Fix OpenRCT2#11752: Track pieces with fractional cost are too cheap t…

…o build

Fixes an inconsistency wuth RCT2 where track prices with a fractional part
did not have their price rounded up when building, but did when refunding.
This created an exploit where refunding such a track piece granted the player
0.50€ more than they spent on the piece.

distribution/changelog.txt

@@ -22,6 +22,7 @@
 - Change: [#16077] When importing SV6 files, the RCT1 land types are only added when they were actually used.
 - Change: [#16424] Following an entity in the title sequence no longer toggles underground view when it's underground.
 - Change: [#16493] Boat Hire and Submarine Ride support costs now match their visual appearance.
+- Fix: [#11752] Track pieces with fractional cost are too cheap to build.
 - Fix: [#13336] Can no longer place Bumble Bee track design (reverts #12707).
 - Fix: [#15571] Non-ASCII characters in scenario description get distorted while saving.
 - Fix: [#15830] Objects with RCT1 images are very glitchy if OpenRCT2 is not linked to an RCT1 install.

src/openrct2/actions/MazePlaceTrackAction.cpp

@@ -119,7 +119,7 @@ GameActions::Result MazePlaceTrackAction::Query() const
 
     const auto& ted = GetTrackElementDescriptor(TrackElemType::Maze);
     money32 price = (((ride->GetRideTypeDescriptor().BuildCosts.TrackPrice * ted.Price) >> 16));
-    res.Cost = canBuild.Cost + price / 2 * 10;
+    res.Cost = ((canBuild.Cost + price) / 2) * 10;
 
     return res;
 }
@@ -161,7 +161,7 @@ GameActions::Result MazePlaceTrackAction::Execute() const
 
     const auto& ted = GetTrackElementDescriptor(TrackElemType::Maze);
     money32 price = (((ride->GetRideTypeDescriptor().BuildCosts.TrackPrice * ted.Price) >> 16));
-    res.Cost = canBuild.Cost + price / 2 * 10;
+    res.Cost = ((canBuild.Cost + price) / 2) * 10;
 
     auto startLoc = _loc.ToTileStart();
 

src/openrct2/actions/TrackPlaceAction.cpp

@@ -393,14 +393,14 @@ GameActions::Result TrackPlaceAction::Query() const
             supportHeight = (10 * COORDS_Z_STEP);
         }
 
-        cost += ((supportHeight / (2 * COORDS_Z_STEP)) * ride->GetRideTypeDescriptor().BuildCosts.SupportPrice) * 5;
+        cost += ((supportHeight / (2 * COORDS_Z_STEP)) * ride->GetRideTypeDescriptor().BuildCosts.SupportPrice);
     }
 
     money32 price = ride->GetRideTypeDescriptor().BuildCosts.TrackPrice;
     price *= ted.Price;
 
     price >>= 16;
-    res.Cost = cost + ((price / 2) * 10);
+    res.Cost = ((cost + price) / 2) * 10;
     res.SetData(std::move(resultData));
 
     return res;
@@ -522,7 +522,7 @@ GameActions::Result TrackPlaceAction::Execute() const
             supportHeight = (10 * COORDS_Z_STEP);
         }
 
-        cost += ((supportHeight / (2 * COORDS_Z_STEP)) * ride->GetRideTypeDescriptor().BuildCosts.SupportPrice) * 5;
+        cost += (supportHeight / (2 * COORDS_Z_STEP)) * ride->GetRideTypeDescriptor().BuildCosts.SupportPrice;
 
         if (!(GetFlags() & GAME_COMMAND_FLAG_GHOST))
         {
@@ -697,7 +697,7 @@ GameActions::Result TrackPlaceAction::Execute() const
     price *= ted.Price;
 
     price >>= 16;
-    res.Cost = cost + ((price / 2) * 10);
+    res.Cost = ((cost + price) / 2) * 10;
     res.SetData(std::move(resultData));
 
     return res;