Added --loglevel and --logfile commandline options

New command line options added to control logging in Attract-Mode:
  --loglevel (silent|info|debug)
  --logfile <log_file>

`--loglevel silent` suppresses all logging output
`--loglevel info` is the default log level
`--loglevel debug` provides additional debug messages

With the windows GUI version of Attract-Mode, logs are written to
"last_run.log" by default.

For all other versions (linux, MacOS, windows console) logs are
written to the console (stdout) by default.

The --logfile option can be used to log to a specified file

Readme.md

@@ -27,9 +27,9 @@ line as follows:
 
 		attract --config /my/config/location
 
-	In the (hopefully unlikely) event that Attract-Mode has difficulty
-finding a display font to use on your system, you can specify one at the
-command line as follows:
+In the (hopefully unlikely) event that Attract-Mode has difficulty finding a
+display font to use on your system, you can specify one at the command line as
+follows:
 
 		attract --font <font_name>
 
@@ -254,5 +254,14 @@ For a full description of the command lines options available, run:
 
 `attract --help`
 
+Attract-Mode by default will print log messages to the console window (stdout).
+To suppress these messages, run with the following command line:
+
+`attract --loglevel silent`
+
+Alternatively, more verbose debug log messages can be enabled by running:
+
+`attract --loglevel debug`
+
 [Compile.md]: Compile.md
 [Layouts.md]: Layouts.md

src/fe_base.cpp

@@ -22,14 +22,26 @@
 
 #include "fe_base.hpp"
 #include "fe_util.hpp"
+
+#ifndef NO_MOVIE
+extern "C"
+{
+#include <libavutil/log.h>
+}
+#endif
+
+#ifndef NO_SWF
+#include "gameswf/gameswf.h"
+#endif
+
 #include <iostream>
 #include <fstream>
 
 #define FE_NAME_D			"Attract-Mode"
 
 const char *FE_NAME			= FE_NAME_D;
 const char *FE_COPYRIGHT		= FE_NAME_D " " FE_VERSION_D \
-	" Copyright (c) 2013-2016 Andrew Mickelson";
+	" Copyright (c) 2013-2017 Andrew Mickelson";
 const char *FE_VERSION 			= FE_VERSION_D;
 
 const char *FE_WHITESPACE=" \t\r";
@@ -41,6 +53,113 @@ const char *FE_EMULATOR_SUBDIR		= "emulators/";
 const char *FE_EMULATOR_FILE_EXTENSION	= ".cfg";
 const char *FE_EMULATOR_DEFAULT		= "default-emulator.cfg";
 
+namespace {
+	std::ofstream g_logfile;
+#ifdef SFML_SYSTEM_WINDOWS
+	std::ofstream g_nullstream( "NUL" );
+#else
+	std::ofstream g_nullstream( "/dev/null" );
+#endif
+	enum FeLogLevel g_log_level=FeLog_Info;
+
+	void ffmpeg_log_callback( void *ptr, int level, const char *fmt, va_list vargs )
+	{
+		if ( level <= av_log_get_level() )
+		{
+			char buff[256];
+			vsnprintf( buff, 256, fmt, vargs );
+			FeLog() << "FFmpeg: " << buff;
+		}
+	}
+
+	void gs_log_callback( bool error, const char *message )
+	{
+		FeLog() << "gameswf: " << message;
+	}
+};
+
+std::ostream &FeDebug()
+{
+	if ( g_log_level == FeLog_Debug )
+		return FeLog();
+	else
+		return g_nullstream;
+}
+
+std::ostream &FeLog()
+{
+	if ( g_log_level == FeLog_Silent )
+		return g_nullstream;
+
+	if ( g_logfile.is_open() )
+		return g_logfile;
+	else
+		return std::cout;
+}
+
+void fe_set_log_file( const std::string &fn )
+{
+	if ( fn.empty() )
+		g_logfile.close();
+	else
+		g_logfile.open( fn.c_str() );
+}
+
+void fe_set_log_level( enum FeLogLevel f )
+{
+	g_log_level = f;
+
+
+#ifndef NO_MOVIE
+	if ( f == FeLog_Silent )
+		av_log_set_callback( NULL );
+	else
+	{
+		av_log_set_callback( ffmpeg_log_callback );
+		av_log_set_level( ( f == FeLog_Debug ) ? AV_LOG_VERBOSE : AV_LOG_ERROR );
+	}
+#endif
+#ifndef NO_SWF
+	if ( f == FeLog_Silent )
+		gameswf::register_log_callback( NULL );
+	else
+	{
+		gameswf::register_log_callback( gs_log_callback );
+
+		gameswf::set_verbose_action( f == FeLog_Debug );
+	}
+#endif
+}
+
+void fe_print_version()
+{
+	FeLog() << FE_NAME << " " << FE_VERSION << " ("
+		<< get_OS_string()
+		<< ", SFML " << SFML_VERSION_MAJOR << '.' << SFML_VERSION_MINOR
+#ifdef USE_FONTCONFIG
+		<< " +FontConfig"
+#endif
+#ifdef USE_XINERAMA
+		<< " +Xinerama"
+#endif
+#ifdef USE_GLES
+		<< " +GLES"
+#endif
+#ifndef NO_SWF
+		<< " +SWF"
+#endif
+#ifdef USE_LIBARCHIVE
+		<< " +7z"
+#endif
+		<< ") " << std::endl;
+#ifdef NO_MOVIE
+	FeLog() << "No Video, using SFML for Audio." << std::endl;
+#else
+	print_ffmpeg_version_info();
+#endif
+
+}
+
 void FeBaseConfigurable::invalid_setting(
 	const std::string & fn,
 	const char *base,
@@ -49,29 +168,29 @@ void FeBaseConfigurable::invalid_setting(
 	const char **valid2,
 	const char *label )
 {
-	std::cerr << "Unrecognized \"" << base << "\" " << label
-					<< " of \"" << setting << "\"";
+	FeLog() << "Unrecognized \"" << base << "\" " << label
+		<< " of \"" << setting << "\"";
 
 	if ( !fn.empty() )
-		std::cerr << " in file: " << fn;
+		FeLog() << " in file: " << fn;
 
-	std::cerr << ".";
+	FeLog() << ".";
 
 	int i=0;
 	if (valid1[i])
-		std::cerr << "  Valid " << label <<"s are: " << valid1[i++];
+		FeLog() << "  Valid " << label <<"s are: " << valid1[i++];
 
 	while (valid1[i])
-		std::cerr << ", " << valid1[i++];
+		FeLog() << ", " << valid1[i++];
 
 	if ( valid2 != NULL )
 	{
 		i=0;
 		while (valid2[i])
-			std::cerr << ", " << valid2[i++];
+			FeLog() << ", " << valid2[i++];
 	}
 
-	std::cerr << std::endl;
+	FeLog() << std::endl;
 }
 
 bool FeBaseConfigurable::load_from_file( const std::string &filename,

src/fe_base.hpp

@@ -24,6 +24,7 @@
 #define FE_BASE_HPP
 
 #include <string>
+#include <ostream>
 
 extern const char *FE_NAME;
 extern const char *FE_COPYRIGHT;
@@ -36,6 +37,19 @@ extern const char *FE_EMULATOR_SUBDIR;
 extern const char *FE_EMULATOR_FILE_EXTENSION;
 extern const char *FE_EMULATOR_DEFAULT;
 
+enum FeLogLevel
+{
+	FeLog_Silent,
+	FeLog_Info,
+	FeLog_Debug
+};
+
+std::ostream &FeLog();
+std::ostream &FeDebug();
+void fe_set_log_file( const std::string & );
+void fe_set_log_level( enum FeLogLevel );
+void fe_print_version();
+
 class FeBaseConfigurable
 {
 protected: