Interface TopDownFrame

The synthetic overhead frame built by buildTopDownFrame.

interface TopDownFrame {
    metresPerPixel: number;
    mvpWorld: Mat4;
    viewportHeight: number;
    viewportWidth: number;
    depth01FromHeightM(m: number): number;
    heightM(depth01: number): number;
    toPixel(lng: number, lat: number): [number, number];
}

Properties

metresPerPixel: number

Ground resolution of the grid, metres per pixel (the long axis).

mvpWorld: Mat4

Mercator-world → clip: an orthographic top-down projection over the stations' bbox.

viewportHeight: number

Grid height in pixels.

viewportWidth: number

Grid width in pixels.

depth01FromHeightM(m: number): number
The window depth a height maps to — the inverse of heightM, and the minDepth01 depth gate that turns this pass into "the highest surface BELOW m" (higher surfaces are nearer, so they sit at smaller depths). Clamped to [0, 1].
Parameters
- m: number
Returns number

heightM(depth01: number): number
Decode a window depth from the pass into metres above the map's zero.
Parameters
- depth01: number
Returns number