IlvMakeSplineInteractor Class Reference

Manager interactor class. More...

#include <ilviews/manager/mkpolyin.h>

Inheritance diagram for IlvMakeSplineInteractor:

List of all members.

Public Member Functions
	IlvMakeSplineInteractor (IlvManager *manager, IlvView *view)
	Constructor.
IlBoolean	accept (IlvPoint &p)
	Lets the interactor accept or refuse a new point location.
virtual void	commit (IlBoolean removeExtraPoints)
void	displayIntermediatePoints (IlBoolean d)
IlBoolean	displayIntermediatePoints ()
virtual void	doIt (IlUInt count, IlvPoint *points)
	Finalizes the interaction by creating an IlvSpline object.
virtual void	drawGhost ()
	Visual feedback during interaction.
virtual void	drawHull ()
	draws the control points of the Bezier curve.
void	react (IlvPoint &p, IlUShort modifier=0)
	Ensures the Bezier spline remains continuously derivable as new points are entered.

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Detailed Description

Manager interactor class.

Library: ilvmgr

Use this class to create IlvSpline (Cubic Bezier) objects in a view controlled by a manager. The virtual member function handleEvent monitors mouse events. To draw a spline, the user:

1. Clicks and drag the left mouse button to add a point and set its tangents and tension.
2. Presses the return or space key, or double clicks to finish.

If the user presses the Control modifier while dragging the left mouse button, the left and right tangents at the current point are dissociated, letting the user create cusps on the Bezier spline.

See also:

IlvSpline, IlvPolySelectInteractor, IlvMakePolylineInteractor, IlvMakeFilledSplineInteractor, IlvMakeClosedSplineInteractor.

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Constructor & Destructor Documentation

IlvMakeSplineInteractor::IlvMakeSplineInteractor	(	IlvManager *	manager,
		IlvView *	view
	)

Constructor.

Initializes a new instance of the IlvMakeSplineInteractor class.

Parameters:

	manager	The manager.
	view	The manager view.

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Member Function Documentation

IlBoolean IlvMakeSplineInteractor::accept

(

IlvPoint &

p

)

[virtual]

Lets the interactor accept or refuse a new point location.

Allows the interactor to determine whether a location chosen by the user is valid for the interaction.

Returns:

IlTrue if the point is accepted and IlFalse if it is not. In the default implementation, the point is accepted if it is not too close to the previous one. More precisely, the point is accepted if the two following conditions are met:

 IlvAbs(cur.x() - prev.x()) >= threshold
 IlvAbs(cur.y() - prev.y()) >= threshold

Parameters:

p

The point, in the object coordinate system.

Reimplemented from IlvMakePolyPointsInteractor.

virtual void IlvMakeSplineInteractor::commit

(

IlBoolean

removeExtraPoints

)

[virtual]

Called by handleEvent when the polypoint is terminated. This method should call doIt() and post an undoable command if need be.

Parameters:

removeExtraPoints

When the curve entry is terminated by a double click, it may be desirable to remove the extra points that have been added in succession by the double click. This flag is set to tell the method that it should get rid of the extraneous points before calling doIt().

Reimplemented from IlvMakePolyPointsInteractor.

Reimplemented in IlvMakeFilledSplineInteractor.

void IlvMakeSplineInteractor::displayIntermediatePoints

(

IlBoolean

d

)

Tells the interactor whether or not to display the control points which are not on the curve.

IlBoolean IlvMakeSplineInteractor::displayIntermediatePoints

(

)

Indicates whether or not the control points which are not on the curve are displayed.

virtual void IlvMakeSplineInteractor::doIt	(	IlUInt	count,
		IlvPoint *	points
	)			[virtual]

Finalizes the interaction by creating an IlvSpline object.

Creates an IlvSpline in the manager from the array of points provided during the interaction.

Parameters:

	count	The number of points in the array.
	points	The array of points, in the object coordinate system.

Implements IlvMakePolyPointsInteractor.

Reimplemented in IlvMakeFilledSplineInteractor, and IlvMakeClosedSplineInteractor.

virtual void IlvMakeSplineInteractor::drawGhost

(

)

[virtual]

Visual feedback during interaction.

Draws a spline in XOR mode.

Implements IlvMakePolyPointsInteractor.

Reimplemented in IlvMakeFilledSplineInteractor, and IlvMakeClosedSplineInteractor.

virtual void IlvMakeSplineInteractor::drawHull

(

)

[virtual]

draws the control points of the Bezier curve.

Draws a square for each end point of the Bezier and a cross for each control point.

Reimplemented from IlvMakePolyPointsInteractor.

void IlvMakeSplineInteractor::react	(	IlvPoint &	p,
		IlUShort	modifier = 0
	)			[virtual]

Ensures the Bezier spline remains continuously derivable as new points are entered.

When a new control point is added, the default implementation realigns the previous control points if needed, to ensure that the Bezier stays continuous at each control point. This behavior is overridden if the user presses the Control modifier while drawing the curve.

Reimplemented from IlvMakePolyPointsInteractor.

Reimplemented in IlvMakeFilledSplineInteractor.