Adds specific case for buildings with IsNavalYard when the AI is sear…

…ching for a suitable building location.

src/extensions/house/houseext_hooks.cpp

@@ -33,6 +33,12 @@
 #include "housetype.h"
 #include "technotype.h"
 #include "super.h"
+#include "building.h"
+#include "buildingtype.h"
+#include "buildingtypeext.h"
+#include "rules.h"
+#include "rulesext.h"
+#include "iomap.h"
 #include "fatal.h"
 #include "debughandler.h"
 #include "asserthandler.h"
@@ -41,6 +47,76 @@
 #include "hooker_macros.h"
 
 
+/**
+ *  A fake class for implementing new member functions which allow
+ *  access to the "this" pointer of the intended class.
+ * 
+ *  @note: This must not contain a constructor or destructor!
+ *  @note: All functions must be prefixed with "_" to prevent accidental virtualization.
+ */
+class HouseClassExt final : public HouseClass
+{
+    public:
+        Cell _Find_Build_Location(BuildingTypeClass *buildingtype, int (__fastcall *callback)(int, Cell &, int, int), int a3 = -1);
+};
+
+
+/**
+ *  #issue-531
+ * 
+ *  Interception of Find_Build_Location. This allows us to find a suitable building
+ *  location for the specific buildings, such as the Naval Yard.
+ * 
+ *  @author: CCHyper
+ */
+Cell HouseClassExt::_Find_Build_Location(BuildingTypeClass *buildingtype, int (__fastcall *callback)(int, Cell &, int, int), int a3)
+{
+    /**
+     *  Find the type class extension instance.
+     */
+    BuildingTypeClassExtension *buildingtypeext = BuildingTypeClassExtensions.find(buildingtype);
+    if (buildingtypeext && buildingtypeext->IsNavalYard) {
+
+        if (RulesExtension) {
+
+            BuildingTypeClass *desired_navalyard = Get_First_Ownable(RulesExtension->BuildNavalYard);
+            ASSERT_PRINT(desired_navalyard != nullptr, "Failed to find a ownable building in BuildNavalYard list!");
+
+            int navalyard_width = desired_navalyard->Width() + 2;
+            int navalyard_height = desired_navalyard->Height() + 2;
+
+            Cell found_cell = Map.Nearby_Location(Coord_Cell(Center), SPEED_FOOT, -1, MZONE_NORMAL, 0, navalyard_width, navalyard_height);
+            if (found_cell) {
+
+                if (ConstructionYards.Count() > 0) {
+                    BuildingClass *conyard = ConstructionYards.Fetch_Head();
+                    if (conyard) {
+
+                        Coordinate conyard_coord = conyard->Center_Coord();
+                        Coordinate found_coord = Map[found_cell].Center_Coord();
+
+                        if (Distance(conyard_coord, found_coord) > Cell_To_Lepton(RulesExtension->AINavalYardAdjacency)) {
+                            return Cell(0,0);
+                        }
+
+                    }
+
+                }
+
+            }
+
+            return found_cell;
+        }
+
+    }
+
+    /**
+     *  Call the original function to find a location for land buildings.
+     */
+    return HouseClass::Find_Build_Location(buildingtype, callback, a3);
+}
+
+
 /**
  *  Patch for InstantSuperRechargeCommandClass
  * 
@@ -167,4 +243,8 @@ void HouseClassExtension_Hooks()
 
     Patch_Jump(0x004BBD26, &_HouseClass_Can_Build_BuildCheat_Patch);
     Patch_Jump(0x004BD30B, &_HouseClass_Super_Weapon_Handler_InstantRecharge_Patch);
+
+    Patch_Call(0x0042D460, &HouseClassExt::_Find_Build_Location);
+    Patch_Call(0x0042D53C, &HouseClassExt::_Find_Build_Location);
+    Patch_Call(0x004C8104, &HouseClassExt::_Find_Build_Location);
 }