Polyglot Particles

A pixi-build workspace that wires together six packages written in four languages around a single C ABI. The point is to show how pixi-build lets you depend on path-based, multi-language packages from one workspace and run them with one command.

particle_core      C       shared lib + headers, defines the ABI
particle_cpp       C++     emitter/modifier impls, exposes vtables
particle_cpp_py    C++     pybind11 module wrapping particle_cpp
particle_rs        Rust    emitter/modifier impls + PyO3 bindings
particle_view      C++     pybind11 module that opens an SDL window
particle_kit       Python  high-level API and entry point

Two pixi-build backends do all the work: pixi-build-cmake for the C and C++ packages (including the two pybind11 Python extensions, which install themselves directly into the host environment's Python_SITEARCH), and pixi-build-python for the Rust crate (via maturin) and the pure-Python kit (via hatchling).

Run it

pixi run demo   # build a Python scene and visualize it
pixi run list   # print every emitter/modifier registered by the cpp + rust libs

How the pieces fit

particle_core ships a header with two vtable types (pc_emitter_vtable_t, pc_modifier_vtable_t) plus a runtime pc_pool_t that integrates particles, runs modifiers, and pulls from emitters each step. Both particle_cpp and particle_rs implement that interface in their own language and export discovery functions (particle_cpp_get_emitter("cone"), etc.).

particle_cpp_py (pybind11) and particle_rs (PyO3) each surface their own emitters/modifiers as Python objects. Each object exposes vtable_addr and state_addr as integers. particle_view is a pybind11 module whose only function is View(w, h).run(emitters=[...], modifiers=[...]) which reads those addresses, builds a pc_pool_t internally, and runs the SDL loop. No dlopen happens between packages; the Python side just hands raw function-pointer integers across the boundary.

particle_kit is the orchestrator: it imports both binding modules and the view, and ships a __main__ that builds a small scene as a smoke test.