first-commit

skills/html-ppt/assets/animations/fx/sparkle-trail.js

@@ -0,0 +1,62 @@
+(function(){
+  window.HPX = window.HPX || {};
+  window.HPX['sparkle-trail'] = function(el){
+    const U = window.HPX._u;
+    const k = U.canvas(el), ctx = k.ctx;
+    k.c.style.pointerEvents = 'none';
+    el.style.cursor = 'crosshair';
+    const pal = U.palette(el);
+    let sparks = [];
+    const onMove = (e) => {
+      const r = el.getBoundingClientRect();
+      const x = e.clientX - r.left, y = e.clientY - r.top;
+      for (let i=0;i<3;i++){
+        sparks.push({
+          x, y,
+          vx: U.rand(-60,60), vy: U.rand(-80,20),
+          life: 1, c: pal[(Math.random()*pal.length)|0],
+          r: U.rand(1.5,3.5)
+        });
+      }
+    };
+    // auto-wiggle if no mouse moves
+    let auto = true, autoT = 0;
+    const onAny = () => { auto = false; };
+    el.addEventListener('pointermove', onMove);
+    el.addEventListener('pointerenter', onAny);
+    const stop = U.loop(() => {
+      ctx.fillStyle = 'rgba(0,0,0,0.15)';
+      ctx.fillRect(0,0,k.w,k.h);
+      if (auto){
+        autoT += 0.04;
+        const x = k.w/2 + Math.cos(autoT)*k.w*0.3;
+        const y = k.h/2 + Math.sin(autoT*1.3)*k.h*0.3;
+        for (let i=0;i<3;i++){
+          sparks.push({
+            x, y,
+            vx: U.rand(-60,60), vy: U.rand(-80,20),
+            life: 1, c: pal[(Math.random()*pal.length)|0],
+            r: U.rand(1.5,3.5)
+          });
+        }
+      }
+      const dt = 1/60;
+      sparks = sparks.filter(s => s.life > 0);
+      for (const s of sparks){
+        s.vy += 160*dt;
+        s.x += s.vx*dt; s.y += s.vy*dt;
+        s.life -= 0.018;
+        ctx.globalAlpha = Math.max(0, s.life);
+        ctx.fillStyle = s.c;
+        ctx.beginPath(); ctx.arc(s.x,s.y,s.r,0,Math.PI*2); ctx.fill();
+      }
+      ctx.globalAlpha = 1;
+    });
+    return { stop(){
+      el.removeEventListener('pointermove', onMove);
+      el.removeEventListener('pointerenter', onAny);
+      el.style.cursor = '';
+      stop(); k.destroy();
+    }};
+  };
+})();