Intermact API Reference

This overview covers the architecture and entry points for v0.1–v1.0 (Phase-1 / Phase-2 / Phase-3) public API; individual symbol pages are generated by TypeDoc from exports and TSDoc comments in packages/*/src. Phase-3 (PCG / 3D / serialization export / plugins) API map is in §Phase-3 below; concept guides at PCG / 3D / Export & embed / Performance / Extensibility.

Full contract and revision history in repo dev-docs/design.md. Conceptual tutorial: Guide · Architecture overview.

Vision and API boundaries

Phase	Version	Theme	Relation to this doc
Phase-1	v0.1	Interactive Manim alternative: 2D primitives, seekable timeline, coordinate axes, reactive tuning	Overview §Phase-1
Phase-2	v0.2	Math toolbox: Scale, LaTeX, Morph matching, interaction picking, layout	Overview §Phase-2
Phase-3	v1.0	PCG, full 3D, serialization/export/embed, plugins	Symbol pages + Plugin guide

Core execution model: seekable timeline

Intermact uses a retained-mode timeline (design.md §3.2):

Phase	Responsibility	Key API
Build	Register objects; scene.play appends tracks to Storyboard	createProgram, buildProgram, Scene2D
Playback	seek / update pure-function evaluation; deterministic snapshot	Player, Track, RenderSnapshot

await scene.play(...) is build-time syntax sugar: logical clock advances instantly, no wall-clock time consumed.

Object three layers: definition · instance · runtime state

IMObject2D (immutable definition: geometry + trait)
    └── scene.register(...) → RegisteredObject2D (animation handle: create / moveTo / morphTo …)
            └── Track evaluation → RuntimeState2D (position, reveal, opacity, geometryOverride …)

• Definition layer: IMObject2D + traits (stroke / fill / morphable / textLayout); primitive factories like circle, polygon.
• Instance layer: RegisteredObject2D — animation methods return Animation data, compiled at play.
• Runtime layer: RuntimeState2D + applyPatch2D; renderer consumes RenderSnapshot.

Scene · Camera · Canvas decoupling

Unlike Manim, scene, camera, and canvas are layered (design.md §9–10):

Layer	Role	Key API
Scene2D	Coordinate domain, object registration, getAxes, orchestrates play	Scene2D
Camera	Orthographic camera description, mounted to viewport	createCamera2D
Canvas	React entry: build program, R3F canvas, timeline overlay	IntermactCanvas

Coordinate transforms: CoordinateTransform2D (abs/rel, polar). Axis objects register via Scene2D.getAxes; ticks generated by Scale (Phase-2).

Package layers and render pipeline

@intermact/react
  └── @intermact/render-r3f     SceneView, computeFit
        └── @intermact/render-three   stroke/fill geometry, ThreeSceneView
              └── @intermact/core     no React / three / DOM

Package	Responsibility
@intermact/core	Model, geometry, timeline, reactive, Scale/constructs/text/interaction; headless in Node
@intermact/render-three	RenderSnapshot → three.js geometry (stroke trim, earcut fill)
@intermact/render-r3f	R3F diff update, camera fit, HiDPI
@intermact/react	IntermactCanvas, useSignal, timeline controls, Inspector

Data flow: Player.getSnapshot() → ThreeSceneView diff → R3F SceneView.

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Phase-1 (v0.1): basic 2D narrative

Guides: Program and scene · Timeline · Geometry · Rendering · Animation · Coordinates · Reactive

Capability	API entry
2D primitives	circle, rectangle, polygon, bezierCurve, arrow
Create / Fade / Move / Tween	RegisteredObject2D, compileSpec
Orchestration	sequence, parallel, stagger, wait
Coordinates and axes	CoordinateTransform2D, Scene2D.getAxes
Reactive tuning	signal, derived, tweenSignal, useSignal
Side effects (not seekable)	call

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Phase-2 (v0.2): math toolbox

Guides: Scale · Math constructs · Morph · Text and LaTeX · Interaction · Layout and Inspector

Scale and ticks (M7)

Capability	API entry
Scale types	linearScale, logScale, normalizeScale
Tick generation	numericTicks
Axis handle	createAxesHandle, AxesHandle (c2p / xScale / yScale)

Math construct library (M8)

Capability	API entry
Coordinate planes	numberLine, numberPlane, polarPlane, complexPlane
Curves and integration	functionGraph, parametricGraph, areaUnderCurve, riemannRectangles, tangentLine
Expression and annotation	matrixObject, tableObject, brace, decimalNumber

Morph and part matching (M9)

Strategy	API entry
arc-length / anchor / matching / cross-fade	morph, transformMatching
Composite object part keys	group2D
Instance methods	RegisteredObject2D.morphTo, transformMatchingTo

Text and LaTeX (M10)

Capability	API entry
Fonts	loadOutlineFontFromBuffer, setDefaultFont, createAssetManager
Text objects	textObject, glyphText
LaTeX	layoutMathJaxLatex, latexObjectFromGlyphs
Writing animation	glyphLocalReveal, computeGlyphRevealSpans
Formula part morph	transformMatchingTex (token → part key, reuses matching)

Interaction system (M11)

Capability	API entry
Draggable sources	draggablePoint, draggableValue, draggablePointSource, draggableValueSource
Hit testing	hitTest, hitProxy, interactive
Pick helpers	pickRectFromObject, pickBandFromObject

Layout and Inspector (M12)

Capability	API entry
Relative layout	LayoutHandle (RegisteredObject2D.layout: alignTo / nextTo / arrange / fitTo)
Layout handle factory	createLayoutHandle
Dev tools	Inspector (React-side scene tree / signals / snapshot debug)

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Phase-3 (v1.0): PCG · 3D · serialization export · plugins

Guides: Procedural generation · 3D scenes and cameras · Export, share, and embed · Performance and big data · Extensibility

PCG procedural generation (M13)

Capability	API entry
Parametric / lattice / tiling	parametricCurve2D, lattice, tiling
Fractal / rules	fractal, recursiveTree, lSystem, cellularAutomaton, cellularAutomatonFrames
Fields	functionGraph, isoline, heatmap, streamlines
Graph / data	graphObject, barChart, scatter, lineChart, mapData
Combinator operators	transformObject, repeatObject, instanceField, mapPoints, along, booleanOp

Full 3D (M14)

Capability	API entry
Scene / camera	Scene3D, RegisteredCamera3D, CoordinateTransform3D
3D factories	polyline3D, curve3D, meshObject, surface3D, pointCloud3D, axes3D
Scalar field isosurface	isosurface, marchingCubes
Nested sub-scenes	RegisteredObject2D.layout · render(scene, camera) (render-r3f RenderedScene)

Serialization / export / embed (M15)

Capability	API entry
Serialization	serialize, deserialize
Share links	encodeShareUrl, decodeShareUrl, SerializedCanvas
Headless frames	snapshotToSVG, sampleFrames, sampleFrameHashes
Video / GIF	recordCanvasVideo, captureFrameSequencePng, encodeGif, exportCanvasGif
Embed	defineIntermactEmbed, buildEmbedIframe

Performance and extensibility (M16 / M17)

Capability	API entry
GPU instancing / point cloud	instanceField, pointCloud3D
Registries	createRegistries, globalRegistries
Plugins	definePlugin, installPlugin, defineObjectType, defineGenerator
Generator dispatch	runGenerator, selectRenderer

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Reactive layer (interactive state)

Aligned with Manim ValueTracker + add_updater (design.md §8), for parameter-driven geometry recomputation:

• signal / computed
• derived + ReactiveEngine
• tweenSignal, bindSignal, useSignal

Each frame: Player.prepareFrame → ReactiveEngine.flush → then generate RenderSnapshot.

How to browse symbols

1. Enter package index pages from Packages below.
2. Sidebar browse by Classes / Interfaces / Functions (includes all Phase-2 exports).
3. To change API docs, edit source TSDoc and run pnpm run gen:reference to regenerate.

Packages

• @intermact/core
• @intermact/react
• @intermact/render-r3f
• @intermact/render-three