fix: fix region align & shuffle

src/core/part.ts

@@ -16,7 +16,7 @@ export type Part = Entity & {
 
   // current region
   region: EntityAccessor<Region>;
-  // current position in region
+  // current position in region, expect to be the same length as region's axes
   position: number[];
 }
 
@@ -30,4 +30,4 @@ export function flipTo(part: Part, side: number) {
 
 export function roll(part: Part, rng: RNG) {
   part.side = rng.nextInt(part.sides);
-}
+}

src/core/region.ts

@@ -3,7 +3,7 @@ import {Part} from "./part";
 import {RNG} from "../utils/rng";
 
 export type Region = Entity & {
-  // aligning axes of the region
+  // aligning axes of the region, expect a part's position to have a matching number of elements
   axes: RegionAxis[];
 
   // current children; expect no overlapped positions
@@ -26,33 +26,30 @@ export type RegionAxis = {
  * @param region
  */
 export function applyAlign(region: Region){
-  for (const axis of region.axes) {
-    if (region.children.length === 0) continue;
+  if (region.children.length === 0) return;
+
+  // 对每个 axis 分别处理
+  for (let axisIndex = 0; axisIndex < region.axes.length; axisIndex++) {
+    const axis = region.axes[axisIndex];
+    if (!axis.align) continue;
 
-    // 获取当前轴向上的所有位置
-    const positions = region.children.map(accessor => accessor.value.position);
-    
     // 根据当前轴的位置排序 children
     region.children.sort((a, b) => {
-      const posA = a.value.position[0] ?? 0;
-      const posB = b.value.position[0] ?? 0;
+      const posA = a.value.position[axisIndex] ?? 0;
+      const posB = b.value.position[axisIndex] ?? 0;
       return posA - posB;
     });
 
     if (axis.align === 'start' && axis.min !== undefined) {
       // 从 min 开始紧凑排列
       region.children.forEach((accessor, index) => {
-        const currentPos = accessor.value.position.slice();
-        currentPos[0] = axis.min! + index;
-        accessor.value.position = currentPos;
+        accessor.value.position[axisIndex] = axis.min! + index;
       });
     } else if (axis.align === 'end' && axis.max !== undefined) {
       // 从 max 开始向前紧凑排列
       const count = region.children.length;
       region.children.forEach((accessor, index) => {
-        const currentPos = accessor.value.position.slice();
-        currentPos[0] = axis.max! - (count - 1 - index);
-        accessor.value.position = currentPos;
+        accessor.value.position[axisIndex] = axis.max! - (count - 1 - index);
       });
     } else if (axis.align === 'center') {
       // 居中排列
@@ -61,13 +58,11 @@ export function applyAlign(region: Region){
       const max = axis.max ?? count - 1;
       const range = max - min;
       const center = min + range / 2;
-      
+
       region.children.forEach((accessor, index) => {
-        const currentPos = accessor.value.position.slice();
         // 计算相对于中心的偏移
         const offset = index - (count - 1) / 2;
-        currentPos[0] = center + offset;
-        accessor.value.position = currentPos;
+        accessor.value.position[axisIndex] = center + offset;
       });
     }
   }
@@ -85,11 +80,9 @@ export function shuffle(region: Region, rng: RNG){
   const children = [...region.children];
   for (let i = children.length - 1; i > 0; i--) {
     const j = rng.nextInt(i + 1);
-    // 交换位置
-    const posI = children[i].value.position.slice();
-    const posJ = children[j].value.position.slice();
-    
-    children[i].value.position = posJ;
-    children[j].value.position = posI;
+    // 交换两个 part 的整个 position 数组
+    const temp = children[i].value.position;
+    children[i].value.position = children[j].value.position;
+    children[j].value.position = temp;
   }
 }