优化预览与导出排版

src/utils.ts

@@ -151,6 +151,60 @@ export const DEFAULT_CUT_LINE_CONFIG: CutLineConfig = {
   color: '#cccccc',
 };
 
+export interface GridCutLinePositions {
+  xs: number[];
+  ys: number[];
+  gridW: number;
+  gridH: number;
+}
+
+/** 收集网格裁切线坐标（去重），每条线只绘制一次，避免转角/外缘叠线变粗 */
+export function collectGridCutLinePositions(
+  originX: number,
+  originY: number,
+  labelW: number,
+  labelH: number,
+  gridCols: number,
+  gridRows: number,
+  columnGap: number,
+  rowGap: number
+): GridCutLinePositions {
+  const gridW = gridCols * labelW + Math.max(0, gridCols - 1) * columnGap;
+  const gridH = gridRows * labelH + Math.max(0, gridRows - 1) * rowGap;
+  const xs = new Set<number>();
+  const ys = new Set<number>();
+
+  for (let c = 0; c < gridCols; c++) {
+    xs.add(originX + c * (labelW + columnGap));
+    xs.add(originX + c * (labelW + columnGap) + labelW);
+  }
+  for (let r = 0; r < gridRows; r++) {
+    ys.add(originY + r * (labelH + rowGap));
+    ys.add(originY + r * (labelH + rowGap) + labelH);
+  }
+
+  return {
+    xs: [...xs].sort((a, b) => a - b),
+    ys: [...ys].sort((a, b) => a - b),
+    gridW,
+    gridH,
+  };
+}
+
+/** 间距为 0 且启用裁切线时，为裁切线预留半线宽通道，避免与标签图重叠导致内外粗细不一 */
+export function getCutLineChannel(
+  columnGap: number,
+  rowGap: number,
+  cutLine: { enabled: boolean; width: number }
+): { x: number; y: number } {
+  if (!cutLine.enabled) return { x: 0, y: 0 };
+  const half = cutLine.width / 2;
+  return {
+    x: columnGap === 0 ? half : 0,
+    y: rowGap === 0 ? half : 0,
+  };
+}
+
 export interface PrintableLabel {
   row: RecordRow;
   /** 原始数据行索引（0-based），用于变量解析 */