Contour Labels (canvas)Coordinated mapsgeoformatSmall circle testKruskal MazeAll the geoshapesReprojecting Vector TilesCloud ContoursHello h3-jsClipping AlbersTranslucent EarthThe truth about the Mercator projectionUsing d3-inertia with observableMercator projection of a Mercator globeD3 Vector Tiles (WIP)Finding intersections between the graticule and the clip sphere of the stereographic projection, method 2Plate tectonicsAnother hex mapEquateur & tropiquesTissot's indicatrixDistance to shoreMultiPolygon clippingSouth Africa’s medial axisSpherical intersectionVolcano Semis (points circulaires)Pencil Airocean45° mapNetCDFBlue noise sphereRubber DymaxionSpherical quasi-random (R2) distributionAutomated label placement (countries)Automated label placement (France)Automated label placement (cities)d3.geoIntersectArcDelaunay.findTriangled3-geo-voronoi and gridded dataElevation vtk.jsMapfillKrigingSpherical HeatmapReproject elevation tiles — detailReproject elevation tiles — worldFisheye Conformal MapSpherical KDE InterpolationSpherical kernel interpolation with nearest neighborsShepard’s methodModified Shepard’s methodSpherical contoursGeo Voronoi interpolationBlurry contoursHow much warmer? (BBC)H3 hexagons & geoContoursHillshading & supersamplingH3 odditiesManhattan VoronoiManhattan Voronoi IIGeoJSON feature editorColorized Manhattan Spanning Treelegra mapslegra country mapsThe complex logarithm projectionCountries small multipleThe 2D approximate Newton-Raphson methodOceanAttitudeCount visible objectsThe Gray-Fuller spatial gridGray-Fuller grid metricsGray-Fuller grid odditiesSpherical smallest-circle problemBounding CirclesCountries Enclosing CirclesFullscreen Seamless Zoomable Map TilesMap Pan & ZoomSpherical EllipsesSynchronized projectionsThe closest countryTriangular tiling of icosahedronHello, polygon-clippingCorées / KoreasHello, procedural-glHello, placekeyZoom World ChoroplethClipping spherical polygonsSpherical phyllotaxisFour-color world map with ClingoHello, jsgeoda!The Sun’s analemmaWorld of squaresWorld of squares (spherical)A map of AfricaTagged bordersClipped geoVoronoiBlue noise sphere IISpherical Perlin NoiseSpherical Delaunay triangulationDynamic simplificationPlot: Voronoi labelsAoC 12: shortest path under constraintsHello, pixi.jsFlight PathsRay out of a convex hullDistance to a segment
Rewind
// a simple duck test for projections and GeoJSON
function rewind(duck, simple) {
return duck?.stream
? geoRewindProjection(duck, simple)
: duck?.type
? geoRewindFeature(duck, simple)
: Array.isArray(duck)
? Array.from(duck, (d) => rewind(d, simple))
: duck;
}
geoRewindFeature = (feature, simple) =>
geoProjectSimple(feature, geoRewindStream(simple))
d3.geoArea(shape) - d3.geoArea(rewind(shape))
rewind(shape)
geoRewindProjection = (projection, simple) => {
const { stream: normalize } = geoRewindStream(simple);
return { stream: (s) => normalize(projection.stream(s)) };
}
function geoRewindStream(simple = true) {
const { geoContains, geoArea } = d3;
let ring, polygon;
return d3.geoTransform({
polygonStart() {
this.stream.polygonStart();
polygon = [];
},
lineStart() {
if (polygon) polygon.push((ring = []));
else this.stream.lineStart();
},
lineEnd() {
if (!polygon) this.stream.lineEnd();
},
point(x, y) {
if (polygon) ring.push([x, y]);
else this.stream.point(x, y);
},
polygonEnd() {
for (let [i, ring] of polygon.entries()) {
ring.push(ring[0].slice());
if (
i
? // a hole must contain the first point of the polygon
!geoContains(
{ type: "Polygon", coordinates: [ring] },
polygon[0][0]
)
: polygon[1]
? // the outer ring must contain the first point of its first hole (if any)
!geoContains(
{ type: "Polygon", coordinates: [ring] },
polygon[1][0]
)
: // a single ring polygon must be smaller than a hemisphere (optional)
simple &&
geoArea({ type: "Polygon", coordinates: [ring] }) > 2 * Math.PI
) {
ring.reverse();
}
this.stream.lineStart();
ring.pop();
for (const [x, y] of ring) this.stream.point(x, y);
this.stream.lineEnd();
}
this.stream.polygonEnd();
polygon = null;
}
});
}
geoProjectSimple = {
const { geoStream } = d3;
return function (object, projection) {
const stream = projection.stream;
let project;
if (!stream) throw new Error("invalid projection");
switch (object && object.type) {
case "Feature":
project = projectFeature;
break;
case "FeatureCollection":
project = projectFeatureCollection;
break;
default:
project = projectGeometry;
break;
}
return project(object, stream);
};
function projectFeatureCollection(o, stream) {
return { ...o, features: o.features.map((f) => projectFeature(f, stream)) };
}
function projectFeature(o, stream) {
return { ...o, geometry: projectGeometry(o.geometry, stream) };
}
function projectGeometryCollection(o, stream) {
return {
...o,
geometries: o.geometries.map((o) => projectGeometry(o, stream))
};
}
function projectGeometry(o, stream) {
return !o
? null
: o.type === "GeometryCollection"
? projectGeometryCollection(o, stream)
: o.type === "Polygon" || o.type === "MultiPolygon"
? projectPolygons(o, stream)
: o;
}
function projectPolygons(o, stream) {
let coordinates = [];
let polygon, line;
geoStream(
o,
stream({
polygonStart() {
coordinates.push((polygon = []));
},
polygonEnd() {},
lineStart() {
polygon.push((line = []));
},
lineEnd() {
line.push(line[0].slice());
},
point(x, y) {
line.push([x, y]);
}
})
);
if (o.type === "Polygon") coordinates = coordinates[0];
return { ...o, coordinates, rewind: true };
}
}
import { ocean } from "@fil/ocean"
import { zoom } from "@d3/versor-zooming"
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