Implement a new event to receive notifications when an object alpha has changed.

source/Core.hpp

@@ -256,6 +256,7 @@ protected:
         Function        mOnShot;
         Function        mOnTouched;
         Function        mOnWorld;
+        Function        mOnAlpha;
     };
 
     /* --------------------------------------------------------------------------------------------
@@ -1008,6 +1009,7 @@ public:
     void EmitCheckpointWorld(Int32 checkpoint_id, Int32 old_world, Int32 new_world);
     void EmitCheckpointRadius(Int32 checkpoint_id, Float32 old_radius, Float32 new_radius);
     void EmitObjectWorld(Int32 object_id, Int32 old_world, Int32 new_world);
+    void EmitObjectAlpha(Int32 object_id, Int32 old_alpha, Int32 new_alpha, Int32 time);
     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);
@@ -1153,6 +1155,7 @@ private:
     Function    mOnObjectShot;
     Function    mOnObjectTouched;
     Function    mOnObjectWorld;
+    Function    mOnObjectAlpha;
     Function    mOnPickupClaimed;
     Function    mOnPickupCollected;
     Function    mOnPickupRespawn;

source/CoreEvents.cpp

@@ -700,6 +700,14 @@ void Core::EmitObjectWorld(Int32 object_id, Int32 old_world, Int32 new_world)
     Emit(mOnObjectWorld, _object.mObj, old_world, new_world);
 }
 
+// ------------------------------------------------------------------------------------------------
+void Core::EmitObjectAlpha(Int32 object_id, Int32 old_alpha, Int32 new_alpha, Int32 time)
+{
+    ObjectInst & _object = m_Objects.at(object_id);
+    Emit(_object.mOnAlpha, old_alpha, new_alpha, time);
+    Emit(mOnObjectAlpha, _object.mObj, old_alpha, new_alpha, time);
+}
+
 // ------------------------------------------------------------------------------------------------
 void Core::EmitPlayerHealth(Int32 player_id, Float32 old_health, Float32 new_health)
 {

source/CoreUtils.cpp

@@ -153,6 +153,7 @@ void Core::ResetFunc(ObjectInst & inst)
     inst.mOnShot.ReleaseGently();
     inst.mOnTouched.ReleaseGently();
     inst.mOnWorld.ReleaseGently();
+    inst.mOnAlpha.ReleaseGently();
 }
 
 // ------------------------------------------------------------------------------------------------
@@ -346,6 +347,7 @@ void Core::ResetFunc()
     Core::Get().mOnObjectShot.ReleaseGently();
     Core::Get().mOnObjectTouched.ReleaseGently();
     Core::Get().mOnObjectWorld.ReleaseGently();
+    Core::Get().mOnObjectAlpha.ReleaseGently();
     Core::Get().mOnPickupClaimed.ReleaseGently();
     Core::Get().mOnPickupCollected.ReleaseGently();
     Core::Get().mOnPickupRespawn.ReleaseGently();
@@ -471,6 +473,7 @@ Function & Core::GetEvent(Int32 evid)
         case EVT_OBJECTSHOT:            return mOnObjectShot;
         case EVT_OBJECTTOUCHED:         return mOnObjectTouched;
         case EVT_OBJECTWORLD:           return mOnObjectWorld;
+        case EVT_OBJECTALPHA:           return mOnObjectAlpha;
         case EVT_PICKUPCLAIMED:         return mOnPickupClaimed;
         case EVT_PICKUPCOLLECTED:       return mOnPickupCollected;
         case EVT_PICKUPRESPAWN:         return mOnPickupRespawn;
@@ -574,6 +577,7 @@ Function & Core::GetObjectEvent(Int32 id, Int32 evid)
         case EVT_OBJECTSHOT:            return inst.mOnShot;
         case EVT_OBJECTTOUCHED:         return inst.mOnTouched;
         case EVT_OBJECTWORLD:           return inst.mOnWorld;
+        case EVT_OBJECTALPHA:           return inst.mOnAlpha;
         default:                        return NullFunction();
     }
 }

source/Entity/Object.cpp

@@ -217,21 +217,33 @@ Int32 CObject::GetAlpha() const
 }
 
 // ------------------------------------------------------------------------------------------------
-void CObject::SetAlpha(Int32 alpha) const
+void CObject::SetAlpha(Int32 alpha)
 {
-    // Validate the managed identifier
+    SetAlphaEx(alpha, 0);
-    Validate();
-    // Perform the requested operation
-    _Func->SetObjectAlpha(m_ID, alpha, 0);
 }
 
 // ------------------------------------------------------------------------------------------------
-void CObject::SetAlphaEx(Int32 alpha, Uint32 time) const
+void CObject::SetAlphaEx(Int32 alpha, Uint32 time)
 {
     // Validate the managed identifier
     Validate();
-    // Perform the requested operation
+    // Grab the current value for this property
+    const Int32 current = _Func->GetObjectAlpha(m_ID);
+    // Don't even bother if it's the same value
+    if (current == alpha)
+    {
+        return;
+    }
+    // Avoid property unwind from a recursive call
     _Func->SetObjectAlpha(m_ID, alpha, time);
+    // Avoid infinite recursive event loops
+    if (!(m_CircularLocks & OBJECTCL_EMIT_OBJECT_ALPHA))
+    {
+        // Prevent this event from triggering while executed
+        BitGuardU32 bg(m_CircularLocks, OBJECTCL_EMIT_OBJECT_ALPHA);
+        // Now forward the event call
+        Core::Get().EmitObjectAlpha(m_ID, current, alpha, time);
+    }
 }
 
 // ------------------------------------------------------------------------------------------------

source/Entity/Object.hpp

@@ -12,7 +12,8 @@ namespace SqMod {
 */
 enum ObjectCircularLocks
 {
-    OBJECTCL_EMIT_OBJECT_WORLD  = (1 << 0)
+    OBJECTCL_EMIT_OBJECT_WORLD  = (1 << 0),
+    OBJECTCL_EMIT_OBJECT_ALPHA  = (2 << 0)
 };
 
 /* ------------------------------------------------------------------------------------------------
@@ -235,12 +236,12 @@ public:
     /* --------------------------------------------------------------------------------------------
      * Modify the alpha of the managed object entity.
     */
-    void SetAlpha(Int32 alpha) const;
+    void SetAlpha(Int32 alpha);
 
     /* --------------------------------------------------------------------------------------------
      * Modify the alpha of the managed object entity over the specified time.
     */
-    void SetAlphaEx(Int32 alpha, Uint32 time) const;
+    void SetAlphaEx(Int32 alpha, Uint32 time);
 
     /* --------------------------------------------------------------------------------------------
      * Move the managed object entity to the specified position over the specified time.

source/SqBase.hpp

@@ -362,6 +362,7 @@ enum EventType
     EVT_OBJECTSHOT,
     EVT_OBJECTTOUCHED,
     EVT_OBJECTWORLD,
+    EVT_OBJECTALPHA,
     EVT_PICKUPCLAIMED,
     EVT_PICKUPCOLLECTED,
     EVT_PICKUPRESPAWN,