# HOpCameraZoom

## Functions

| `HOpCameraZoom`
| `~HOpCameraZoom`
const char * | `GetName`
int | `OnLButtonDown`
int | `OnLButtonDownAndMove`
int | `OnLButtonUp`
void | `SetLightFollowsCamera`
bool | `GetLightFollowsCamera`
HBaseOperator * | `Clone`

## Detailed Description

class HOpCameraZoom : public HBaseOperator

  The HOpCameraZoom class zooms the camera toward a target.

  HOpCameraZoom implements three of the mouse button handlers defined on the base class and maps the event information to HOOPS camera routines. This provides the basic functionality for interactively zooming in or out from a model in realtime. The operation consists of the following steps:

  1. Left Button Down: The zoom is initiated.

  2. Left Button Down and Drag: The camera zooms to the default target.

  3. Left Button Up: The operation ends.

  More Detailed Description: see event methods.

  Public Functions

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

    Constructs an HOpCameraZoom 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 ~HOpCameraZoom()
  virtual const char *GetName()
    Returns

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

  virtual int OnLButtonDown(HEventInfo &hevent)

    OnLButtonDown draws a bounding box around the scene, records the first mouse position, and calculates the current camera target based on the first point.

    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 tests for left button down, records points as the mouse is moved, recalculates the current target for each point, and zooms the camera towards that current target. The method makes calculations to avoid unneccessary zoom when the camera is close to the target. If this operator is set so that the lights follow the camera, lighting targets will also be recalculated and lights reoriented.

    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 updates the scene with current camera and lighting information and cleans up.

    Parameters

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

    Returns

      An HOperatorReturn indicating the status of the event.

  inline void SetLightFollowsCamera(bool follow)

    SetLightFollowsCamera sets the lights to follow the camera or to stay in one place during orbit. This has the effect of either lighting the scene during orbit or allowing the camera to move through shadow. The default is off.

    Parameters

      follow – Pass true to have the light follow the camera.

  inline bool GetLightFollowsCamera()
    Returns

      True if the light follows the camera or false if it doesn’t.

  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 HOpCameraZoom object.