| import {range} from "d3-array"; |
| import {abs, ceil, epsilon} from "./math.js"; |
|
|
| function graticuleX(y0, y1, dy) { |
| var y = range(y0, y1 - epsilon, dy).concat(y1); |
| return function(x) { return y.map(function(y) { return [x, y]; }); }; |
| } |
|
|
| function graticuleY(x0, x1, dx) { |
| var x = range(x0, x1 - epsilon, dx).concat(x1); |
| return function(y) { return x.map(function(x) { return [x, y]; }); }; |
| } |
|
|
| export default function graticule() { |
| var x1, x0, X1, X0, |
| y1, y0, Y1, Y0, |
| dx = 10, dy = dx, DX = 90, DY = 360, |
| x, y, X, Y, |
| precision = 2.5; |
|
|
| function graticule() { |
| return {type: "MultiLineString", coordinates: lines()}; |
| } |
|
|
| function lines() { |
| return range(ceil(X0 / DX) * DX, X1, DX).map(X) |
| .concat(range(ceil(Y0 / DY) * DY, Y1, DY).map(Y)) |
| .concat(range(ceil(x0 / dx) * dx, x1, dx).filter(function(x) { return abs(x % DX) > epsilon; }).map(x)) |
| .concat(range(ceil(y0 / dy) * dy, y1, dy).filter(function(y) { return abs(y % DY) > epsilon; }).map(y)); |
| } |
|
|
| graticule.lines = function() { |
| return lines().map(function(coordinates) { return {type: "LineString", coordinates: coordinates}; }); |
| }; |
|
|
| graticule.outline = function() { |
| return { |
| type: "Polygon", |
| coordinates: [ |
| X(X0).concat( |
| Y(Y1).slice(1), |
| X(X1).reverse().slice(1), |
| Y(Y0).reverse().slice(1)) |
| ] |
| }; |
| }; |
|
|
| graticule.extent = function(_) { |
| if (!arguments.length) return graticule.extentMinor(); |
| return graticule.extentMajor(_).extentMinor(_); |
| }; |
|
|
| graticule.extentMajor = function(_) { |
| if (!arguments.length) return [[X0, Y0], [X1, Y1]]; |
| X0 = +_[0][0], X1 = +_[1][0]; |
| Y0 = +_[0][1], Y1 = +_[1][1]; |
| if (X0 > X1) _ = X0, X0 = X1, X1 = _; |
| if (Y0 > Y1) _ = Y0, Y0 = Y1, Y1 = _; |
| return graticule.precision(precision); |
| }; |
|
|
| graticule.extentMinor = function(_) { |
| if (!arguments.length) return [[x0, y0], [x1, y1]]; |
| x0 = +_[0][0], x1 = +_[1][0]; |
| y0 = +_[0][1], y1 = +_[1][1]; |
| if (x0 > x1) _ = x0, x0 = x1, x1 = _; |
| if (y0 > y1) _ = y0, y0 = y1, y1 = _; |
| return graticule.precision(precision); |
| }; |
|
|
| graticule.step = function(_) { |
| if (!arguments.length) return graticule.stepMinor(); |
| return graticule.stepMajor(_).stepMinor(_); |
| }; |
|
|
| graticule.stepMajor = function(_) { |
| if (!arguments.length) return [DX, DY]; |
| DX = +_[0], DY = +_[1]; |
| return graticule; |
| }; |
|
|
| graticule.stepMinor = function(_) { |
| if (!arguments.length) return [dx, dy]; |
| dx = +_[0], dy = +_[1]; |
| return graticule; |
| }; |
|
|
| graticule.precision = function(_) { |
| if (!arguments.length) return precision; |
| precision = +_; |
| x = graticuleX(y0, y1, 90); |
| y = graticuleY(x0, x1, precision); |
| X = graticuleX(Y0, Y1, 90); |
| Y = graticuleY(X0, X1, precision); |
| return graticule; |
| }; |
|
|
| return graticule |
| .extentMajor([[-180, -90 + epsilon], [180, 90 - epsilon]]) |
| .extentMinor([[-180, -80 - epsilon], [180, 80 + epsilon]]); |
| } |
|
|
| export function graticule10() { |
| return graticule()(); |
| } |
|
|
