nandi/jolt-native · d682bfa

⑂ d682bfa

Point the docs at the flake

README's build section described zig, DotSlash and `scripts/`, none of which
exist any more, and glimmer-vidya's named a buck2 recipe.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

nandi committed 2026-09-05T22:04:19-07:00 Browse files

d682bfa parent: 5ae197f

modified README.md +41 -17 Viewed

@@ -39,29 +39,53 @@ than naming one.
39	39
40	40	## Building
41	41
	42	+The flake is the toolchain. `nix develop` is where the compiler, the C
	43	+toolchain, PipeWire's headers and the kernel headers bindgen wants come from,
	44	+so nothing needs to be installed beyond nix itself — no `cc` on PATH, no
	45	+rustup, no NDK.
	46	+
42	47	```bash
43		-just build # release .so files in target/release
44		-just test # the whole workspace
45		-just libdir # where to point LD_LIBRARY_PATH
	48	+nix develop # then:
	49	+just build # release .so files in target/release
	50	+just test # the whole workspace
	51	+just libdir # where to point LD_LIBRARY_PATH
46	52	```
47	53
48		-Everything is compiled by `zig cc`, which brings its own glibc sysroot and
49		-Linux headers, so no system C or C++ toolchain is needed — this repo builds
50		-on a machine with no `cc` on its PATH at all. The pinned tools come from
51		-DotSlash files in `scripts/`, fetched on first use; `dotslash` must be on PATH.
	54	+`just build` is the edit loop; the nix outputs are the artifact, built against
	55	+a pinned compiler and a pinned crate graph:
52	56
53		-Two things sit outside that promise and are worth knowing about:
	57	+```bash
	58	+nix build # all three objects → result/lib
	59	+nix build .#android # both device objects → result/lib/arm64-v8a
	60	+nix flake check # fmt, clippy, tests, all three objects
	61	+```
54	62
55		-* bindgen runs libclang directly and does not inherit zig's header search
56		- path, so `v4l2r` cannot find `linux/videodev2.h`. The justfile points it at
57		- zig's bundled copies. That is what `scripts/zig-include` is for, and why
58		- building through `just` rather than bare `cargo` is the supported path.
	63	+Two things are worth knowing about:
	64	+
	65	+* bindgen runs libclang directly, so `v4l2r` needs to be pointed at
	66	+ `linux/videodev2.h`. The flake sets `V4L2R_VIDEODEV2_H_PATH` and
	67	+ `BINDGEN_EXTRA_CLANG_ARGS` from nixpkgs' `linuxHeaders` in both the devShell
	68	+ and the build, which is why building inside `nix develop` rather than a bare
	69	+ shell is the supported path.
59	70	* PipeWire is a real system dependency — `libspa-sys` wants `pkg-config`
60		- and PipeWire's headers. It is behind the default-on `pipewire` feature of
61		- `jolt-moq`; `just test-minimal` builds without it. Turning it off costs
62		- device names: only ALSA PCMs remain visible ("pipewire", "sysdefault")
63		- rather than the real sources a browser would offer, which makes picking a
64		- microphone guesswork.
	71	+ and PipeWire's headers, and the flake supplies both. It is behind the
	72	+ default-on `pipewire` feature of `jolt-moq`; `just test-minimal` builds
	73	+ without it, for a machine outside the flake. Turning it off costs device
	74	+ names: only ALSA PCMs remain visible ("pipewire", "sysdefault") rather than
	75	+ the real sources a browser would offer, which makes picking a microphone
	76	+ guesswork.
	77	+
	78	+### Android
	79	+
	80	+```bash
	81	+just ffi-android # nix build .#android
	82	+```
	83	+
	84	+Same sources and same `Cargo.lock` as the desktop objects; only the target
	85	+configuration moves. The NDK comes from nixpkgs, so this needs nothing
	86	+installed either. The camera wants two things from the APK that the build
	87	+cannot supply: a `CameraCapture` class in its `classes.dex`, and a call to
	88	+`joltmoq_android_init` — see `android/jolt_main.c`.
65	89
66	90	## jolt-moq
67	91

  ## Building
++The flake is the toolchain. `nix develop` is where the compiler, the C
++toolchain, PipeWire's headers and the kernel headers bindgen wants come from,
++so **nothing needs to be installed** beyond nix itself — no `cc` on PATH, no
++rustup, no NDK.
++
  ```bash
--just build      # release .so files in target/release
++nix develop                 # then:
--just test       # the whole workspace
++just build                  # release .so files in target/release
--just libdir     # where to point LD_LIBRARY_PATH
++just test                   # the whole workspace
++just libdir                 # where to point LD_LIBRARY_PATH
  ```
--Everything is compiled by `zig cc`, which brings its own glibc sysroot and
++`just build` is the edit loop; the nix outputs are the artifact, built against
--Linux headers, so **no system C or C++ toolchain is needed** — this repo builds
++a pinned compiler and a pinned crate graph:
--on a machine with no `cc` on its PATH at all. The pinned tools come from
--DotSlash files in `scripts/`, fetched on first use; `dotslash` must be on PATH.
--Two things sit outside that promise and are worth knowing about:
++```bash
++nix build                   # all three objects  → result/lib
++nix build .#android         # both device objects → result/lib/arm64-v8a
++nix flake check             # fmt, clippy, tests, all three objects
++```
--* **bindgen runs libclang directly** and does not inherit zig's header search
++Two things are worth knowing about:
--  path, so `v4l2r` cannot find `linux/videodev2.h`. The justfile points it at
++
--  zig's bundled copies. That is what `scripts/zig-include` is for, and why
++* **bindgen runs libclang directly**, so `v4l2r` needs to be pointed at
--  building through `just` rather than bare `cargo` is the supported path.
++  `linux/videodev2.h`. The flake sets `V4L2R_VIDEODEV2_H_PATH` and
++  `BINDGEN_EXTRA_CLANG_ARGS` from nixpkgs' `linuxHeaders` in both the devShell
++  and the build, which is why building inside `nix develop` rather than a bare
++  shell is the supported path.
  * **PipeWire** is a real system dependency — `libspa-sys` wants `pkg-config`
--  and PipeWire's headers. It is behind the default-on `pipewire` feature of
++  and PipeWire's headers, and the flake supplies both. It is behind the
--  `jolt-moq`; `just test-minimal` builds without it. Turning it off costs
++  default-on `pipewire` feature of `jolt-moq`; `just test-minimal` builds
--  device *names*: only ALSA PCMs remain visible ("pipewire", "sysdefault")
++  without it, for a machine outside the flake. Turning it off costs device
--  rather than the real sources a browser would offer, which makes picking a
++  *names*: only ALSA PCMs remain visible ("pipewire", "sysdefault") rather than
--  microphone guesswork.
++  the real sources a browser would offer, which makes picking a microphone
++  guesswork.
++
++### Android
++
++```bash
++just ffi-android            # nix build .#android
++```
++
++Same sources and same `Cargo.lock` as the desktop objects; only the target
++configuration moves. The NDK comes from nixpkgs, so this needs nothing
++installed either. The camera wants two things from the APK that the build
++cannot supply: a `CameraCapture` class in its `classes.dex`, and a call to
++`joltmoq_android_init` — see `android/jolt_main.c`.
  ## jolt-moq

modified jolt/glimmer-vidya/README.md +1 -1 Viewed

@@ -68,7 +68,7 @@ it on the loop thread. Handlers are held on the jolt side and never sent.
68	68	`libvidya` built from [`../ffi`](../ffi), the Rust/egui implementation:
69	69
70	70	```sh
71		-just ffi # buck2 → ../build/libvidya.so
	71	+just ffi-android # nix build .#android → ../result/lib/arm64-v8a/libvidya.so
72	72	```
73	73
74	74	Then put it on the search path when running anything here:

  `libvidya` built from [`../ffi`](../ffi), the Rust/egui implementation:
  ```sh
--just ffi            # buck2 → ../build/libvidya.so
++just ffi-android    # nix build .#android → ../result/lib/arm64-v8a/libvidya.so
  ```
  Then put it on the search path when running anything here: