feat: author first playable mystery

src/boardDomain.ts

@@ -16,6 +16,29 @@ export function moveBoardPoint(origin: { x: number; y: number }, screenDelta: {
   return { x: origin.x + screenDelta.x / zoom, y: origin.y + screenDelta.y / zoom }
 }
 
+export function nextOpenBoardPosition(
+  evidence: Pick<Evidence, 'x' | 'y' | 'width'>[],
+  preferred: { x: number; y: number },
+  size: { width: number; height?: number },
+  bounds = { width: 2400, height: 1500 },
+) {
+  const height = size.height || 160
+  const gap = 28
+  const overlaps = (x: number, y: number) => evidence.some(item =>
+    x < item.x + item.width + gap && x + size.width + gap > item.x &&
+    y < item.y + 160 + gap && y + height + gap > item.y)
+  const xStep = size.width + 46
+  const yStep = height + 46
+  for (let row = 0; row < 7; row += 1) {
+    for (const column of [0, 1, -1, 2, -2, 3, -3]) {
+      const x = Math.max(80, Math.min(bounds.width - size.width - 80, preferred.x + column * xStep))
+      const y = Math.max(100, Math.min(bounds.height - height - 80, preferred.y + row * yStep))
+      if (!overlaps(x, y)) return { x, y }
+    }
+  }
+  return { x: Math.max(80, Math.min(bounds.width - size.width - 80, preferred.x)), y: Math.min(bounds.height - height - 80, preferred.y + evidence.length * 24) }
+}
+
 export function panViewport(origin: Viewport, screenDelta: { x: number; y: number }): Viewport {
   return { ...origin, x: origin.x + screenDelta.x, y: origin.y + screenDelta.y }
 }