DirtyTalk

DirtyTalk is the family of packages BlaC is built on. They answer one question: after a mutation, what changed, who cares, and when do we tell them?

You do not need to install or import these to use BlaC — @blac/core wires them up for you. This page exists so the layering is on record.

The idea

A renderer mutates a scene and must repaint. A state container mutates state and must notify subscribers. Both face the same three questions, and the naive answer pushes the work down to every consumer — re-walking the whole state tree once per subscriber, or repainting the whole canvas because a single dirty bit lost track of where the change was.

DirtyTalk computes “what changed” once, at the source, as a Region — a value with empty, union, and intersects. Each subscriber declares an interest region. Waking the right subscribers is then one cheap intersects check each, against one shared dirty region: work proportional to the number of subscribers, not to the size of the state times the number of subscribers.

The packages

Package	Role	A Region is
@dirtytalk/engine	The abstract algebra and scheduling glue: the Space<Region> and Scheduler interfaces, and DirtyChannel<Region>. Ships no concrete Region.	abstract — you supply one
@dirtytalk/spatial	The 2D-rendering instantiation. RectSpace, a SceneNode / SceneRoot tree, and a PointerRouter.	a list of damage rects
@dirtytalk/structural	The state-container instantiation. PathSetSpace, a PathInterner, the trackRender proxy recorder, and diff helpers.	a set of interned path IDs

Each domain package answers the same algebra in its own terms. “Union two dirty regions” means concatenating damage lists in spatial and set-union in structural. The DirtyChannel machinery — coalescing, selective fan-out, re-entrancy handling, error isolation — is written once in the engine and reused by both.

@blac/core is a consumer of @dirtytalk/structural: BlaC’s per-consumer path tracking is that package’s path-set model. BlaC also re-exports untracked from it.

All three are standalone and framework-agnostic — usable with no React and no BlaC — but they are documented here only at this level. For BlaC itself, start at the introduction.