Use windows API to convert UTF-16 for clipboard

imgui.cpp

@@ -9485,11 +9485,11 @@ static const char* GetClipboardTextFn_DefaultImpl(void*)
         ::CloseClipboard();
         return NULL;
     }
-    if (ImWchar* wbuf_global = (ImWchar*)::GlobalLock(wbuf_handle))
+    if (const WCHAR* wbuf_global = (const WCHAR*)::GlobalLock(wbuf_handle))
     {
-        int buf_len = ImTextCountUtf8BytesFromStr(wbuf_global, NULL) + 1;
+        int buf_len = ::WideCharToMultiByte(CP_UTF8, 0, wbuf_global, -1, NULL, 0, NULL, NULL);
         buf_local.resize(buf_len);
-        ImTextStrToUtf8(buf_local.Data, buf_len, wbuf_global, NULL);
+        ::WideCharToMultiByte(CP_UTF8, 0, wbuf_global, -1, buf_local.Data, buf_len, NULL, NULL);
     }
     ::GlobalUnlock(wbuf_handle);
     ::CloseClipboard();
@@ -9500,15 +9500,15 @@ static void SetClipboardTextFn_DefaultImpl(void*, const char* text)
 {
     if (!::OpenClipboard(NULL))
         return;
-    const int wbuf_length = ImTextCountCharsFromUtf8(text, NULL) + 1;
-    HGLOBAL wbuf_handle = ::GlobalAlloc(GMEM_MOVEABLE, (SIZE_T)wbuf_length * sizeof(ImWchar));
+    const int wbuf_length = ::MultiByteToWideChar(CP_UTF8, 0, text, -1, NULL, 0);
+    HGLOBAL wbuf_handle = ::GlobalAlloc(GMEM_MOVEABLE, (SIZE_T)wbuf_length * sizeof(WCHAR));
     if (wbuf_handle == NULL)
     {
         ::CloseClipboard();
         return;
     }
-    ImWchar* wbuf_global = (ImWchar*)::GlobalLock(wbuf_handle);
-    ImTextStrFromUtf8(wbuf_global, wbuf_length, text, NULL);
+    WCHAR* wbuf_global = (WCHAR*)::GlobalLock(wbuf_handle);
+    ::MultiByteToWideChar(CP_UTF8, 0, text, -1, wbuf_global, wbuf_length);
     ::GlobalUnlock(wbuf_handle);
     ::EmptyClipboard();
     if (::SetClipboardData(CF_UNICODETEXT, wbuf_handle) == NULL)