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Adjust and document deltoidalHexecontahedral and rhombicDodecahedral.
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Fil committed Jun 10, 2024
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14 changes: 13 additions & 1 deletion README.md
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Expand Up @@ -96,7 +96,19 @@ The cubic projection.

[<img src="https://raw.githubusercontent.com/d3/d3-geo-polygon/main/test/snapshots/dodecahedral.png" width="480" height="250">](https://observablehq.com/@fil/dodecahedral-projection)

The dodecahedral projection.
The pentagonal dodecahedral projection.

<a href="#geoRhombicDodecahedral" name="geoRhombicDodecahedral">#</a> d3.<b>geoRhombicDodecahedral</b>() · [Source](https://github.com/d3/d3-geo-polygon/blob/main/src/polyhedral/rhombic.js), [Examples](https://observablehq.com/d/881a8431e638b408)

[<img src="https://raw.githubusercontent.com/d3/d3-geo-polygon/main/test/snapshots/rhombicDodecahedral.png" width="480" height="250">](https://observablehq.com/d/881a8431e638b408)

The rhombic dodecahedral projection.

<a href="#geoDeltoidalHexecontahedral" name="geoDeltoidalHexecontahedral">#</a> d3.<b>geoDeltoidalHexecontahedral</b>() · [Source](https://github.com/d3/d3-geo-polygon/blob/main/src/polyhedral/deltoidal.js), [Examples](https://observablehq.com/d/881a8431e638b408)

[<img src="https://raw.githubusercontent.com/d3/d3-geo-polygon/main/test/snapshots/deltoidalHexecontahedral.png" width="480" height="250">](https://observablehq.com/d/881a8431e638b408)

The deltoidal hexecontahedral projection.

<a href="#geoIcosahedral" name="geoIcosahedral">#</a> d3.<b>geoIcosahedral</b>() · [Source](https://github.com/d3/d3-geo-polygon/blob/main/src/icosahedral.js), [Examples](https://observablehq.com/@fil/icosahedral-projections)

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205 changes: 101 additions & 104 deletions src/deltoidal.js
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Expand Up @@ -8,16 +8,19 @@
*/
import { atan, degrees } from "./math.js";
import voronoi from "./polyhedral/voronoi.js";
import { geoCentroid, geoInterpolate } from "d3-geo";


export default function() {
export default function () {
var theta = atan(0.5) * degrees;

// construction inspired by
// https://en.wikipedia.org/wiki/Regular_icosahedron#Spherical_coordinates
var vertices = [[0, 90], [0, -90]].concat(
[0,1,2,3,4,5,6,7,8,9].map(function(i) {
var phi = (i * 36 + 180) % 360 - 180;
var vertices = [
[0, 90],
[0, -90],
].concat(
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9].map(function (i) {
var phi = ((i * 36 + 180) % 360) - 180;
return [phi, i & 1 ? theta : -theta];
})
);
Expand All @@ -43,126 +46,120 @@ export default function() {
[1, 4, 6],
[1, 6, 8],
[1, 8, 10],
[1, 10, 2] // South
].map(function(face) {
var t = face.map(function(i) {
[1, 10, 2], // South
].map(function (face) {
var t = face.map(function (i) {
return vertices[i];
});
// create 3 polygons from these using centroid and midpoints
var f1 = [
t[0],
d3.geoInterpolate(t[0],t[1])(0.5),
d3.geoCentroid({type:"MultiPoint", coordinates:t}),
d3.geoInterpolate(t[0],t[2])(0.5)
t[0],
geoInterpolate(t[0], t[1])(0.5),
geoCentroid({ type: "MultiPoint", coordinates: t }),
geoInterpolate(t[0], t[2])(0.5),
];
var f2 = [
t[1],
d3.geoInterpolate(t[1],t[2])(0.5),
d3.geoCentroid({type:"MultiPoint", coordinates:t}),
d3.geoInterpolate(t[1],t[0])(0.5)
t[1],
geoInterpolate(t[1], t[2])(0.5),
geoCentroid({ type: "MultiPoint", coordinates: t }),
geoInterpolate(t[1], t[0])(0.5),
];
var f3 = [
t[2],
d3.geoInterpolate(t[2],t[0])(0.5),
d3.geoCentroid({type:"MultiPoint", coordinates:t}),
d3.geoInterpolate(t[2],t[1])(0.5)
t[2],
geoInterpolate(t[2], t[0])(0.5),
geoCentroid({ type: "MultiPoint", coordinates: t }),
geoInterpolate(t[2], t[1])(0.5),
];
return [f1, f2, f3];
});

var polygons = {
type: "FeatureCollection",
features: polyhedron.flat().map(function(face) {
face.push(face[0]);
features: polyhedron.flat().map(function (face) {
return {
properties: { sitecoordinates: d3.geoCentroid({type:"MultiPoint", coordinates: face}) },
properties: {
sitecoordinates: geoCentroid({
type: "MultiPoint",
coordinates: face,
}),
},
geometry: {
type: "Polygon",
coordinates: [ face ]
}
coordinates: [[...face, face[0]]],
},
};
})
}),
};

var parents = [
-1, // 0
2, // 1
0, // 2
5, // 3
5, // 4
22, // 5
8, // 6
8, // 7
28, // 8
11, // 9
11, // 10
34, // 11
14, // 12
14, // 13
40, // 14
16, // 15
2, // 16
16, // 17
17, // 18
18, // 19
18, // 20
19, // 21
21, // 22
21, // 23
23, // 24
24, // 25
24, // 26
25, // 27
27, // 28
27, // 29
29, // 30
30, // 31
30, // 32
31, // 33
33, // 34
33, // 35
35, // 36
36, // 37
36, // 38
37, // 39
39, // 40
39, // 41
41, // 42
42, // 43
42, // 44
46, // 45
20, // 46
46, // 47
49, // 48
26, // 49
49, // 50
52, // 51
32, // 52
52, // 53
55, // 54
38, // 55
55, // 56
58, // 57
44, // 58
58, // 59
];
-1, // 0
2, // 1
0, // 2
5, // 3
5, // 4
22, // 5
8, // 6
8, // 7
28, // 8
11, // 9
11, // 10
34, // 11
14, // 12
14, // 13
40, // 14
16, // 15
2, // 16
16, // 17
17, // 18
18, // 19
18, // 20
19, // 21
21, // 22
21, // 23
23, // 24
24, // 25
24, // 26
25, // 27
27, // 28
27, // 29
29, // 30
30, // 31
30, // 32
31, // 33
33, // 34
33, // 35
35, // 36
36, // 37
36, // 38
37, // 39
39, // 40
39, // 41
41, // 42
42, // 43
42, // 44
46, // 45
20, // 46
46, // 47
49, // 48
26, // 49
49, // 50
52, // 51
32, // 52
52, // 53
55, // 54
38, // 55
55, // 56
58, // 57
44, // 58
58, // 59
];

//return polygons;
return voronoi()
.parents(parents)
.angle(0)
.polygons(polygons)
.rotate([108,0])
.scale(131.777)
.center([162, 0]);
}


/*
// Jarke J. van Wijk, "Unfolding the Earth: Myriahedral Projections",
// The Cartographic Journal Vol. 45 No. 1 pp. 32–42 February 2008, fig. 8
// https://bl.ocks.org/espinielli/475f5fde42a5513ab7eba3f53033ea9e
d3.geoIcosahedral().parents([-1,0,1,11,3,0,7,1,7,8,9,10,11,12,13,6,8,10,19,15])
.angle(-60)
.rotate([-83.65929, 25.44458, -87.45184])
*/
.parents(parents)
.polygons(polygons)
.angle(3)
.rotate([108, 0])
.translate([72, 252])
.scale(136.67);
}
86 changes: 46 additions & 40 deletions src/rhombic.js
Original file line number Diff line number Diff line change
Expand Up @@ -7,26 +7,27 @@
*/
import { atan, degrees } from "./math.js";
import voronoi from "./polyhedral/voronoi.js";
import { geoCentroid } from "d3-geo";

export default function() {
export default function () {
var phi1 = atan(Math.SQRT1_2) * degrees;
var vertices = [
[0, 90], // 0
[0, phi1], // 1
[90, phi1], // 2
[180, phi1], // 3
[-90, phi1], // 4
[45, 0], // 5
[135, 0], // 6
[-135, 0], // 7
[-45, 0], // 8
[0, -phi1], // 9
[90, -phi1], // 10
[0, 90], // 0
[0, phi1], // 1
[90, phi1], // 2
[180, phi1], // 3
[-90, phi1], // 4
[45, 0], // 5
[135, 0], // 6
[-135, 0], // 7
[-45, 0], // 8
[0, -phi1], // 9
[90, -phi1], // 10
[180, -phi1], // 11
[-90, -phi1], // 12
[0, -90] // 13
[0, -90], // 13
];

// rhombic dodecahedron
var polyhedron = [
[0, 1, 8, 4],
Expand All @@ -42,46 +43,51 @@ export default function() {
[8, 9, 13, 12],
[5, 10, 13, 9],
[6, 11, 13, 10],
[7, 12, 13, 11]
].map(function(face) {
return face.map(function(i) {
return vertices[i];
});
[7, 12, 13, 11],
].map(function (face) {
return face.map(function (i) {
return vertices[i];
});
});

var polygons = {
type: "FeatureCollection",
features: polyhedron.map(function(face) {
features: polyhedron.map(function (face) {
return {
properties: { sitecoordinates: d3.geoCentroid({type:"MultiPoint", coordinates: face}) },
properties: {
sitecoordinates: geoCentroid({
type: "MultiPoint",
coordinates: face,
}),
},
geometry: {
type: "Polygon",
coordinates: [[...face, face[0]]]
}
coordinates: [[...face, face[0]]],
},
};
})
}),
};

var parents = [
-1, // 0
0, // 1
6, // 2
2, // 3
1, // 4
9, // 5
11, // 6
3, // 7
4, // 8
8, // 9
5, // 10
10, // 11
];

-1, // 0
0, // 1
6, // 2
2, // 3
1, // 4
9, // 5
11, // 6
3, // 7
4, // 8
8, // 9
5, // 10
10, // 11
];

return voronoi()
.polygons(polygons)
.parents(parents)
.angle(20)
.rotate([-76.5, 27, -84]);
.rotate([0.001, 0])
.translate([213, 252])
.scale(106.48)
}

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