Add on-demand recalculation option to ManipulationPivot

radiant/selection/ManipulationPivot.cpp

@@ -12,7 +12,9 @@ namespace
 }
 
 ManipulationPivot::ManipulationPivot() :
-	_entityPivotIsOrigin(false)
+	_entityPivotIsOrigin(false),
+	_needsRecalculation(true),
+	_operationActive(false)
 {}
 
 void ManipulationPivot::initialise()
@@ -25,14 +27,24 @@ void ManipulationPivot::initialise()
 }
 
 // Returns the pivot-to-world transform
-const Matrix4& ManipulationPivot::getMatrix4() const
+const Matrix4& ManipulationPivot::getMatrix4()
 {
+	if (_needsRecalculation && !_operationActive)
+	{
+		updateFromSelection();
+	}
+
 	return _pivot2World;
 }
 
 // Returns the position of the pivot point relative to origin
-const Vector3& ManipulationPivot::getVector3() const
+const Vector3& ManipulationPivot::getVector3()
 {
+	if (_needsRecalculation && !_operationActive)
+	{
+		updateFromSelection();
+	}
+
 	return _pivot2World.t().getVector3();
 }
 
@@ -41,11 +53,17 @@ void ManipulationPivot::setFromMatrix(const Matrix4& newPivot2World)
 	_pivot2World = newPivot2World;
 }
 
+void ManipulationPivot::setNeedsRecalculation(bool needsRecalculation)
+{
+	_needsRecalculation = needsRecalculation;
+}
+
 // Call this before an operation is started, such that later
 // transformations can be applied on top of the correct starting point
 void ManipulationPivot::beginOperation()
 {
 	_pivot2WorldStart = _pivot2World;
+	_operationActive = true;
 }
 
 // Reverts the matrix to the state it had at the beginning of the operation
@@ -57,6 +75,7 @@ void ManipulationPivot::revertToStart()
 void ManipulationPivot::endOperation()
 {
 	_pivot2WorldStart = _pivot2World;
+	_operationActive = false;
 }
 
 void ManipulationPivot::applyTranslation(const Vector3& translation)
@@ -69,6 +88,8 @@ void ManipulationPivot::applyTranslation(const Vector3& translation)
 
 void ManipulationPivot::updateFromSelection()
 {
+	_needsRecalculation = false;
+
 	Vector3 objectPivot;
 
 	const SelectionInfo& info = GlobalSelectionSystem().getSelectionInfo();

radiant/selection/ManipulationPivot.h

@@ -27,19 +27,29 @@ class ManipulationPivot
 	// Use a single Entity's "origin" keyvalue as pivot
 	bool _entityPivotIsOrigin;
 
+	// "dirty" flag
+	bool _needsRecalculation;
+
+	// During operations, we want to block pivot recalculations
+	bool _operationActive;
+
 public:
 	ManipulationPivot();
 
 	void initialise();
 
 	// Returns the pivot-to-world transform
-	const Matrix4& getMatrix4() const;
+	const Matrix4& getMatrix4();
 
 	// Returns the position of the pivot point relative to origin
-	const Vector3& getVector3() const;
+	const Vector3& getVector3();
 
 	void setFromMatrix(const Matrix4& newPivot2World);
 
+	// Set the dirty flag of the matrix, this will trigger 
+	// an updateFromSelection() next time getMatrix4() is called
+	void setNeedsRecalculation(bool needsRecalculation);
+
 	// Call this before an operation is started, such that later
 	// transformations can be applied on top of the correct starting point
 	void beginOperation();

radiant/selection/RadiantSelectionSystem.cpp

@@ -188,6 +188,7 @@ bool RadiantSelectionSystem::nothingSelected() const
 void RadiantSelectionSystem::pivotChanged() const  
 {
     _pivotChanged = true;
+	const_cast<RadiantSelectionSystem&>(*this)._pivot.setNeedsRecalculation(true);
     SceneChangeNotify();
 }
 
@@ -831,7 +832,7 @@ const Matrix4& RadiantSelectionSystem::getPivot2World() const
     // Questionable const design - almost everything needs to be declared const here...
     const_cast<RadiantSelectionSystem*>(this)->recalculatePivot2World();
 
-    return _pivot.getMatrix4();
+    return const_cast<RadiantSelectionSystem*>(this)->_pivot.getMatrix4();
 }
 
 void RadiantSelectionSystem::constructStatic()