Reference · Markers on the globe
projectfunction
Project a longitude and latitude (degrees) to the screen. z is the cosine of the angle from the middle of the disc: above 0 the point faces
the viewer, below it is on the far side. North is up.
Import it
import { project } from "@johnmorrisdotca/chikyu-earth/markers";Definition
function project(lon: number, lat: number, pose: Pose): { x: number; y: number; z: number; }Parameters
| Name | Type | Description |
|---|---|---|
lon | number | Longitude in degrees east. |
lat | number | Latitude in degrees north. |
pose | Pose | The view. |
Returns
{ x: number; y: number; z: number; }
The point's x and y in pixels and z, the cosine of its angle from the middle of the disc.
Examples
import { project } from "@johnmorrisdotca/chikyu-earth/markers";
const where = project(139.69, 35.69, { lon: 139.69, lat: 35.69, radius: 200, cx: 210, cy: 210 });
console.log(where.x, where.y, where.z);210 210 1What it prints (run when this page was built)