First commit.

Signed-off-by: Chen Xiao <abigwc@gmail.com>
2026-05-08 14:43:16 +08:00
commit 0b64e2de94
10989 changed files with 2253791 additions and 0 deletions
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+import {sin, cos, sqrt, pi, tau} from "../math.js";
+
+const ka = 0.89081309152928522810;
+const kr = sin(pi / 10) / sin(7 * pi / 10);
+const kx = sin(tau / 10) * kr;
+const ky = -cos(tau / 10) * kr;
+
+export default {
+  draw(context, size) {
+    const r = sqrt(size * ka);
+    const x = kx * r;
+    const y = ky * r;
+    context.moveTo(0, -r);
+    context.lineTo(x, y);
+    for (let i = 1; i < 5; ++i) {
+      const a = tau * i / 5;
+      const c = cos(a);
+      const s = sin(a);
+      context.lineTo(s * r, -c * r);
+      context.lineTo(c * x - s * y, s * x + c * y);
+    }
+    context.closePath();
+  }
+};