Fixed kart paths randomness issue (and probably many others) : don't continuously call srand, srand is made to be called ONCE only, repeatedly calling srand gives very poor randomisation

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@7082 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/karts/controller/ai_base_controller.cpp

@@ -44,7 +44,7 @@ AIBaseController::AIBaseController(Kart *kart,
         m_next_node_index.reserve(m_quad_graph->getNumNodes());
         m_successor_index.reserve(m_quad_graph->getNumNodes());
         std::vector<unsigned int> next;
-
+        
         for(unsigned int i=0; i<m_quad_graph->getNumNodes(); i++)
         {
             next.clear();
@@ -52,12 +52,18 @@ AIBaseController::AIBaseController(Kart *kart,
             // For now pick one part on random, which is not adjusted during the 
             // race. Long term statistics might be gathered to determine the
             // best way, potentially depending on race position etc.
-            int indx = rand() % next.size();
+            int r = rand();
+            int indx = (int)(
+                             (r / (float)(RAND_MAX - 1)) * next.size()
+                             );
+            
+            if (next.size() > 1)
+                printf("Next road : %i mapped to %i -> %i\n", r, (int)next.size(), indx);
             m_successor_index.push_back(indx);
             m_next_node_index.push_back(next[indx]);
 
         }
-
+        
         const unsigned int look_ahead=10;
         // Now compute for each node in the graph the list of the next 'look_ahead'
         // graph nodes. This is the list of node that is tested in checkCrashes.

src/karts/controller/new_ai_controller.cpp

@@ -548,8 +548,6 @@ void NewAIController::handleRaceStart()
     //5% in medium and less than 1% of the karts in hard.
     if( m_time_till_start <  0.0f )
     {
-        srand(( unsigned ) time( 0 ));
-
         //Each kart starts at a different, random time, and the time is
         //smaller depending on the difficulty.
         m_time_till_start = ( float ) rand() / RAND_MAX * m_max_start_delay;

src/karts/kart_properties_manager.cpp

@@ -366,7 +366,6 @@ std::vector<std::string> KartPropertiesManager::getRandomKartList(int count,
         else
             i++;
     }
-    std::srand((unsigned int)std::time(0));
     std::random_shuffle(karts.begin(), karts.end());
 
     // Loop over all karts to fill till either all slots are filled, or

src/main.cpp

@@ -639,6 +639,8 @@ void cleanTuxKart()
 
 int main(int argc, char *argv[] ) 
 {
+    srand(( unsigned ) time( 0 ));
+    
     try {
         // Init the minimum managers so that user config exists, then
         // handle all command line options that do not need (or must

src/utils/random_generator.cpp

@@ -30,7 +30,6 @@ RandomGenerator::RandomGenerator()
     m_c = 12345;
     m_all_random_generators.push_back(this);
     m_random_value = 3141591;
-    std::srand((unsigned int)std::time(0));
 }   // RandomGenerator
 
 // ----------------------------------------------------------------------------