Third-Party Libraries

Relevant source files

• COPYRIGHT.txt
• modules/cvtt/SCsub
• modules/fbx/fbx_document.cpp
• modules/fbx/fbx_document.h
• modules/gltf/skin_tool.cpp
• modules/gltf/skin_tool.h
• modules/meshoptimizer/SCsub
• modules/tinyexr/SCsub
• modules/tinyexr/config.py
• modules/tinyexr/image_loader_tinyexr.cpp
• thirdparty/README.md
• thirdparty/doctest/LICENSE.txt
• thirdparty/doctest/doctest.h
• thirdparty/doctest/patches/0001-ciso646-version.patch
• thirdparty/meshoptimizer/LICENSE.md
• thirdparty/meshoptimizer/clusterizer.cpp
• thirdparty/meshoptimizer/indexcodec.cpp
• thirdparty/meshoptimizer/indexgenerator.cpp
• thirdparty/meshoptimizer/meshoptimizer.h
• thirdparty/meshoptimizer/partition.cpp
• thirdparty/meshoptimizer/quantization.cpp
• thirdparty/meshoptimizer/simplifier.cpp
• thirdparty/meshoptimizer/vertexcodec.cpp
• thirdparty/meshoptimizer/vertexfilter.cpp
• thirdparty/tinyexr/LICENSE
• thirdparty/tinyexr/exr_reader.hh
• thirdparty/tinyexr/streamreader.hh
• thirdparty/tinyexr/tinyexr.cc
• thirdparty/tinyexr/tinyexr.h
• thirdparty/ufbx/ufbx.c
• thirdparty/ufbx/ufbx.h

This page documents the external libraries bundled under the thirdparty/ directory of the Godot Engine repository: their purposes, versions, licenses, and how they integrate into the engine. It does not cover Godot's own subsystems that consume these libraries; for that context, see the relevant system pages (e.g., Rendering System Text Shaping System Build System).

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Overview

Godot bundles third-party libraries directly into the source tree rather than relying on system-provided packages. This ensures reproducible builds across all target platforms. Each library lives in its own subdirectory under thirdparty/, and the canonical inventory with upstream URLs, versions, and applied patches is maintained in thirdparty/README.md1-7

Licensing information for all bundled libraries is tracked in COPYRIGHT.txt1-37 using the Debian machine-readable copyright format.

Many libraries have Godot-specific patch files (.patch) stored alongside their source, applied to fix build issues or integrate the library more tightly with engine internals.

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Directory Structure

Each library occupies a named subdirectory. The naming convention matches the entries in thirdparty/README.md8-1130

thirdparty/
├── accesskit/
├── amd-fsr/
├── amd-fsr2/
├── angle/
├── astcenc/
├── basis_universal/
├── brotli/
├── certs/
├── clipper2/
├── cvtt/
├── d3d12ma/
├── directx_headers/
├── doctest/
├── dr_libs/
├── embree/
├── enet/
├── etcpak/
├── fonts/
├── freetype/
├── gamepadmotionhelpers/
├── glad/
├── glslang/
├── graphite/
├── grisu2/
├── harfbuzz/
├── icu4c/
├── jolt_physics/
├── libbacktrace/
├── libjpeg-turbo/
├── libktx/
├── libogg/
├── libpng/
├── libtheora/
├── libvorbis/
├── libwebp/
├── linuxbsd_headers/
├── manifold/
├── mbedtls/
├── meshoptimizer/
├── metal-cpp/
├── mingw-std-threads/
├── miniupnpc/
├── minizip/
├── misc/
├── msdfgen/
├── openxr/
├── pcre2/
├── re-spirv/
├── recastnavigation/
├── rvo2/
├── sdl/
├── smaa/
├── spirv-cross/
├── spirv-headers/
├── spirv-reflect/
├── swappy-frame-pacing/
├── thorvg/
├── tinyexr/
├── ufbx/
├── vhacd/
├── volk/
├── vulkan/
├── wayland/
├── wayland-protocols/
├── wslay/
├── xatlas/
├── zlib/
└── zstd/

Sources: thirdparty/README.md1-1130 COPYRIGHT.txt1-50

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Library Inventory by Category

Rendering & GPU

Directory	Library	Version	License	Purpose
amd-fsr	AMD FidelityFX Super Resolution 1	1.0.2	MIT	Spatial upscaling (ffx_a.h, ffx_fsr1.h) thirdparty/README.md20-30
amd-fsr2	AMD FidelityFX Super Resolution 2	2.2.1	MIT	Temporal upscaling pipeline thirdparty/README.md32-48
angle	ANGLE	chromium/5907	BSD-3-Clause	GLES header stubs thirdparty/README.md50-60
d3d12ma	D3D12 Memory Allocator	3.1.0	MIT	GPU memory allocation for Direct3D 12 thirdparty/README.md153-168
directx_headers	DirectX Headers	main	MIT	D3D12 API headers thirdparty/README.md170-185
glad	glad	2.0.4	CC0 1.0 + Apache 2.0	OpenGL/EGL/GLX function loader
glslang	glslang	vulkan-sdk-1.4.335.0	glslang	GLSL→SPIR-V compiler
metal-cpp	metal-cpp	26.0	Apache 2.0	C++ bindings for Apple Metal
re-spirv	re-spirv	git	MIT	SPIR-V specialization constant optimizer
smaa	SMAA	git (2013)	MIT	Anti-aliasing lookup textures
spirv-cross	SPIRV-Cross	git	Apache 2.0	SPIR-V → GLSL/MSL cross-compiler
spirv-headers	SPIRV-Headers	vulkan-sdk-1.4.335.0	MIT	SPIR-V opcode/type definitions
spirv-reflect	SPIRV-Reflect	vulkan-sdk-1.4.335.0	Apache 2.0	SPIR-V shader reflection
volk	volk	vulkan-sdk-1.4.335.0	MIT	Vulkan function pointer loader
vulkan	Vulkan Headers + VMA	vulkan-sdk-1.4.335.0	Apache 2.0	Vulkan API headers

Sources: thirdparty/README.md20-185 COPYRIGHT.txt153-178

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Texture Compression & Image Formats

Directory	Library	Version	License	Purpose
astcenc	Arm ASTC Encoder	5.3.0	Apache 2.0	ASTC texture encode/decode thirdparty/README.md62-72
basis_universal	Basis Universal	git	Apache 2.0	Supercompressed texture transcoding thirdparty/README.md74-94
cvtt	Convection Kernels	git	MIT	BC1–BC7 compression thirdparty/README.md137-151
libpng	libpng	1.6.54	libpng/zlib	PNG encode/decode
tinyexr	TinyEXR	git	BSD-3-Clause	OpenEXR image load/save thirdparty/tinyexr/tinyexr.h1-28
ufbx	ufbx	0.23.1	MIT	FBX file parsing thirdparty/ufbx/ufbx.c1-8
thorvg	ThorVG	1.0.3	MIT	Vector graphics (SVG) rendering

Sources: thirdparty/README.md62-151 thirdparty/tinyexr/tinyexr.h1-66 thirdparty/ufbx/ufbx.c1-100

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Networking & Security

Directory	Library	Version	License	Purpose
certs	Mozilla CA bundle	git	MPL 2.0	TLS root certificate trust store thirdparty/README.md109-118
enet	ENet	1.3.18	MIT	Reliable UDP networking thirdparty/README.md243-250
mbedtls	Mbed TLS	3.6.5	Apache 2.0	TLS/SSL, cryptography

Sources: thirdparty/README.md109-250

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Utilities & Tools

Directory	Library	Version	License	Purpose
doctest	doctest	2.4.12	MIT	Unit test framework thirdparty/README.md188-201
meshoptimizer	meshoptimizer	1.2	MIT	Mesh compression and simplification thirdparty/meshoptimizer/meshoptimizer.h1-8

Sources: thirdparty/README.md188-201 thirdparty/meshoptimizer/meshoptimizer.h1-15

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Integration Patterns

Pattern 1: Library Consumed Directly by Engine Code

Some libraries are used directly by the engine's resource loaders or scene processing logic via wrapper classes.

Diagram: ufbx usage in FBXDocument

Details:

• FBXDocument uses ufbx to parse FBX files modules/fbx/fbx_document.cpp61-62
• It provides custom file access callbacks _file_access_read_fn and _file_access_skip_fn to ufbx to leverage Godot's FileAccess modules/fbx/fbx_document.cpp63-72
• Data is converted from ufbx structures (e.g., ufbx_vec3, ufbx_quat, ufbx_transform) to Godot types like Vector3, Quaternion, and Transform3D modules/fbx/fbx_document.cpp74-91

Sources: modules/fbx/fbx_document.cpp61-91 thirdparty/ufbx/ufbx.c1-100

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Pattern 2: Image Format Loaders

Godot utilizes specialized libraries for high-dynamic-range image formats like OpenEXR.

Diagram: TinyEXR Integration in Godot

Details:

• TinyEXR is used within modules/tinyexr/image_loader_tinyexr.cpp to provide support for OpenEXR files modules/tinyexr/image_loader_tinyexr.cpp31-38
• ImageLoaderTinyEXR::load_image parses the EXR version and header from memory before loading the image data modules/tinyexr/image_loader_tinyexr.cpp54-73
• It supports mapping EXR channels (R, G, B, A, Y) to Godot's Image::Format (e.g., FORMAT_RGBAH, FORMAT_RGBF) modules/tinyexr/image_loader_tinyexr.cpp94-142

Sources: thirdparty/tinyexr/tinyexr.h1-100 modules/tinyexr/image_loader_tinyexr.cpp39-142

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Pattern 3: Mesh Optimization and Simplification

Godot integrates meshoptimizer to provide mesh simplification and vertex cache optimization.

Diagram: Mesh Simplification Pipeline

Details:

• meshoptimizer provides utilities for vertex remapping and mesh simplification thirdparty/meshoptimizer/meshoptimizer.h53-104
• The simplifier.cpp implementation uses quadric error metrics for surface simplification thirdparty/meshoptimizer/simplifier.cpp23-31
• It includes spatial hashing via PositionHasher to identify binary equivalent vertices for remapping thirdparty/meshoptimizer/simplifier.cpp111-148
• The library supports SIMD optimizations (SSE, NEON, WASM) for vertex decoding and filtering thirdparty/meshoptimizer/vertexcodec.cpp7-51 thirdparty/meshoptimizer/vertexfilter.cpp7-37

Sources: thirdparty/meshoptimizer/meshoptimizer.h1-128 thirdparty/meshoptimizer/simplifier.cpp23-241 thirdparty/meshoptimizer/vertexcodec.cpp7-120 thirdparty/meshoptimizer/vertexfilter.cpp7-60

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Godot-Specific Patches

Many libraries carry .patch files to ensure they work correctly within the Godot ecosystem.

Patch Purpose	Example Libraries
Disable exceptions	clipper2, embree thirdparty/README.md133-232
External zlib/zstd redirection	basis_universal thirdparty/README.md88-89
Build and Mingw support	amd-fsr2, d3d12ma, directx_headers thirdparty/README.md46-184

Sources: thirdparty/README.md44-238