Function projectLngLatHeightToCss

projectLngLatHeightToCss(
    frameMatrix: Mat4,
    cssWidth: number,
    cssHeight: number,
    lng: number,
    lat: number,
    height: number,
): [number, number] | null
Project a 3D geographic position through a frame matrix to CSS-pixel screen coordinates — the height-aware complement of map.project (which is ground-level only). Pure math, no GL.
Parameters
- frameMatrix: Mat4
  The mercator-world → clip matrix (MapLibre's mainMatrix, f64).
- cssWidth: number
  Canvas width in CSS pixels.
- cssHeight: number
  Canvas height in CSS pixels.
- lng: number
  Longitude in degrees.
- lat: number
  Latitude in degrees.
- height: number
  Metres above the rendered ground datum (mercator z=0).
Returns [number, number] | null
[x, y] in CSS pixels (top-left origin), or null when behind the camera.