function GetRect(const ARect: TRectF): TRectF; virtual;
virtual System::Types::TRectF __fastcall GetRect(const System::Types::TRectF &ARect);
Returns the rectangle that defines the drawing edge of the bitmap onto which the effect is drawn.
By default, GetRect returns the rectangle received through the
ARect parameter. Subclasses of TEffect compute specific rectangles, depending on their properties. GetRect is called by ApplyEffect; you do not need to call it explicitly.