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Author: wichern

libs/s25main/ai/aijh/AIConstruction.cpp

@@ -466,12 +466,10 @@ helpers::OptionalEnum<BuildingType> AIConstruction::ChooseMilitaryBuilding(const
     const BuildingType biggestBld = GetBiggestAllowedMilBuilding().value();
 
     const Inventory& inventory = aii.GetInventory();
-    uint8_t playerId = aii.GetPlayerId();
-    if((AI::randomValue<int>(0, 2) == 0 || inventory.people[Job::Private] < 15)
+    if((inventory.people[Job::Private] < 15 || AI::random())
        && (inventory.goods[GoodType::Stones] > 6 || bldPlanner.GetNumBuildings(BuildingType::Quarry) > 0))
         bld = BuildingType::Guardhouse;
-    if(aijh.getAIInterface().isHarborPosClose(pt, 19) && AI::randomValue<int>(0, 9) != 0
-       && aijh.ggs.isEnabled(AddonId::SEA_ATTACK))
+    if(aijh.getAIInterface().isHarborPosClose(pt, 19) && !AI::random(9) && aijh.ggs.isEnabled(AddonId::SEA_ATTACK))
     {
         if(aii.CanBuildBuildingtype(BuildingType::Watchtower))
             return BuildingType::Watchtower;
@@ -481,12 +479,13 @@ helpers::OptionalEnum<BuildingType> AIConstruction::ChooseMilitaryBuilding(const
     {
         if(aijh.UpdateUpgradeBuilding() < 0 && bldPlanner.GetNumBuildingSites(biggestBld) < 1
            && (inventory.goods[GoodType::Stones] > 20 || bldPlanner.GetNumBuildings(BuildingType::Quarry) > 0)
-           && AI::randomValue<int>(0, 9) != 0)
+           && !AI::random(9u))
         {
             return biggestBld;
         }
     }
 
+    uint8_t playerId = aii.GetPlayerId();
     sortedMilitaryBlds military = aii.gwb.LookForMilitaryBuildings(pt, 3);
     for(const nobBaseMilitary* milBld : military)
     {
@@ -495,7 +494,7 @@ helpers::OptionalEnum<BuildingType> AIConstruction::ChooseMilitaryBuilding(const
         // Prüfen ob Feind in der Nähe
         if(milBld->GetPlayer() != playerId && distance < 35)
         {
-            int randmil = AI::randomValue<int>(0, std::numeric_limits<int>::max());
+            const auto randmil = AI::randomValue(0, std::numeric_limits<int>::max());
             bool buildCatapult = randmil % 8 == 0 && aii.CanBuildCatapult()
                                  && bldPlanner.GetNumAdditionalBuildingsWanted(BuildingType::Catapult) > 0;
             // another catapult within "min" radius? ->dont build here!

libs/s25main/ai/aijh/AIPlayerJH.cpp

@@ -344,9 +344,8 @@ void AIPlayerJH::PlanNewBuildings(const unsigned gf)
         DistributeGoodsByBlocking(GoodType::Boards, 30);
         DistributeGoodsByBlocking(GoodType::Stones, 50);
         // go to the picked random warehouse and try to build around it
-        int randomStore = AI::randomValue<int>(0, storehouses.size() - 1);
         auto it = storehouses.begin();
-        std::advance(it, randomStore);
+        std::advance(it, AI::randomIndex(storehouses));
         const MapPoint whPos = (*it)->GetPos();
         UpdateNodesAround(whPos, 15); // update the area we want to build in first
         for(const BuildingType i : bldToTest)
@@ -365,7 +364,7 @@ void AIPlayerJH::PlanNewBuildings(const unsigned gf)
     const std::list<nobMilitary*>& militaryBuildings = aii.GetMilitaryBuildings();
     if(militaryBuildings.empty())
         return;
-    int randomMiliBld = AI::randomValue<int>(0, militaryBuildings.size() - 1);
+    const int randomMiliBld = static_cast<int>(AI::randomIndex(militaryBuildings));
     auto it2 = militaryBuildings.begin();
     std::advance(it2, randomMiliBld);
     MapPoint bldPos = (*it2)->GetPos();
@@ -1209,7 +1208,7 @@ void AIPlayerJH::HandleExpedition(const noShip* ship)
         aii.FoundColony(ship);
     else
     {
-        const unsigned offset = AI::randomValue<unsigned>(0, helpers::MaxEnumValue_v<ShipDirection> - 1);
+        const unsigned offset = AI::randomValue(0u, helpers::MaxEnumValue_v<ShipDirection> - 1u);
         for(auto dir : helpers::EnumRange<ShipDirection>{})
         {
             dir = ShipDirection((rttr::enum_cast(dir) + offset) % helpers::MaxEnumValue_v<ShipDirection>);
@@ -1254,7 +1253,7 @@ void AIPlayerJH::HandleTreeChopped(const MapPoint pt)
 
     UpdateNodesAround(pt, 3);
 
-    if(AI::randomValue<int>(0, 1) == 0)
+    if(AI::random())
         AddMilitaryBuildJob(pt);
     else // if (random % 12 == 0)
         AddBuildJob(BuildingType::Woodcutter, pt);
@@ -1536,7 +1535,7 @@ void AIPlayerJH::TryToAttack()
         // We skip the current building with a probability of limit/numMilBlds
         // -> For twice the number of blds as the limit we will most likely skip every 2nd building
         // This way we check roughly (at most) limit buildings but avoid any preference for one building over an other
-        if(AI::randomValue<unsigned>(0, numMilBlds - 1) > limit)
+        if(AI::random(numMilBlds - 1u, limit))
             continue;
 
         if(milBld->GetFrontierDistance() == FrontierDistance::Far) // inland building? -> skip it
@@ -1569,7 +1568,7 @@ void AIPlayerJH::TryToAttack()
 
     // shuffle everything but headquarters and harbors without any troops in them
     std::shuffle(potentialTargets.begin() + hq_or_harbor_without_soldiers, potentialTargets.end(),
-                 std::mt19937(AI::randomValue<unsigned>(0, 2047)));
+                 AI::getRandomGenerator());
 
     // check for each potential attacking target the number of available attacking soldiers
     for(const nobBaseMilitary* target : potentialTargets)
@@ -1702,8 +1701,7 @@ void AIPlayerJH::TrySeaAttack()
     unsigned limit = 15;
     unsigned skip = 0;
     if(searcharoundharborspots.size() > 15)
-        skip =
-          std::max<int>(AI::randomValue<int>(0, static_cast<int>(searcharoundharborspots.size() / 15) * 15), 1) - 1;
+        skip = AI::randomValue(0u, static_cast<unsigned>(searcharoundharborspots.size() / 15u)) * 15u;
     for(unsigned i = skip; i < searcharoundharborspots.size() && limit > 0; i++)
     {
         limit--;

libs/s25main/ai/random.cpp

@@ -8,8 +8,7 @@ namespace AI {
 
 std::minstd_rand& getRandomGenerator()
 {
-    std::random_device rnd_dev;
-    static std::minstd_rand rng(rnd_dev());
+    static std::minstd_rand rng(std::random_device{}());
     return rng;
 }
 

libs/s25main/ai/random.h

@@ -17,4 +17,25 @@ T randomValue(T min = std::numeric_limits<T>::min(), T max = std::numeric_limits
     return helpers::randomValue(getRandomGenerator(), min, max);
 }
 
+// Return a random bool:
+//   random()           ... will return true|false with 50% chance each
+//   random(15)         ... will return true in 1/15 of the cases
+inline bool random(unsigned total = 1u)
+{
+    return helpers::randomValue(getRandomGenerator(), 0u, total) == 0u;
+}
+
+//   random(20, 5)      ... will return true in ~3/4 of the cases (random(20) > 5)
+inline bool random(unsigned total, unsigned chance)
+{
+    return helpers::randomValue(getRandomGenerator(), 0u, total) > chance;
+}
+
+template<typename ContainerT>
+inline unsigned randomIndex(const ContainerT& container)
+{
+    RTTR_Assert(!container.empty());
+    return helpers::randomValue(getRandomGenerator(), 0u, static_cast<unsigned>(container.size()) - 1u);
+}
+
 } // namespace AI