What is bound

Generated by mix ex_mujoco.gen from MuJoCo's own headers. Regenerating is the only way to edit this page, and mix ex_mujoco.gen --check fails when it disagrees with the headers.

Functions

Bound by hand

These need a decision per call — an error buffer to allocate, an output array whose length is the caller's business, a state signature — so they are written out in c_src/ex_mujoco_nif.cpp rather than generated.

• load_xml/1 — the error is a caller-sized char buffer; here it is our buffer and an exception
• load_xml_string/1 — a parsed spec has to be compiled and freed around the model, which is a lifetime question
• data/1 — the data block belongs to a model, so the handle holds both
• reset/1 — the step surface is (data), because the handle carries its model
• forward/1 — same: ExMujoco.forward/1 takes the data, not model and data
• step/1 — same: ExMujoco.step/1 takes the data
• state_size/2 — paired with get_state and set_state, which share the signature's meaning
• get_state/2 — writes into a buffer whose length state_size fixed; allocated here
• set_state/3 — reads a buffer whose length state_size fixed; checked here
• data_state_size/2 — the same count, asked of the data put_state is given
• contact_force/2 — writes six numbers into a caller's array; allocated here
• version/0 — the library's own version, checked against the headers at load time
• header_version/0 — the header's version, for the same check

Not bound

426 of MuJoCo's 551 functions take something a NIF cannot honestly invent — a callback, a void*, an output array whose length nothing states, a variadic argument list — and binding one means deciding that question, one function at a time. The other 87 are expressible and simply not bound yet: a name in c_src/manifest.exs, and mix ex_mujoco.gen.

Decisions worth naming:

• mjSpec — building a model at run time (mjs_addBody and the rest) is v0.2; loading XML, from a path or from a string, is enough to run anything meanwhile
• mj_copyData — it answers the destination it was given, and a handle to a data block you already hold is not a useful answer; copying state is state/2 and put_state/3
• mj_printData, mj_printModel — they write into a buffer the caller sizes; a string-returning wrapper is a design decision, not a translation
• mjrContext — offscreen rendering is v0.3 — it needs a GL context per platform (EGL, OSMesa, CGL, WGL) and owns a thread

Fields

MuJoCo's own API reference describes each of them; the names and the units are MuJoCo's, and its documentation is the documentation for the field.

Enums

All 83 enums MuJoCo declares are generated into ExMujoco.Types with the values resolved from the headers — including the ones C numbers implicitly and the ones that are an OR of their siblings.