feat: more accurate file sorting on windows (#798)

src/uosc/lib/utils.lua

@@ -5,7 +5,62 @@
 
 --- In place sorting of filenames
 ---@param filenames string[]
-function sort_filenames(filenames)
+
+----- winapi start -----
+-- in windows system, we can use the sorting function provided by the win32 API
+-- see https://learn.microsoft.com/en-us/windows/win32/api/shlwapi/nf-shlwapi-strcmplogicalw
+-- this function was taken from https://github.com/mpvnet-player/mpv.net/issues/575#issuecomment-1817413401
+local winapi = {}
+
+if state.platform == 'windows' then
+	-- is_ffi_loaded is false usually means the mpv builds without luajit
+	local is_ffi_loaded, ffi = pcall(require, 'ffi')
+
+	if is_ffi_loaded then
+		winapi = {
+			ffi = ffi,
+			C = ffi.C,
+			CP_UTF8 = 65001,
+			shlwapi = ffi.load('shlwapi'),
+		}
+
+		-- ffi code from https://github.com/po5/thumbfast, Mozilla Public License Version 2.0
+		ffi.cdef[[
+			int __stdcall MultiByteToWideChar(unsigned int CodePage, unsigned long dwFlags, const char *lpMultiByteStr,
+			int cbMultiByte, wchar_t *lpWideCharStr, int cchWideChar);
+			int __stdcall StrCmpLogicalW(wchar_t *psz1, wchar_t *psz2);
+		]]
+
+		winapi.utf8_to_wide = function(utf8_str)
+			if utf8_str then
+				local utf16_len = winapi.C.MultiByteToWideChar(winapi.CP_UTF8, 0, utf8_str, -1, nil, 0)
+
+				if utf16_len > 0 then
+					local utf16_str = winapi.ffi.new('wchar_t[?]', utf16_len)
+
+					if winapi.C.MultiByteToWideChar(winapi.CP_UTF8, 0, utf8_str, -1, utf16_str, utf16_len) > 0 then
+						return utf16_str
+					end
+				end
+			end
+
+			return ''
+		end
+	end
+end
+----- winapi end -----
+
+function sort_filenames_windows(filenames)
+	table.sort(filenames, function(a, b)
+		local a_wide = winapi.utf8_to_wide(a)
+		local b_wide = winapi.utf8_to_wide(b)
+		return winapi.shlwapi.StrCmpLogicalW(a_wide, b_wide) == -1
+	end)
+
+	return filenames
+end
+
+function sort_filenames_lua(filenames)
 	-- alphanum sorting for humans in Lua
 	-- http://notebook.kulchenko.com/algorithms/alphanumeric-natural-sorting-for-humans-in-lua
 	local function padnum(n, d)
@@ -24,6 +79,15 @@ function sort_filenames(filenames)
 	return filenames
 end
 
+function sort_filenames(filenames)
+	local is_ffi_loaded = pcall(require, 'ffi')
+	if state.platform == 'windows' and is_ffi_loaded then
+		sort_filenames_windows(filenames)
+	else
+		sort_filenames_lua(filenames)
+	end
+end
+
 -- Creates in-between frames to animate value from `from` to `to` numbers.
 ---@param from number
 ---@param to number|fun():number