Documentation / @ripl/terminal / TerminalContext

Class: TerminalContext

Defined in: terminal/src/context.ts:175

Terminal rendering context that rasterizes Ripl elements into character-based output via a TerminalOutput adapter.

Affine transforms, clipping and hit testing are all honored. A character grid still cannot honor the whole canvas contract, so the following constraints apply:

• Text metrics are approximate: every glyph occupies exactly one terminal cell, so measureText reports one cell of width per character regardless of font, and the font state (family, size, weight) has no visual effect.
• Rotated text runs along the grid: a glyph fills a whole cell and cannot itself be rotated, so a rotated run advances along whichever of eight compass directions the transform is nearest. A quarter-turn axis title reads down the side of a chart; it is not drawn sideways.
• Stroke width approximates a non-uniform scale: a round pen is genuinely elliptical under one, so lineWidth maps through the geometric mean of the transform's scale factors.
• Fills use the even-odd rule only: the scanline rasterizer ignores a nonzero fill rule (see TerminalContext.applyFill). Hit testing honors both.
• Stroke joins and caps are always round: lineWidth is honored by stamping a round brush along the path, so lineCap, lineJoin and miterLimit have no effect. lineDash/lineDashOffset are honored, with arc length approximated by plotted-pixel count.
• Gradients and patterns resolve to one color: a cell cannot interpolate, so a multi-color paint paints as its first non-transparent color.
• No shadows, filters, or compositing: shadow*, filter and globalCompositeOperation are ignored. globalCompositeOperation: 'destination-out' warns, because canvas erases where the terminal draws — the output is inverted rather than merely degraded.
• Text on a path is drawn straight: ContextText.pathData/startOffset are ignored and the run is laid out from its anchor along a straight line.
• No images: drawImage is inherited as a no-op.

Extends

• Context<Element>

Constructors

Constructor

new TerminalContext(output, options?): TerminalContext

Defined in: terminal/src/context.ts:207

Parameters

Parameter	Type
output	TerminalOutput
options?	TerminalContextOptions

Returns

TerminalContext

Overrides

Context.constructor

Properties

Property	Modifier	Type	Default value	Description	Overrides	Inherited from	Defined in
currentState	protected	BaseState	undefined	-	-	Context.currentState	core/src/context/context.ts:104
element	readonly	Element	undefined	The underlying DOM element the context renders into.	-	Context.element	core/src/context/context.ts:111
height	public	number	undefined	Current height of the rendering surface, in logical pixels — CSS pixels, unaffected by the device pixel ratio.	-	Context.height	core/src/context/context.ts:124
hitTestHonorsTransform	public	boolean	false	A hit point arrives in logical space while a path's recorded commands are in the element's own local space, and no transform is in force by the time a hit test runs — so the point has to be mapped back through the element's world transform, as it is on canvas.	Context.hitTestHonorsTransform	-	terminal/src/context.ts:200
meta	readonly	TMeta	undefined	Arbitrary metadata attached to the context.	-	Context.meta	core/src/context/context.ts:113
parent?	public	EventBus<ContextEventMap>	undefined	The parent event bus that emitted events bubble up to, if any.	-	Context.parent	core/src/core/event-bus.ts:107
renderDepth	protected	number	0	-	-	Context.renderDepth	core/src/context/context.ts:105
renderedElements	public	RenderElement[]	undefined	Elements rendered during the current pass, used for hit testing.	-	Context.renderedElements	core/src/context/context.ts:132
renderElement?	public	RenderElement	undefined	The element currently being rendered, if any.	-	Context.renderElement	core/src/context/context.ts:130
saveDepth	protected	number	0	-	-	Context.saveDepth	core/src/context/context.ts:106
scaleX	public	Scale<number, number>	undefined	Scale mapping logical x coordinates onto this backend's surface x coordinates. Drives drawing, not a conversion seam for callers — use Context.toSurfacePoint.	-	Context.scaleX	core/src/context/context.ts:126
scaleY	public	Scale<number, number>	undefined	Scale mapping logical y coordinates onto this backend's surface y coordinates. Drives drawing, not a conversion seam for callers — use Context.toSurfacePoint.	-	Context.scaleY	core/src/context/context.ts:128
states	protected	BaseState[]	undefined	-	-	Context.states	core/src/context/context.ts:103
type	readonly	string	undefined	The context type identifier (e.g. canvas, svg).	-	Context.type	core/src/context/context.ts:109
width	public	number	undefined	Current width of the rendering surface, in logical pixels — CSS pixels, unaffected by the device pixel ratio.	-	Context.width	core/src/context/context.ts:122
defaultKey	readonly	typeof defaultKey	undefined	The key under which resources are retained when no explicit key is provided.	-	Context.defaultKey	core/src/core/disposer.ts:11

Accessors

$events

Get Signature

get $events(): keyof ContextEventMap[]

Defined in: core/src/context/context.ts:135

The event types a context can emit. See EventBus.$events.

Returns

keyof ContextEventMap[]

Inherited from

Context.$events

---

currentRenderElement

Get Signature

get currentRenderElement(): RenderElement | undefined

Defined in: core/src/context/context.ts:153

The element currently being rendered; setting a non-abstract element also records it in Context.renderedElements.

Returns

RenderElement | undefined

Set Signature

set currentRenderElement(element): void

Defined in: core/src/context/context.ts:157

Parameters

Parameter	Type
element	RenderElement | undefined

Returns

void

Inherited from

Context.currentRenderElement

---

direction

Get Signature

get direction(): Direction

Defined in: core/src/context/context.ts:184

Directionality used when rendering text.

Returns

Direction

Set Signature

set direction(value): void

Defined in: core/src/context/context.ts:188

Directionality used when rendering text.

Parameters

Parameter	Type
value	Direction

Returns

void

Directionality used when rendering text.

Inherited from

Context.direction

---

fill

Get Signature

get fill(): string

Defined in: core/src/context/context.ts:166

Fill style (CSS color, gradient, or pattern) used to paint filled regions.

Returns

string

Set Signature

set fill(value): void

Defined in: core/src/context/context.ts:170

Fill style (CSS color, gradient, or pattern) used to paint filled regions.

Parameters

Parameter	Type
value	string

Returns

void

Fill style (CSS color, gradient, or pattern) used to paint filled regions.

Inherited from

Context.fill

---

filter

Get Signature

get filter(): string

Defined in: core/src/context/context.ts:175

CSS filter string applied to subsequent drawing operations (e.g. blur(4px)).

Returns

string

Set Signature

set filter(value): void

Defined in: core/src/context/context.ts:179

CSS filter string applied to subsequent drawing operations (e.g. blur(4px)).

Parameters

Parameter	Type
value	string

Returns

void

CSS filter string applied to subsequent drawing operations (e.g. blur(4px)).

Inherited from

Context.filter

---

font

Get Signature

get font(): string

Defined in: core/src/context/context.ts:193

CSS font shorthand used when rendering text.

Returns

string

Set Signature

set font(value): void

Defined in: core/src/context/context.ts:197

CSS font shorthand used when rendering text.

Parameters

Parameter	Type
value	string

Returns

void

CSS font shorthand used when rendering text.

Inherited from

Context.font

---

fontKerning

Get Signature

get fontKerning(): FontKerning

Defined in: core/src/context/context.ts:202

Whether font kerning is applied when rendering text.

Returns

FontKerning

Set Signature

set fontKerning(value): void

Defined in: core/src/context/context.ts:206

Whether font kerning is applied when rendering text.

Parameters

Parameter	Type
value	FontKerning

Returns

void

Whether font kerning is applied when rendering text.

Inherited from

Context.fontKerning

---

globalCompositeOperation

Get Signature

get globalCompositeOperation(): unknown

Defined in: core/src/context/context.ts:220

Compositing operation controlling how new drawing is blended with existing content.

Returns

unknown

Set Signature

set globalCompositeOperation(value): void

Defined in: core/src/context/context.ts:224

Compositing operation controlling how new drawing is blended with existing content.

Parameters

Parameter	Type
value	unknown

Returns

void

Compositing operation controlling how new drawing is blended with existing content.

Inherited from

Context.globalCompositeOperation

---

lineCap

Get Signature

get lineCap(): LineCap

Defined in: core/src/context/context.ts:229

Cap style drawn at the endpoints of stroked lines.

Returns

LineCap

Set Signature

set lineCap(value): void

Defined in: core/src/context/context.ts:233

Cap style drawn at the endpoints of stroked lines.

Parameters

Parameter	Type
value	LineCap

Returns

void

Cap style drawn at the endpoints of stroked lines.

Inherited from

Context.lineCap

---

lineDash

Get Signature

get lineDash(): number[]

Defined in: core/src/context/context.ts:238

Dash pattern as alternating stroke and gap lengths; empty for a solid line.

Returns

number[]

Set Signature

set lineDash(value): void

Defined in: core/src/context/context.ts:242

Dash pattern as alternating stroke and gap lengths; empty for a solid line.

Parameters

Parameter	Type
value	number[]

Returns

void

Dash pattern as alternating stroke and gap lengths; empty for a solid line.

Inherited from

Context.lineDash

---

lineDashOffset

Get Signature

get lineDashOffset(): number

Defined in: core/src/context/context.ts:247

Distance into the line dash pattern at which dashing begins.

Returns

number

Set Signature

set lineDashOffset(value): void

Defined in: core/src/context/context.ts:251

Distance into the line dash pattern at which dashing begins.

Parameters

Parameter	Type
value	number

Returns

void

Distance into the line dash pattern at which dashing begins.

Inherited from

Context.lineDashOffset

---

lineJoin

Get Signature

get lineJoin(): LineJoin

Defined in: core/src/context/context.ts:256

Join style drawn where two stroked segments meet.

Returns

LineJoin

Set Signature

set lineJoin(value): void

Defined in: core/src/context/context.ts:260

Join style drawn where two stroked segments meet.

Parameters

Parameter	Type
value	LineJoin

Returns

void

Join style drawn where two stroked segments meet.

Inherited from

Context.lineJoin

---

lineWidth

Get Signature

get lineWidth(): number

Defined in: core/src/context/context.ts:265

Width, in pixels, of stroked lines.

Returns

number

Set Signature

set lineWidth(value): void

Defined in: core/src/context/context.ts:269

Width, in pixels, of stroked lines.

Parameters

Parameter	Type
value	number

Returns

void

Width, in pixels, of stroked lines.

Inherited from

Context.lineWidth

---

miterLimit

Get Signature

get miterLimit(): number

Defined in: core/src/context/context.ts:274

Miter length limit ratio applied to miter line joins.

Returns

number

Set Signature

set miterLimit(value): void

Defined in: core/src/context/context.ts:278

Miter length limit ratio applied to miter line joins.

Parameters

Parameter	Type
value	number

Returns

void

Miter length limit ratio applied to miter line joins.

Inherited from

Context.miterLimit

---

opacity

Get Signature

get opacity(): number

Defined in: core/src/context/context.ts:211

Global alpha applied to everything drawn, from 0 to 1. Assignment replaces the current alpha; element and group opacity instead composite multiplicatively through CONTEXT_OPERATIONS.

Returns

number

Set Signature

set opacity(value): void

Defined in: core/src/context/context.ts:215

Global alpha applied to everything drawn, from 0 to 1.

Parameters

Parameter	Type
value	number

Returns

void

Global alpha applied to everything drawn, from 0 to 1.

Inherited from

Context.opacity

---

rotation

Get Signature

get rotation(): Rotation

Defined in: core/src/context/context.ts:391

Rotation applied to the element's transform, as radians or a deg/rad string.

Returns

Rotation

Set Signature

set rotation(value): void

Defined in: core/src/context/context.ts:395

Rotation applied to the element's transform, as radians or a deg/rad string.

Parameters

Parameter	Type
value	Rotation

Returns

void

Rotation applied to the element's transform, as radians or a deg/rad string.

Inherited from

Context.rotation

---

shadowBlur

Get Signature

get shadowBlur(): number

Defined in: core/src/context/context.ts:283

Gaussian blur radius applied to drawn shadows.

Returns

number

Set Signature

set shadowBlur(value): void

Defined in: core/src/context/context.ts:287

Gaussian blur radius applied to drawn shadows.

Parameters

Parameter	Type
value	number

Returns

void

Gaussian blur radius applied to drawn shadows.

Inherited from

Context.shadowBlur

---

shadowColor

Get Signature

get shadowColor(): string

Defined in: core/src/context/context.ts:292

Color of drawn shadows.

Returns

string

Set Signature

set shadowColor(value): void

Defined in: core/src/context/context.ts:296

Color of drawn shadows.

Parameters

Parameter	Type
value	string

Returns

void

Color of drawn shadows.

Inherited from

Context.shadowColor

---

shadowOffsetX

Get Signature

get shadowOffsetX(): number

Defined in: core/src/context/context.ts:301

Horizontal offset, in pixels, of drawn shadows.

Returns

number

Set Signature

set shadowOffsetX(value): void

Defined in: core/src/context/context.ts:305

Horizontal offset, in pixels, of drawn shadows.

Parameters

Parameter	Type
value	number

Returns

void

Horizontal offset, in pixels, of drawn shadows.

Inherited from

Context.shadowOffsetX

---

shadowOffsetY

Get Signature

get shadowOffsetY(): number

Defined in: core/src/context/context.ts:310

Vertical offset, in pixels, of drawn shadows.

Returns

number

Set Signature

set shadowOffsetY(value): void

Defined in: core/src/context/context.ts:314

Vertical offset, in pixels, of drawn shadows.

Parameters

Parameter	Type
value	number

Returns

void

Vertical offset, in pixels, of drawn shadows.

Inherited from

Context.shadowOffsetY

---

stroke

Get Signature

get stroke(): string

Defined in: core/src/context/context.ts:319

Stroke style (CSS color, gradient, or pattern) used to paint outlines.

Returns

string

Set Signature

set stroke(value): void

Defined in: core/src/context/context.ts:323

Stroke style (CSS color, gradient, or pattern) used to paint outlines.

Parameters

Parameter	Type
value	string

Returns

void

Stroke style (CSS color, gradient, or pattern) used to paint outlines.

Inherited from

Context.stroke

---

supportsPathCaching

Get Signature

get supportsPathCaching(): boolean

Defined in: terminal/src/context.ts:203

Terminal paths are inert command recorders, so a cached path stays valid across frames.

Returns

boolean

Overrides

Context.supportsPathCaching

---

textAlign

Get Signature

get textAlign(): TextAlignment

Defined in: core/src/context/context.ts:328

Horizontal alignment of text relative to the drawing position.

Returns

TextAlignment

Set Signature

set textAlign(value): void

Defined in: core/src/context/context.ts:332

Horizontal alignment of text relative to the drawing position.

Parameters

Parameter	Type
value	TextAlignment

Returns

void

Horizontal alignment of text relative to the drawing position.

Inherited from

Context.textAlign

---

textBaseline

Get Signature

get textBaseline(): TextBaseline

Defined in: core/src/context/context.ts:337

Vertical baseline used when positioning text.

Returns

TextBaseline

Set Signature

set textBaseline(value): void

Defined in: core/src/context/context.ts:341

Vertical baseline used when positioning text.

Parameters

Parameter	Type
value	TextBaseline

Returns

void

Vertical baseline used when positioning text.

Inherited from

Context.textBaseline

---

transformOriginX

Get Signature

get transformOriginX(): TransformOrigin

Defined in: core/src/context/context.ts:400

Horizontal origin about which rotation and scaling are applied.

Returns

TransformOrigin

Set Signature

set transformOriginX(value): void

Defined in: core/src/context/context.ts:404

Horizontal origin about which rotation and scaling are applied.

Parameters

Parameter	Type
value	TransformOrigin

Returns

void

Horizontal origin about which rotation and scaling are applied.

Inherited from

Context.transformOriginX

---

transformOriginY

Get Signature

get transformOriginY(): TransformOrigin

Defined in: core/src/context/context.ts:409

Vertical origin about which rotation and scaling are applied.

Returns

TransformOrigin

Set Signature

set transformOriginY(value): void

Defined in: core/src/context/context.ts:413

Vertical origin about which rotation and scaling are applied.

Parameters

Parameter	Type
value	TransformOrigin

Returns

void

Vertical origin about which rotation and scaling are applied.

Inherited from

Context.transformOriginY

---

transformScaleX

Get Signature

get transformScaleX(): number

Defined in: core/src/context/context.ts:373

Horizontal scale factor applied to the element's transform.

Returns

number

Set Signature

set transformScaleX(value): void

Defined in: core/src/context/context.ts:377

Horizontal scale factor applied to the element's transform.

Parameters

Parameter	Type
value	number

Returns

void

Horizontal scale factor applied to the element's transform.

Inherited from

Context.transformScaleX

---

transformScaleY

Get Signature

get transformScaleY(): number

Defined in: core/src/context/context.ts:382

Vertical scale factor applied to the element's transform.

Returns

number

Set Signature

set transformScaleY(value): void

Defined in: core/src/context/context.ts:386

Vertical scale factor applied to the element's transform.

Parameters

Parameter	Type
value	number

Returns

void

Vertical scale factor applied to the element's transform.

Inherited from

Context.transformScaleY

---

translateX

Get Signature

get translateX(): number

Defined in: core/src/context/context.ts:355

Horizontal translation, in pixels, applied to the element's transform.

Returns

number

Set Signature

set translateX(value): void

Defined in: core/src/context/context.ts:359

Horizontal translation, in pixels, applied to the element's transform.

Parameters

Parameter	Type
value	number

Returns

void

Horizontal translation, in pixels, applied to the element's transform.

Inherited from

Context.translateX

---

translateY

Get Signature

get translateY(): number

Defined in: core/src/context/context.ts:364

Vertical translation, in pixels, applied to the element's transform.

Returns

number

Set Signature

set translateY(value): void

Defined in: core/src/context/context.ts:368

Vertical translation, in pixels, applied to the element's transform.

Parameters

Parameter	Type
value	number

Returns

void

Vertical translation, in pixels, applied to the element's transform.

Inherited from

Context.translateY

---

zIndex

Get Signature

get zIndex(): number

Defined in: core/src/context/context.ts:346

Stacking order used to sort elements during rendering; higher values draw on top.

Returns

number

Set Signature

set zIndex(value): void

Defined in: core/src/context/context.ts:350

Stacking order used to sort elements during rendering; higher values draw on top.

Parameters

Parameter	Type
value	number

Returns

void

Stacking order used to sort elements during rendering; higher values draw on top.

Inherited from

Context.zIndex

Methods

applyClip()

applyClip(path, fillRule?): void

Defined in: terminal/src/context.ts:485

Confines subsequent drawing to the given path, intersected with any clip already in force.

Parameters

Parameter	Type	Description
path	ContextPath	The clip geometry.
fillRule?	FillRule	Accepted for signature compatibility; the scanline rasterizer implements only the even-odd rule.

Returns

void

Overrides

Context.applyClip

---

applyFill()

applyFill(element, fillRule?): void

Defined in: terminal/src/context.ts:440

Rasterizes and fills the given path or text element using the current fill color, composited with the current opacity. A paint that resolves to nothing (none, transparent, or zero effective alpha) draws nothing at all.

Parameters

Parameter	Type
element	ContextElement
fillRule?	FillRule

Returns

void

Overrides

Context.applyFill

---

applyGroupPaint()

protected applyGroupPaint(group): void

Defined in: core/src/context/context.ts:603

Applies a group's own inherited paint (fill, stroke, opacity, font, line, shadow, text) to the context so descendants pick it up from the copied state. Transforms are applied separately, so they are skipped here.

Two boundary semantics are fixed here and every backend must honour them:

• Opacity composites multiplicatively. CONTEXT_OPERATIONS multiplies rather than assigns, so nested groups compound and a leaf's own alpha stacks under its ancestors' instead of replacing it.
• A group's gradient or pattern resolves against the group's own box. The group is the Context.currentRenderElement for the duration of the boundary, so a paint that bakes geometry at set time (canvas) and one that resolves it per leaf (SVG) agree on the same reference box: group.getBoundingBox(true), never a sibling's and never the surface.

Parameters

Parameter	Type
group	Element

Returns

void

Inherited from

Context.applyGroupPaint

---

applyStroke()

applyStroke(element): void

Defined in: terminal/src/context.ts:461

Rasterizes and strokes the given path or text element's outline using the current stroke color, composited with the current opacity. Stroked text is drawn as its glyphs in the stroke color, since a character cell has no outline to trace.

Parameters

Parameter	Type
element	ContextElement

Returns

void

Overrides

Context.applyStroke

---

batch()

batch<TResult>(body): TResult

Defined in: core/src/context/context.ts:534

Clears the rendering surface and brackets the callback in markRenderStart/markRenderEnd, returning the callback's result. On exit the state stack is unwound to the depth captured on entry, giving the scene root the same guarantee Context.popGroup gives a group: a root-level clip: true shape deliberately skips its own restore() so the clip persists to later siblings, and with no enclosing group to absorb it that save would otherwise leak one state per frame, unbounded.

The surface is only cleared at render depth 0: a pass entered while an outer one is open continues it (matching Context.markRenderStart) rather than wiping what it drew.

Type Parameters

Type Parameter	Default type
TResult	void

Parameters

Parameter	Type
body	() => TResult

Returns

TResult

Inherited from

Context.batch

---

clear()

clear(): void

Defined in: terminal/src/context.ts:331

Homes the cursor and clears the rasterizer grid.

Returns

void

Overrides

Context.clear

---

createPath()

createPath(id?): TerminalPath

Defined in: terminal/src/context.ts:424

Creates a TerminalPath that records drawing commands for later rasterization.

Parameters

Parameter	Type
id?	string

Returns

TerminalPath

Overrides

Context.createPath

---

createText()

createText(options): ContextText

Defined in: terminal/src/context.ts:429

Creates a text element from the given options.

Parameters

Parameter	Type
options	TextOptions

Returns

ContextText

Overrides

Context.createText

---

destroy()

destroy(): void

Defined in: terminal/src/context.ts:580

Restores the terminal's SGR and cursor state before tearing the context down.

Returns

void

Overrides

Context.destroy

---

dispose()

protected dispose(key?): void

Defined in: core/src/core/disposer.ts:25

Disposes all resources under the given key, or all resources if no key is provided.

Parameters

Parameter	Type
key?	PropertyKey

Returns

void

Inherited from

Context.dispose

---

drawImage()

drawImage(image, x, y, width?, height?): void

Defined in: core/src/context/context.ts:748

Draws an image onto the rendering surface at the given position and optional size.

Parameters

Parameter	Type
image	CanvasImageSource
x	number
y	number
width?	number
height?	number

Returns

void

Inherited from

Context.drawImage

---

emit()

Call Signature

emit<TEvent>(event): TEvent

Defined in: core/src/core/event-bus.ts:185

Emits an event, invoking all matching handlers and bubbling to the parent if applicable. Handlers for the event's own type run first, then EVENT_WILDCARD subscriptions.

Type Parameters

Type Parameter	Default type
TEvent extends Event<undefined>	Event<undefined>

Parameters

Parameter	Type
event	TEvent

Returns

TEvent

Inherited from

Context.emit

Call Signature

emit<TEvent>(type, data): Event<ContextEventMap[TEvent]>

Defined in: core/src/core/event-bus.ts:186

Emits an event, invoking all matching handlers and bubbling to the parent if applicable. Handlers for the event's own type run first, then EVENT_WILDCARD subscriptions.

Type Parameters

Type Parameter
TEvent extends keyof ContextEventMap

Parameters

Parameter	Type
type	TEvent
data	ContextEventMap[TEvent]

Returns

Event<ContextEventMap[TEvent]>

Inherited from

Context.emit

---

export()

export(): ContextExport

Defined in: terminal/src/context.ts:557

Captures the current grid as a plain-text string, an openable URL, and RGBA image data. The URL is minted once and reused, so release() has a single object URL to revoke.

Returns

ContextExport

Overrides

Context.export

---

getDefaultState()

protected getDefaultState(): BaseState

Defined in: core/src/context/context.ts:446

Returns

BaseState

Inherited from

Context.getDefaultState

---

has()

has(type): boolean

Defined in: core/src/core/event-bus.ts:123

Returns whether there are any listeners registered for the given event type. Wildcard subscriptions (EVENT_WILDCARD) are not listeners for any concrete type, so a bus observed only through the wildcard still reports false here.

Parameters

Parameter	Type
type	keyof ContextEventMap

Returns

boolean

Inherited from

Context.has

---

hitTest()

protected hitTest(events, x, y): RenderElement[]

Defined in: core/src/context/context.ts:808

Tests which rendered elements intersect the given point for the given event types, returning them topmost-first — the exact reverse of the order they were painted in.

The point is in logical space — the space pointer event payloads report — so a handler passes the coordinates it was given straight through.

Paint order is the sole key. Context.renderedElements already records the resolved stacking order (groups paint as contiguous stacking contexts), whereas RenderElement.zIndex is additive across the parent chain and so says nothing about two descendants of different groups; sorting by it discarded correct information.

Parameters

Parameter	Type
events	string[]
x	number
y	number

Returns

RenderElement[]

Inherited from

Context.hitTest

---

invalidateTrackedElements()

invalidateTrackedElements(event?): void

Defined in: core/src/context/context.ts:496

Clears the cached list of tracked elements for interaction, forcing a rebuild on the next hit test.

Parameters

Parameter	Type
event?	string

Returns

void

Inherited from

Context.invalidateTrackedElements

---

isPointInPath()

isPointInPath(path, x, y, fillRule?): boolean

Defined in: terminal/src/context.ts:507

Tests whether a logical-space point falls inside the given path.

Parameters

Parameter	Type	Description
path	ContextPath	The path to test against.
x	number	X coordinate in logical space.
y	number	Y coordinate in logical space.
fillRule?	FillRule	The fill rule to apply. Defaults to nonzero, as canvas does.

Returns

boolean

true when the point is inside the path.

Overrides

Context.isPointInPath

---

isPointInStroke()

isPointInStroke(path, x, y): boolean

Defined in: terminal/src/context.ts:523

Tests whether a logical-space point falls on the given path's stroke.

Parameters

Parameter	Type	Description
path	ContextPath	The path to test against.
x	number	X coordinate in logical space.
y	number	Y coordinate in logical space.

Returns

boolean

true when the point is on the stroke.

Overrides

Context.isPointInStroke

---

layer()

layer<TResult>(body): TResult

Defined in: core/src/context/context.ts:472

Executes a callback within a save/restore pair, returning the callback's result.

Type Parameters

Type Parameter	Default type
TResult	void

Parameters

Parameter	Type
body	() => TResult

Returns

TResult

Inherited from

Context.layer

---

markRenderEnd()

markRenderEnd(): void

Defined in: terminal/src/context.ts:415

Ends the render pass and, at the outermost depth, flushes the rasterized output to the terminal.

Returns

void

Overrides

Context.markRenderEnd

---

markRenderStart()

markRenderStart(): void

Defined in: core/src/context/context.ts:510

Signals the start of a render pass; resets the rendered-elements list at depth 0.

Returns

void

Inherited from

Context.markRenderStart

---

measureText()

measureText(text): TextMetrics

Defined in: terminal/src/context.ts:532

Measures text in logical units, sizing each glyph to one character cell.

Parameters

Parameter	Type
text	string

Returns

TextMetrics

Overrides

Context.measureText

---

off()

off<TEvent>(type, handler): void

Defined in: core/src/core/event-bus.ts:144

Removes a previously registered handler for the given event type.

Type Parameters

Type Parameter
TEvent extends keyof ContextEventMap

Parameters

Parameter	Type
type	TEvent
handler	EventHandler<ContextEventMap[TEvent]>

Returns

void

Inherited from

Context.off

---

on()

on<TEvent>(type, handler, options?): Disposable

Defined in: core/src/core/event-bus.ts:131

Subscribes a handler to the given event type and returns a disposable for cleanup. Pass EVENT_WILDCARD to receive every event emitted on the bus regardless of type.

Type Parameters

Type Parameter
TEvent extends keyof ContextEventMap

Parameters

Parameter	Type
type	TEvent
handler	EventHandler<ContextEventMap[TEvent]>
options?	EventSubscriptionOptions

Returns

Disposable

Inherited from

Context.on

---

once()

once<TEvent>(type, handler, options?): Disposable

Defined in: core/src/core/event-bus.ts:159

Subscribes a handler that is automatically removed after it fires once.

Type Parameters

Type Parameter
TEvent extends keyof ContextEventMap

Parameters

Parameter	Type
type	TEvent
handler	EventHandler<ContextEventMap[TEvent]>
options?	EventSubscriptionOptions

Returns

Disposable

Inherited from

Context.once

---

popGroup()

popGroup(): void

Defined in: core/src/context/context.ts:620

Closes the most recently opened group boundary, unwinding the state stack back to the depth captured at Context.pushGroup and restoring the render element that was current before it. This absorbs any dangling save() left by a group-scoped clip (which deliberately skips its own restore so the clip persists to later siblings), confining the clip to the group rather than leaking it to the scene.

Returns

void

Inherited from

Context.popGroup

---

pushGroup()

pushGroup(group): void

Defined in: core/src/context/context.ts:573

Opens a group boundary: saves the current drawing state and applies the group's own transform and inherited paint (see applyGroupPaint for the opacity and gradient-bounds semantics every backend must honour), so that descendant elements render within the group's coordinate system, inherit its paint through the copied state (the render-tree cascade), and composite under its opacity. Any group-scoped clip is confined to the group. Every Context.pushGroup must be balanced by a matching Context.popGroup. Backends that render hierarchy structurally (such as SVG) override this to nest descendants under a group node.

Parameters

Parameter	Type	Description
group	Element	The group element whose boundary is being entered.

Returns

void

Inherited from

Context.pushGroup

---

requestRender()

requestRender(): void

Defined in: core/src/context/context.ts:505

Requests that the bound scene repaint on the next frame, for context-level changes (e.g. a 3D camera move) that mutate no element and so would otherwise be skipped by the renderer's dirty check.

Returns

void

Inherited from

Context.requestRender

---

rescale()

protected rescale(width, height): void

Defined in: terminal/src/context.ts:294

Installs the letterbox mapping and reports the new size. The base implementation resets scaleX/scaleY to identity and then emits resize, which a bound scene handles by repainting synchronously — so the mapping has to be complete before the emit, or that repaint places points with the old scales and extents with the new one.

Parameters

Parameter	Type
width	number
height	number

Returns

void

Overrides

Context.rescale

---

reset()

reset(): void

Defined in: terminal/src/context.ts:356

Resets the drawing state, the saved-state stack, the transform, the clip region, and the character grid.

Returns

void

Overrides

Context.reset

---

restore()

restore(): void

Defined in: terminal/src/context.ts:344

Restores the drawing state, the transform, and the clip region saved most recently.

Returns

void

Overrides

Context.restore

---

retain()

protected retain(value, key?): void

Defined in: core/src/core/disposer.ts:14

Registers a disposable resource under an optional key for later cleanup.

Parameters

Parameter	Type	Default value
value	Disposable	undefined
key	PropertyKey	Disposer.defaultKey

Returns

void

Inherited from

Context.retain

---

rotate()

rotate(angle): void

Defined in: terminal/src/context.ts:368

Applies a rotation transformation, in radians.

Parameters

Parameter	Type
angle	number

Returns

void

Overrides

Context.rotate

---

save()

save(): void

Defined in: terminal/src/context.ts:337

Pushes the drawing state, the current transform, and the clip region onto the saved-state stack.

Returns

void

Overrides

Context.save

---

scale()

scale(x, y): void

Defined in: terminal/src/context.ts:373

Applies a scale transformation with the given horizontal and vertical factors.

Parameters

Parameter	Type
x	number
y	number

Returns

void

Overrides

Context.scale

---

setTransform()

setTransform(a, b, c, d, e, f): void

Defined in: terminal/src/context.ts:396

Replaces the current transformation matrix.

The matrix is in logical space, and this backend keeps its letterbox outside the transform, so the identity restores the context's own baseline with nothing to recompose underneath.

Parameters

Parameter	Type	Description
a	number	Horizontal scaling.
b	number	Vertical skewing.
c	number	Horizontal skewing.
d	number	Vertical scaling.
e	number	Horizontal translation, in logical units.
f	number	Vertical translation, in logical units.

Returns

void

Overrides

Context.setTransform

---

toLogicalPoint()

toLogicalPoint(x, y): [number, number]

Defined in: terminal/src/context.ts:314

Maps a point from the braille raster grid back into the logical space elements are authored in, undoing the letterbox mapping TerminalContext.rescale installs.

The base implementation reads only the slope of scaleX/scaleY and so would drop the centring offset, placing a hit test on the non-limiting axis by the letterbox margin.

Parameters

Parameter	Type	Description
x	number	X coordinate in raster space.
y	number	Y coordinate in raster space.

Returns

[number, number]

The [x, y] pair in logical space.

Overrides

Context.toLogicalPoint

---

toSurfacePoint()

toSurfacePoint(x, y): [number, number]

Defined in: terminal/src/context.ts:326

Maps a point from logical space into the braille raster grid, matching what scaleX/scaleY do when drawing. The inverse of TerminalContext.toLogicalPoint.

Parameters

Parameter	Type	Description
x	number	X coordinate in logical space.
y	number	Y coordinate in logical space.

Returns

[number, number]

The [x, y] pair in raster space.

Overrides

Context.toSurfacePoint

---

transform()

transform(a, b, c, d, e, f): void

Defined in: terminal/src/context.ts:410

Multiplies the current transformation matrix by the given one.

Parameters

Parameter	Type	Description
a	number	Horizontal scaling.
b	number	Vertical skewing.
c	number	Horizontal skewing.
d	number	Vertical scaling.
e	number	Horizontal translation, in logical units.
f	number	Vertical translation, in logical units.

Returns

void

Overrides

Context.transform

---

translate()

translate(x, y): void

Defined in: terminal/src/context.ts:378

Applies a translation transformation, in logical units.

Parameters

Parameter	Type
x	number
y	number

Returns

void

Overrides

Context.translate