fix(magnets): keep elongated five-pocket layouts in a cross

.changeset/fix-oval-cross.md

@@ -0,0 +1,5 @@
+---
+'basekit': patch
+---
+
+Keep saved five-pocket magnet layouts in a cross on elongated bases and matching holders.

README.md

@@ -57,7 +57,7 @@ Make a round, square, or hex token for objectives, Oath of Moment, or anything e
 - Printable 15, 20, 30, and 35mm flying stems with adjustable peg or ball-joint connections.
 - Round, square, and hex tokens with wrapped text and traced image silhouettes.
 - Shared magnet dimensions across bases, holders, movement trays, and spray trays.
-- Balanced or five-pocket cross magnet arrangements for bases and holders.
+- Balanced or five-pocket cross magnet arrangements for bases and holders. Saved cross layouts keep one centre pocket and four outer pockets on both axes, including elongated footprints.
 - Exact size labels, filenames, dimensions, and high-quality exports.
 - Browser-saved settings with shared base and holder preferences, and a confirmed reset for each generator or for the shared settings.
 - Copyable links that open the current generator with the same settings.

src/geometry/base.test.ts

@@ -197,6 +197,45 @@ describe('buildBase', () => {
     expect(positions.filter(({ x, y }) => Math.hypot(x, y) > 1e-6)).toHaveLength(4)
   })
 
+  it.each([
+    [83, 52.5],
+    [52.5, 83],
+  ])('keeps five-pocket crosses on both axes of an elongated %s × %s well', (halfWidth, halfLength) => {
+    expect(magnetPositions(5, halfWidth, halfLength, 4.9, { layout: 'five-cross', ellipticalRow: true })).toEqual([
+      { x: 0, y: 0, r: 0 },
+      { x: 0, y: 26.25, r: 26.25 },
+      { x: -26.25, y: 0, r: 26.25 },
+      { x: 0, y: -26.25, r: 26.25 },
+      { x: 26.25, y: 0, r: 26.25 },
+    ])
+  })
+
+  it('drills the legacy 170 × 109 oval cross on both axes', () => {
+    const base = presetFor({ shape: 'oval', width: 170, length: 109, label: '170×109', use: '' }, 8, 1)
+    const config = {
+      ...base,
+      wallThickness: 2,
+      magnets: { ...base.magnets, layout: 'five-cross' as const, count: 5, diameter: 6 },
+      ribs: { ...base.ribs, count: 4 },
+      segments: exportSegmentsFor(170),
+    }
+    const { mesh } = build(config)
+    const centers = [
+      [0, 0],
+      [0, 26.25],
+      [-26.25, 0],
+      [0, -26.25],
+      [26.25, 0],
+    ]
+    for (const [x, y] of centers) {
+      const pocket = pocketAt(mesh, x, y, 3.1)
+      expect(pocket.maxRadius).toBeCloseTo(3.1, 1)
+      expect(pocket.minZ).toBeCloseTo(config.height - config.magnets.thickness - config.magnets.depthClearance, 5)
+      expect(pocket.maxZ).toBeCloseTo(config.height, 5)
+    }
+    expect(duplicateVertices(mesh)).toBe(0)
+  })
+
   it.for([RECT_SIZES[0], RECT_SIZES[1], ROUND_SIZES[0], ROUND_SIZES[1]])('still fits a size label on a cramped $label base', (size) => {
     // The well of a small base is mostly boss and ribs, and the label used to be
     // dropped silently when the first direction tried had no room.

src/geometry/base.ts

@@ -48,13 +48,20 @@ export function magnetPositions(
   options: MagnetPositionOptions = {},
 ): Circle[] {
   if (count <= 0) return []
+  const short = Math.min(halfWidth, halfLength)
+  const radius = Math.max(Math.min(short * 0.5, short - clear), 0)
   if (options.layout === 'five-cross') {
-    return [{ x: 0, y: 0, r: 0 }, ...magnetPositions(4, halfWidth, halfLength, clear, { ...options, layout: 'balanced' })]
+    return [
+      { x: 0, y: 0, r: 0 },
+      { x: 0, y: radius, r: radius },
+      { x: -radius, y: 0, r: radius },
+      { x: 0, y: -radius, r: radius },
+      { x: radius, y: 0, r: radius },
+    ]
   }
   if (count === 1) return [{ x: 0, y: 0, r: 0 }]
 
   const long = Math.max(halfWidth, halfLength)
-  const short = Math.min(halfWidth, halfLength)
   if (!magnetsRing(halfWidth, halfLength)) {
     const ellipseReach = long * Math.sqrt(Math.max(0, 1 - (clear / short) ** 2)) - clear
     const reach = Math.max(options.ellipticalRow ? ellipseReach : long - clear, 0)
@@ -65,7 +72,6 @@ export function magnetPositions(
     })
   }
 
-  const radius = Math.max(Math.min(short * 0.5, short - clear), 0)
   return Array.from({ length: count }, (_, i) => {
     const a = Math.PI / 2 + (2 * Math.PI * i) / count
     return { x: radius * Math.cos(a), y: radius * Math.sin(a), r: radius }

src/geometry/holder.test.ts

@@ -173,7 +173,13 @@ describe('holderLayout', () => {
     }
     const oval = holderGroup('oval', 1, { shape: 'oval', width: 60, length: 35 })
 
-    expect(holderSlotMagnetCenters(oval, settings)).toHaveLength(5)
+    expect(holderSlotMagnetCenters(oval, settings)).toEqual([
+      { x: 0, y: 0 },
+      { x: 0, y: 7.75 },
+      { x: -7.75, y: 0 },
+      { x: 0, y: -7.75 },
+      { x: 7.75, y: 0 },
+    ])
   })
 
   it('fits forty 32mm models within a 7×5 box without false overflow', () => {