# HOpConstructCylinder

## Functions

| `HOpConstructCylinder`
| `~HOpConstructCylinder`
const char * | `GetName`
int | `OnLButtonDown`
int | `OnNoButtonDownAndMove`
int | `OnLButtonDownAndMove`
int | `OnLButtonUp`
HBaseOperator * | `Clone`

## Detailed Description

class HOpConstructCylinder : public HBaseOperator

  The HOpConstructCylinder class provides support for constructing a cylinder and inserting it into the model.

  HOpConstructCylinder implements four of the mouse button event handlers defined on the base class and maps the event information to local methods that rubberband a cylinder and insert a corresponding HOOPS shell into the HOOPS database. This provides the basic functionality for drawing a temporary three-dimensional, tesselated cylinder with a circular base, a circular cap of equivalent size, and a number of rectangular, facetted sides with the default as 30. The operation consists of the following steps:

  1. Left Button Down: Register the center point of the cylinder base.

  2. Left Button Down and Drag: Rubberbands the circular base to the desired circumference.

  3. Left Button Up: The base circumference finalized.

  4. No Button Down and Drag: Rubberbands the cylinder to the desired height.

  5. Left Button Down: The height is finalized, the cylinder is cleared from the scene and the operation ends.

  More Detailed Description: see event methods.

  Subclassed by HOpCreateCylinder

  Public Functions

  HOpConstructCylinder(HBaseView *view, int DoRepeat = 0, int DoCapture = 1)

    Constructs an HOpConstructCylinder object.

    Parameters

      - view – A pointer to an HBaseView object.

      - DoRepeat – An integer denoting whether this is a repeatable operator. This parameter has been deprecated.

      - DoCapture – An integer denoting whether the mouse state should be captured, which means that all mouse events should be received after a mousedown, even if it leaves the window. This parameter has been deprecated.

  virtual ~HOpConstructCylinder()
  virtual const char *GetName()
    Returns

      A pointer to a character string denoting the name of the operator, which is ‘HOpConstructCylinder’.

  virtual int OnLButtonDown(HEventInfo &hevent)

    OnLButtonDown records the first pointer position and initiates the cylinder-drawing mechanism. The first point is used as the center of the cylinder’s circular base. If the drawing mechanism has already been started such as LButtonDown having been called once already, LButtonDown finalizes the height of the cylinder, clears the scene and ends the operation.

    Parameters

      hevent – An HEventInfo object containing information about the current event.

    Returns

      An HOperatorReturn indicating the status of the event.

  virtual int OnNoButtonDownAndMove(HEventInfo &hevent)

    OnNoButtonDownAndMove draws rubberband lines from the base the cylinder to the cap. Note that the basic work is done by repeated internal calls to HOpConstructCylinder::ConstructWireframeCylinder.

    Parameters

      hevent – An HEventInfo object containing information about the current event.

    Returns

      An HOperatorReturn indicating the status of the event.

  virtual int OnLButtonDownAndMove(HEventInfo &hevent)

    OnLButtonDownAndMove draws a rubberbanded line along the circumference of a circle centered on the first pointer position. Note that the basic drawing work is done by HUtility::CreateAxisCircle, while OnLButtonDownAndMove computes and keeps track of the radial vector that defines the cylinder’s base.

    Parameters

      hevent – An HEventInfo object containing information about the current event.

    Returns

      An HOperatorReturn indicating the status of the event.

  virtual int OnLButtonUp(HEventInfo &hevent)

    OnLButtonUp finalizes the size of the base, sets the value of m_RadiusLength and m_radius_world_vector, and cleans up. This function is not called after the second call to OnLButtonDown.

    Parameters

      hevent – An HEventInfo object containing information about the current event.

    Returns

      An HOperatorReturn indicating the status of the event.

  virtual HBaseOperator *Clone()

    Creates a new operator which is a copy of the current operator. The user is responsible for deleting the newly created operator.

    Returns

      A pointer to the newly created HOpConstructCylinder object.