Free C PDF API to Generate New PDFs & Add Images/Barcodes.

Getting Started with PDFGen

The recommend way to install PDFGen is using GitHub. Please use the following command for a smooth installation.

Install PDFGen via GitHub

 Git clone https://github.com/AndreRenaud/PDFGen.git

You can also install it manually; download the latest release files directly from GitHub repository.

Create Basic PDF File via C API

PDFGen is an open-source, lightweight C library designed specifically for generating and managing PDF documents with ease. it supports various features for working with PDF documents, such as inserting text and images, adding new pages, manage fonts, and many more. The following example shows how software developers can create a single-page PDF with a title and a body of text inside C applications.

#include 
#include "pdfgen.h"

int main(void) {
    // 1. Create a new PDF document with A4 page size
    struct pdf_info info = {
        .creator = "My App",
        .producer = "My App",
        .title = "My First PDF",
        .author = "John Doe",
    };
    struct pdf_doc *pdf = pdf_create(PDF_A4_WIDTH, PDF_A4_HEIGHT, &info);
    
    // 2. Set up a font
    const int font_size = 20;
    
    // 3. Add a new page
    pdf_append_page(pdf);
      
    // 6. Save the PDF to a file
    pdf_save(pdf, "hello_world.pdf");
    
    // 7. Free the allocated memory
    pdf_destroy(pdf);
    
    printf("PDF generated successfully!\n");
    return 0;
}

PDF Text Manipulation via C Library

The open source PDFGen library has included complete support handling text inside PDF documents via C++ library. The library provides robust text handling capabilities, allowing you to use standard PDF fonts like Times-Roman, Helvetica, and Courier and control text appearance by setting the font size, color, and rotation of the text. The library also supports adding text at specific coordinates on the page. The following example shows how to add Text inside a PDF document using C commands.

#include "pdfgen.h"

int main(void) {
    struct pdf_info info = {
        .creator = "My Application",
        .title = "My First PDF",
        .author = "Me"
    };
    struct pdf_doc *pdf = pdf_create(PDF_A4_WIDTH, PDF_A4_HEIGHT, &info);
    pdf_set_font(pdf, "Times-Roman");
    pdf_append_page(pdf);
    pdf_add_text(pdf, NULL, "Hello, PDFGen!", 12, 50, 20, PDF_BLACK);
    pdf_save(pdf, "hello.pdf");
    pdf_destroy(pdf);
    return 0;
}

 

Drawing Shapes and Embed Images in PDFs

The open source PDFGen library has provided powerful support for drawing shapes and adding images inside a PDF documents with ease. For documents that require more than just text, PDFGen offers a suite of functions for drawing basic shapes and lines. With just a couple of lines of code software developers can draw lines, rectangles, and circles to create shapes, charts, or borders inside their own applications. The following example demonstrates how software developers can draw graphics and add a JPEG image inside C Apps.

#include "pdfgen.h"

int main(void) {
    // ... (PDF creation boilerplate as above) ...
    pdf_append_page(pdf);
    // Draw a red line
    pdf_add_line(pdf, NULL, 50, 50, 200, 50, 3, PDF_RED);
    // Draw a blue-filled rectangle
    pdf_add_filled_rect(pdf, NULL, 50, 100, 150, 50, PDF_BLUE);
    // ... (Save and destroy PDF) ...
    return 0;
}

Barcode Generation inside PDF via C Library

A standout feature of PDFGen is its built-in support for generating barcodes inside PDF documents. This is particularly useful for applications that need to produce invoices, shipping labels, or inventory tags. The library supports two common barcode standards. Code-128, which is a high-density linear barcode symbology and Code-39 which is a variable-length, discrete barcode symbology. Here is a useful example that shows how to add a Barcode to a PDF file inside C applications.

#include "pdfgen.h"

int main(void) {
    // ... (PDF creation boilerplate) ...
    pdf_append_page(pdf);
    pdf_add_barcode(pdf, NULL, PDF_BARCODE_128, 50, 200, 200, 50, "PDFGen-12345", PDF_BLACK);
    // ... (Save and destroy PDF) ...
    return 0;
}