org.j3d.aviatrix3d
Class Viewport

java.lang.Object
  org.j3d.aviatrix3d.SceneGraphObject
      org.j3d.aviatrix3d.Viewport

Direct Known Subclasses:

CompositeViewport, MultipassViewport, SimpleViewport, Viewport2D

public abstract class Viewport
extends SceneGraphObject

Abstract representation of a viewport on the drawable surface.

A viewport defines the amount of screen to cover in pixel dimensions. Viewports may be used to segregate the rendered surface into multiple separate entities. An example of this is the 4-view CAD application, where each viewport has a different viewpoint looking into a shared scene graph structure.

Viewports define their coordinate system in the window-system interface: The x,y position is the lower left corner, with height going up the screen and width heading to the right.

Viewports cannot be shared amongst multiple parent layers.

Version:

$Revision: 1.6 $

Author:

Justin Couch

Field Summary

static int	COMPOSITE The viewport is a composite type, having many local layers defined
static int	FLAT The viewport is a 2D type, allowing only flat projections and automatically calculated view environment information.
static int	MULTIPASS The viewport is a multipass type, allowing multiple rendering passes for a single layer.
static int	SIMPLE The viewport is a simple type, having single scene defined
protected int	viewHeight The width of the viewport in pixels
protected int	viewportType The viewport type constant
protected int	viewWidth The width of the viewport in pixels
protected int	viewX The lower left X position of the viewpoint, in pixels
protected int	viewY The lower left Y position of the viewpoint, in pixels

Fields inherited from class org.j3d.aviatrix3d.SceneGraphObject

alive, LISTENER_SET_TIMING_ERR_PROP, updateHandler

Constructor Summary

protected

Viewport(int type) Create a default instance of this viewport.

Method Summary

void	getDimensions(int[] dim) Get the dimensions of the viewport, copied into the user-provided array.
int	getHeight() Convenience method to fetch the height of the viewport.
int	getType() Get the type that this layer represents
int	getWidth() Convenience method to fetch the width of the viewport.
int	getX() Convenience method to fetch the starting X position.
int	getY() Convenience method to fetch the starting Y position.
boolean	isValid() Check to see if this is a valid viewport.
void	setDimensions(int x, int y, int width, int height) Set the dimensions of the viewport in pixels.

Methods inherited from class org.j3d.aviatrix3d.SceneGraphObject

checkForCyclicChild, checkForCyclicParent, dataChanged, getAppUpdateWriteTimingMessage, getBoundsWriteTimingMessage, getDataWriteTimingMessage, getUserData, isLive, setLive, setUpdateHandler, setUserData

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

SIMPLE

public static final int SIMPLE

The viewport is a simple type, having single scene defined

See Also:

Constant Field Values

COMPOSITE

public static final int COMPOSITE

The viewport is a composite type, having many local layers defined

See Also:

Constant Field Values

MULTIPASS

public static final int MULTIPASS

The viewport is a multipass type, allowing multiple rendering passes for a single layer.

See Also:

Constant Field Values

FLAT

public static final int FLAT

The viewport is a 2D type, allowing only flat projections and automatically calculated view environment information.

See Also:

Constant Field Values

viewportType

protected final int viewportType

The viewport type constant

viewX

protected int viewX

The lower left X position of the viewpoint, in pixels

viewY

protected int viewY

The lower left Y position of the viewpoint, in pixels

viewWidth

protected int viewWidth

The width of the viewport in pixels

viewHeight

protected int viewHeight

The width of the viewport in pixels

Constructor Detail

Viewport

protected Viewport(int type)

Create a default instance of this viewport. All values are set to zero.

Parameters:

type - The type constant for this layer

Method Detail

setDimensions

public void setDimensions(int x,
                          int y,
                          int width,
                          int height)
                   throws InvalidWriteTimingException

Set the dimensions of the viewport in pixels. Coordinates are defined in the space of the parent component that is being rendered to.

Parameters:

x - The lower left x coordinate for the view

y - The lower left y coordinate for the view

width - The width of the viewport in pixels

height - The height of the viewport in pixels

Throws:

InvalidWriteTimingException - An attempt was made to write outside of the ApplicationUpdateObserver callback method

getDimensions

public void getDimensions(int[] dim)

Get the dimensions of the viewport, copied into the user-provided array. The array must be at least 4 units in length, and the values are copied in the order x, y, width, height.

Parameters:

dim - The array to copy the values into

getX

public int getX()

Convenience method to fetch the starting X position.

Returns:

The lower left X coordinate, in pixels

getY

public int getY()

Convenience method to fetch the starting Y position.

Returns:

The lower left Y coordinate, in pixels

getWidth

public int getWidth()

Convenience method to fetch the width of the viewport.

Returns:

The width amount, in pixels

getHeight

public int getHeight()

Convenience method to fetch the height of the viewport.

Returns:

The height amount, in pixels

getType

public int getType()

Get the type that this layer represents

Returns:

A layer type descriptor

isValid

public boolean isValid()

Check to see if this is a valid viewport. A valid viewport requires that the width and height are both greater than zero and that X + width and Y + height are positive.

Returns:

true if the viewport represents a valid screen space