# Constants

Import these from `@grafloria/renderer`.

## Constants

### `BUILTIN_ICONS`

Grafloria's line icons, 24×24, stroked (never filled). Drawn by hand for this
library — the five Mermaid architecture-beta names. An href icon must be a
raster data URI (SVG data URIs are refused: SVG can carry script), so vector
icons are these paths, not user data.

```ts
const BUILTIN_ICONS: Readonly<Record<string, readonly string[]>>
```

### `DEFAULT_ARROW_RADIUS`

```ts
const DEFAULT_ARROW_RADIUS: 10
```

### `DEFAULT_ENDPOINT_RADIUS`

```ts
const DEFAULT_ENDPOINT_RADIUS: 8
```

### `DEFAULT_HTML_LABEL_HEIGHT`

```ts
const DEFAULT_HTML_LABEL_HEIGHT: 28
```

### `DEFAULT_HTML_LABEL_WIDTH`

Default box for an HTML / template label (a `foreignObject` needs a size).

```ts
const DEFAULT_HTML_LABEL_WIDTH: 120
```

### `DEFAULT_LABEL_HEIGHT`

```ts
const DEFAULT_LABEL_HEIGHT: 18
```

### `DEFAULT_LABEL_WIDTH`

```ts
const DEFAULT_LABEL_WIDTH: 40
```

### `DEFAULT_LINK_HIT_AREA_WIDTH`

Default width of the SVG renderer's transparent interaction stroke.

```ts
const DEFAULT_LINK_HIT_AREA_WIDTH: 12
```

### `DEFAULT_LINK_HIT_TOLERANCE`

Grab distance (WORLD units) for a link body — "how close to the line counts
as clicking it".

Exported because it is now a CROSS-BACKEND contract, not an implementation
detail of one hit path: `InteractionController` applies it to resolve a link
in SVG mode, and the Canvas backend strokes each link's pick region with
exactly `2 x` this width on the colour-keyed hit canvas. If the two ever
disagreed, switching backend would change which link is under the cursor. (It was previously a bare `5` inlined in the controller.)

This is the FLOOR, not the whole contract — see {@link linkBodyHitTolerance}.

```ts
const DEFAULT_LINK_HIT_TOLERANCE: 5
```

### `DEFAULT_PARALLEL_SPACING`

Default gap between adjacent links of a parallel bundle.

```ts
const DEFAULT_PARALLEL_SPACING: 16
```

### `DEFAULT_SELF_LOOP_SIZE`

Default self-loop bulge / lateral span / per-loop growth.

```ts
const DEFAULT_SELF_LOOP_SIZE: 40
```

### `DEFAULT_SELF_LOOP_SPACING`

```ts
const DEFAULT_SELF_LOOP_SPACING: 18
```

### `GRAFLORIA_BASE_STYLE_ID`

Id of the SHARED stylesheet: the theme-independent, `var(--grafloria-*)`-based
rules. Identical for every renderer on the page, so it is injected once and
deduped by this id — instances only own their tiny variable block.

```ts
const GRAFLORIA_BASE_STYLE_ID: "grafloria-renderer-styles"
```

### `GRAFLORIA_INSTANCE_OVERRIDE_PREFIX`

Prefix of a renderer's OVERRIDE `<style>` element — the design-token bridge and
the accessibility media queries.

A SEPARATE element from the theme block, and always inserted after it, because
the cascade inside the variables is the whole mechanism:
  theme values  <  host design tokens  <  prefers-contrast  <  forced-colors
Same selector, same specificity — so only SOURCE ORDER decides, and source
order is only guaranteed if we own it.

```ts
const GRAFLORIA_INSTANCE_OVERRIDE_PREFIX: "grafloria-renderer-overrides-"
```

### `GRAFLORIA_INSTANCE_STYLE_PREFIX`

Prefix of a renderer's own `<style>` element id (one per instance).

```ts
const GRAFLORIA_INSTANCE_STYLE_PREFIX: "grafloria-renderer-theme-"
```

### `ROUTE_INFLUENCE_PAD`

How far outside a link's routed bounding box an obstacle can still have shaped
that route. The router pushes off the port by `gapOffset` (30), keeps
`obstacleMargin` (20) clearance from every body, and moves on a `gridSize`
(10) lattice — so an obstacle that shaped this route is within ~60 units of
it. 80 buys margin over that without pulling in half the diagram.

This is the one approximation in the cache, and it is deliberately generous:
being too eager here costs a re-route, being too clever costs a wrong route.

```ts
const ROUTE_INFLUENCE_PAD: 80
```