Re #784 New -n/--norandom cli switch for 'repeatable randomness' (srand never called in this case) + removed CMake option OPTION_REPEATABLE_RANDOM

git-svn-id: https://svn.code.sf.net/p/speed-dreams/code/trunk@5240 30fe4595-0a0c-4342-8851-515496e4dcbd

Former-commit-id: 0c9df0fd9590265e45e18cbd5cc1d0b053d047a7
Former-commit-id: d8faa7b0605ba4c2c80ddc4eec30de8ef9245734

cmake/options.cmake

@@ -58,9 +58,6 @@ MACRO(ADD_SD_COMPILE_OPTIONS)
 
     SET(OPTION_TRACE_LEVEL "5" CACHE STRING "Trace level integer threshold, only if OPTION_TRACE (traces with higher level are not logged ; 0=Fatal, 1=Error, 2=Warning, 3=Info, 4=Trace, 5=Debug, ...)")
 
-    SET(OPTION_REPEATABLE_RANDOM false CACHE BOOL "Not for production use ; if On, enables repeatable random processes (srand is called multiple times)")
-    MARK_AS_ADVANCED(OPTION_REPEATABLE_RANDOM)
-  
     SET(OPTION_PROFILER false CACHE BOOL "Enable profiler")
   
     SET(OPTION_SCHEDULE_SPY false CACHE BOOL "Enable fine grained scheduling spy")
@@ -129,10 +126,6 @@ MACRO(ADD_SD_COMPILE_OPTIONS)
       ADD_DEFINITIONS(-DTRACE_LEVEL=${OPTION_TRACE_LEVEL})
     ENDIF(OPTION_TRACE_LEVEL)
 
-    IF(OPTION_REPEATABLE_RANDOM)
-      ADD_DEFINITIONS(-DREPEATABLE_RANDOM)
-    ENDIF(OPTION_REPEATABLE_RANDOM)
-
     IF(OPTION_XRANDR)
       ADD_DEFINITIONS(-DUSE_RANDR_EXT)
     ENDIF(OPTION_XRANDR)

src/libs/learning/Distribution.cpp

@@ -21,7 +21,7 @@ static const float PI = 3.1415927f;
 
 void setRandomSeed(unsigned int seed)
 {
-	//srand(seed); // Already done in tgf::gfInit (needed only once in the process life time)
+	srand(seed); 
 }
 
 real urandom()

src/libs/tgf/application.cpp

@@ -23,6 +23,7 @@
 */
 
 #include <cerrno>
+#include <ctime>
 #include <limits>
 #include <iostream>
 
@@ -95,6 +96,7 @@ void GfApplication::initialize(bool bLoggingEnabled, int argc, char **argv)
 	registerOption("D", "datadir", /* nHasValue = */ true);
 	registerOption("e", "tracelevel", /* nHasValue = */ true);
 	registerOption("t", "tracestream", /* nHasValue = */ true);
+	registerOption("n", "norandom", /* nHasValue = */ false);
 	
 	// Help about the command line options.
 	addOptionsHelpSyntaxLine("[-l|--localdir <dir path>] [-L|--libdir <dir path>]");
@@ -104,6 +106,7 @@ void GfApplication::initialize(bool bLoggingEnabled, int argc, char **argv)
 							 " [-t|--tracestream stdout|stderr|<file name>]");
 #endif
 	addOptionsHelpSyntaxLine("[-v|--version]");
+	addOptionsHelpSyntaxLine("[-n|--norandom]");
 	
 	addOptionsHelpExplainLine
 		("- locadir : Root dir of the tree where user settings files are stored");
@@ -123,11 +126,13 @@ void GfApplication::initialize(bool bLoggingEnabled, int argc, char **argv)
 		("            (default=" SD_DATADIR ")");
 #ifdef TRACE_OUT
 	addOptionsHelpExplainLine
-		("- tracelevel  : Maximum level of displayed traces");
+		("- tracelevel  : Maximum level of displayed traces for the default logger");
 	addOptionsHelpExplainLine
 		("                (0=Fatal, 1=Error, 2=Warning, 3=Info, 4=Trace, 5=Debug, ... ; default=5)");
 	addOptionsHelpExplainLine
-		("- tracestream : Target output stream for the traces (default=stderr)");
+		("- tracestream : Target output stream for the default logger (default=stderr)");
+	addOptionsHelpExplainLine
+		("- norandom : Force reproducible random sequences for every game session (default=off)");
 #endif
 }
 
@@ -319,6 +324,8 @@ bool GfApplication::parseOptions()
 	int nDefTraceLevel = std::numeric_limits<int>::min();
 	std::string strDefTraceStream;
 	
+	bool bTrueRandom = true;
+
 	std::list<Option>::const_iterator itOpt;
 	for (itOpt = _lstOptions.begin(); itOpt != _lstOptions.end(); itOpt++)
 	{
@@ -372,6 +379,11 @@ bool GfApplication::parseOptions()
 		{
 			strDefTraceStream = itOpt->strValue;
 		}
+		// Initialize random generator or not.
+		else if (itOpt->strLongName == "norandom")
+		{
+			bTrueRandom = false;
+		}
 		else
 		{
 			// If we get here, this is normal : the derived classes might have declared
@@ -411,6 +423,19 @@ bool GfApplication::parseOptions()
 		GfLogDefault.setLevelThreshold(nDefTraceLevel);
 	if (!strDefTraceStream.empty())
 		GfLogDefault.setStream(strDefTraceStream);
+
+	
+	// Initialize random generator with "random" seed, or not (=> always same rand() sequence).
+	if (bTrueRandom)
+	{
+		GfLogInfo("Initializing random number generator for 'true randomness'\n");
+		srand((unsigned)time(0));
+	}
+	// Note: Never calling srand is equivalent to calling it once with seed=1.
+	else
+	{
+		GfLogInfo("Not initializing random number generator, for 'repeatable randomness'\n");
+	}
 	
 	return true;
 }

src/libs/tgf/tgf.cpp

@@ -27,7 +27,6 @@
 
 #include <cstdio>
 #include <cerrno>
-#include <ctime>
 #include <cmath>
 #include <cstring>
 
@@ -453,9 +452,6 @@ void GfInit(bool bWithLogging)
 
 	gfParamInit();
 
-	// Initialize random generator.
-	srand((unsigned)time(NULL));
-
 	// Initialize SDL and useful subsystems (some others may be initialized in tgfclient).
 	if (SDL_Init(SDL_INIT_TIMER) < 0)
 		GfLogFatal("Couldn't initialize SDL(timer) (%s)\n", SDL_GetError());

src/modules/racing/standardgame/racecareer.cpp

@@ -513,7 +513,6 @@ void ReCareerNew()
 
 	t = time(NULL);
 	stm = localtime(&t);
-	//srand((unsigned int)t); // Already done in tgf::gfInit (needed only once in the process life time)
 	snprintf( buf, 1024, "%sresults/%s/%%s-%4d-%02d-%02d-%02d-%02d%%s%%s%%s.xml%%s", GfLocalDir(), ReInfo->_reFilename,
 	          stm->tm_year + 1900, stm->tm_mon + 1, stm->tm_mday, stm->tm_hour, stm->tm_min );
 	filename = strdup(buf); // Makes it possible to reuse buf