first-commit

skills/html-ppt/assets/animations/fx/matrix-rain.js

@@ -0,0 +1,33 @@
+(function(){
+  window.HPX = window.HPX || {};
+  window.HPX['matrix-rain'] = function(el){
+    const U = window.HPX._u;
+    const k = U.canvas(el), ctx = k.ctx;
+    const glyphs = 'アイウエオカキクケコサシスセソタチツテトナニヌネノ0123456789ABCDEF'.split('');
+    const fs = 16;
+    let cols = 0, drops = [];
+    const init = () => {
+      cols = Math.ceil(k.w/fs);
+      drops = Array.from({length:cols}, () => U.rand(-20, 0));
+    };
+    init();
+    let lw = k.w, lh = k.h;
+    const stop = U.loop(() => {
+      if (k.w!==lw || k.h!==lh){ init(); lw=k.w; lh=k.h; }
+      ctx.fillStyle = 'rgba(0,0,0,0.08)';
+      ctx.fillRect(0,0,k.w,k.h);
+      ctx.font = fs+'px monospace';
+      for (let i=0;i<cols;i++){
+        const ch = glyphs[(Math.random()*glyphs.length)|0];
+        const x = i*fs, y = drops[i]*fs;
+        ctx.fillStyle = '#9fffc9';
+        ctx.fillText(ch, x, y);
+        ctx.fillStyle = '#00ff6a';
+        ctx.fillText(ch, x, y - fs);
+        drops[i] += 1;
+        if (y > k.h && Math.random() > 0.975) drops[i] = 0;
+      }
+    });
+    return { stop(){ stop(); k.destroy(); } };
+  };
+})();