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