nngn

https://bbguimaraes.com/nngn

Graphics/physics/audio/game engine.

• documentation
• building

Documentation

Documentation generated from comments using Doxygen is available here. It can of course also be read inline in the source code. Source code is organized in the following directories:

• src: main source code directory. Most of the code is contained in one of the subdirectories, which form mostly-independent modules.
• src/lua: Lua libray and scripts.
• scripts: auxiliary scripts for building and interacting with the program.
• tests: unit and integration tests for the C++ and Lua components.
• tools: external and independent tools that interact with the engine to display information and control execution (inspection, profiling, configuration, etc.).

Building

All targets use autotools. For a native binary, simply execute:

./configure
make

See dependencies for the required packages.

The following build environments are regularly tested and known to work:

• Linux with GCC/Clang
• FreeBSD with GCC/Clang
• Windows with `mingw`
• WebAssembly with `emscripten`

MinGW

Cross-compiling with mingw is supported with the usual configure arguments:

./configure --build=x86_64-pc-linux-gnu --host=x86_64-w64-mingw32 # …

See scripts/src_build.sh for an example of how to build dependencies from source.

Emscripten

A WebAssembly application can be built using emscripten. It provides all dependencies listed below, except for Lua, which must be built from source. See scripts/src_build.sh for an example.

Then, follow the autotools process, prefixing configure with emconfigure. pkg-config doesn't currently work with it, but the scripts/emscripten/pkgconfig directory has dummy files that can be used:

EM_PKG_CONFIG_LIBDIR=scripts/emscripten/pkgconfig emconfigure ./configure #…
make nngn.js

The following configure options are relevant when targeting WebAssembly:

• --disable-benchmarks
• --disable-tests
• --disable-tools
• --without-opencl
• --without-vulkan

Optional features

Some additional capabilities can be enabled via the usual configure script option format. Some of them, described in dependencies, require additional libraries. The ones in this section do not, but can be selectively enabled.

• --enable-lua-alloc: use a custom Lua allocator (see lua_Alloc in the documentation) which tracks all memory alloctions for each state. This information can be visualized at runtime.

Dependencies

These are the required packages for building the main program, along with the versions known to work:

• lua (5.4.4): embedded scripting language

The default build of the program is very minimal. Additional functionality can be enabled by passing extra flags to the configure script.

See scripts/container.sh for an example script that creates a container with all the build dependencies.

--with-opencl

Enables the OpenCL compute backend. Requires:

• OpenCL (2.2): heterogeneous computing library

--with-opengl

Enables the OpenGL graphics backend. Requires:

• glfw (3.3): portable GUI library
• gl (4.5, 3.1es): graphics library
• glew (2.1.0): OpenGL extension loading library

--with-vulkan

Enables the Vulkan graphics backend. Requires:

• glfw (3.3): portable GUI library
• vulkan (1.1.130): graphics library
• glslang (11.1.0): GLSL compiler

Additionally, if the VulkanMemoryAllocator library is present (determined by the vk_mem_alloc.h header file), it is used for some of the memory allocations. This default can be disabled with --without-vma.

--with-libpng

Enables loading images. Requires:

• libpng (1.6.37): PNG loading library

--with-freetype2

Enables loading fonts. Requires:

• freetype2 (2.10.1): font library

Tests

Building the tests requires Qt5Core and Qt5Test (5.14.0) and can be enabled with the --enable-tests flag. A clang-tidy check is also available via make tidy.

The tests can be compiled and executed with several compiler protections and sanitizers.

The following compilers have been tested:

• gcc (11.1.0)
• clang (12.0.1)

The following compiler flags have been tested:

• -D_GLIBCXX_SANITIZE_VECTOR
• -fsanitize-address-use-after-scope
• -fstack-protector

The following sanitizers have been tested:

• address
• leak
• undefined
• pointer-compare
• pointer-subtract

Benchmarks

Building the benchmakrs requires Qt5Core and Qt5Test (5.14.0) and can be enabled with the --enable-benchmarks flag.

Tools

Buildings auxiliary tools requires Qt5Widgets, QtNetwork, Qt5Charts, and rustc (1.41.1) and can be enabled with the --enable-tools flag.

FreeBSD

The packages required for a minimal build in FreeBSD are (available as pre-built packages via pkg):

• autoconf
• automake
• gcc11
• pkgconf