Options 

CMake options 

All of the following CMake options simply define the corresponding macro for compilation. Therefore, when using another build system these compile definitions can simply be set to 0 or 1, and the fastgltf headers also define a fallback if undefined. However, you should not define any of those macros within your source files, since that would break compilation and/or linking.

`FASTGLTF_USE_64BIT_FLOAT`

Instead of using a normal 32-bit float for all of the types the glTF spec refers to as num, this option instead makes fastgltf use 64-bit double.

`FASTGLTF_USE_CUSTOM_SMALLVECTOR`

While fastgltf uses its custom SmallVector class in various areas by default, it might be useful to enable it in more places.

`FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL`

fastgltf by default comes with a custom memory allocator which makes use of std::pmr functionality. This allocator allocates fixed-size blocks of memory as needed and divides them up for all heap allocations fastgltf performs. All of this functionality can be disabled using this flag. All types will then be normal std containers and use standard heap allocation with new and malloc.

`FASTGLTF_COMPILE_AS_CPP20`

This BOOL option controls the C++ standard the library is compiled as. When NO fastgltf is always compiled as C++17. When YES fastgltf is compiled as C++20, including the tests. This might allow the compiler to perform certain optimisations, since fastgltf then uses some specialized stdlib functions instead.

`FASTGLTF_ENABLE_CPP_MODULES`

When this setting is YES the fastgltf::module target will be exposed, as long as the CMake script detects a compiler which supports modules. Note that this is currently not supported by all compilers and generators. See the CMake docs for more details.

`FASTGLTF_USE_STD_MODULE`

This BOOL option makes the fastgltf C++ module import the std module, which is available since C++23. This can have further compiler time benefits, but is only experimentally supported with CMake 3.30 or newer, and only with some toolchains. Therefore, this option should be used with caution and issues are likely.

`FASTGLTF_ENABLE_TESTS`

To build and run the tests and benchmarks you need to set this BOOL option to YES. When this option is set, the fastgltf_tests target will be configured. The tests target depends on various dependencies, which will need to be downloaded before configuring CMake using fetch_test_deps.py.

`FASTGLTF_ENABLE_EXAMPLES`

To build and run the examples you need to this BOOL option to YES. When this option is set, all targets from examples will be configured. The CMake targets depend on various dependencies, which will need to be downloaded before configuring CMake using fetch_test_deps.py.

`FASTGLTF_ENABLE_DOCS`

This BOOL option controls whether the targets and commands related to the documentation should be configured. Setting this to YES requires Doxygen, Sphinx and breathe to be installed.

`FASTGLTF_ENABLE_GLTF_RS`

When this BOOL option is set to YES fastgltf will use corrosion, which is downloaded using fetch_test_deps.py, to link against the gltf-rs Rust library for comparison within the benchmarks. Note that this option has no effect when FASTGLTF_ENABLE_TESTS is set to NO.