org.j3d.terrain.roam

Class ROAMPatch

java.lang.Object

org.j3d.terrain.roam.ROAMPatch

public abstract class ROAMPatch
extends Object

A patch represents a single piece of terrain geometry that can be rendered as a standalone block within ROAM.

A patch represents a single block of geometry within the overall scheme of the terrain data. Apart from a fixed size nothing else is fixed in this patch. The patch consists of a single TriangleArray that uses a geometry updater (geometry by reference is used) to update the geometry each frame as necessary. It will, when instructed, dynamically recalculate what vertices need to be shown and set those into the geometry array.

This is an abstract representation that renderer-specific items should be extending with their own geometry handling.

Version:

$Revision: 1.3 $

Author:

Justin Couch, Paul Byrne

Field Summary

Fields

Modifier and Type	Field and Description
protected float	maxY The maximum Y for this patch
protected float	minY The minimumY for this patch
protected TreeNode	NWTree The values of the nodes in the NW triangle of this patch
protected int	PATCH_SIZE The final size in number of grid points for this patch
protected boolean	resetRequested Flag to indicate if a clear has been requested
protected TreeNode	SETree The values of the nodes in the NW triangle of this patch
protected TerrainData	terrainData Source terrain data
protected Point	tileOrigin The origin of the patch in tile coordinates
protected VertexData	vertexData Raw vertex collection information
protected org.j3d.util.frustum.ViewFrustum	viewFrustum The view frustum used for this terrain

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	ROAMPatch(TerrainData terrain, int patchSize, org.j3d.util.frustum.ViewFrustum frustum, int patchX, int patchY) Create a new patch based on the terrain and appearance information.

Method Summary

Modifier and Type	Method and Description
void	clear() Instruct this patch that it is about to be removed from active duty.
protected void	createGeometry() Create the geometry needed for this patch.
protected void	setOrigin(int xOrig, int yOrig) Setup this patch with new data from the terrain.
String	toString2() Create a string representation of this patch.
abstract void	updateGeometry() Request an update to the geometry.

Methods inherited from class java.lang.Object

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

Field Detail

PATCH_SIZE

protected final int PATCH_SIZE

The final size in number of grid points for this patch

NWTree

protected TreeNode NWTree

The values of the nodes in the NW triangle of this patch

SETree

protected TreeNode SETree

The values of the nodes in the NW triangle of this patch

tileOrigin

protected Point tileOrigin

The origin of the patch in tile coordinates

terrainData

protected TerrainData terrainData

Source terrain data

viewFrustum

protected org.j3d.util.frustum.ViewFrustum viewFrustum

The view frustum used for this terrain

vertexData

protected VertexData vertexData

Raw vertex collection information

maxY

protected float maxY

The maximum Y for this patch

minY

protected float minY

The minimumY for this patch

resetRequested

protected boolean resetRequested

Flag to indicate if a clear has been requested

Constructor Detail

ROAMPatch

protected ROAMPatch(TerrainData terrain,
                    int patchSize,
                    org.j3d.util.frustum.ViewFrustum frustum,
                    int patchX,
                    int patchY)

Create a new patch based on the terrain and appearance information.

Parameters:

terrain - The raw height map info to use for this terrain

patchSize - The number of grid points to use in the patch on a side

frustum - The view frustum container used

Method Detail

updateGeometry

public abstract void updateGeometry()

Request an update to the geometry. If the geometry is visible then tell J3D that we would like to update the geometry. It does not directly do the update because we are using GeomByRef and so need to wait for the renderer to tell us when it is OK to do the updates.

clear

public void clear()

Instruct this patch that it is about to be removed from active duty. That means it should set all the geometry to be non-renderable, and clear all references to neightbours. It may be re-activated at some later stage.

setOrigin

protected void setOrigin(int xOrig,
                         int yOrig)

Setup this patch with new data from the terrain. The patch now exists in a different part of the world. After construction, this can be called at any time to set up the node for runtime use.

Parameters:

xOrig - The tileOrigin of the X grid coord for this patch in the global set of grid coordinates

yOrig - The tileOrigin of the Y grid coord for this patch in the global set of grid coordinates

createGeometry

protected void createGeometry()

Create the geometry needed for this patch. Just sets how many vertices are to be used based on the triangles of the two halves of the tree.

toString2

public String toString2()

Create a string representation of this patch.

Returns:

A string representation of the patch