From b7997a5e885258c2ab5e5137f01da2e6984d9e3e Mon Sep 17 00:00:00 2001
From: Evil Eye <malusluminis@hotmail.com>
Date: Sat, 16 Aug 2025 11:33:58 +0200
Subject: [PATCH] Use a simpler way of formatting floats

---
 apps/openmw/mwgui/tooltips.cpp       | 56 +++++-----------------------
 apps/openmw_tests/mwgui/tooltips.cpp |  2 +-
 2 files changed, 10 insertions(+), 48 deletions(-)

diff --git a/apps/openmw/mwgui/tooltips.cpp b/apps/openmw/mwgui/tooltips.cpp
index 788123c625..678847532c 100644
--- a/apps/openmw/mwgui/tooltips.cpp
+++ b/apps/openmw/mwgui/tooltips.cpp
@@ -30,50 +30,6 @@
 
 #include "itemmodel.hpp"
 
-namespace
-{
-    template <unsigned short Precision = 2>
-    struct LimitedFloat
-    {
-        float mValue;
-
-        constexpr unsigned short getPrecision() { return Precision; }
-    };
-}
-
-template <>
-struct std::formatter<LimitedFloat<>, char>
-{
-    template <class ParseContext>
-    constexpr ParseContext::iterator parse(ParseContext& ctx)
-    {
-        return ctx.begin();
-    }
-
-    template <class FmtContext>
-    FmtContext::iterator format(LimitedFloat<> v, FmtContext& ctx) const
-    {
-        constexpr unsigned short precision = v.getPrecision();
-        // FLOAT_MAX needs 39 digits + 1 for the sign + 1 for the decimal separator
-        constexpr std::size_t bufferSize = 41 + precision;
-        char buffer[bufferSize];
-        std::to_chars_result result
-            = std::to_chars(buffer, buffer + bufferSize, v.mValue, std::chars_format::fixed, precision);
-        if (result.ec != std::errc())
-        {
-            // Should never happen, but just default to regular float formatting
-            return std::format_to(ctx.out(), "{}", v.mValue);
-        }
-        // Trim result so 1.00 turns into 1
-        char* end = result.ptr;
-        while (end > buffer && *(end - 1) == '0')
-            --end;
-        if (end > buffer && *(end - 1) == '.')
-            --end;
-        return std::ranges::copy(buffer, end, ctx.out()).out;
-    }
-};
-
 namespace MWGui
 {
     ToolTips::ToolTips()
@@ -687,7 +643,13 @@ namespace MWGui
 
     std::string ToolTips::toString(const float value)
     {
-        return std::format("{}", LimitedFloat(value));
+        std::string s = std::format("{:.2f}", value);
+        // Trim result so 1.00 turns into 1
+        while (!s.empty() && s.back() == '0')
+            s.pop_back();
+        if (!s.empty() && s.back() == '.')
+            s.pop_back();
+        return s;
     }
 
     std::string ToolTips::toString(const int value)
@@ -699,14 +661,14 @@ namespace MWGui
     {
         if (weight == 0)
             return {};
-        return std::format("\n{}: {}", prefix, LimitedFloat(weight));
+        return std::format("\n{}: {}", prefix, toString(weight));
     }
 
     std::string ToolTips::getPercentString(const float value, std::string_view prefix)
     {
         if (value == 0)
             return {};
-        return std::format("\n{}: {}%", prefix, LimitedFloat(value * 100));
+        return std::format("\n{}: {}%", prefix, toString(value * 100));
     }
 
     std::string ToolTips::getValueString(const int value, std::string_view prefix)
diff --git a/apps/openmw_tests/mwgui/tooltips.cpp b/apps/openmw_tests/mwgui/tooltips.cpp
index 61784dbfbd..ee41b23721 100644
--- a/apps/openmw_tests/mwgui/tooltips.cpp
+++ b/apps/openmw_tests/mwgui/tooltips.cpp
@@ -16,7 +16,7 @@ namespace MWGui
             EXPECT_EQ(ToolTips::toString(1234567.12f), "1234567.12");
             EXPECT_EQ(ToolTips::toString(0.001f), "0");
             EXPECT_EQ(ToolTips::toString(0.01f), "0.01");
-            EXPECT_EQ(ToolTips::toString(0.01f), "0.01");
+            EXPECT_EQ(ToolTips::toString(0.012f), "0.01");
             EXPECT_EQ(ToolTips::toString(std::numeric_limits<float>::infinity()), "inf");
             EXPECT_EQ(ToolTips::toString(std::numeric_limits<float>::quiet_NaN()), "nan");
         }