--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/web/drawing.ts	Sun May 12 19:02:10 2024 -0700
@@ -0,0 +1,64 @@
+
+export function svgPathFromPoints(pts: { forEach: (arg0: (p: any) => void) => void }) {
+  let out = "";
+  pts.forEach(function (p: Number[] | { elements: Number[] }) {
+    let x, y;
+    if ((p as any).elements) {
+      // for vec2
+      [x, y] = (p as any).elements;
+    } else {
+      [x, y] = p as Number[];
+    }
+    if (out.length === 0) {
+      out = "M ";
+    } else {
+      out += "L ";
+    }
+    out += "" + x + "," + y + " ";
+  });
+  return out;
+};
+
+export function line(
+  ctx: { moveTo: (arg0: any, arg1: any) => void; lineTo: (arg0: any, arg1: any) => any },
+  p1: { e: (arg0: number) => any },
+  p2: { e: (arg0: number) => any }
+) {
+  ctx.moveTo(p1.e(1), p1.e(2));
+  return ctx.lineTo(p2.e(1), p2.e(2));
+};
+
+// http://stackoverflow.com/a/4959890
+export function roundRect(
+  ctx: {
+    beginPath: () => void;
+    moveTo: (arg0: any, arg1: any) => void;
+    lineTo: (arg0: number, arg1: number) => void;
+    arc: (arg0: number, arg1: number, arg2: any, arg3: number, arg4: number, arg5: boolean) => void;
+    closePath: () => any;
+  },
+  sx: number,
+  sy: number,
+  ex: number,
+  ey: number,
+  r: number
+) {
+  const d2r = Math.PI / 180;
+  if (ex - sx - 2 * r < 0) {
+    r = (ex - sx) / 2;
+  } // ensure that the radius isn't too large for x
+  if (ey - sy - 2 * r < 0) {
+    r = (ey - sy) / 2;
+  } // ensure that the radius isn't too large for y
+  ctx.beginPath();
+  ctx.moveTo(sx + r, sy);
+  ctx.lineTo(ex - r, sy);
+  ctx.arc(ex - r, sy + r, r, d2r * 270, d2r * 360, false);
+  ctx.lineTo(ex, ey - r);
+  ctx.arc(ex - r, ey - r, r, d2r * 0, d2r * 90, false);
+  ctx.lineTo(sx + r, ey);
+  ctx.arc(sx + r, ey - r, r, d2r * 90, d2r * 180, false);
+  ctx.lineTo(sx, sy + r);
+  ctx.arc(sx + r, sy + r, r, d2r * 180, d2r * 270, false);
+  return ctx.closePath();
+};