perf: skip LOGF formatting when logging is silent

LOGF/LOGF_COLOR always ran fmt::sprintf even when the output was discarded; at
emulator log volume the formatting alone costs frames. Add Log::IsSilent() and
short-circuit before formatting. Behavior-preserving on all platforms (it only
skips work whose result is thrown away); before init it reports non-silent so
early logs still print.

(cherry picked from commit 1749e0fc68)

src/common/logging/log.cpp

@@ -178,6 +178,11 @@ Direction GetDirection() {
 	return g_direction;
 }
 
+bool IsSilent() {
+	// Before init LOGF must keep writing to stdout, so report non-silent.
+	return g_initialized && g_direction == Direction::Silent;
+}
+
 void Write(std::string_view text) {
 	WriteImpl(text);
 }

src/common/logging/log.h

@@ -15,6 +15,7 @@ KYTY_SUBSYSTEM_DEFINE(Log);
 enum class Direction { Silent, Console, File };
 
 Direction GetDirection();
+bool      IsSilent();
 void      Write(std::string_view text);
 void      Write(fmt::text_style style, std::string_view text);
 void      WriteFatal(std::string_view text);
@@ -41,8 +42,18 @@ inline constexpr auto BrightWhite   = fmt::fg(fmt::terminal_color::bright_white)
 } // namespace Log
 
 // NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
-#define LOGF(...) ::Log::Write(::fmt::sprintf(__VA_ARGS__))
+#define LOGF(...)                                                                                  \
+	do {                                                                                           \
+		if (!::Log::IsSilent()) {                                                                  \
+			::Log::Write(::fmt::sprintf(__VA_ARGS__));                                             \
+		}                                                                                          \
+	} while (false)
 // NOLINTNEXTLINE(cppcoreguidelines-macro-usage)
-#define LOGF_COLOR(style, ...) ::Log::Write((style), ::fmt::sprintf(__VA_ARGS__))
+#define LOGF_COLOR(style, ...)                                                                     \
+	do {                                                                                           \
+		if (!::Log::IsSilent()) {                                                                  \
+			::Log::Write((style), ::fmt::sprintf(__VA_ARGS__));                                    \
+		}                                                                                          \
+	} while (false)
 
 #endif /* KYTY_COMMON_LOGGING_LOG_H_ */