Implement a new event to receive notifications when a checkpoint world has changed.

source/Core.hpp

@@ -159,6 +159,7 @@ protected:
         // ----------------------------------------------------------------------------------------
         Function        mOnEntered;
         Function        mOnExited;
+        Function        mOnWorld;
     };
 
     /* --------------------------------------------------------------------------------------------
@@ -1002,6 +1003,7 @@ public:
     /* --------------------------------------------------------------------------------------------
      * Miscellaneous events.
     */
+    void EmitCheckpointWorld(Int32 checkpoint_id, Int32 old_world, Int32 new_world);
     void EmitPlayerHealth(Int32 player_id, Float32 old_health, Float32 new_health);
     void EmitPlayerArmour(Int32 player_id, Float32 old_armour, Float32 new_armour);
     void EmitPlayerWeapon(Int32 player_id, Int32 old_weapon, Int32 new_weapon);
@@ -1151,6 +1153,7 @@ private:
     Function    mOnPickupRespawn;
     Function    mOnCheckpointEntered;
     Function    mOnCheckpointExited;
+    Function    mOnCheckpointWorld;
     Function    mOnEntityPool;
     Function    mOnClientScriptData;
     Function    mOnPlayerUpdate;

source/CoreEvents.cpp

@@ -676,6 +676,14 @@ void Core::EmitCheckpointExited(Int32 checkpoint_id, Int32 player_id)
     Emit(mOnCheckpointExited, _player.mObj, _checkpoint.mObj);
 }
 
+// ------------------------------------------------------------------------------------------------
+void Core::EmitCheckpointWorld(Int32 checkpoint_id, Int32 old_world, Int32 new_world)
+{
+    CheckpointInst & _checkpoint = m_Checkpoints.at(checkpoint_id);
+    Emit(_checkpoint.mOnWorld, old_world, new_world);
+    Emit(mOnCheckpointWorld, _checkpoint.mObj, old_world, new_world);
+}
+
 // ------------------------------------------------------------------------------------------------
 void Core::EmitPlayerHealth(Int32 player_id, Float32 old_health, Float32 new_health)
 {

source/CoreUtils.cpp

@@ -132,6 +132,7 @@ void Core::ResetFunc(CheckpointInst & inst)
     inst.mOnCustom.ReleaseGently();
     inst.mOnEntered.ReleaseGently();
     inst.mOnExited.ReleaseGently();
+    inst.mOnWorld.ReleaseGently();
 }
 
 // ------------------------------------------------------------------------------------------------
@@ -347,6 +348,7 @@ void Core::ResetFunc()
     Core::Get().mOnPickupRespawn.ReleaseGently();
     Core::Get().mOnCheckpointEntered.ReleaseGently();
     Core::Get().mOnCheckpointExited.ReleaseGently();
+    Core::Get().mOnCheckpointWorld.ReleaseGently();
     Core::Get().mOnEntityPool.ReleaseGently();
     Core::Get().mOnClientScriptData.ReleaseGently();
     Core::Get().mOnPlayerUpdate.ReleaseGently();
@@ -469,6 +471,7 @@ Function & Core::GetEvent(Int32 evid)
         case EVT_PICKUPRESPAWN:         return mOnPickupRespawn;
         case EVT_CHECKPOINTENTERED:     return mOnCheckpointEntered;
         case EVT_CHECKPOINTEXITED:      return mOnCheckpointExited;
+        case EVT_CHECKPOINTWORLD:       return mOnCheckpointWorld;
         case EVT_ENTITYPOOL:            return mOnEntityPool;
         case EVT_CLIENTSCRIPTDATA:      return mOnClientScriptData;
         case EVT_PLAYERUPDATE:          return mOnPlayerUpdate;
@@ -531,6 +534,7 @@ Function & Core::GetCheckpointEvent(Int32 id, Int32 evid)
         case EVT_CHECKPOINTCUSTOM:      return inst.mOnCustom;
         case EVT_CHECKPOINTENTERED:     return inst.mOnEntered;
         case EVT_CHECKPOINTEXITED:      return inst.mOnExited;
+        case EVT_CHECKPOINTWORLD:       return inst.mOnWorld;
         default:                        return NullFunction();
     }
 }

source/Entity/Checkpoint.cpp

@@ -45,7 +45,7 @@ Object & CCheckpoint::GetNull()
 // ------------------------------------------------------------------------------------------------
 CCheckpoint::CCheckpoint(Int32 id)
     : m_ID(VALID_ENTITYGETEX(id, SQMOD_CHECKPOINT_POOL))
-    , m_Tag(ToStrF("%d", id))
+    , m_Tag(ToStrF("%d", id)), m_Data(), m_CircularLocks(0)
 {
     /* ... */
 }
@@ -184,12 +184,27 @@ Int32 CCheckpoint::GetWorld() const
 }
 
 // ------------------------------------------------------------------------------------------------
-void CCheckpoint::SetWorld(Int32 world) const
+void CCheckpoint::SetWorld(Int32 world)
 {
     // Validate the managed identifier
     Validate();
-    // Perform the requested operation
+    // Grab the current value for this property
+    const Int32 current = _Func->GetCheckPointWorld(m_ID);
+    // Don't even bother if it's the same value
+    if (current == world)
+    {
+        return;
+    }
+    // Avoid property unwind from a recursive call
     _Func->SetCheckPointWorld(m_ID, world);
+    // Avoid infinite recursive event loops
+    if (!(m_CircularLocks & CHECKPOINTCL_EMIT_CHECKPOINT_WORLD))
+    {
+        // Prevent this event from triggering while executed
+        BitGuardU32 bg(m_CircularLocks, CHECKPOINTCL_EMIT_CHECKPOINT_WORLD);
+        // Now forward the event call
+        Core::Get().EmitCheckpointWorld(m_ID, current, world);
+    }
 }
 
 // ------------------------------------------------------------------------------------------------

source/Entity/Checkpoint.hpp

@@ -7,6 +7,14 @@
 // ------------------------------------------------------------------------------------------------
 namespace SqMod {
 
+/* ------------------------------------------------------------------------------------------------
+ * Circular locks employed by the checkpoint manager.
+*/
+enum CheckpointCircularLocks
+{
+    CHECKPOINTCL_EMIT_CHECKPOINT_WORLD  = (1 << 0)
+};
+
 /* ------------------------------------------------------------------------------------------------
  * Manages a single checkpoint entity.
 */
@@ -39,6 +47,11 @@ private:
     */
     Object  m_Data;
 
+    /* --------------------------------------------------------------------------------------------
+     * Prevent events from triggering themselves.
+    */
+    Uint32  m_CircularLocks;
+
     /* --------------------------------------------------------------------------------------------
      * Base constructor.
     */
@@ -197,7 +210,7 @@ public:
     /* --------------------------------------------------------------------------------------------
      * Modify the world in which the managed checkpoint entity exists.
     */
-    void SetWorld(Int32 world) const;
+    void SetWorld(Int32 world);
 
     /* --------------------------------------------------------------------------------------------
      * Retrieve the color of the managed checkpoint entity.

source/SqBase.hpp

@@ -366,6 +366,7 @@ enum EventType
     EVT_PICKUPRESPAWN,
     EVT_CHECKPOINTENTERED,
     EVT_CHECKPOINTEXITED,
+    EVT_CHECKPOINTWORLD,
     EVT_ENTITYPOOL,
     EVT_CLIENTSCRIPTDATA,
     EVT_PLAYERUPDATE,