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| import ImageLayer from 'ol/layer/Image.js';
import Map from 'ol/Map.js';
import View from 'ol/View.js';
import {Raster as RasterSource, Stamen} from 'ol/source.js';
const Xn = 0.95047;
const Yn = 1;
const Zn = 1.08883;
const t0 = 4 / 29;
const t1 = 6 / 29;
const t2 = 3 * t1 * t1;
const t3 = t1 * t1 * t1;
const twoPi = 2 * Math.PI;
function rgb2hcl(pixel) {
const red = rgb2xyz(pixel[0]);
const green = rgb2xyz(pixel[1]);
const blue = rgb2xyz(pixel[2]);
const x = xyz2lab(
(0.4124564 * red + 0.3575761 * green + 0.1804375 * blue) / Xn
);
const y = xyz2lab(
(0.2126729 * red + 0.7151522 * green + 0.072175 * blue) / Yn
);
const z = xyz2lab(
(0.0193339 * red + 0.119192 * green + 0.9503041 * blue) / Zn
);
const l = 116 * y - 16;
const a = 500 * (x - y);
const b = 200 * (y - z);
const c = Math.sqrt(a * a + b * b);
let h = Math.atan2(b, a);
if (h < 0) {
h += twoPi;
}
pixel[0] = h;
pixel[1] = c;
pixel[2] = l;
return pixel;
}
function hcl2rgb(pixel) {
const h = pixel[0];
const c = pixel[1];
const l = pixel[2];
const a = Math.cos(h) * c;
const b = Math.sin(h) * c;
let y = (l + 16) / 116;
let x = isNaN(a) ? y : y + a / 500;
let z = isNaN(b) ? y : y - b / 200;
y = Yn * lab2xyz(y);
x = Xn * lab2xyz(x);
z = Zn * lab2xyz(z);
pixel[0] = xyz2rgb(3.2404542 * x - 1.5371385 * y - 0.4985314 * z);
pixel[1] = xyz2rgb(-0.969266 * x + 1.8760108 * y + 0.041556 * z);
pixel[2] = xyz2rgb(0.0556434 * x - 0.2040259 * y + 1.0572252 * z);
return pixel;
}
function xyz2lab(t) {
return t > t3 ? Math.pow(t, 1 / 3) : t / t2 + t0;
}
function lab2xyz(t) {
return t > t1 ? t * t * t : t2 * (t - t0);
}
function rgb2xyz(x) {
return (x /= 255) <= 0.04045 ? x / 12.92 : Math.pow((x + 0.055) / 1.055, 2.4);
}
function xyz2rgb(x) {
return (
255 * (x <= 0.0031308 ? 12.92 * x : 1.055 * Math.pow(x, 1 / 2.4) - 0.055)
);
}
const raster = new RasterSource({
sources: [
new Stamen({
layer: 'watercolor',
}),
],
operation: function (pixels, data) {
const hcl = rgb2hcl(pixels[0]);
let h = hcl[0] + (Math.PI * data.hue) / 180;
if (h < 0) {
h += twoPi;
} else if (h > twoPi) {
h -= twoPi;
}
hcl[0] = h;
hcl[1] *= data.chroma / 100;
hcl[2] *= data.lightness / 100;
return hcl2rgb(hcl);
},
lib: {
rgb2hcl: rgb2hcl,
hcl2rgb: hcl2rgb,
rgb2xyz: rgb2xyz,
lab2xyz: lab2xyz,
xyz2lab: xyz2lab,
xyz2rgb: xyz2rgb,
Xn: Xn,
Yn: Yn,
Zn: Zn,
t0: t0,
t1: t1,
t2: t2,
t3: t3,
twoPi: twoPi,
},
});
const controls = {};
raster.on('beforeoperations', function (event) {
const data = event.data;
for (const id in controls) {
data[id] = Number(controls[id].value);
}
});
const map = new Map({
layers: [
new ImageLayer({
source: raster,
}),
],
target: 'map',
view: new View({
center: [0, 2500000],
zoom: 2,
maxZoom: 18,
}),
});
const controlIds = ['hue', 'chroma', 'lightness'];
controlIds.forEach(function (id) {
const control = document.getElementById(id);
const output = document.getElementById(id + 'Out');
control.addEventListener('input', function () {
output.innerText = control.value;
raster.changed();
});
output.innerText = control.value;
controls[id] = control;
});
|
)
