Helps programmers make code easier to maintain.
Published
Edited
Jul 5, 2021
11 stars
class Hex {
constructor(x, y, radius, rotation = 0) {
this.x = x;
this.y = y;
this.radius = radius;
this.rotation = rotation;
// Trigonometry :)
this.corners = [
[x + radius * Math.cos(Math.PI * 0/6 - rotation), y + radius * Math.sin(Math.PI * 0/6 - rotation)],
[x + radius * Math.cos(Math.PI * 2/6 - rotation), y + radius * Math.sin(Math.PI * 2/6 - rotation)],
[x + radius * Math.cos(Math.PI * 4/6 - rotation), y + radius * Math.sin(Math.PI * 4/6 - rotation)],
[x + radius * Math.cos(Math.PI * 6/6 - rotation), y + radius * Math.sin(Math.PI * 6/6 - rotation)],
[x + radius * Math.cos(Math.PI * 8/6 - rotation), y + radius * Math.sin(Math.PI * 8/6 - rotation)],
[x + radius * Math.cos(Math.PI * 10/6 - rotation), y + radius * Math.sin(Math.PI * 10/6 - rotation)]
];
}
render(svg, stroke) {
svg.append("path")
.attr("d", draw(this.corners))
.attr("stroke", stroke)
.attr("fill", "none");
}
}
class HexFlower {
constructor(x, y, radius, rotation = 0) {
this.x = x;
this.y = y;
this.radius = radius;
this.rotation = rotation;
// See the above explanation to learn how to arrive at this formula
this.cellRadius = radius / Math.sqrt(7);
// You can use basic trigonometry to arrive at this formula for the 'height' of a regular hexagon. By
// 'height' here, I mean the height of the hexagon when it's resting on one of its six sides. The √3/2
// relation is well-known. See e.g. https://en.wikipedia.org/wiki/Hexagon
this.cellHeight = 2 * this.cellRadius * Math.sqrt(3) / 2;
// These coordinates give the directions towards the centers of each of the surrounding cells.
const directions = [
[Math.cos(Math.PI * 1/6 - rotation), Math.sin(Math.PI * 1/6 - rotation)],
[Math.cos(Math.PI * 3/6 - rotation), Math.sin(Math.PI * 3/6 - rotation)],
[Math.cos(Math.PI * 5/6 - rotation), Math.sin(Math.PI * 5/6 - rotation)],
[Math.cos(Math.PI * 7/6 - rotation), Math.sin(Math.PI * 7/6 - rotation)],
[Math.cos(Math.PI * 9/6 - rotation), Math.sin(Math.PI * 9/6 - rotation)],
[Math.cos(Math.PI * 11/6 - rotation), Math.sin(Math.PI * 11/6 - rotation)]
];
this.petals = directions.map(
([x1, y1]) => new Hex(x + this.cellHeight * x1, y + this.cellHeight * y1, this.cellRadius, rotation));
this.center = new Hex(x, y, this.cellRadius, rotation);
}
render(svg, petalStroke, centerStroke = petalStroke) {
for (const petal of this.petals) {
petal.render(svg, petalStroke);
}
this.center.render(svg, centerStroke);
}
renderFractal(renderer, colors, level) {
if (level <= 0) {
return;
}
renderer.render(this, colors.getPetalColor(level), colors.getCenterColor(level));
// See notes below for an explanation of this formula
const flowerRotation = -Math.asin(Math.sqrt(3/7)/2);
const flowers = [this.center].concat(this.petals).map(
h => new HexFlower(h.x, h.y, this.cellRadius, this.rotation + flowerRotation));
for (const flower of flowers) {
flower.renderFractal(renderer, colors, level - 1);
}
}
}
class AllCellsRenderer {
constructor(svg) {
this.svg = svg;
}
render(flower, petalStroke, centerStroke = petalStroke) {
for (const petal of flower.petals) {
petal.render(this.svg, petalStroke);
}
flower.center.render(this.svg, centerStroke);
}
}
class RandomCellSkippingRenderer {
constructor(svg, renderProbability = 0.5) {
this.svg = svg;
this.renderProbability = renderProbability;
}
render(flower, petalStroke, centerStroke = petalStroke) {
for (const petal of flower.petals) {
if (Math.random() < this.renderProbability) {
petal.render(this.svg, petalStroke);
}
}
if (Math.random() < this.renderProbability) {
flower.center.render(this.svg, centerStroke);
}
}
}
class LinearColorRanges {
constructor(levels, petalColors, centerColors = petalColors) {
this.getPetalColor = d3.scaleLinear().domain([1, levels]).range(petalColors);
this.getCenterColor = d3.scaleLinear().domain([1, levels]).range(centerColors);
}
}
class RandomColorDimmer {
constructor(inner, dimFactor = 1) {
this.inner = inner;
this.dimFactor = dimFactor;
}
getPetalColor(level) {
const color = this.inner.getPetalColor(level);
return d3.color(color).darker(Math.random() * this.dimFactor);
}
getCenterColor(level) {
const color = this.inner.getCenterColor(level);
return d3.color(color).darker(Math.random() * this.dimFactor);
}
}
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.