feat: secure analysis PLY sampling

server/pointcloudSample.test.ts

@@ -2,7 +2,7 @@ import { mkdtempSync, rmSync, writeFileSync } from 'node:fs';
 import { tmpdir } from 'node:os';
 import { join } from 'node:path';
 import { afterEach, describe, expect, it } from 'vitest';
-import { samplePointcloudFile } from './pointcloudSample';
+import { samplePointcloudFile, samplePointcloudFiles } from './pointcloudSample';
 
 const temporaryDirectories: string[] = [];
 
@@ -58,3 +58,32 @@ describe('samplePointcloudFile', () => {
     expect(points.map((point) => point.error)).toEqual([0.25, -0.5]);
   });
 });
+
+describe('samplePointcloudFiles', () => {
+  it('合并彩色与无色 PLY，并使用 28 字节彩色步长', async () => {
+    const plain = writeBinaryPly(['x', 'y', 'z'], [[1, 2, 3], [4, 5, 6]]);
+    const colored = writeBinaryPly(
+      ['x', 'y', 'z', 'red', 'green', 'blue'],
+      [[7, 8, 9, 255, 128, 0], [10, 11, 12, 0, 64, 255]],
+    );
+
+    const result = await samplePointcloudFiles([plain, colored], 4, 10);
+
+    expect(result.pointCount).toBe(4);
+    expect(result.hasColor).toBe(true);
+    expect(result.hasError).toBe(false);
+    expect(result.buffer.byteLength).toBe(4 * 28);
+    expect(result.fileStats.map((file) => file.sampled)).toEqual([2, 2]);
+  });
+
+  it('限制总采样数量，无色 PLY 使用 16 字节步长', async () => {
+    const first = writeBinaryPly(['x', 'y', 'z'], Array.from({ length: 10 }, (_, i) => [i, i, i]));
+    const second = writeBinaryPly(['x', 'y', 'z'], Array.from({ length: 10 }, (_, i) => [i + 10, i, i]));
+
+    const result = await samplePointcloudFiles([first, second], 100, 6);
+
+    expect(result.pointCount).toBe(6);
+    expect(result.hasColor).toBe(false);
+    expect(result.buffer.byteLength).toBe(6 * 16);
+  });
+});