41 lines
1.3 KiB
JavaScript
41 lines
1.3 KiB
JavaScript
(function(){
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window.HPX = window.HPX || {};
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window.HPX['magnetic-field'] = function(el){
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const U = window.HPX._u;
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const k = U.canvas(el), ctx = k.ctx;
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const pal = U.palette(el);
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const N = 60;
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const parts = Array.from({length:N}, (_,i) => ({
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phase: Math.random()*Math.PI*2,
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freq: U.rand(0.4, 1.2),
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amp: U.rand(30, 90),
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y0: U.rand(0.15, 0.85),
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c: pal[i%pal.length],
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trail: []
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}));
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const stop = U.loop((t) => {
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ctx.fillStyle = 'rgba(0,0,0,0.08)';
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ctx.fillRect(0,0,k.w,k.h);
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for (const p of parts){
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const x = ((t*80 + p.phase*50) % (k.w+100)) - 50;
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const y = k.h*p.y0 + Math.sin(x*0.02 + p.phase + t*p.freq)*p.amp;
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p.trail.push([x,y]);
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if (p.trail.length > 18) p.trail.shift();
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ctx.strokeStyle = p.c;
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ctx.lineWidth = 2;
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ctx.beginPath();
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for (let i=0;i<p.trail.length;i++){
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const [tx,ty] = p.trail[i];
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if (i===0) ctx.moveTo(tx,ty); else ctx.lineTo(tx,ty);
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}
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ctx.globalAlpha = 0.7;
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ctx.stroke();
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ctx.globalAlpha = 1;
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ctx.fillStyle = p.c;
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ctx.beginPath(); ctx.arc(x,y,2.5,0,Math.PI*2); ctx.fill();
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}
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});
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return { stop(){ stop(); k.destroy(); } };
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};
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})();
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