Utility class for making new GUI controls.
Unless you are creating your own GUI controls from scratch, you should not use these functions.
| hasModalWindow | A global property, which is true if a ModalWindow is being displayed, false otherwise. | 
| hotControl | The controlID of the current hot control. | 
| keyboardControl | The controlID of the control that has keyboard focus. | 
| systemCopyBuffer | Get access to the system-wide clipboard. | 
| AlignRectToDevice | Align a local space rectangle to the pixel grid. | 
| ExitGUI | Puts the GUI in a state that will prevent all subsequent immediate mode GUI functions from evaluating for the remainder of the GUI loop by throwing an ExitGUIException. | 
| GetControlID | Get a unique ID for a control. | 
| GetStateObject | Get a state object from a controlID. | 
| GUIToScreenPoint | Convert a point from GUI position to screen space. | 
| QueryStateObject | Get an existing state object from a controlID. | 
| RotateAroundPivot | Helper function to rotate the GUI around a point. | 
| ScaleAroundPivot | Helper function to scale the GUI around a point. | 
| ScreenToGUIPoint | Convert a point from screen space to GUI position. |