pdfio_stream_t *st,
    pdfio_linecap_t lc
);

  pdfioContentSetLineJoin
Set the line joining style.

bool  pdfioContentSetLineJoin (
    pdfio_stream_t *st,
    pdfio_linejoin_t lj
);

  pdfioContentSetLineWidth
Set the line width.

bool  pdfioContentSetLineWidth (
    pdfio_stream_t *st,
    double width
);

  pdfioContentSetMiterLimit
Set the miter limit.

bool  pdfioContentSetMiterLimit (
    pdfio_stream_t *st,
    double limit
);

  pdfioContentSetStrokeColorDeviceCMYK
Set the device CMYK stroke color.

bool  pdfioContentSetStrokeColorDeviceCMYK (
    pdfio_stream_t *st,
    double c,
    double m,
    double y,
    double k
);

  pdfioContentSetStrokeColorDeviceGray
Set the device gray stroke color.

bool  pdfioContentSetStrokeColorDeviceGray (
    pdfio_stream_t *st,
    double g
);

  pdfioContentSetStrokeColorDeviceRGB
Set the device RGB stroke color.

bool  pdfioContentSetStrokeColorDeviceRGB (
    pdfio_stream_t *st,
    double r,
    double g,
    double b
);

  pdfioContentSetStrokeColorGray
Set the calibrated gray stroke color.

bool  pdfioContentSetStrokeColorGray (
    pdfio_stream_t *st,
    double g
);

  pdfioContentSetStrokeColorRGB
Set the calibrated RGB stroke color.

bool  pdfioContentSetStrokeColorRGB (
    pdfio_stream_t *st,
    double r,
    double g,
    double b
);

  pdfioContentSetStrokeColorSpace
Set the stroke color space.

bool  pdfioContentSetStrokeColorSpace (
    pdfio_stream_t *st,
    const char *name
);

  pdfioContentSetTextCharacterSpacing
Set the spacing between characters.

bool  pdfioContentSetTextCharacterSpacing (
    pdfio_stream_t *st,
    double spacing
);

  pdfioContentSetTextFont
Set the text font and size.

bool  pdfioContentSetTextFont (
    pdfio_stream_t *st,
    const char *name,
    double size
);

  pdfioContentSetTextLeading
Set text leading (line height) value.

bool  pdfioContentSetTextLeading (
    pdfio_stream_t *st,
    double leading
);

  pdfioContentSetTextMatrix
Set the text transform matrix.

bool  pdfioContentSetTextMatrix (
    pdfio_stream_t *st,
    pdfio_matrix_t m
);

  pdfioContentSetTextRenderingMode
Set the text rendering mode.

bool  pdfioContentSetTextRenderingMode (
    pdfio_stream_t *st,
    pdfio_textrendering_t mode
);

  pdfioContentSetTextRise
Set the text baseline offset.

bool  pdfioContentSetTextRise (
    pdfio_stream_t *st,
    double rise
);

  pdfioContentSetTextWordSpacing
Set the inter-word spacing.

bool  pdfioContentSetTextWordSpacing (
    pdfio_stream_t *st,
    double spacing
);

  pdfioContentSetTextXScaling
Set the horizontal scaling value.

bool  pdfioContentSetTextXScaling (
    pdfio_stream_t *st,
    double percent
);

  pdfioContentStroke
Stroke the current path.

bool  pdfioContentStroke (
    pdfio_stream_t *st
);

  pdfioContentTextBegin
Begin a text block.

bool  pdfioContentTextBegin (
    pdfio_stream_t *st
);

  pdfioContentTextEnd
End a text block.

bool  pdfioContentTextEnd (
    pdfio_stream_t *st
);

  pdfioContentTextMeasure
Measure a text string and return its width.

double  pdfioContentTextMeasure (
    pdfio_obj_t *font,
    const char *s,
    double size
);

This function measures the given text string "s" and returns its width based on "size". The text string must always use the UTF-8 (Unicode) encoding but any control characters (such as newlines) are ignored.

  pdfioContentTextMoveLine
Move to the next line and offset.

bool  pdfioContentTextMoveLine (
    pdfio_stream_t *st,
    double tx,
    double ty
);

  pdfioContentTextMoveTo
Offset within the current line.

bool  pdfioContentTextMoveTo (
    pdfio_stream_t *st,
    double tx,
    double ty
);

  pdfioContentTextNewLine
Move to the next line.

bool  pdfioContentTextNewLine (
    pdfio_stream_t *st
);

  pdfioContentTextNewLineShow
Move to the next line and show text.

bool  pdfioContentTextNewLineShow (
    pdfio_stream_t *st,
    double ws,
    double cs,
    bool unicode,
    const char *s
);

This function moves to the next line and then shows some text with optional word and character spacing in a PDF content stream. The "unicode" argument specifies that the current font maps to full Unicode. The "s" argument specifies a UTF-8 encoded string.

  pdfioContentTextNewLineShowf
Show formatted text.

bool  pdfioContentTextNewLineShowf (
    pdfio_stream_t *st,
    double ws,
    double cs,
    bool unicode,
    const char *format,
    ...
);

This function moves to the next line and shows some formatted text with optional word and character spacing in a PDF content stream. The "unicode" argument specifies that the current font maps to full Unicode. The "format" argument specifies a UTF-8 encoded printf-style format string.

  pdfioContentTextShow
Show text.

bool  pdfioContentTextShow (
    pdfio_stream_t *st,
    bool unicode,
    const char *s
);

This function shows some text in a PDF content stream. The "unicode" argument specifies that the current font maps to full Unicode. The "s" argument specifies a UTF-8 encoded string.

  pdfioContentTextShowJustified
Show justified text.

bool  pdfioContentTextShowJustified (
    pdfio_stream_t *st,
    bool unicode,
    size_t num_fragments,
    const double *offsets,
    const char *const *fragments
);

This function shows some text in a PDF content stream. The "unicode" argument specifies that the current font maps to full Unicode. The "fragments" argument specifies an array of UTF-8 encoded strings.

  pdfioContentTextShowf

bool  pdfioContentTextShowf (
    pdfio_stream_t *st,
    bool unicode,
    const char *format,
    ...
);

  pdfioDictCopy
Copy a dictionary to a PDF file.

pdfio_dict_t * pdfioDictCopy (
    pdfio_file_t *pdf,
    pdfio_dict_t *dict
);

  pdfioDictCreate
Create a dictionary to hold key/value pairs.

pdfio_dict_t * pdfioDictCreate (
    pdfio_file_t *pdf
);

  pdfioDictGetArray
Get a key array value from a dictionary.

pdfio_array_t * pdfioDictGetArray (
    pdfio_dict_t *dict,
    const char *key
);

  pdfioDictGetBinary
Get a key binary string value from a dictionary.

unsigned char * pdfioDictGetBinary (
    pdfio_dict_t *dict,
    const char *key,
    size_t *length
);

  pdfioDictGetBoolean
Get a key boolean value from a dictionary.

bool  pdfioDictGetBoolean (
    pdfio_dict_t *dict,
    const char *key
);

  pdfioDictGetDate
Get a date value from a dictionary.

time_t  pdfioDictGetDate (
    pdfio_dict_t *dict,
    const char *key
);

  pdfioDictGetDict
Get a key dictionary value from a dictionary.

pdfio_dict_t * pdfioDictGetDict (
    pdfio_dict_t *dict,
    const char *key
);

  pdfioDictGetName
Get a key name value from a dictionary.

const char * pdfioDictGetName (
    pdfio_dict_t *dict,
    const char *key
);

  pdfioDictGetNumber
Get a key number value from a dictionary.

double  pdfioDictGetNumber (
    pdfio_dict_t *dict,
    const char *key
);

  pdfioDictGetObj
Get a key indirect object value from a dictionary.

pdfio_obj_t * pdfioDictGetObj (
    pdfio_dict_t *dict,
    const char *key
);

  pdfioDictGetRect
Get a key rectangle value from a dictionary.

pdfio_rect_t * pdfioDictGetRect (
    pdfio_dict_t *dict,
    const char *key,
    pdfio_rect_t *rect
);

  pdfioDictGetString
Get a key string value from a dictionary.

const char * pdfioDictGetString (
    pdfio_dict_t *dict,
    const char *key
);

  pdfioDictGetType
Get a key value type from a dictionary.

pdfio_valtype_t  pdfioDictGetType (
    pdfio_dict_t *dict,
    const char *key
);

  pdfioDictIterateKeys
Iterate the keys in a dictionary.

void pdfioDictIterateKeys (
    pdfio_dict_t *dict,
    pdfio_dict_cb_t cb,
    void *cb_data
);

This function iterates the keys in a dictionary, calling the supplied function "cb":

    bool
    my_dict_cb(pdfio_dict_t *dict, const char *key, void *cb_data)
    {
    ... "key" contains the dictionary key ...
    ... return true to continue or false to stop ...
    }
The iteration continues as long as the callback returns true or all keys have been iterated.

  pdfioDictSetArray
Set a key array in a dictionary.

bool  pdfioDictSetArray (
    pdfio_dict_t *dict,
    const char *key,
    pdfio_array_t *value
);

  pdfioDictSetBinary
Set a key binary string in a dictionary.

bool  pdfioDictSetBinary (
    pdfio_dict_t *dict,
    const char *key,
    const unsigned char *value,
    size_t valuelen
);

  pdfioDictSetBoolean
Set a key boolean in a dictionary.

bool  pdfioDictSetBoolean (
    pdfio_dict_t *dict,
    const char *key,
    bool value
);

  pdfioDictSetDate
Set a date value in a dictionary.

bool  pdfioDictSetDate (
    pdfio_dict_t *dict,
    const char *key,
    time_t value
);

  pdfioDictSetDict
Set a key dictionary in a dictionary.

bool  pdfioDictSetDict (
    pdfio_dict_t *dict,
    const char *key,
    pdfio_dict_t *value
);

  pdfioDictSetName
Set a key name in a dictionary.

bool  pdfioDictSetName (
    pdfio_dict_t *dict,
    const char *key,
    const char *value
);

  pdfioDictSetNull
Set a key null in a dictionary.

bool  pdfioDictSetNull (
    pdfio_dict_t *dict,
    const char *key
);

  pdfioDictSetNumber
Set a key number in a dictionary.

bool  pdfioDictSetNumber (
    pdfio_dict_t *dict,
    const char *key,
    double value
);

  pdfioDictSetObj
Set a key indirect object reference in a dictionary.

bool  pdfioDictSetObj (
    pdfio_dict_t *dict,
    const char *key,
    pdfio_obj_t *value
);

  pdfioDictSetRect
Set a key rectangle in a dictionary.

bool  pdfioDictSetRect (
    pdfio_dict_t *dict,
    const char *key,
    pdfio_rect_t *value
);

  pdfioDictSetString
Set a key literal string in a dictionary.

bool  pdfioDictSetString (
    pdfio_dict_t *dict,
    const char *key,
    const char *value
);

  pdfioDictSetStringf
Set a key formatted string in a dictionary.

bool  pdfioDictSetStringf (
    pdfio_dict_t *dict,
    const char *key,
    const char *format,
    ...
);

  pdfioFileClose
Close a PDF file and free all memory used for it.

bool  pdfioFileClose (
    pdfio_file_t *pdf
);

  pdfioFileCreate
Create a PDF file.

pdfio_file_t * pdfioFileCreate (
    const char *filename,
    const char *version,
    pdfio_rect_t *media_box,
    pdfio_rect_t *crop_box,
    pdfio_error_cb_t error_cb,
    void *error_cbdata
);

This function creates a new PDF file. The "filename" argument specifies the name of the PDF file to create.

The "version" argument specifies the PDF version number for the file or NULL for the default ("2.0").

The "media_box" and "crop_box" arguments specify the default MediaBox and CropBox for pages in the PDF file - if NULL then a default "Universal" size of 8.27x11in (the intersection of US Letter and ISO A4) is used.

The "error_cb" and "error_cbdata" arguments specify an error handler callback and its data pointer - if NULL the default error handler is used that writes error messages to stderr.

  pdfioFileCreateArrayObj
Create a new object in a PDF file containing an array.

pdfio_obj_t * pdfioFileCreateArrayObj (
    pdfio_file_t *pdf,
    pdfio_array_t *array
);

This function creates a new object with an array value in a PDF file. You must call pdfioObjClose to write the object to the file.

  pdfioFileCreateFontObjFromBase
Create one of the base 14 PDF fonts.

pdfio_obj_t * pdfioFileCreateFontObjFromBase (
    pdfio_file_t *pdf,
    const char *name
);

This function creates one of the base 14 PDF fonts. The "name" parameter specifies the font nane:

•   "Courier"

•   "Courier-Bold"

•   "Courier-BoldItalic"

•   "Courier-Italic"

•   "Helvetica"

•   "Helvetica-Bold"

•   "Helvetica-BoldOblique"

•   "Helvetica-Oblique"

•   "Symbol"

•   "Times-Bold"

•   "Times-BoldItalic"

•   "Times-Italic"

•   "Times-Roman"

•   "ZapfDingbats"

Base fonts always use the Windows CP1252 (ISO-8859-1 with additional characters such as the Euro symbol) subset of Unicode.

  pdfioFileCreateFontObjFromFile
Add a font object to a PDF file.

pdfio_obj_t * pdfioFileCreateFontObjFromFile (
    pdfio_file_t *pdf,
    const char *filename,
    bool unicode
);

This function embeds a TrueType/OpenType font into a PDF file. The "unicode" parameter controls whether the font is encoded for two-byte characters (potentially full Unicode, but more typically a subset) or to only support the Windows CP1252 (ISO-8859-1 with additional characters such as the Euro symbol) subset of Unicode.

  pdfioFileCreateICCObjFromFile
Add an ICC profile object to a PDF file.

pdfio_obj_t * pdfioFileCreateICCObjFromFile (
    pdfio_file_t *pdf,
    const char *filename,
    size_t num_colors
);

  pdfioFileCreateImageObjFromData
Add image object(s) to a PDF file from memory.

pdfio_obj_t * pdfioFileCreateImageObjFromData (
    pdfio_file_t *pdf,
    const unsigned char *data,
    size_t width,
    size_t height,
    size_t num_colors,
    pdfio_array_t *color_data,
    bool alpha,
    bool interpolate
);

This function creates image object(s) in a PDF file from a data buffer in memory. The "data" parameter points to the image data as 8-bit color values. The "width" and "height" parameters specify the image dimensions. The "num_colors" parameter specifies the number of color components (1 for grayscale, 3 for RGB, and 4 for CMYK) and the "alpha" parameter specifies whether each color tuple is followed by an alpha value. The "color_data" parameter specifies an optional color space array for the image - if NULL, the image is encoded in the corresponding device color space. The "interpolate" parameter specifies whether to interpolate when scaling the image on the page.

Note: When creating an image object with alpha, a second image object is created to hold the "soft mask" data for the primary image.

  pdfioFileCreateImageObjFromFile
Add an image object to a PDF file from a file.

pdfio_obj_t * pdfioFileCreateImageObjFromFile (
    pdfio_file_t *pdf,
    const char *filename,
    bool interpolate
);

This function creates an image object in a PDF file from a JPEG or PNG file. The "filename" parameter specifies the name of the JPEG or PNG file, while the "interpolate" parameter specifies whether to interpolate when scaling the image on the page.

5   Note: Currently PNG support is limited to grayscale, RGB, or indexed files

5   without interlacing or alpha. Transparency (masking) based on color/index

5   is supported.

  pdfioFileCreateNumberObj
Create a new object in a PDF file containing a number.

pdfio_obj_t * pdfioFileCreateNumberObj (
    pdfio_file_t *pdf,
    double number
);

This function creates a new object with a number value in a PDF file. You must call pdfioObjClose to write the object to the file.

  pdfioFileCreateObj
Create a new object in a PDF file.

pdfio_obj_t * pdfioFileCreateObj (
    pdfio_file_t *pdf,
    pdfio_dict_t *dict
);

  pdfioFileCreateOutput
Create a PDF file through an output callback.

pdfio_file_t * pdfioFileCreateOutput (
    pdfio_output_cb_t output_cb,
    void *output_cbdata,
    const char *version,
    pdfio_rect_t *media_box,
    pdfio_rect_t *crop_box,
    pdfio_error_cb_t error_cb,
    void *error_cbdata
);

This function creates a new PDF file that is streamed though an output callback. The "output_cb" and "output_cbdata" arguments specify the output callback and its data pointer which is called whenever data needs to be written:

    ssize_t
    output_cb(void *output_cbdata, const void *buffer, size_t bytes)
    {
      // Write buffer to output and return the number of bytes written
    }
The "version" argument specifies the PDF version number for the file or NULL for the default ("2.0").

The "media_box" and "crop_box" arguments specify the default MediaBox and CropBox for pages in the PDF file - if NULL then a default "Universal" size of 8.27x11in (the intersection of US Letter and ISO A4) is used.

The "error_cb" and "error_cbdata" arguments specify an error handler callback and its data pointer - if NULL the default error handler is used that writes error messages to stderr.

5   Note: Files created using this API are slightly larger than those

5   created using the pdfioFileCreate function since stream lengths are

5   stored as indirect object references.

  pdfioFileCreatePage
Create a page in a PDF file.

pdfio_stream_t * pdfioFileCreatePage (
    pdfio_file_t *pdf,
    pdfio_dict_t *dict
);

  pdfioFileCreateStringObj
Create a new object in a PDF file containing a string.

pdfio_obj_t * pdfioFileCreateStringObj (
    pdfio_file_t *pdf,
    const char *string
);

This function creates a new object with a string value in a PDF file. You must call pdfioObjClose to write the object to the file.

  pdfioFileCreateTemporary

pdfio_file_t * pdfioFileCreateTemporary (
    char *buffer,
    size_t bufsize,
    const char *version,
    pdfio_rect_t *media_box,
    pdfio_rect_t *crop_box,
    pdfio_error_cb_t error_cb,
    void *error_cbdata
);

  pdfioFileFindObj
Find an object using its object number.

pdfio_obj_t * pdfioFileFindObj (
    pdfio_file_t *pdf,
    size_t number
);

This differs from pdfioFileGetObj which takes an index into the list of objects while this function takes the object number.

  pdfioFileGetAuthor
Get the author for a PDF file.

const char * pdfioFileGetAuthor (
    pdfio_file_t *pdf
);

  pdfioFileGetCatalog
Get the document catalog dictionary.

pdfio_dict_t * pdfioFileGetCatalog (
    pdfio_file_t *pdf
);

  pdfioFileGetCreationDate
Get the creation date for a PDF file.

time_t  pdfioFileGetCreationDate (
    pdfio_file_t *pdf
);

  pdfioFileGetCreator
Get the creator string for a PDF file.

const char * pdfioFileGetCreator (
    pdfio_file_t *pdf
);

  pdfioFileGetID
Get the PDF file's ID strings.

pdfio_array_t * pdfioFileGetID (
    pdfio_file_t *pdf
);

  pdfioFileGetKeywords
Get the keywords for a PDF file.

const char * pdfioFileGetKeywords (
    pdfio_file_t *pdf
);

  pdfioFileGetName
Get a PDF's filename.

const char * pdfioFileGetName (
    pdfio_file_t *pdf
);

  pdfioFileGetNumObjs
Get the number of objects in a PDF file.

size_t  pdfioFileGetNumObjs (
    pdfio_file_t *pdf
);

  pdfioFileGetNumPages
Get the number of pages in a PDF file.

size_t  pdfioFileGetNumPages (
    pdfio_file_t *pdf
);

  pdfioFileGetObj
Get an object from a PDF file.

pdfio_obj_t * pdfioFileGetObj (
    pdfio_file_t *pdf,
    size_t n
);

  pdfioFileGetPage
Get a page object from a PDF file.

pdfio_obj_t * pdfioFileGetPage (
    pdfio_file_t *pdf,
    size_t n
);

  pdfioFileGetPermissions
Get the access permissions of a PDF file.

pdfio_permission_t  pdfioFileGetPermissions (
    pdfio_file_t *pdf,
    pdfio_encryption_t *encryption
);

This function returns the access permissions of a PDF file and (optionally) the type of encryption that has been used.

  pdfioFileGetProducer
Get the producer string for a PDF file.

const char * pdfioFileGetProducer (
    pdfio_file_t *pdf
);

  pdfioFileGetSubject
Get the subject for a PDF file.

const char * pdfioFileGetSubject (
    pdfio_file_t *pdf
);

  pdfioFileGetTitle
Get the title for a PDF file.

const char * pdfioFileGetTitle (
    pdfio_file_t *pdf
);

  pdfioFileGetVersion
Get the PDF version number for a PDF file.

const char * pdfioFileGetVersion (
    pdfio_file_t *pdf
);

  pdfioFileOpen
Open a PDF file for reading.

pdfio_file_t * pdfioFileOpen (
    const char *filename,
    pdfio_password_cb_t password_cb,
    void *password_cbdata,
    pdfio_error_cb_t error_cb,
    void *error_cbdata
);

This function opens an existing PDF file. The "filename" argument specifies the name of the PDF file to create.

The "password_cb" and "password_cbdata" arguments specify a password callback and its data pointer for PDF files that use one of the standard Adobe "security" handlers. The callback returns a password string or NULL to cancel the open. If NULL is specified for the callback function and the PDF file requires a password, the open will always fail.

The "error_cb" and "error_cbdata" arguments specify an error handler callback and its data pointer - if NULL the default error handler is used that writes error messages to stderr.

  pdfioFileSetAuthor
Set the author for a PDF file.

void pdfioFileSetAuthor (
    pdfio_file_t *pdf,
    const char *value
);

  pdfioFileSetCreationDate
Set the creation date for a PDF file.

void pdfioFileSetCreationDate (
    pdfio_file_t *pdf,
    time_t value
);

  pdfioFileSetCreator
Set the creator string for a PDF file.

void pdfioFileSetCreator (
    pdfio_file_t *pdf,
    const char *value
);

  pdfioFileSetKeywords
Set the keywords string for a PDF file.

void pdfioFileSetKeywords (
    pdfio_file_t *pdf,
    const char *value
);

  pdfioFileSetPermissions
Set the PDF permissions, encryption mode, and passwords.

bool  pdfioFileSetPermissions (
    pdfio_file_t *pdf,
    pdfio_permission_t permissions,
    pdfio_encryption_t encryption,
    const char *owner_password,
    const char *user_password
);

This function sets the PDF usage permissions, encryption mode, and passwords.

5   Note: This function must be called before creating or copying any

5   objects. Due to fundamental limitations in the PDF format, PDF encryption

5   offers little protection from disclosure. Permissions are not enforced in

5   any meaningful way.

  pdfioFileSetSubject
Set the subject for a PDF file.

void pdfioFileSetSubject (
    pdfio_file_t *pdf,
    const char *value
);

  pdfioFileSetTitle
Set the title for a PDF file.

void pdfioFileSetTitle (
    pdfio_file_t *pdf,
    const char *value
);

  pdfioImageGetBytesPerLine
Get the number of bytes to read for each line.

size_t  pdfioImageGetBytesPerLine (
    pdfio_obj_t *obj
);

  pdfioImageGetHeight
Get the height of an image object.

double  pdfioImageGetHeight (
    pdfio_obj_t *obj
);

  pdfioImageGetWidth
Get the width of an image object.

double  pdfioImageGetWidth (
    pdfio_obj_t *obj
);

  pdfioObjClose
Close an object, writing any data as needed to the PDF
                    file.

bool  pdfioObjClose (
    pdfio_obj_t *obj
);

  pdfioObjCopy
Copy an object to another PDF file.

pdfio_obj_t * pdfioObjCopy (
    pdfio_file_t *pdf,
    pdfio_obj_t *srcobj
);

  pdfioObjCreateStream
Create an object (data) stream for writing.

pdfio_stream_t * pdfioObjCreateStream (
    pdfio_obj_t *obj,
    pdfio_filter_t filter
);

  pdfioObjGetArray
Get the array associated with an object.

pdfio_array_t * pdfioObjGetArray (
    pdfio_obj_t *obj
);

  pdfioObjGetDict
Get the dictionary associated with an object.

pdfio_dict_t * pdfioObjGetDict (
    pdfio_obj_t *obj
);

  pdfioObjGetGeneration
Get the object's generation number.

unsigned short  pdfioObjGetGeneration (
    pdfio_obj_t *obj
);

  pdfioObjGetLength
Get the length of the object's (data) stream.

size_t  pdfioObjGetLength (
    pdfio_obj_t *obj
);

  pdfioObjGetNumber
Get the object's number.

size_t  pdfioObjGetNumber (
    pdfio_obj_t *obj
);

  pdfioObjGetSubtype
Get an object's subtype.

const char * pdfioObjGetSubtype (
    pdfio_obj_t *obj
);

This function returns an object's PDF subtype name, if any. Common subtype names include:

•   "CIDFontType0": A CID Type0 font

•   "CIDFontType2": A CID TrueType font

•   "Image": An image or image mask

•   "Form": A fillable form

•   "OpenType": An OpenType font

•   "Type0": A composite font

•   "Type1": A PostScript Type1 font

•   "Type3": A PDF Type3 font

•   "TrueType": A TrueType font</li> </ul>

  pdfioObjGetType
Get an object's type.

const char * pdfioObjGetType (
    pdfio_obj_t *obj
);

This function returns an object's PDF type name, if any. Common type names include:

•   "CMap": A character map for composite fonts

•   "Font": An embedded font (pdfioObjGetSubtype will tell you the
      font format)

•   "FontDescriptor": A font descriptor

•   "Page": A (visible) page

•   "Pages": A page tree node

•   "Template": An invisible template page

•   "XObject": An image, image mask, or form (pdfioObjGetSubtype will
      tell you which)</li> </ul>

  pdfioObjOpenStream
Open an object's (data) stream for reading.

pdfio_stream_t * pdfioObjOpenStream (
    pdfio_obj_t *obj,
    bool decode
);

  pdfioPageCopy
Copy a page to a PDF file.

bool  pdfioPageCopy (
    pdfio_file_t *pdf,
    pdfio_obj_t *srcpage
);

  pdfioPageDictAddColorSpace
Add a color space to the page dictionary.

bool  pdfioPageDictAddColorSpace (
    pdfio_dict_t *dict,
    const char *name,
    pdfio_array_t *data
);

This function adds a named color space to the page dictionary.

The names "DefaultCMYK", "DefaultGray", and "DefaultRGB" specify the default device color space used for the page.

The "data" array contains a calibrated, indexed, or ICC-based color space array that was created using the pdfioArrayCreateCalibratedColorFromMatrix, pdfioArrayCreateCalibratedColorFromPrimaries, pdfioArrayCreateICCBasedColor, or pdfioArrayCreateIndexedColor functions.

  pdfioPageDictAddFont
Add a font object to the page dictionary.

bool  pdfioPageDictAddFont (
    pdfio_dict_t *dict,
    const char *name,
    pdfio_obj_t *obj
);

  pdfioPageDictAddImage
Add an image object to the page dictionary.

bool  pdfioPageDictAddImage (
    pdfio_dict_t *dict,
    const char *name,
    pdfio_obj_t *obj
);

  pdfioPageGetNumStreams
Get the number of content streams for a page object.

size_t  pdfioPageGetNumStreams (
    pdfio_obj_t *page
);

  pdfioPageOpenStream
Open a content stream for a page.

pdfio_stream_t * pdfioPageOpenStream (
    pdfio_obj_t *page,
    size_t n,
    bool decode
);

  pdfioStreamClose
Close a (data) stream in a PDF file.

bool  pdfioStreamClose (
    pdfio_stream_t *st
);

  pdfioStreamConsume
Consume bytes from the stream.

bool  pdfioStreamConsume (
    pdfio_stream_t *st,
    size_t bytes
);

  pdfioStreamGetToken
Read a single PDF token from a stream.

bool  pdfioStreamGetToken (
    pdfio_stream_t *st,
    char *buffer,
    size_t bufsize
);

This function reads a single PDF token from a stream. Operator tokens, boolean values, and numbers are returned as-is in the provided string buffer. String values start with the opening parenthesis ('(') but have all escaping resolved and the terminating parenthesis removed. Hexadecimal string values start with the opening angle bracket ('<') and have all whitespace and the terminating angle bracket removed.

  pdfioStreamPeek
Peek at data in a stream.

ssize_t  pdfioStreamPeek (
    pdfio_stream_t *st,
    void *buffer,
    size_t bytes
);

  pdfioStreamPrintf
Write a formatted string to a stream.

bool  pdfioStreamPrintf (
    pdfio_stream_t *st,
    const char *format,
    ...
);

  pdfioStreamPutChar
Write a single character to a stream.

bool  pdfioStreamPutChar (
    pdfio_stream_t *st,
    int ch
);

  pdfioStreamPuts
Write a literal string to a stream.

bool  pdfioStreamPuts (
    pdfio_stream_t *st,
    const char *s
);

  pdfioStreamRead
Read data from a stream.

ssize_t  pdfioStreamRead (
    pdfio_stream_t *st,
    void *buffer,
    size_t bytes
);

This function reads data from a stream. When reading decoded image data from a stream, you must read whole scanlines. The pdfioImageGetBytesPerLine function can be used to determine the proper read length.

  pdfioStreamWrite
Write data to a stream.

bool  pdfioStreamWrite (
    pdfio_stream_t *st,
    const void *buffer,
    size_t bytes
);

  pdfioStringCreate
Create a durable literal string.

char * pdfioStringCreate (
    pdfio_file_t *pdf,
    const char *s
);

This function creates a literal string associated with the PDF file "pdf". The "s" string points to a nul-terminated C string.

NULL is returned on error, otherwise a char * that is valid until pdfioFileClose is called.

  pdfioStringCreatef
Create a durable formatted string.

char * pdfioStringCreatef (
    pdfio_file_t *pdf,
    const char *format,
    ...
);

This function creates a formatted string associated with the PDF file "pdf". The "format" string contains printf-style format characters.

NULL is returned on error, otherwise a char * that is valid until pdfioFileClose is called.

STRUCTURES

  pdfio_rect_s
PDF rectangle

struct pdfio_rect_s
{
  double x1;
  double x2;
  double y1;
  double y2;
};

TYPES

  pdfio_array_t
Array of PDF values

typedef struct _pdfio_array_s pdfio_array_t;

  pdfio_cs_t
Standard color spaces

typedef enum pdfio_cs_e pdfio_cs_t;

  pdfio_dict_cb_t
Dictionary iterator callback

typedef bool(*)(pdfio_dict_t *dict, const char *key, void *cb_data) pdfio_dict_cb_t;

  pdfio_dict_t
Key/value dictionary

typedef struct _pdfio_dict_s pdfio_dict_t;

  pdfio_encryption_t
PDF encryption modes

typedef enum pdfio_encryption_e pdfio_encryption_t;

  pdfio_error_cb_t
Error callback

typedef bool(*)(pdfio_file_t *pdf, const char *message, void *data) pdfio_error_cb_t;

  pdfio_file_t
PDF file

typedef struct _pdfio_file_s pdfio_file_t;

  pdfio_filter_t
Compression/decompression filters for streams

typedef enum pdfio_filter_e pdfio_filter_t;

  pdfio_linecap_t
Line capping modes

typedef enum pdfio_linecap_e pdfio_linecap_t;

  pdfio_linejoin_t
Line joining modes

typedef enum pdfio_linejoin_e pdfio_linejoin_t;

  pdfio_matrix_t[3][2]
Transform matrix

typedef double pdfio_matrix_t[3][2];

  pdfio_obj_t
Numbered object in PDF file

typedef struct _pdfio_obj_s pdfio_obj_t;

  pdfio_output_cb_t
Output callback for pdfioFileCreateOutput

typedef ssize_t(*)(void *ctx const void *data size_t datalen) pdfio_output_cb_t;

  pdfio_password_cb_t
Password callback for pdfioFileOpen

typedef const char *(*)(void *data const char *filename) pdfio_password_cb_t;

  pdfio_permission_t
PDF permission bitfield

typedef int pdfio_permission_t;

  pdfio_rect_t
PDF rectangle

typedef struct pdfio_rect_s pdfio_rect_t;

  pdfio_stream_t
Object data stream in PDF file

typedef struct _pdfio_stream_s pdfio_stream_t;

  pdfio_textrendering_t
Text rendering modes

typedef enum pdfio_textrendering_e pdfio_textrendering_t;

  pdfio_valtype_t
PDF value types

typedef enum pdfio_valtype_e pdfio_valtype_t;

AUTHOR

Michael R Sweet

COPYRIGHT

Copyright (c) 2021-2024 by Michael R Sweet