# HOpCreateNurbs3D

## Functions

| `HOpCreateNurbs3D`
| `~HOpCreateNurbs3D`
HBaseOperator * | `Clone`
const char * | `GetName`
int | `OnLButtonDown`
int | `OnLButtonUp`
int | `OnLButtonDownAndMove`
HC_KEY | `InsertNurbs`
void | `InsertNurbsFromMessage`
void | `EmitModifyControlPointMessage`
void | `ModifyControlPointFromMessage`
void | `EmitFinishNurbsEditing`
void | `FinishNurbsEditingFromMessage`

## Detailed Description

class HOpCreateNurbs3D : public HBaseOperator

  The HOpCreateNurbs3D class provides support for the interactive construction of various surface types.

  HOpCreateNurbs3D implements three of the mouse event handlers defined on the base class to allow the user to interactively modify a nurbs surface by dragging it’s control points with the mouse.

  The operation consists of the following steps:

  1. Left Button Down: The operation is initiated and control point for dragging is specified.

  2. Left Button Down and Drag: The control point moves with mouse position and the surface is recalculated.

  3. Left Button Up: The surface editing is finalized.

  More Detailed Description: see event methods.

  Public Functions

  HOpCreateNurbs3D(HBaseView *view, int DoRepeat = 0, int DoCapture = 1)

    Constructs an HOpCreateNurbs3D 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 ~HOpCreateNurbs3D()
  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 HOpCreateNurbs3D object.

  virtual const char *GetName()
    Returns

      A pointer to a character string denoting the name of the operator which is ‘HOpCreateNurbs3D’.

  virtual int OnLButtonDown(HEventInfo &hevent)

    OnLButtonDown records the control point that will be used to manipulate the surface.

    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 nurbs manipulation.

    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 receives control point manipulation information in plane parallel to viewplane and update the scene.

    Parameters

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

    Returns

      An HOperatorReturn indicating the status of the event.

  Public Static Functions

  static HC_KEY InsertNurbs(HBaseView *pView, HNurbsSurface *pNurbsSurface, bool emit_message)

    This method insert the given surface into the scene.

    Parameters

      - pView – A pointer to the current view object.

      - pNurbsSurface – A pointer to the nurbs surface object.

      - emit_message – Indicates that a message should be sent to the emit_message_function

  static void InsertNurbsFromMessage(const char *in_data, unsigned int data_length, HBaseView *m_pView)

    This method has been deprecated. This method inserts the surface into the scene based on the HNet message.

    Parameters

      - in_data – A character pointer containing the surface data.

      - data_length – The size of the message.

      - pView – A pointer to the current view object.

  static void EmitModifyControlPointMessage(HBaseView *pView, HC_KEY key, int control_point, float x, float y, float z)

    This method sends a modify control point message to other clients.

    Parameters

      - pView – A pointer to the current view object.

      - key – The surface key.

      - control_point – The number identifying the manipulated control point of surface.

      - x – The new control point x position.

      - y – The new control point y position.

      - z – The new control point z position.

  static void ModifyControlPointFromMessage(const char *in_data, unsigned int data_length, HBaseView *pView)

    This method receives a modify control points based on an HNet message.

    Parameters

      - in_data – A character pointer containing the new control point data.

      - data_length – The size of the message.

      - pView – A pointer to the current view object.

  static void EmitFinishNurbsEditing(HBaseView *pView, HC_KEY key, bool emit_message)

    This method emits the finalized Nurbs editing message to other clients.

    Parameters

      - pView – A pointer to the current view object.

      - key – The surface key.

      - emit_message – Indicates that a message should be sent to the emit_message_function

  static void FinishNurbsEditingFromMessage(const char *in_data, unsigned int data_length, HBaseView *pView)

    This method receives the Finish Nurbs editing message.

    Parameters

      - in_data – A character pointer indicating the end of surface editing.

      - data_length – The size of the message.

      - pView – A pointer to the current view object.