refactor file and assets search

engine/asset.cpp

@@ -10,6 +10,73 @@
 AAssetManager* Asset::m_am;
 #endif
 
+std::vector<std::string> Asset::list_files(std::string folder, bool is_asset, const std::string& filter_regex)
+{
+    std::vector<std::string> names;
+#ifdef _WIN32
+    WIN32_FIND_DATAA fd;
+    HANDLE hFind = ::FindFirstFileA((folder + "*").c_str(), &fd);
+    if (hFind != INVALID_HANDLE_VALUE) 
+    {
+        do 
+        {
+            // read all (real) files in current folder
+            // , delete '!' read other 2 default folder . and ..
+            if (!(fd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)) 
+            {
+                names.push_back(fd.cFileName);
+            }
+        } while (::FindNextFileA(hFind, &fd));
+        ::FindClose(hFind);
+    }
+#elif __ANDROID__
+    if (is_asset)
+    {
+        AAssetDir* dir = AAssetManager_openDir(Asset::m_am, folder.c_str());
+        while (const char* name = AAssetDir_getNextFileName(dir))
+        {
+            //LOG("asset: %s", name);
+            names.push_back(name);
+        }
+        AAssetDir_close(dir);
+    }
+    else
+    {
+
+    }
+#else
+    if (is_asset)
+    {
+        NSString* bundle_path = [[NSBundle mainBundle] resourcePath];
+        std::string base = [bundle_path cStringUsingEncoding : 1];
+        std::string abs_path = base + "/" + folder;
+    }
+
+    DIR *dp;
+    struct dirent *ep;
+    dp = opendir(abs_path.c_str());
+
+    if (dp != NULL)
+    {
+        while ((ep = readdir(dp)))
+            if (ep->d_type != DT_DIR)
+                names.push_back(ep->d_name);
+        closedir(dp);
+    }
+    else
+        LOG("Couldn't open the directory: %s", folder.c_str());
+#endif
+
+    if (!filter_regex.empty())
+    {
+        std::regex r(filter_regex);
+        names.erase(std::remove_if(names.begin(), names.end(),
+            [&r](const std::string& s) { return !std::regex_match(s, r); }), names.end());
+    }
+
+    return names;
+}
+
 bool Asset::open(const char* path)
 {
     LOG("Asset::open %s", path);