src/render/series.ts

Functions

Imports

It imports src/render/figure.ts. Imported by src/plot/scatter.ts, src/render/bar-model.ts, src/render/line-model.ts, src/science/genome.ts, src/science/network.ts, src/science/titer.ts.

Source

1import type { LegendItem, SeriesColor } from "./figure.js";
2
3/** The number of palette slots every theme defines, and so the most series one chart can show. */
4const MAX_SERIES = 8;
5
6/** How a chart's series map onto palette slots. */
7export interface SeriesPlan {
8  readonly names: readonly string[];
9  /** The CSS color reference for each series, in order, for Plot's color scale range. */
10  readonly range: readonly string[];
11  readonly legend: readonly LegendItem[];
12  readonly slotColors: ReadonlyMap<number, SeriesColor>;
13  slot(name: string): number;
14}
15
16/** A CSS reference to a palette slot. */
17function slotColor(slot: number): string {
18  return `var(--enarratio-series-${slot})`;
19}
20
21/**
22 * Assigns series to palette slots in order, and applies per-series color overrides to their
23 * slots. Throws when there are more series than slots or an override names no series, because
24 * both would otherwise draw a chart that is quietly wrong.
25 */
26export function planSeries(
27  kind: string,
28  names: readonly string[],
29  colors: Readonly<Record<string, SeriesColor>> | undefined,
30): SeriesPlan {
31  if (names.length > MAX_SERIES) {
32    throw new Error(
33      `${kind}: ${names.length} series, but a theme has ${MAX_SERIES} colors; group the smallest series into "Other"`,
34    );
35  }
36  const slots = new Map(names.map((name, i) => [name, i + 1]));
37  const slotColors = new Map<number, SeriesColor>();
38  for (const [name, color] of Object.entries(colors ?? {})) {
39    const slot = slots.get(name);
40    if (slot === undefined) {
41      throw new Error(
42        `${kind}: colors names "${name}", which is not a series (${names.join(", ")})`,
43      );
44    }
45    slotColors.set(slot, color);
46  }
47  return {
48    names,
49    range: names.map((_, i) => slotColor(i + 1)),
50    legend: names.map((label, i) => ({ label, slot: i + 1 })),
51    slotColors,
52    slot(name) {
53      const slot = slots.get(name);
54      if (slot === undefined) throw new Error(`${kind}: unknown series "${name}"`);
55      return slot;
56    },
57  };
58}