feat:提交

tests/dev1/dataHandle/common/ComparePoint.ts

@@ -0,0 +1,62 @@
+interface Vec2 { x: number; y: number }
+
+export type CompareVectorFn = (v1: Vec2, v2: Vec2) => number
+
+const comparePointCache: Map<string, CompareVectorFn> = new Map()
+
+const ALLKEY = ['x', 'X', 'y', 'Y', 'z', 'Z']
+const KEY = ['x', 'y', 'z']
+
+/**
+ * 构建返回一个用来排序的函数.根据key创建排序规则.
+ *
+ * 当key = "xyz" 时,点集按 x从小到大,y从小到大 z从小到大
+ *   key = "X"   时,点集按 x从大到小
+ * 以此类推.
+ *
+ * 例子:
+ * let pts:Vector3[] =...;
+ * pts.sort(comparePoint("x")); //x从小到大排序
+ * pts.sort(comparePoint("zX")); //z从小到大 x从大到小
+ *
+ * @export
+ * @param {string} sortKey
+ */
+export function ComparePoint(sortKey: string): CompareVectorFn
+{
+  if (comparePointCache.has(sortKey))
+    return comparePointCache.get(sortKey)
+
+  let sortIndex = []
+
+  for (let char of sortKey)
+  {
+    let index = ALLKEY.indexOf(char)
+
+    let i2 = index / 2
+    let ci = Math.floor(i2)
+    sortIndex.push([KEY[ci], i2 > ci ? 1 : -1])
+  }
+
+  let compareFunction = (v1: Vec2, v2: Vec2): number =>
+  {
+    if (!v1)
+      return -1
+    if (!v2)
+      return 1
+    for (let s of sortIndex)
+    {
+      let vv1 = v1[s[0]]
+      let vv2 = v2[s[0]]
+      if (vv1 === vv2)
+        continue
+      if (vv2 > vv1)
+        return s[1]
+      else return -s[1]
+    }
+    return 0
+  }
+
+  comparePointCache.set(sortKey, compareFunction)
+  return compareFunction
+}