| import {abs, atan2, cos, epsilon, pi, sign, sin, sqrt} from "../math.js"; |
| import {conicProjection} from "./conic.js"; |
| import {equirectangularRaw} from "./equirectangular.js"; |
|
|
| export function conicEquidistantRaw(y0, y1) { |
| var cy0 = cos(y0), |
| n = y0 === y1 ? sin(y0) : (cy0 - cos(y1)) / (y1 - y0), |
| g = cy0 / n + y0; |
|
|
| if (abs(n) < epsilon) return equirectangularRaw; |
|
|
| function project(x, y) { |
| var gy = g - y, nx = n * x; |
| return [gy * sin(nx), g - gy * cos(nx)]; |
| } |
|
|
| project.invert = function(x, y) { |
| var gy = g - y, |
| l = atan2(x, abs(gy)) * sign(gy); |
| if (gy * n < 0) |
| l -= pi * sign(x) * sign(gy); |
| return [l / n, g - sign(n) * sqrt(x * x + gy * gy)]; |
| }; |
|
|
| return project; |
| } |
|
|
| export default function() { |
| return conicProjection(conicEquidistantRaw) |
| .scale(131.154) |
| .center([0, 13.9389]); |
| } |
|
|
