multisite/src/components/HeroBackground.tsx
2026-05-24 22:46:44 +08:00

231 lines
7.2 KiB
TypeScript

"use client";
import { useThemeMode } from '@/hooks/useThemeMode'
import { useEffect, useRef } from "react";
const STAR_TONES = [255, 210, 160, 110, 65];
const WAVE_TONES = [55, 90, 125, 165, 205];
const WAVE_CONFIGS = [
{ amp: 26, freq: 0.011, speed: 0.35, phase: 0.0, yBase: 0.38, width: 1.6, toneIdx: 0 },
{ amp: 20, freq: 0.015, speed: 0.50, phase: 1.3, yBase: 0.52, width: 1.8, toneIdx: 1 },
{ amp: 30, freq: 0.008, speed: 0.28, phase: 2.6, yBase: 0.63, width: 2.2, toneIdx: 2 },
{ amp: 16, freq: 0.019, speed: 0.65, phase: 0.8, yBase: 0.74, width: 2.0, toneIdx: 3 },
{ amp: 22, freq: 0.013, speed: 0.42, phase: 3.2, yBase: 0.85, width: 2.6, toneIdx: 4 },
];
interface Star {
x: number; y: number; r: number;
v: number; baseAlpha: number;
phase: number; twinkleSpeed: number;
vx: number; vy: number;
}
interface Wave {
amp: number; freq: number; speed: number;
phase: number; yBase: number; width: number;
v: number;
}
function initStars(W: number, H: number): Star[] {
return Array.from({ length: 180 }, () => {
const toneIdx = Math.floor(Math.random() * STAR_TONES.length);
return {
x: Math.random() * W,
y: Math.random() * H,
r: 0.4 + Math.random() * 1.6,
v: STAR_TONES[toneIdx],
baseAlpha: 0.5 + toneIdx * 0.1,
phase: Math.random() * Math.PI * 2,
twinkleSpeed: 0.8 + Math.random() * 2.0,
vx: (Math.random() - 0.5) * 0.3,
vy: (Math.random() - 0.5) * 0.15,
};
});
}
function initWaves(): Wave[] {
return WAVE_CONFIGS.map(c => ({ ...c, v: WAVE_TONES[c.toneIdx] }));
}
function drawStars(ctx: CanvasRenderingContext2D, stars: Star[], W: number, H: number, ga: number) {
const now = Date.now() / 1000;
for (const s of stars) {
s.x += s.vx; s.y += s.vy;
if (s.x < 0) s.x = W; if (s.x > W) s.x = 0;
if (s.y < 0) s.y = H; if (s.y > H) s.y = 0;
const twinkle = 0.35 + 0.65 * ((Math.sin(now * s.twinkleSpeed + s.phase) + 1) / 2);
ctx.beginPath();
ctx.arc(s.x, s.y, s.r, 0, Math.PI * 2);
ctx.fillStyle = `rgba(${s.v},${s.v},${s.v},${s.baseAlpha * twinkle * ga})`;
ctx.fill();
}
}
function buildWavePts(w: Wave, W: number, H: number, now: number) {
const pts: { x: number; y: number }[] = [];
for (let x = 0; x <= W; x += 8) {
pts.push({ x, y: H * w.yBase + Math.sin(x * w.freq + w.phase + now * w.speed) * w.amp });
}
return pts;
}
function drawWavePath(ctx: CanvasRenderingContext2D, pts: { x: number; y: number }[], W: number, H: number) {
ctx.beginPath();
ctx.moveTo(pts[0].x, pts[0].y);
for (let i = 0; i < pts.length - 1; i++) {
const mx = (pts[i].x + pts[i + 1].x) / 2;
const my = (pts[i].y + pts[i + 1].y) / 2;
ctx.quadraticCurveTo(pts[i].x, pts[i].y, mx, my);
}
ctx.lineTo(pts[pts.length - 1].x, pts[pts.length - 1].y);
}
function drawWaves(ctx: CanvasRenderingContext2D, waves: Wave[], W: number, H: number, ga: number, bgR: number) {
const now = Date.now() / 1000;
const bg = Math.round(bgR);
for (const w of waves) {
const v = w.v;
const yBase = H * w.yBase;
const pts = buildWavePts(w, W, H, now);
const grad = ctx.createLinearGradient(0, yBase - w.amp, 0, yBase + w.amp * 3);
grad.addColorStop(0, `rgba(${v},${v},${v},${0.030 * ga})`);
grad.addColorStop(0.4, `rgba(${v},${v},${v},${0.012 * ga})`);
grad.addColorStop(1, `rgba(${bg},${bg},${bg},0)`);
drawWavePath(ctx, pts, W, H);
ctx.lineTo(W, H); ctx.lineTo(0, H); ctx.closePath();
ctx.fillStyle = grad;
ctx.fill();
drawWavePath(ctx, pts, W, H);
ctx.strokeStyle = `rgba(${v},${v},${v},${0.85 * ga})`;
ctx.lineWidth = w.width;
ctx.lineJoin = "round";
ctx.lineCap = "round";
ctx.stroke();
}
}
// ── Component ────────────────────────────────────────────────────────────────
interface HeroBackgroundProps {
/** Controlled from outside if you have a global theme toggle. */
isDark?: boolean;
/** Fires when the internal toggle is clicked (omit to hide the button). */
onToggle?: (isDark: boolean) => void;
/** Show the built-in toggle button. Defaults to true. */
showToggle?: boolean;
}
export default function HeroBackground({
isDark: externalIsDark,
onToggle,
showToggle = true,
}: HeroBackgroundProps) {
const canvasRef = useRef<HTMLCanvasElement>(null);
// REPLACE WITH:
const { isDark: hookDark, toggle } = useThemeMode();
// Use external control if provided, otherwise hook
const isDark = externalIsDark !== undefined ? externalIsDark : hookDark;
// REPLACE WITH:
function handleToggle() {
toggle();
onToggle?.(!isDark);
}
useEffect(() => {
const canvas = canvasRef.current;
if (!canvas) return;
const ctx = canvas.getContext("2d");
if (!ctx) return;
let W = 0, H = 0;
let stars: Star[] = [];
let waves: Wave[] = [];
let rafId: number;
// Animated bg colour
let bgR = 0, bgG = 0, bgB = 0;
let crossfade = 0;
function resize() {
W = canvas!.width = canvas!.offsetWidth;
H = canvas!.height = canvas!.offsetHeight;
stars = initStars(W, H);
waves = initWaves();
}
function loop() {
// Read current target from closure — updated via ref below
const dark = darkRef.current;
const targetBg = dark ? 0 : 255;
const targetCross = dark ? 0 : 1;
bgR += (targetBg - bgR) * 0.04;
bgG += (targetBg - bgG) * 0.04;
bgB += (targetBg - bgB) * 0.04;
crossfade += (targetCross - crossfade) * 0.03;
ctx!.fillStyle = `rgb(${Math.round(bgR)},${Math.round(bgG)},${Math.round(bgB)})`;
ctx!.fillRect(0, 0, W, H);
const sa = 1 - crossfade;
const wa = crossfade;
if (sa > 0.01) drawStars(ctx!, stars, W, H, sa);
if (wa > 0.01) drawWaves(ctx!, waves, W, H, wa, bgR);
rafId = requestAnimationFrame(loop);
}
const ro = new ResizeObserver(resize);
ro.observe(canvas);
resize();
rafId = requestAnimationFrame(loop);
return () => {
cancelAnimationFrame(rafId);
ro.disconnect();
};
}, []);
// Keep a ref so the loop closure always reads the latest isDark
const darkRef = useRef(isDark);
useEffect(() => { darkRef.current = isDark; }, [isDark]);
return (
<div style={{ position: "relative", width: "100%", height: "100%" }}>
<canvas
ref={canvasRef}
style={{ display: "block", width: "100%", height: "100%" }}
/>
{showToggle && (
<button
onClick={handleToggle}
style={{
position: "absolute",
top: 20,
right: 20,
display: "flex",
alignItems: "center",
gap: 8,
padding: "8px 16px",
fontSize: 13,
cursor: "pointer",
borderRadius: 999,
border: `1px solid ${isDark ? "rgba(255,255,255,0.2)" : "rgba(0,0,0,0.18)"}`,
background: isDark ? "rgba(255,255,255,0.08)" : "rgba(0,0,0,0.07)",
color: isDark ? "#fff" : "#111",
transition: "background 0.4s, color 0.4s, border-color 0.4s",
}}
>
{isDark ? "☀" : "☾"} {isDark ? "Light mode" : "Dark mode"}
</button>
)}
</div>
);
}