Module paths 

Project state root: where the engine’s state tree is anchored, and the names of the directories hanging off it.

Everything the engine writes for a project lives under one state directory: the compiled blobs (data/), the regenerable cache (cache/: 0 for the running application, 1 for a build, the baked asset thumbnails included), fetched source assets (assets/), named worlds (worlds/), the runtime save files (saves/), and the mutable settings file (settings).

Nothing here has a default. A host installs the state directory via set_state_dir before anything reads the tree, and until it does every path below resolves to None. The naming of that directory is the host’s business, not this crate’s: the dev CLI hides it inside the project, a shipped application puts it beside its executable, and an embedder points it wherever its own layout implies. Reads that cannot proceed without a state tree report CnResult::NoStateRoot; the caches and the settings file simply do nothing.

The read-only content of the tree (data/) and the runtime-writable state (saves/ + settings) usually share one root, but a shipped application installed in a read-only location (Program Files) cannot write beside its data. Such an application installs a separate writable root via set_writable_state_dir so only saves/ and settings relocate to a per-user directory while data/ stays beside the executable.

Resolution touches no files: these functions compute paths. Reading the tree is super::source (finding a source asset) and super::blob (the compiled blob).

Functions

assets_dir

The state root’s assets/ directory.

build_cache_path

The build cache segment, cache/1: one container holding every payload, expansion, and baked thumbnail a cook produced, indexed by producer and key. A build writes this file and no other, so a cook running against a live application never shares a file with the segment that application writes.

bundled_runtime_cache_path

The runtime cache segment a bundle ships, read-only. cn export warms it with the shader binaries a first launch would otherwise compile; because those artifacts are backend IR (DXBC / SPIR-V) rather than machine code, one warmed at package time is valid on any machine.

clear_state_dir

Remove an installed state dir, leaving the process with no state tree.

clear_writable_state_dir

Remove an installed writable-state dir, restoring writable state to the content root beside data/.

crashes_dir

Directory holding crash reports (and minidumps) written by the crash reporting machinery. Resolves under the writable-state dir like saves/, since a shipped install’s content root may be read-only. Created on first write; capped by the writer’s retention pruning, never by a build.

data_dir

The state root’s data/ directory.

preview_saves_dir

Sandboxed sibling of saves_dir for preview sessions (see the TransientSaves protocol resource): the save UI keeps working against this directory, but the real saves are never touched and the sandbox is wiped at each session start.

runtime_cache_in

The runtime cache segment inside state_dir, for a caller naming a state tree other than the installed one: cn export warms the segment it writes into a bundle before that bundle is ever launched.

runtime_cache_path

The runtime cache segment, cache/0: one container holding every regenerable artifact the running application produces for its own later launches, indexed by producer and key. Resolves under the writable-state dir, since a shipped install’s content root may be read-only.

saves_dir

Directory holding the runtime save files (auto, save1 ..). Created on first write by the running application, never by a build. Resolves under the writable-state dir, which is the content root unless an application redirected it.

set_state_dir

Anchor the state tree at dir for the rest of the process, so data/, saves/, and settings resolve under it. Every host installs one before reading project state: the dev CLI its project directory, a shipped application the directory beside its executable (or inside its app bundle), an embedder whatever its own layout implies.

set_writable_state_dir

Anchor the runtime-writable state (saves/ + settings) at dir, leaving the read-only content (data/) at the installed state dir. A shipped application installs this when its content dir is not writable (a read-only install such as Program Files), redirecting only what it writes at runtime to a per-user directory. When unset, writable state stays beside data/.

settings_path

The mutable settings file (CBOR). Written by the in-engine settings menu, never by a build. A sibling of data/ in the common case, or under the writable-state dir when a read-only install redirected it.

state_dir

The state directory, or None when no host installed one.

worlds_dir

The state root’s worlds/ directory.

writable_state_dir

The directory holding runtime-writable state (saves/ + settings): the writable override when one is installed, otherwise the state dir (writable state sits beside data/).