com.sun.j3d.utils.picking
Class PickCanvas

java.lang.Object
  extended by com.sun.j3d.utils.picking.PickTool
      extended by com.sun.j3d.utils.picking.PickCanvas

public class PickCanvas
extends PickTool

A subclass of PickTool, simplifies picking using mouse events from a canvas. This class allows picking using canvas x,y locations by generating the appropriate pick shape.

The pick tolerance specifies the distance from the pick center to include in the pick shape. A tolerance of 0.0 may speedup picking slightly, but also make it very difficult to pick points and lines.

The pick canvas can be used to make a series of picks. For example, to initialize the pick canvas:

     PickCanvas pickCanvas = new PickCanvas(canvas, scene);
     pickCanvas.setMode(PickTool.GEOMETRY_INTERSECT_INFO); 
     pickCanvas.setTolerance(4.0f);
 

Then for each mouse event:

     pickCanvas.setShapeLocation(mouseEvent);
     PickResult[] results = pickCanvas.pickAll();
 

NOTE: For the pickAllSorted or pickClosest methods, the picks will be sorted by the distance from the ViewPlatform to the intersection point.

See Also:
PickTool

Field Summary
 
Fields inherited from class com.sun.j3d.utils.picking.PickTool
BOUNDS, GEOMETRY, GEOMETRY_INTERSECT_INFO, INTERSECT_COORD, INTERSECT_FULL, INTERSECT_TEST, userDefineShape
 
Constructor Summary
PickCanvas(Canvas3D c, BranchGroup b)
          Constructor with Canvas3D for mouse events and BranchGroup to be picked.
PickCanvas(Canvas3D c, Locale l)
          Constructor with Canvas3D for mouse events and Locale to be picked.
 
Method Summary
 Canvas3D getCanvas()
          Inquire the canvas to be used for picking operations.
 float getTolerance()
          Get the pick tolerance.
 void setShapeLocation(int xpos, int ypos)
          Set the pick location.
 void setShapeLocation(java.awt.event.MouseEvent mevent)
          Set the pick location.
 void setTolerance(float t)
          Set the picking tolerance.
 
Methods inherited from class com.sun.j3d.utils.picking.PickTool
getBranchGroup, getLocale, getMode, getPickShape, getStartPosition, pickAll, pickAllSorted, pickAny, pickClosest, setBranchGroup, setCapabilities, setMode, setShape, setShapeBounds, setShapeConeRay, setShapeConeSegment, setShapeCylinderRay, setShapeCylinderSegment, setShapeRay, setShapeSegment
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

PickCanvas

public PickCanvas(Canvas3D c,
                  BranchGroup b)
Constructor with Canvas3D for mouse events and BranchGroup to be picked.


PickCanvas

public PickCanvas(Canvas3D c,
                  Locale l)
Constructor with Canvas3D for mouse events and Locale to be picked.

Method Detail

getCanvas

public Canvas3D getCanvas()
Inquire the canvas to be used for picking operations.

Returns:
the canvas.

setTolerance

public void setTolerance(float t)
Set the picking tolerance. Objects within this distance (in pixels) to the mouse x,y location will be picked. The default tolerance is 2.0.

Parameters:
t - The tolerance
Throws:
java.lang.IllegalArgumentException - if the tolerance is less than 0.

getTolerance

public float getTolerance()
Get the pick tolerance.


setShapeLocation

public void setShapeLocation(java.awt.event.MouseEvent mevent)
Set the pick location. Defines the location on the canvas where the pick is to be performed.

Parameters:
mevent - The MouseEvent for the picking point

setShapeLocation

public void setShapeLocation(int xpos,
                             int ypos)
Set the pick location. Defines the location on the canvas where the pick is to be performed (upper left corner of canvas is 0,0).

Parameters:
xpos - the X position of the picking point
ypos - the Y position of the picking point


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