fix(editor): Diamond hit test shortcut (#11631)

---------

Signed-off-by: Mark Tolmacs <mark@lazycat.hu>

packages/element/src/distance.ts

@@ -75,9 +75,7 @@ const distanceToRectanguloidElement = (
 
   return Math.min(
     ...sides.map((s) => distanceToLineSegment(rotatedPoint, s)),
-    ...corners
-      .map((a) => curvePointDistance(a, rotatedPoint))
-      .filter((d): d is number => d !== null),
+    ...corners.map((a) => curvePointDistance(a, rotatedPoint)),
   );
 };
 
@@ -104,9 +102,7 @@ const distanceToDiamondElement = (
 
   return Math.min(
     ...sides.map((s) => distanceToLineSegment(rotatedPoint, s)),
-    ...curves
-      .map((a) => curvePointDistance(a, rotatedPoint))
-      .filter((d): d is number => d !== null),
+    ...curves.map((a) => curvePointDistance(a, rotatedPoint)),
   );
 };
 

packages/element/src/utils.ts

@@ -431,10 +431,20 @@ export function deconstructDiamondElement(
 
   const baseCorners = getDiamondBaseCorners(element, offset);
 
-  const corners = baseCorners.map(
-    (corner) =>
-      curveCatmullRomCubicApproxPoints(curveOffsetPoints(corner, offset))!,
-  );
+  const corners =
+    offset > 0
+      ? baseCorners.map(
+          (corner) =>
+            curveCatmullRomCubicApproxPoints(
+              curveOffsetPoints(corner, offset),
+            )!,
+        )
+      : [
+          [baseCorners[0]],
+          [baseCorners[1]],
+          [baseCorners[2]],
+          [baseCorners[3]],
+        ];
 
   const sides = [
     lineSegment<GlobalPoint>(

packages/math/src/curve.ts

@@ -267,7 +267,10 @@ export function curveClosestPoint<Point extends GlobalPoint | LocalPoint>(
     pointDistance(p, bezierEquation(c, t)),
   );
 
-  if (!solution) {
+  // `solution` is only nullish when the search window is narrower than the
+  // tolerance (e.g. a caller-supplied tolerance larger than the window). A
+  // legitimate solution of `t = 0` must not be treated as a failure.
+  if (solution == null) {
     return null;
   }
 
@@ -287,8 +290,10 @@ export function curvePointDistance<Point extends GlobalPoint | LocalPoint>(
 ) {
   const closest = curveClosestPoint(c, p);
 
+  // No closest point found: report an "infinitely far" distance so this curve
+  // is never mistaken for the nearest component when fed into `Math.min`.
   if (!closest) {
-    return 0;
+    return Infinity;
   }
 
   return pointDistance(p, closest);