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/*
* This file is part of the GeoLatte project.
*
* GeoLatte is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GeoLatte is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with GeoLatte. If not, see This class holds the the maximum spatial extent and tree-depth of the implied
* QuadTree-index for a {@code MortonCode}.
*
* @author Karel Maesen, Geovise BVBA
* creation-date: 2/19/13
*/
public class MortonContext {
final private static String ERR_MSG_MAX_DEPTH = "Max. depth is limited to " + (Integer.SIZE - 1);
final private static String ERR_MSG_NULL = "No Null arguments allowed.";
final private int depth;
final private Envelope
extent;
final private int numOfDivisionsAlongAxis;
final private double leafWidth;
final private double leafHeight;
/**
* Constructs a {@code MortonContext} with the specified extent and max. tree-depth
*
* @param extent the extent for this instance
* @param depth the tree-depth
*/
public MortonContext(Envelope
extent, int depth) {
if (extent == null) {
throw new IllegalArgumentException(ERR_MSG_NULL);
}
if (depth >= Integer.SIZE) {
throw new IllegalArgumentException(ERR_MSG_MAX_DEPTH);
}
this.depth = depth;
this.extent = extent;
this.numOfDivisionsAlongAxis = (int) (Math.pow(2, depth));
this.leafWidth = (extent.extentAlongDimension(0)) / numOfDivisionsAlongAxis;
this.leafHeight = (extent.extentAlongDimension(1)) / numOfDivisionsAlongAxis;
}
/**
* Returns the maximum X-coordinate of the extent.
*
* @return the maximum X-coordinate of the extent
*/
public double getMaxX() {
return extent.upperRight().getCoordinate(0);
}
/**
* Returns the maximum Y-coordinate of the extent.
*
* @return the maximum Y-coordinate of the extent
*/
public double getMaxY() {
return extent.upperRight().getCoordinate(1);
}
/**
* Returns the minimum X-coordinate of the extent
*
* @return the minimum X-coordinate of the extent
*/
public double getMinX() {
return extent.lowerLeft().getCoordinate(0);
}
/**
* Returns the minimum Y-coordinate of the extent
*
* @return the minimum Y-coordinate of the extent
*/
public double getMinY() {
return extent.lowerLeft().getCoordinate(1);
}
/**
* Returns the maximum tree-depth
*
* @return the maximum tree-depth
*/
public int getDepth() {
return depth;
}
/**
* Returns the CrsId of the spatial extent
*
* @return the CrsId of the spatial extent
*/
public CoordinateReferenceSystem getCoordinateReferenceSystem() {
return extent.getCoordinateReferenceSystem();
}
/**
* Returns the number of subdivisions along an (X- or Y-)axis.
*
*
The leaves of a Quadtree form a grid-cell structure that completely
* covers the extent. This method returns the number of subdivisions along
* a single axis. It is the square root of the total number of leaves.
*
* @return the number of subdivisions along an (X- or Y-)axis.
*/
int getNumberOfDivisionsAlongAxis() {
return this.numOfDivisionsAlongAxis;
}
/**
* Returns the width of the extent of a leaf in the QuadTree at tree-depth (lowest-level)
*
* @return the width of the extent of a leaf in the QuadTree at tree-depth (lowest-level)
*/
double getLeafWidth(){
return this.leafWidth;
}
/**
* Returns the height of the extent of a leaf in the QuadTree at tree-depth (lowest-level)
*
* @return the height of the extent of a leaf in the QuadTree at tree-depth (lowest-level)
*/
double getLeafHeight(){
return this.leafHeight;
}
/**
* Checks whether the specified {@code Point} is contained in the extent.
*
* @param pos a {@code Point} value
* @return true if the specified point is contained in the extent, false otherwise
* @throws IllegalArgumentException if the specified point does not share this extent's {@code CrsId}
*/
public boolean extentContains(P pos) {
return this.extent.contains(pos);
}
/**
* Checks whether the specified {@code Envelope} is contained in the extent.
*
* @param envelope an {@code Envelope} value
* @return true if the specified envelope is contained in the extent, false otherwise
* @throws IllegalArgumentException if the specified envelope does not share this extent's {@code CrsId}
*/
public boolean extentContains(Envelope envelope) {
return this.extent.contains(envelope);
}
/**
* Returns the spatial extent of this instance
* @return an {@code Envelope} representing the spatial extent of this instance
*/
public Envelope
getExtent() {
return extent;
}
}