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magnetic-field.js
根目录 / assets / animations / fx / magnetic-field.js
1 (function(){
2 window.HPX = window.HPX || {};
3 window.HPX['magnetic-field'] = function(el){
4 const U = window.HPX._u;
5 const k = U.canvas(el), ctx = k.ctx;
6 const pal = U.palette(el);
7 const N = 60;
8 const parts = Array.from({length:N}, (_,i) => ({
9 phase: Math.random()*Math.PI*2,
10 freq: U.rand(0.4, 1.2),
11 amp: U.rand(30, 90),
12 y0: U.rand(0.15, 0.85),
13 c: pal[i%pal.length],
14 trail: []
15 }));
16 const stop = U.loop((t) => {
17 ctx.fillStyle = 'rgba(0,0,0,0.08)';
18 ctx.fillRect(0,0,k.w,k.h);
19 for (const p of parts){
20 const x = ((t*80 + p.phase*50) % (k.w+100)) - 50;
21 const y = k.h*p.y0 + Math.sin(x*0.02 + p.phase + t*p.freq)*p.amp;
22 p.trail.push([x,y]);
23 if (p.trail.length > 18) p.trail.shift();
24 ctx.strokeStyle = p.c;
25 ctx.lineWidth = 2;
26 ctx.beginPath();
27 for (let i=0;i<p.trail.length;i++){
28 const [tx,ty] = p.trail[i];
29 if (i===0) ctx.moveTo(tx,ty); else ctx.lineTo(tx,ty);
30 }
31 ctx.globalAlpha = 0.7;
32 ctx.stroke();
33 ctx.globalAlpha = 1;
34 ctx.fillStyle = p.c;
35 ctx.beginPath(); ctx.arc(x,y,2.5,0,Math.PI*2); ctx.fill();
36 }
37 });
38 return { stop(){ stop(); k.destroy(); } };
39 };
40 })();
41
41 lines JAVASCRIPT