@visx/vendor
Version:
vendored packages for visx
91 lines (88 loc) • 3.41 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = void 0;
var _index = _interopRequireDefault(require("./index.js"));
var _math = require("../math.js");
function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
var _default = (0, _index.default)(function () {
return true;
}, clipAntimeridianLine, clipAntimeridianInterpolate, [-_math.pi, -_math.halfPi]); // Takes a line and cuts into visible segments. Return values: 0 - there were
// intersections or the line was empty; 1 - no intersections; 2 - there were
// intersections, and the first and last segments should be rejoined.
exports.default = _default;
function clipAntimeridianLine(stream) {
var lambda0 = NaN,
phi0 = NaN,
sign0 = NaN,
clean; // no intersections
return {
lineStart: function () {
stream.lineStart();
clean = 1;
},
point: function (lambda1, phi1) {
var sign1 = lambda1 > 0 ? _math.pi : -_math.pi,
delta = (0, _math.abs)(lambda1 - lambda0);
if ((0, _math.abs)(delta - _math.pi) < _math.epsilon) {
// line crosses a pole
stream.point(lambda0, phi0 = (phi0 + phi1) / 2 > 0 ? _math.halfPi : -_math.halfPi);
stream.point(sign0, phi0);
stream.lineEnd();
stream.lineStart();
stream.point(sign1, phi0);
stream.point(lambda1, phi0);
clean = 0;
} else if (sign0 !== sign1 && delta >= _math.pi) {
// line crosses antimeridian
if ((0, _math.abs)(lambda0 - sign0) < _math.epsilon) lambda0 -= sign0 * _math.epsilon; // handle degeneracies
if ((0, _math.abs)(lambda1 - sign1) < _math.epsilon) lambda1 -= sign1 * _math.epsilon;
phi0 = clipAntimeridianIntersect(lambda0, phi0, lambda1, phi1);
stream.point(sign0, phi0);
stream.lineEnd();
stream.lineStart();
stream.point(sign1, phi0);
clean = 0;
}
stream.point(lambda0 = lambda1, phi0 = phi1);
sign0 = sign1;
},
lineEnd: function () {
stream.lineEnd();
lambda0 = phi0 = NaN;
},
clean: function () {
return 2 - clean; // if intersections, rejoin first and last segments
}
};
}
function clipAntimeridianIntersect(lambda0, phi0, lambda1, phi1) {
var cosPhi0,
cosPhi1,
sinLambda0Lambda1 = (0, _math.sin)(lambda0 - lambda1);
return (0, _math.abs)(sinLambda0Lambda1) > _math.epsilon ? (0, _math.atan)(((0, _math.sin)(phi0) * (cosPhi1 = (0, _math.cos)(phi1)) * (0, _math.sin)(lambda1) - (0, _math.sin)(phi1) * (cosPhi0 = (0, _math.cos)(phi0)) * (0, _math.sin)(lambda0)) / (cosPhi0 * cosPhi1 * sinLambda0Lambda1)) : (phi0 + phi1) / 2;
}
function clipAntimeridianInterpolate(from, to, direction, stream) {
var phi;
if (from == null) {
phi = direction * _math.halfPi;
stream.point(-_math.pi, phi);
stream.point(0, phi);
stream.point(_math.pi, phi);
stream.point(_math.pi, 0);
stream.point(_math.pi, -phi);
stream.point(0, -phi);
stream.point(-_math.pi, -phi);
stream.point(-_math.pi, 0);
stream.point(-_math.pi, phi);
} else if ((0, _math.abs)(from[0] - to[0]) > _math.epsilon) {
var lambda = from[0] < to[0] ? _math.pi : -_math.pi;
phi = direction * lambda / 2;
stream.point(-lambda, phi);
stream.point(0, phi);
stream.point(lambda, phi);
} else {
stream.point(to[0], to[1]);
}
}