@geogirafe/lib-geoportal
Version:
GeoGirafe is a flexible application to build online geoportals.
71 lines (70 loc) • 2.39 kB
JavaScript
// SPDX-License-Identifier: Apache-2.0
import * as d3 from 'd3';
// Compute point colors
export function computeColors(values, colormap = 'spectral', domain = []) {
const N = values.length;
// Set color palette
let colorPalette;
switch (colormap) {
case 'spectral':
colorPalette = d3.scaleSequential(d3.interpolateSpectral).domain(domain);
break;
case 'viridis':
colorPalette = d3.scaleSequential(d3.interpolateViridis).domain(domain);
break;
case 'greys':
colorPalette = d3.scaleSequential(d3.interpolateGreys).domain(domain);
break;
case 'magma':
colorPalette = d3.scaleSequential(d3.interpolateMagma).domain(domain);
break;
case 'blues':
colorPalette = d3.scaleSequential(d3.interpolateBlues).domain(domain);
break;
case 'custom':
colorPalette = d3
.scaleOrdinal()
// @ts-expect-error: D3 typing issue
.domain([1, 2, 3, 4, 5, 6, 7, 9, 11, 14, 15, 17, 18, 19, 21, 22, 25, 26, 29, 31, 41])
.range([
'#C0C0C0',
'#DEB887',
'#9ACD32',
'#32CD32',
'#008000',
'#B22222',
'#FFFF00',
'#87CEFA',
'#B8860B',
'#BA55D3',
'#FF1493',
'#EEE8AA',
'#FFD700',
'#7FFFD4',
'#DDA0DD',
'#A0522D',
'#FFA500',
'#FA8072',
'#FF6347',
'#BC8F8F',
'#6495ED'
]);
break;
case 'uniform':
// @ts-expect-error: D3 typing issue
colorPalette = d3.scaleOrdinal().domain([1]).range(['#DEB887']);
break;
default:
// @ts-expect-error: D3 typing issue
colorPalette = d3.scaleOrdinal().domain([1]).range([colormap]);
}
const rgb = new Uint8Array(N * 3);
values.forEach((d, index) => {
// @ts-expect-error: D3 typing issue
const color = d3.color(colorPalette(d));
rgb[index * 3 + 0] = color.r;
rgb[index * 3 + 1] = color.g;
rgb[index * 3 + 2] = color.b;
});
return rgb;
}