Files
infinifi/web/bg.js

70 lines
1.8 KiB
JavaScript

const DOT_COLOR_LIGHT_MODE = "#dce0e8";
const DOT_COLOR_DARK_MODE = "#45475a";
const DOT_RADIUS = 1 * devicePixelRatio;
const canvas = document.getElementById("bg");
const ctx = canvas.getContext("2d");
let mouseX = 0;
let mouseY = 0;
let dotColor = "#dce0e8";
function resizeCanvas(width, height) {
const devicePixelRatio = window.devicePixelRatio || 1;
canvas.style.width = `${width}px`;
canvas.style.height = `${height}px`;
canvas.width = width * devicePixelRatio;
canvas.height = height * devicePixelRatio;
}
function clearCanvas() {
ctx.clearRect(0, 0, canvas.width, canvas.height);
}
function drawDot(x, y) {
const distance = Math.sqrt((x - mouseX) ** 2 + (y - mouseY) ** 2);
const effectRadius = 100;
const radius =
DOT_RADIUS +
2 *
devicePixelRatio *
((effectRadius - Math.min(distance, effectRadius)) / effectRadius);
ctx.beginPath();
ctx.arc(x, y, radius, 0, 2 * Math.PI, false);
ctx.fillStyle = dotColor;
ctx.fill();
}
function drawPattern() {
clearCanvas();
for (let x = 0; x < canvas.width; x += 10 * devicePixelRatio) {
for (let y = 0; y < canvas.height; y += 10 * devicePixelRatio) {
drawDot(x, y);
}
}
}
window.addEventListener("resize", () => {
resizeCanvas(window.innerWidth, window.innerHeight);
drawPattern();
});
window.addEventListener("mousemove", (event) => {
mouseX = event.clientX * devicePixelRatio;
mouseY = event.clientY * devicePixelRatio;
drawPattern();
});
if (window.matchMedia) {
const query = window.matchMedia("(prefers-color-scheme: dark)");
dotColor = query.matches ? DOT_COLOR_DARK_MODE : DOT_COLOR_LIGHT_MODE;
query.addEventListener("change", (event) => {
dotColor = event.matches ? DOT_COLOR_DARK_MODE : DOT_COLOR_LIGHT_MODE;
drawPattern();
});
}
resizeCanvas(window.innerWidth, window.innerHeight);
drawPattern();