editor, main: add fmtlib dependency

snprintf in imgui code is slow.

1 files changed, 20 insertions, 0 deletions

diff --git a/compat/format.hpp b/compat/format.hpp
new file mode 100644
index 00000000..e126e77b
--- /dev/null
+++ b/compat/format.hpp
@@ -0,0 +1,20 @@
+#pragma once
+#include <fmt/core.h>
+#include <fmt/compile.h>
+
+namespace floormat {
+
+using namespace fmt::literals;
+
+template<std::size_t N, typename Fmt, typename... Xs>
+std::size_t snformat(char(&buf)[N], Fmt&& fmt, Xs&&... args)
+{
+    constexpr std::size_t n = N > 0 ? N - 1 : 0;
+    auto result = fmt::format_to_n(buf, n, std::forward<Fmt>(fmt), std::forward<Xs>(args)...);
+    const auto len = std::min(n, result.size);
+    if constexpr(N > 0)
+        buf[len] = '\0';
+    return len;
+}
+
+} // namespace floormat