Generating PDF Reports in C++: libharu Library and Beyond

Generating PDF Reports in C++ with libharu and PoDoFo

In modern C++ development, there is often a need to programmatically create PDF documents: from simple text reports to complex multi-page documents with tables, charts, and images. In this article, we will take a detailed look at two popular libraries for generating PDFs in C++ — libharu and PoDoFo, and provide practical examples of their use.

1. libharu Library

libharu is a lightweight, cross-platform library for creating PDF files in C. It has no external dependencies (except zlib for compression), supports Unicode, font embedding, images (JPEG/PNG), and basic vector primitives. It is ideal for generating simple reports, invoices, and certificates.

Installation (Linux / Windows)

• Linux (Ubuntu/Debian): sudo apt-get install libhpdf-dev
• Windows (vcpkg): vcpkg install libharu
• Windows (build from source): download the archive from GitHub, build using CMake.

Example: creating a simple PDF with text and a line

#include <hpdf.h>#include <stdio.h>

int main() {    HPDF_Doc pdf = HPDF_New(NULL, NULL);    if (!pdf) { fprintf(stderr, "Error creating document"); return 1; }

    HPDF_Page page = HPDF_AddPage(pdf);    HPDF_Page_SetSize(page, HPDF_PAGE_SIZE_A4, HPDF_PAGE_PORTRAIT);

    // Title    HPDF_Page_BeginText(page);    HPDF_Page_SetFontAndSize(page, HPDF_GetFont(pdf, "Helvetica", NULL), 24);    HPDF_Page_TextOut(page, 50, 750, "Q1 Sales Report");    HPDF_Page_EndText(page);

    // Line under the title    HPDF_Page_SetLineWidth(page, 1.5);    HPDF_Page_MoveTo(page, 50, 735);    HPDF_Page_LineTo(page, 545, 735);    HPDF_Page_Stroke(page);

    // Save    HPDF_SaveToFile(pdf, "report.pdf");    HPDF_Free(pdf);    printf("PDF created: report.pdf");    return 0;}

Example: adding a table (simulation)

libharu does not have a built-in table module, but tables can be drawn manually:

void draw_table(HPDF_Page page, float x, float y, float col_width, float row_height, int rows, int cols) {    for (int r = 0; r <= rows; ++r) {        HPDF_Page_MoveTo(page, x, y - r * row_height);        HPDF_Page_LineTo(page, x + cols * col_width, y - r * row_height);        HPDF_Page_Stroke(page);    }    for (int c = 0; c <= cols; ++c) {        HPDF_Page_MoveTo(page, x + c * col_width, y);        HPDF_Page_LineTo(page, x + c * col_width, y - rows * row_height);        HPDF_Page_Stroke(page);    }}

2. PoDoFo Library

PoDoFo is a more modern and powerful C++ library with C++17 support. It provides an object-oriented API, support for forms, annotations, bookmarks, TrueType/OpenType font embedding, as well as reading and editing existing PDFs. PoDoFo is better suited for complex reports with dynamic content.

Installation

• Linux: sudo apt-get install libpodofo-dev (the version may be old; it is better to build from source)
• Windows: via vcpkg: vcpkg install podofo
• Build from source: requires CMake, zlib, libpng, freetype, fontconfig.

Example: creating a PDF with a table and an image

#include <podofo/podofo.h>#include <iostream>

int main() {    using namespace PoDoFo;

    PdfMemDocument doc;    PdfPage* page = doc.CreatePage(PdfPage::CreateStandardPageSize(PdfPageSize::A4));    PdfPainter painter;    painter.SetCanvas(*page);

    // Font    auto