make split weapon check cells instead of techno array

Author: Coronia

src/Ext/Bullet/Hooks.DetonateLogics.cpp

@@ -6,6 +6,7 @@
 #include <Ext/WarheadType/Body.h>
 #include <Ext/WeaponType/Body.h>
 #include <Ext/Techno/Body.h>
+#include <Utilities/Helpers.Alex.h>
 
 #include <AircraftClass.h>
 #include <TacticalClass.h>
@@ -480,11 +481,11 @@ DEFINE_HOOK(0x469EC0, BulletClass_Logics_AirburstWeapon, 0x6)
 				{
 					// Do random cells for amount matching Cluster.
 					int count = 0;
-					int targetCount = targets.Count;
+					const int targetCount = targets.Count;
 
 					while (count < clusterCount)
 					{
-						int index = ScenarioClass::Instance->Random.RandomRanged(0, targetCount);
+						const int index = random.RandomRanged(0, targetCount);
 						auto const pTarget = targets.GetItem(index);
 
 						if (count > targetCount || newTargets.FindItemIndex(pTarget) < 0)
@@ -497,7 +498,7 @@ DEFINE_HOOK(0x469EC0, BulletClass_Logics_AirburstWeapon, 0x6)
 				else
 				{
 					// Do evenly selected cells for amount matching Cluster.
-					double stepSize = (targets.Count - 1.0) / (clusterCount - 1.0);
+					const double stepSize = (targets.Count - 1.0) / (clusterCount - 1.0);
 
 					for (int i = 0; i < clusterCount; i++)
 					{
@@ -514,27 +515,30 @@ DEFINE_HOOK(0x469EC0, BulletClass_Logics_AirburstWeapon, 0x6)
 		}
 		else
 		{
-			for (auto const pTechno : TechnoClass::Array)
+			const float cellSpread = static_cast<float>(pTypeExt->Splits_TargetingDistance.Get()) / Unsorted::LeptonsPerCell;
+			const bool isAA = pType->AA;
+			const bool retargetSelf = pTypeExt->RetargetSelf;
+			const bool useWeaponTargeting = pTypeExt->Splits_UseWeaponTargeting;
+
+			for (auto const pTechno : Helpers::Alex::getCellSpreadItems(coordsTarget, cellSpread, true))
 			{
-				if (pTechno->IsInPlayfield && pTechno->IsOnMap && pTechno->Health > 0 && (pTypeExt->RetargetSelf || pTechno != pThis->Owner))
+				if (pTechno->IsInPlayfield && pTechno->IsOnMap && pTechno->IsAlive && pTechno->Health > 0 && !pTechno->InLimbo
+					&& (retargetSelf || pTechno != pSource))
 				{
-					auto const coords = pTechno->GetCoords();
-
-					if (coordsTarget.DistanceFrom(coords) < pTypeExt->Splits_TargetingDistance.Get()
-						&& (pType->AA || !pTechno->IsInAir())
-						&& IsAllowedSplitsTarget(pSource, pOwner, pWeapon, pTechno, pTypeExt->Splits_UseWeaponTargeting))
+					if ((isAA || !pTechno->IsInAir()) &&
+						IsAllowedSplitsTarget(pSource, pOwner, pWeapon, pTechno, useWeaponTargeting))
 					{
 						targets.AddItem(pTechno);
 					}
 				}
 			}
 
-			int range = pTypeExt->Splits_TargetCellRange;
+			const int range = pTypeExt->Splits_TargetCellRange;
 
 			while (targets.Count < clusterCount)
 			{
-				int x = random.RandomRanged(-range, range);
-				int y = random.RandomRanged(-range, range);
+				const int x = random.RandomRanged(-range, range);
+				const int y = random.RandomRanged(-range, range);
 
 				CellStruct cell = { static_cast<short>(cellTarget.X + x), static_cast<short>(cellTarget.Y + y) };
 				auto const pCell = MapClass::Instance.GetCellAt(cell);
@@ -579,8 +583,8 @@ DEFINE_HOOK(0x469EC0, BulletClass_Logics_AirburstWeapon, 0x6)
 				if (auto const pBullet = pTypeSplits->CreateBullet(pTarget, pSource, damage, pWeapon->Warhead, pWeapon->Speed, pWeapon->Bright))
 				{
 					auto coords = pThis->Location;
-					int scatterMin = pTypeExt->AirburstWeapon_SourceScatterMin.Get();
-					int scatterMax = pTypeExt->AirburstWeapon_SourceScatterMax.Get();
+					const int scatterMin = pTypeExt->AirburstWeapon_SourceScatterMin.Get();
+					const int scatterMax = pTypeExt->AirburstWeapon_SourceScatterMax.Get();
 
 					if (pType->Airburst && pTypeExt->Airburst_TargetAsSource)
 					{
@@ -592,7 +596,7 @@ DEFINE_HOOK(0x469EC0, BulletClass_Logics_AirburstWeapon, 0x6)
 
 					if (scatterMin > 0 || scatterMax > 0)
 					{
-						int distance = ScenarioClass::Instance->Random.RandomRanged(scatterMin, scatterMax);
+						const int distance = random.RandomRanged(scatterMin, scatterMax);
 						coords = MapClass::GetRandomCoordsNear(coords, distance, false);
 					}