Published
Edited
Jul 7, 2021
3 forks
9 stars
Kerkovits projectionA map of AfricaCupola ProjectionClipping spherical polygonsA conformal AiroceanFill with strokeMarkley’s tetrahedral mapSynchronized projectionsSatellite GLSLVan Der Grinten IV GLSLVan Der Grinten III GLSLVan Der Grinten II GLSLWinkel Tripel GLSLLee Modified Stereographic GLSLMiller Oblated Stereographic GLSLModified Stereographic GS48 GLSLModified Stereographic GS50 GLSLFoucaut GLSLLagrange GLSLKavrayskiy VII GLSLEisenlohr GLSLEckert VI GLSLEckert V GLSLEckert IV GLSLEckert III GLSLEckert II GLSLEckert I GLSLBertin1953 GLSLRobinson GLSLMiller GLSLRectangular Polyconic GLSLPatterson GLSLPolyconic GLSLLoximuthal GLSLCylindrical Stereographic GLSLCylindrical Equal-Area GLSLTransverse Fahey GLSLFahey GLSLCollignon GLSLBromley GLSLBottomley GLSLHammer GLSLBonne GLSLBoggs GLSLBerghaus GLSLBaker Transverse GLSLBaker GLSLAugust GLSLAiry GLSLAitoff GLSLArmadillo GLSLLarrivée GLSLCylindrical Equal-Area GLSLAzimuthal Equidistant GLSLLittrow GLSLVan Der Grinten GLSLEquirectangular GLSLConic Conformal GLSLConic Equidistant GLSLAlbers GLSLConic Equal-Area GLSLEqual Earth GLSLTimes GLSLWagner IV GLSLWagner VI GLSLWagner VII GLSLWiechel GLSLAtlantis GLSLMollweide GLSLMercator GLSLTransverse Mercator GLSLCordiform GLSLVersor zooming for Three.jsAzimuthal Equal-Area GLSLBriesemeister GLSLRectilinear GLSLPhytoplanktonDanseiji projectionsTransverse MollweideThe 2D approximate Newton-Raphson methodInverting Lee’s Tetrahedral projectionAmerican PolyconicThe complex logarithm projectionRaster projection with GPU.jsH3 hexagons & geoContoursModified Stereographic ProjectionsFisheye Conformal Map (Cox)Fisheye Conformal MapFisheye Conformal Map (Tetrahedral)Reproject elevation tiles — worldTransverse projectionsThe Imago projectionD3 ProjectionsImago Projection Distorsion AnalysisEPSG:5530Imago tilingCordiform map projections 💛💗💖MultiPolygon clippingThe Nicolosi Globular ProjectionFisheye GlobeHerbert Bayer’s Pacific OceanThe Behrmann projectionOronce Finé’s triangle projectionDa Vinci’s octant projectionThe Lotus projection (1958)The Voronoi projectionUsing proj4js with D3 and PlotMurphey Butterfly ProjectionEquateur & tropiquesVega projectionsMercator projection of a Mercator globeThe truth about the Mercator projectionOcean-centric Mollweide projectionBuckminster Fuller’s triangle transformationExperimental two world projectionsTobler’s hyperelliptical projection (1973)Jacques Bertin’s projection (1953)A map without Antarctica (Bertin1953 projection)Square Root Azimuthal projectionThe Log-Azimuthal projectionPeirce Quincuncial Projection, centered on the South PoleTranslucent Earth (Satellite projection)Lee’s conformal projection in a tetrahedronAirocean projectionCubic projectionsCox conformal projection in a triangleIcosahedral projectionsDodecahedral projectionThe Cahill-Keyes projection (1975)Polyhedral projections with d3-geo-polygonWagner customizable projectionParametrized Equal Earth ProjectionThe Hufnagel projection systemTissot's indicatrixAn equal-area projection for the cubic EarthBase map
WebMercator to globe
Also listed in…
GLSL projections
projection = d3.geoOrthographic().rotate([-120, -30, 0])
import { zoom } from "@d3/versor-zooming"
maxTextureSize = {
const gl = document.createElement("canvas").getContext("webgl");
return gl.getParameter(gl.MAX_TEXTURE_SIZE);
}
image = d3.image(
"https://upload.wikimedia.org/wikipedia/commons/f/f7/Normal_Mercator_map_85deg.jpg",
{
crossOrigin: "anonymous"
}
)
// the image must be "power of 2" to use a mipmap
imageP2 = {
const w = Math.min(
maxTextureSize,
2 ** Math.ceil(Math.log(image.naturalWidth) / Math.log(2))
), // better upscale if possible
h = w / 1;
const context = DOM.context2d(w, h, 1);
context.drawImage(image, 0, 0, w, h);
return Object.assign(context.canvas, { style: "max-height: 100px;" });
}
function mapShader(projection, glsl, postprojection, footer) {
const pixelRatio = Math.min(1.5, devicePixelRatio);
const canvas = document.createElement("canvas");
canvas.width = Math.floor(width * pixelRatio);
canvas.height = Math.floor(height * pixelRatio);
canvas.style.width = `${width}px`;
canvas.style.height = `${height}px`;
const regl = createREGL({
canvas,
attributes: { antialias: false, preserveDrawingBuffer: true },
optionalExtensions: ['OES_standard_derivatives', 'EXT_shader_texture_lod']
});
const texture = regl.texture({
data: imageP2,
mipmap: "nice",
min: "linear mipmap linear",
mag: "linear",
wrapS: "repeat",
flipY: true
});
const draw = createDrawCommand(
regl,
projection,
glsl,
postprojection,
footer,
width,
height,
texture
);
return Object.assign(canvas, { regl, draw });
}
createREGL = require("regl")
createDrawCommand = (
regl,
projection,
proj,
postprojection,
footer,
width,
height,
texture
) =>
regl({
frag: fragmentShader(proj, postprojection, footer),
vert: vertexShader(),
attributes: {
position: [-4, 0, 0, -4, 4, 4]
},
count: 3,
uniforms: {
texture,
u_scale: () => projection.scale(),
u_angle: () => projection.angle(),
u_translate: () => {
// accounts for projection.center()
const r = projection.rotate(),
t = projection.rotate([0, 0])([0, 0]);
projection.rotate(r);
return t;
},
u_rotate: () => projection.rotate(),
u_size: () => [width, height]
},
depth: { enable: false }
})
fragmentShader = (projection, postprojection, footer) => `
#ifdef GL_EXT_shader_texture_lod
#extension GL_EXT_shader_texture_lod : enable
#endif
#ifdef GL_OES_standard_derivatives
#extension GL_OES_standard_derivatives : enable
#endif
precision highp float;
uniform sampler2D texture;
uniform vec3 u_rotate;
const float pi = 3.141592653589793;
const float halfPi = pi * 0.5;
const float tau = pi * 2.0;
const float radians = pi / 180.0;
const float degrees = 1.0 / radians;
varying vec2 p;
${applyRotation()}
void main(void) {
float x = p.x;
float y = p.y;
float lambda, phi;
bool transparent = false;
// inverse projection
${projection}
// rotate
applyRotation(u_rotate, lambda, phi);
// texture coordinates
vec2 t = vec2(fract(lambda / tau - 0.5), 0.5 + phi / pi);
#ifdef GL_OES_standard_derivatives
// avoid a mipmap seam by controlling the derivative of t.x
if (fwidth(t.x) > 0.25 && t.x < 0.5) t.x += 1.0;
#endif
${postprojection}
// read the textures
#ifdef GL_EXT_shader_texture_lod
float scale = 0.8 * cos(phi * 0.97);
gl_FragColor = texture2DGradEXT(texture, vec2(t.x, t.y * 0.996 + 0.002), dFdx(t) * scale, dFdy(t) * scale);
#else
gl_FragColor = texture2D(texture, t);
#endif
if (transparent) gl_FragColor.a = 0.0;
${footer || "// no footer"}
}
`
vertexShader = () => `
precision highp float;
uniform float u_scale;
uniform float u_angle;
uniform vec2 u_translate;
uniform vec2 u_size;
attribute vec2 position;
varying vec2 p;
vec2 rotate2d(vec2 p, float a) {
float s = sin(a), c = cos(a);
return mat2(c, -s, s, c) * p;
}
void main () {
p = u_translate - 0.5 * u_size * (position * vec2(1, -1) + 1.0);
p = rotate2d(p, -u_angle * 0.017453292519943295) / u_scale * vec2(-1, 1);
gl_Position = vec4(position, 0, 1);
}`
applyRotation = () => `
// rotations, ported from d3-geo
void applyRotation(in vec3 rotate, inout float lambda, inout float phi) {
float x, y, rho, c, cosphi, z, deltaLambda, deltaPhi, deltaGamma, cosDeltaPhi,
sinDeltaPhi, cosDeltaGamma, sinDeltaGamma, k, circle, proj, a, b;
cosphi = cos(phi);
x = cos(lambda) * cosphi;
y = sin(lambda) * cosphi;
z = sin(phi);
deltaLambda = rotate.x * radians;
deltaPhi = rotate.y * radians;
deltaGamma = rotate.z * radians;
cosDeltaPhi = cos(deltaPhi);
sinDeltaPhi = sin(deltaPhi);
cosDeltaGamma = cos(deltaGamma);
sinDeltaGamma = sin(deltaGamma);
k = z * cosDeltaGamma - y * sinDeltaGamma;
lambda = atan(y * cosDeltaGamma + z * sinDeltaGamma,
x * cosDeltaPhi + k * sinDeltaPhi)
- deltaLambda;
k = k * cosDeltaPhi - x * sinDeltaPhi;
k = clamp(k, -1.0, 1.0); // avoid a hole at the poles
phi = asin(k);
}
`
height = {
// fullscreen?
if (width > 1000) return window.screen ? window.screen.height : width * .75;
const [[x0, y0], [x1, y1]] = d3
.geoPath(projection.fitWidth(width, { type: "Sphere" }))
.bounds({ type: "Sphere" });
const dy = Math.ceil(y1 - y0),
l = Math.min(Math.ceil(x1 - x0), dy);
projection.scale((projection.scale() * (l - 1)) / l).precision(0.2);
return dy;
}
projection.fitExtent([[10, 10], [width - 10, height - 10]], { type: "Sphere" })
d3 = require("d3@7", "d3-geo-projection@3")
import { checkbox, select } from "@jashkenas/inputs"
import {fullscreen} from "@fil/fullscreen"
fullscreen(map)
import { radians } from "@fil/math"
One platform to build and deploy the best data apps
Experiment and prototype by building visualizations in live JavaScript notebooks. Collaborate with your team and decide which concepts to build out.
Use Observable Framework to build data apps locally. Use data loaders to build in any language or library, including Python, SQL, and R.
Seamlessly deploy to Observable. Test before you ship, use automatic deploy-on-commit, and ensure your projects are always up-to-date.