# Interface: Borders

GPU-ready world border geometry consumed directly by the renderer.

## Remarks

`vertices` is interleaved in `BORDER_VERTEX_STRIDE_BYTES` chunks:
- bytes 0..7: longitude and latitude as f32 degrees.
- bytes 8..19: unit-sphere ECEF x/y/z as f32.
- bytes 20..23: render layer as u32. Layer `0` is coastline, `1` is a
  major administrative boundary, and `2` is a minor administrative
  boundary; other layers are accepted but render with the fallback tier.

`indices` contains u32 line-strip indices. Independent polylines are
separated by the `0xffffffff` primitive-restart sentinel.

## Properties

| Property | Modifier | Type | Description |
| :------ | :------ | :------ | :------ |
| <a id="property-indices"></a> `indices` | `readonly` | `Uint32Array`\<`ArrayBuffer`\> | U32 line-strip indices with primitive-restart separators. |
| <a id="property-vertices"></a> `vertices` | `readonly` | `Uint8Array`\<`ArrayBuffer`\> | Interleaved vertex bytes in the border vertex layout. |