From ae846debd4d546f3b2c78a949ce237543f76dc80 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Tue, 27 Apr 2021 12:21:01 +0200
Subject: [PATCH] Add C++ current culture sync with localization system

---
 Source/Engine/Localization/Localization.cpp | 26 +++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/Source/Engine/Localization/Localization.cpp b/Source/Engine/Localization/Localization.cpp
index 8148de07a..1de886590 100644
--- a/Source/Engine/Localization/Localization.cpp
+++ b/Source/Engine/Localization/Localization.cpp
@@ -10,6 +10,7 @@
 #include "Engine/Content/Content.h"
 #include "Engine/Profiler/ProfilerCPU.h"
 #include "Engine/Serialization/Serialization.h"
+#include <locale>
 
 class LocalizationService : public EngineService
 {
@@ -163,6 +164,31 @@ void LocalizationService::OnLocalizationChanged()
         Instance.LocalizedStringTables.Add(table->Get(), table->Count());
     }
 
+    // Change C++ locale (eg. used by fmt lib for values formatting)
+    {
+        char localeName[100];
+        const auto& currentCulture = Instance.CurrentCulture.GetName();
+        if (currentCulture.IsEmpty())
+        {
+            localeName[0] = 0;
+        }
+        else
+        {
+            StringUtils::ConvertUTF162ANSI(currentCulture.GetText(), localeName, currentCulture.Length());
+            for (int32 i = 0; i < currentCulture.Length(); i++)
+                if (localeName[i] == '-')
+                    localeName[i] = '_';
+            localeName[currentCulture.Length() + 0] = '.';
+            localeName[currentCulture.Length() + 1] = 'U';
+            localeName[currentCulture.Length() + 2] = 'T';
+            localeName[currentCulture.Length() + 3] = 'F';
+            localeName[currentCulture.Length() + 4] = '-';
+            localeName[currentCulture.Length() + 5] = '8';
+            localeName[currentCulture.Length() + 6] = 0;
+        }
+        std::locale::global(std::locale(localeName));
+    }
+
     // Send event
     Localization::LocalizationChanged();
 }