# Constants

Import these from `@grafloria/engine`.

## Constants

### `DEFAULT_GROUP_HEADER_HEIGHT`

```ts
const DEFAULT_GROUP_HEADER_HEIGHT: 24
```

### `DEFAULT_GROUP_PADDING`

Defaults for groups AUTHORED in code (constructor path). A fitted frame needs
breathing room and a title band or its label lands under the first member. Loaded documents are exempt: restore assigns the stored values (padding
verbatim — possibly undefined, which getPadding() resolves to 0 — and
headerHeight number-or-0), so legacy geometry is byte-stable.

```ts
const DEFAULT_GROUP_PADDING: 16
```

### `DEFAULT_PORT_SNAP_RADIUS`

How near a port must be to a point for {@link DiagramModel.findNearestPort} to
consider it, in world units. Roughly a fingertip at 100% zoom.

```ts
const DEFAULT_PORT_SNAP_RADIUS: 24
```

### `DEFAULT_SIMPLIFY_EPSILON`

Douglas-Peucker tolerance, in WORLD units.

0.6 is tuned against real traces: below ~0.4 you keep the sensor jitter you were
trying to remove; above ~1.2 a deliberate small loop (the dot of an "i", a tick) starts
to visibly flatten. At 0.6 a 500-point scribble lands around 40-70 points and is
indistinguishable from the raw trace at 100% zoom.

It is world-space, so ink drawn while zoomed OUT is simplified more aggressively in
screen terms — which is right: you cannot see detail you did not draw.

```ts
const DEFAULT_SIMPLIFY_EPSILON: 0.6
```

### `DEFAULT_STROKE_STYLE`

```ts
const DEFAULT_STROKE_STYLE: StrokeStyle
```

### `LINK_LABEL_SLOT_POSITIONS`

Where each of the three edge label SLOTS sits
along the path.

Pulled IN from the endpoints on purpose: at exactly 0 and 1 a slot label would
land under the arrowhead and on top of the port. 0.12 / 0.88 clears both while
still reading as "at the start / at the end of this edge".

ONE definition, shared by the model (LinkModel.addLabel), the renderer
(LabelRenderer) and the edge optimizer — three places that must never disagree
about where a label actually is.

```ts
const LINK_LABEL_SLOT_POSITIONS: Record<'start' | 'center' | 'end', number>
```