TelegramPWA/src/util/colors.ts
2025-12-22 22:53:29 +01:00

285 lines
6.8 KiB
TypeScript

import { preloadImage } from './files';
import { clamp, lerp } from './math.ts';
const LUMA_THRESHOLD = 128;
type Number3 = [number, number, number];
type Number4 = [number, number, number, number];
type Rgba = {
r: number;
g: number;
b: number;
a?: number;
};
function clearHex(hex: string) {
return hex.length % 2 === 0 ? hex : hex.slice(1);
}
/**
* HEX > RGB
* input: 'xxxxxx' (ex. 'ed15fa') case-insensitive
* output: [r, g, b] ([0-255, 0-255, 0-255])
*/
export function hex2rgb(hex: string): Number3 {
const cleanHex = clearHex(hex);
return [
parseInt(cleanHex.substring(0, 2), 16),
parseInt(cleanHex.substring(2, 4), 16),
parseInt(cleanHex.substring(4, 6), 16),
];
}
export function hex2rgba(hex: string): Number4 {
const cleanHex = clearHex(hex);
return [
...hex2rgb(cleanHex),
cleanHex.length === 8 ? parseInt(cleanHex.substring(6, 8), 16) : 255,
];
}
export function hex2rgbaObj(hex: string): Rgba {
const [r, g, b, a] = hex2rgba(hex);
return { r, g, b, a };
}
export function rgb2hex([r, g, b]: Number3) {
return `#${((1 << 24) + (r << 16) + (g << 8) + b).toString(16).slice(1)}`;
}
export function rgba2hex([r, g, b, a]: Number4) {
return `${rgb2hex([r, g, b])}${a.toString(16)}`;
}
/**
* Converts an RGB color value to HSV. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSV_color_space.
* Assumes r, g, and b are contained in the set [0, 255] and
* returns h, s, and v in the set [0, 1].
*
* @param Number r The red color value
* @param Number g The green color value
* @param Number b The blue color value
* @return Array The HSV representation
*/
export function rgb2hsv([r, g, b]: Number3): Number3 {
r /= 255;
g /= 255;
b /= 255;
const max = Math.max(r, g, b), min = Math.min(r, g, b);
const d = max - min;
let h!: number;
const s: number = max === 0 ? 0 : d / max;
const v: number = max;
if (max === min) {
h = 0; // achromatic
} else {
switch (max) {
case r:
h = (g - b) / d + (g < b ? 6 : 0);
break;
case g:
h = (b - r) / d + 2;
break;
case b:
h = (r - g) / d + 4;
break;
}
h /= 6;
}
return [h, s, v];
}
export function rgba2hsva([r, g, b, a]: Number4): Number4 {
return [...rgb2hsv([r, g, b]), a];
}
/**
* Converts an HSV color value to RGB. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSV_color_space.
* Assumes h, s, and v are contained in the set [0, 1] and
* returns r, g, and b in the set [0, 255].
*
* @param Number h The hue
* @param Number s The saturation
* @param Number v The value
* @return Array The RGB representation
*/
export function hsv2rgb([h, s, v]: Number3): Number3 {
let r!: number, g!: number, b!: number;
const i = Math.floor(h * 6);
const f = h * 6 - i;
const p = v * (1 - s);
const q = v * (1 - f * s);
const t = v * (1 - (1 - f) * s);
switch (i % 6) {
case 0:
r = v;
g = t;
b = p;
break;
case 1:
r = q;
g = v;
b = p;
break;
case 2:
r = p;
g = v;
b = t;
break;
case 3:
r = p;
g = q;
b = v;
break;
case 4:
r = t;
g = p;
b = v;
break;
case 5:
r = v;
g = p;
b = q;
break;
}
return [
Math.round(r * 255),
Math.round(g * 255),
Math.round(b * 255),
];
}
export function hsva2rgba([h, s, v, a]: Number4): Number4 {
return [...hsv2rgb([h, s, v]), a];
}
export async function getAverageColor(url: string): Promise<Number3> {
// Only visit every 5 pixels
const blockSize = 5;
const black: Number3 = [0, 0, 0];
let data;
let i = -4;
const rgb: Number3 = [0, 0, 0];
let count = 0;
const canvas = document.createElement('canvas');
const context = canvas.getContext && canvas.getContext('2d');
if (!context) {
return black;
}
const image = await preloadImage(url);
const height = image.naturalHeight || image.offsetHeight || image.height;
const width = image.naturalWidth || image.offsetWidth || image.width;
canvas.height = height;
canvas.width = width;
context.drawImage(image, 0, 0);
try {
data = context.getImageData(0, 0, width, height);
} catch (e) {
return black;
}
const length = data.data.length;
while ((i += blockSize * 4) < length) {
if (data.data[i + 3] === 0) continue; // Ignore fully transparent pixels
++count;
rgb[0] += data.data[i];
rgb[1] += data.data[i + 1];
rgb[2] += data.data[i + 2];
}
rgb[0] = Math.floor(rgb[0] / count);
rgb[1] = Math.floor(rgb[1] / count);
rgb[2] = Math.floor(rgb[2] / count);
return rgb;
}
export function getColorLuma([r, g, b]: Number3) {
return 0.2126 * r + 0.7152 * g + 0.0722 * b;
}
// https://stackoverflow.com/a/64090995
export function hsl2rgb([h, s, l]: Number3): Number3 {
const a = s * Math.min(l, 1 - l);
const f = (n: number, k = (n + h / 30) % 12) => l - a * Math.max(Math.min(k - 3, 9 - k, 1), -1);
return [f(0), f(8), f(4)];
}
// Function was adapted from https://github.com/telegramdesktop/tdesktop/blob/35ff621b5b52f7e3553fb0f990ea13ade7101b8e/Telegram/SourceFiles/data/data_wall_paper.cpp#L518
export function getPatternColor(rgb: Number3) {
const hsv = rgb2hsv(rgb);
const [h] = hsv;
let [, s, v] = hsv;
s = Math.min(1, s + 0.05 + 0.1 * (1 - s));
v = v > 0.5
? Math.max(0, v * 0.65)
: Math.max(0, Math.min(1, 1 - v * 0.65));
const newRgb = hsv2rgb([h, s, v]);
return rgba2hex([...newRgb, 102]);
}
export function int2cssRgba(color: number): string {
const alpha = (color >> 24) & 0xff;
const red = (color >> 16) & 0xff;
const green = (color >> 8) & 0xff;
const blue = color & 0xff;
const alphaFloat = alpha / 255;
return `rgba(${red}, ${green}, ${blue}, ${alphaFloat})`;
}
export function int2hex(color: number): string {
return `#${color.toString(16).padStart(6, '0')}`;
}
export function getTextColor(color: number): string {
const r = (color >> 16) & 0xff;
const g = (color >> 8) & 0xff;
const b = color & 0xff;
const luma = getColorLuma([r, g, b]);
return luma > LUMA_THRESHOLD ? 'black' : 'white';
}
export function lerpRgbaObj(start: Rgba, end: Rgba, interpolationRatio: number): Rgba {
const r = Math.round(lerp(start.r, end.r, interpolationRatio));
const g = Math.round(lerp(start.g, end.g, interpolationRatio));
const b = Math.round(lerp(start.b, end.b, interpolationRatio));
const a = start.a !== undefined
? Math.round(lerp(start.a, end.a!, interpolationRatio))
: undefined;
return { r, g, b, a };
}
export function adjustHsv(hex: string, satDelta: number, valDelta: number) {
const hsva = rgba2hsva(hex2rgba(hex));
const [h, , , a] = hsva;
let [, s, v] = hsva;
if (s > 0.1 && s < 0.9) s = clamp(s + satDelta, 0, 1);
v = clamp(v + valDelta, 0, 1);
return rgba2hex(hsva2rgba([h, s, v, a]));
}