PDFium-GDE (PDFium GDExtension) for Godot 4.5+

This is a Godot 4.5+ GDExtension that brings Google's PDFium library to Godot. It allows you to load PDF files, render pages to images, and extract text data (including bounding boxes) directly within your game or application.

Features

• Document Loading: Load PDFs from res://, user://, or absolute system paths.
• High-Quality Rendering: Convert PDF pages to Godot Image resources with adjustable DPI.
• Text Extraction: Retrieve text content along with its position/rect on the page (great for highlighting or search).
• Lazy Loading: Documents are opened only when accessed, saving memory.
• Editor Integration: Full support for load() and preload() in GDScript via a custom import plugin.
• PDF Generation & Export: Create new PDF documents from scratch and save them to the filesystem (res://, user://, or absolute paths).
• Document Editing: Add, remove, extract, or merge pages. Add document-wide watermarks; insert images, text (with custom fonts and alignment), and drawn shapes (rectangles, paths) into existing or new PDFs.

Installation (Pre-built Release)

1. Download the latest version.
2. Extract the downloaded zip file into your project's root folder.
3. Enable the plugin in Project Settings -> Plugins.

Building From Source

Prerequisites

• Python 3.6+
• SCons
• A C++20 compatible compiler (MSVC, GCC, or Clang)

Compilation

1. Clone the repository recursively to get the godot-cpp submodule:

   git clone --recursive https://github.com/pdfium-gde/pdfium-gde.git
   

2. Run SCons in the root directory:

   # for Windows
   scons platform=windows target=template_debug
   scons platform=windows target=template_release
   
   # for Linux
   scons platform=linux target=template_debug
   scons platform=linux target=template_release
   
   # for macOS
   scons platform=macos target=template_debug
   scons platform=macos target=template_release
   

   The compiled binaries will be placed in OS-specific folders under demo/addons/pdfium-gde/.
3. Crucial Step: You must copy the pdfium.dll (or libpdfium.so/libpdfium.dylib) from the corresponding platform folder in lib/ (e.g., lib/windows.x86_64/) to the same OS-specific directory as the compiled GDExtension (e.g., demo/addons/pdfium-gde/windows/).
4. Finalize: Copy the entire demo/addons/pdfium-gde/ folder into your project's addons folder, and enable the plugin in Project Settings -> Plugins.

Quick Start

Loading via Import System

Simply drop a .pdf into your project. It will be automatically recognized.

var doc = load("res://my_document.pdf")
var page = doc.get_page(0)
var img = page.render_to_image(2.0) # Render at 2x scale (144 DPI)

$TextureRect.texture = ImageTexture.create_from_image(img)

Loading External Files

var doc = PDFDocument.new()
var err = doc.load_from_file("C:/Users/Name/Downloads/manual.pdf")
if err == OK:
    var metadata = doc.get_metadata("Title")

var page = doc.get_page(0)
var img = page.render_to_image(2.0) # Render at 2x scale (144 DPI)

$TextureRect.texture = ImageTexture.create_from_image(img)

Creating and Exporting a New PDF

# initialize the document
var doc = PDFDocument.new()
doc.create_empty_doc()

# create a page (defaults to Vector2(1280, 720))
var page1 = doc.create_page(Vector2(1280, 720))

# add a background rectangle (with a blue border and semi-transparent red fill)
page1.add_rect(Rect2(50, 450, 200, 100), Color(1, 0, 0, 0.5), Color(0, 0, 1, 1), 2.0)

# add an image
var img = Image.load_from_file("res://icon.png")
page1.add_image(img, Rect2(0, 0, 128, 128))

# add text with a standard font, bold, and centered
var pos = Vector2(1280 / 2.0, 50)
page1.add_text("Hello World!", pos, "Helvetica", 24.0, Color.BLACK, PDFPage.ALIGN_CENTER, true, false)

# save the generated document
doc.save_to_file("user://generated_output.pdf")

Creating a PDFPage From a Viewport

# grab a viewport as an Image
var img = viewport.get_texture().get_image()

# initialize the document
var doc = PDFDocument.new()
doc.create_empty_doc()

# automatically create a page matching the image size
doc.create_page_from_image(img)

# save the generated document
doc.save_to_file("user://viewport_capture.pdf")

Editing an Existing PDF

var doc = PDFDocument.new()
if doc.load_from_file("res://existing.pdf") != OK:
    return

# delete the second page (index 1)
doc.delete_page(1)

# get the first page and add a custom TTF font text
var page = doc.get_page(0)
page.add_text("Watermark", Vector2(50, 100), "res://fonts/MyFont.ttf", 16.0, Color.RED)

# export the modified PDF
doc.save_to_file("user://edited_output.pdf")

Extracting and Merging Pages

var doc1 = PDFDocument.new()
doc1.load_from_file("res://doc1.pdf")

var doc2 = PDFDocument.new()
doc2.load_from_file("res://doc2.pdf")

# extract the 1st and 3rd pages from doc1 into a new document (pass empty array for all pages)
var extracted = doc1.extract_pages([0, 2])
extracted.save_to_file("user://extracted.pdf")

# append only the 2nd and 5th pages of doc2 to the end of doc1 (pass empty array for all pages)
doc1.merge_with(doc2, [1, 4])
doc1.save_to_file("user://merged.pdf")

Watermarking Pages

var doc = PDFDocument.new()
doc.load_from_file("res://document.pdf")

var logo = Image.load_from_file("res://watermark.png")

# add a 50% transparent watermark exactly at the center of all pages
doc.add_watermark_image(logo, Vector2(0.5, 0.5), Vector2(0, 0), 1.0, 0.5)

# add a small logo at the bottom right of the 1st page, tucked 20px inwards (index 0)
doc.add_watermark_image(logo, Vector2(1.0, 1.0), Vector2(-20, -20), 0.25, 0.8, [0])

doc.save_to_file("user://watermarked_output.pdf")

Contributing

Contributions are welcome! If you find a bug or have a feature request, please open an issue or submit a pull request.

Support

If you find this project useful, please give it a star! It helps more people discover this addon.

License

• This GDExtension is released under the zlib License (see LICENSE for details).
• This project uses PDFium which is licensed under the Apache License 2.0 (see THIRDPARTY.md for details).