| 1 | (function(){ |
| 2 | window.HPX = window.HPX || {}; |
| 3 | window.HPX['firework'] = function(el){ |
| 4 | const U = window.HPX._u; |
| 5 | const k = U.canvas(el), ctx = k.ctx; |
| 6 | const pal = U.palette(el); |
| 7 | let rockets = [], sparks = []; |
| 8 | const launch = () => { |
| 9 | rockets.push({ |
| 10 | x: U.rand(k.w*0.2, k.w*0.8), y: k.h+10, |
| 11 | vx: U.rand(-30,30), vy: U.rand(-520,-380), |
| 12 | tgtY: U.rand(k.h*0.15, k.h*0.45), |
| 13 | c: pal[(Math.random()*pal.length)|0] |
| 14 | }); |
| 15 | }; |
| 16 | const burst = (x, y, c) => { |
| 17 | const n = 70; |
| 18 | for (let i=0;i<n;i++){ |
| 19 | const a = Math.random()*Math.PI*2; |
| 20 | const s = U.rand(60, 240); |
| 21 | sparks.push({x,y,vx:Math.cos(a)*s,vy:Math.sin(a)*s,life:1,c}); |
| 22 | } |
| 23 | }; |
| 24 | let last = -1; |
| 25 | const stop = U.loop((t) => { |
| 26 | ctx.fillStyle = 'rgba(0,0,0,0.18)'; |
| 27 | ctx.fillRect(0,0,k.w,k.h); |
| 28 | if (t - last > 0.7) { launch(); last = t; } |
| 29 | const dt = 1/60; |
| 30 | rockets = rockets.filter(r => { |
| 31 | r.x += r.vx*dt; r.y += r.vy*dt; r.vy += 260*dt; |
| 32 | ctx.fillStyle = r.c; |
| 33 | ctx.beginPath(); ctx.arc(r.x, r.y, 2.5, 0, Math.PI*2); ctx.fill(); |
| 34 | if (r.y <= r.tgtY || r.vy >= 0) { burst(r.x, r.y, r.c); return false; } |
| 35 | return true; |
| 36 | }); |
| 37 | sparks = sparks.filter(p => p.life > 0); |
| 38 | for (const p of sparks){ |
| 39 | p.vy += 90*dt; |
| 40 | p.vx *= 0.98; p.vy *= 0.98; |
| 41 | p.x += p.vx*dt; p.y += p.vy*dt; |
| 42 | p.life -= 0.012; |
| 43 | ctx.globalAlpha = Math.max(0, p.life); |
| 44 | ctx.fillStyle = p.c; |
| 45 | ctx.beginPath(); ctx.arc(p.x, p.y, 2, 0, Math.PI*2); ctx.fill(); |
| 46 | } |
| 47 | ctx.globalAlpha = 1; |
| 48 | }); |
| 49 | return { stop(){ stop(); k.destroy(); } }; |
| 50 | }; |
| 51 | })(); |
| 52 |