fix(snapline): snapline cannot show when zoomed & add a build line to CONTRIBUTING.md

Author: HawtinZeng

CONTRIBUTING.md

@@ -20,6 +20,9 @@ LogicFlow 维护同学会确认 issue 意图，更新合适的标签，关联 mi
 # 先创建开发分支开发，分支名应该有含义，避免使用 update、tmp 之类的
 $ git checkout -b branch-name
 
+# 先 build 所有 workspace 依赖，避免在开发某个包时，找不到 workspace 依赖
+$ pnpm run build
+
 # 开发某个包时，利用 build:watch 监听变化实时打包更新
 $ cd packages/core # or other packages, such as packages/extensions
 $ pnpm run build:watch

packages/core/src/model/SnaplineModel.ts

@@ -95,19 +95,21 @@ export class SnaplineModel {
       // 排除当前节点
       if (item.id !== draggingNode.id) {
         const itemData = getNodeBBox(item)
+
         // 如果节点的最大最小Y轴坐标与节点的最大最小Y轴坐标相等，展示水平线
+        const epsilon = 1
         if (
-          itemData.minY === draggingData?.minY ||
-          itemData.maxY === draggingData?.minY
+          equal(itemData.minY, draggingData?.minY, epsilon) ||
+          equal(itemData.maxY, draggingData?.minY, epsilon)
         ) {
           // 找到则停止循环。减少不必要的遍历
           isShowHorizontal = true
           horizontalY = draggingData.minY
           break
         }
         if (
-          itemData.minY === draggingData?.maxY ||
-          itemData.maxY === draggingData?.maxY
+          equal(itemData.minY, draggingData?.maxY, epsilon) ||
+          equal(itemData.maxY, draggingData?.maxY, epsilon)
         ) {
           isShowHorizontal = true
           horizontalY = draggingData.maxY
@@ -151,18 +153,19 @@ export class SnaplineModel {
       if (item.id !== draggingNode.id) {
         const itemData = getNodeBBox(item)
         // 如果节点的最大最小X轴坐标与节点的最大最小X轴坐标相等，展示垂直线
+        const epsilon = 1
         if (
-          itemData.minX === draggingData?.minX ||
-          itemData.maxX === draggingData?.minX
+          equal(itemData.minX, draggingData?.minX, epsilon) ||
+          equal(itemData.maxX, draggingData?.minX, epsilon)
         ) {
           // 找到则停止循环。减少不必要的遍历
           isShowVertical = true
           verticalX = draggingData.minX
           break
         }
         if (
-          itemData.minX === draggingData?.maxX ||
-          itemData.maxX === draggingData?.maxX
+          equal(itemData.minX, draggingData?.maxX, epsilon) ||
+          equal(itemData.maxX, draggingData?.maxX, epsilon)
         ) {
           isShowVertical = true
           verticalX = draggingData.maxX
@@ -235,4 +238,12 @@ export class SnaplineModel {
   }
 }
 
+function equal(num1: number, num2: number, epsilon: number) {
+  if (Math.abs(num1 - num2) <= epsilon) {
+    return true
+  } else {
+    return false
+  }
+}
+
 export default SnaplineModel