Public
Edited
Nov 5, 2024
Importers
7 stars
spatialSubdivision = function(H, rnd) {
const nb = 2*(H.length-1)+1;
const H2 = [];
// for each cell in new array
for (let i = 0; i < nb; i++) {
H2[i] = [];
let I = i>>1;
for (let j = 0; j < nb; j++) {
let J = j>>1;
// Interpolate current cells
H2[i][j] = (H[I][J]+H[I+(i&1)][J]+H[I][J+(j&1)]+H[I+(i&1)][J+(j&1)])/4;
// Add randomness on new cells
if (i&1 || j&1) H2[i][j] += rnd();
}
}
return H2;
}
generateHeightmap = (nbIters, seed, { p1 = 0.5, p2 = 1.1 } = {}) => {
const prng = minstRand0(seed);
let H = [
[prng(), prng()],
[prng(), prng()]
];
// Generate heightmap array
let f = p1;
for (let n = 0; n < nbIters; n++) {
let f2 = 2 * f;
H = spatialSubdivision(H, function () {
return prng() * f2 - f;
});
f /= 2 ** p2;
}
const N = H.length;
console.log(N);
// Compute heightmap stats
let [min, max] = [+Infinity, -Infinity];
for (let i = 0; i < N; i++) {
for (let j = 0; j < N; j++) {
let h = H[i][j];
min = Math.min(min, h);
max = Math.max(max, h);
}
}
for (let i = 0; i < N; i++) {
for (let j = 0; j < N; j++) {
H[i][j] -= min;
}
}
return { heightmap: H, max: max - min };
}
viewof heightmap = {
const nbIters = 10;
const { heightmap, max } = generateHeightmap(nbIters, seed, shaping);
const N = heightmap.length - 1;
const { context, dispatch } = viewofCanvas(256, 256);
dispatch({ data: heightmap, hunit: 1, vunit: N / 4 });
return canvas(context, samplePixel(heightmap, 256 / max));
}
{
const palette = colorShades([253, 205, 159], 256);
const colormap = { ...shademap.colormap, palette };
const dims = [width, Math.floor(width * 0.6)];
return orbitalCanvas({ ...shademap, colormap }, dims);
}
({
...shademap,
colormap: { ...shademap.colormap, palette: colorShades([253, 205, 159], 256) }
})
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
