name.martingeisse.stackd.common.geometry.SectionId.java Source code

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Here is the source code for name.martingeisse.stackd.common.geometry.SectionId.java

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/**
 * Copyright (c) 2010 Martin Geisse
 *
 * This file is distributed under the terms of the MIT license.
 */

package name.martingeisse.stackd.common.geometry;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.builder.HashCodeBuilder;

/**
 * A section ID is used as the identifying key for a section, and also
 * stores the location of the section in the grid. The location is measured
 * in cluster-size units.
 * 
 * Although possible in general, this class is not derived from {@link BaseVector3i}
 * since section IDs use coordinates in cluster-size units, not cube units, so
 * extending a vector class would encourage mistakes that could be caught by the
 * type system.
 */
public final class SectionId {

    /**
     * the x
     */
    private final int x;

    /**
     * the y
     */
    private final int y;

    /**
     * the z
     */
    private final int z;

    /**
     * Constructor for known (x, y, z) coordinates of the section in cluster-size units.
     * @param x the x coordinate of the location in the grid, measured in cluster-size units
     * @param y the y coordinate of the location in the grid, measured in cluster-size units
     * @param z the z coordinate of the location in the grid, measured in cluster-size units
     */
    public SectionId(int x, int y, int z) {
        this.x = x;
        this.y = y;
        this.z = z;
    }

    /**
     * Constructor for scaling a cube-unit (x, y, z) position to cluster-size units.
     * @param x the x coordinate of the cube position
     * @param y the y coordinate of the cube position
     * @param z the z coordinate of the cube position
     * @param clusterSize the cluster size
     */
    public SectionId(int x, int y, int z, ClusterSize clusterSize) {
        int shift = clusterSize.getShiftBits();
        this.x = x >> shift;
        this.y = y >> shift;
        this.z = z >> shift;

    }

    /**
     * Constructor for scaling a cube-unit (x, y, z) position to cluster-size units.
     * @param position the cube position
     * @param clusterSize the cluster size
     */
    public SectionId(ReadableVector3i position, ClusterSize clusterSize) {
        int shift = clusterSize.getShiftBits();
        this.x = position.getX() >> shift;
        this.y = position.getY() >> shift;
        this.z = position.getZ() >> shift;
    }

    /**
     * Constructor for scaling a cube-unit (x, y, z) position to cluster-size units.
     * @param position the cube position
     * @param clusterSize the cluster size
     */
    public SectionId(ReadableVector3d position, ClusterSize clusterSize) {
        int shift = clusterSize.getShiftBits();
        this.x = (int) Math.floor(position.getX()) >> shift;
        this.y = (int) Math.floor(position.getY()) >> shift;
        this.z = (int) Math.floor(position.getZ()) >> shift;
    }

    /**
     * Constructor.
     * @param identifierText the text returned by {@link #getIdentifierText()}.
     * @throws IllegalArgumentException if the identifier text is malformed
     */
    public SectionId(String identifierText) throws IllegalArgumentException {
        final String[] idTextSegments = StringUtils.split(identifierText, '_');
        if (idTextSegments.length != 3) {
            throw new IllegalArgumentException(identifierText);
        }
        try {
            x = Integer.parseInt(idTextSegments[0]);
            y = Integer.parseInt(idTextSegments[1]);
            z = Integer.parseInt(idTextSegments[2]);
        } catch (final NumberFormatException e) {
            throw new IllegalArgumentException(identifierText);
        }
    }

    /**
     * Getter method for the x.
     * @return the x
     */
    public int getX() {
        return x;
    }

    /**
     * Getter method for the y.
     * @return the y
     */
    public int getY() {
        return y;
    }

    /**
     * Getter method for the z.
     * @return the z
     */
    public int getZ() {
        return z;
    }

    /**
     * Converts this ID to a string that is unique among all IDs, i.e. that can be
     * converted back to an ID equal to this one.
     * @return the identifier text
     */
    public String getIdentifierText() {
        StringBuilder builder = new StringBuilder();
        builder.append(x);
        builder.append('_');
        builder.append(y);
        builder.append('_');
        builder.append(z);
        return builder.toString();
    }

    /* (non-Javadoc)
     * @see java.lang.Object#equals(java.lang.Object)
     */
    @Override
    public boolean equals(Object obj) {
        if (obj instanceof SectionId) {
            SectionId other = (SectionId) obj;
            return (x == other.x && y == other.y && z == other.z);
        }
        return false;
    }

    /* (non-Javadoc)
     * @see java.lang.Object#hashCode()
     */
    @Override
    public int hashCode() {
        return new HashCodeBuilder().append(x).append(y).append(z).toHashCode();
    }

    /* (non-Javadoc)
     * @see java.lang.Object#toString()
     */
    @Override
    public String toString() {
        return "(" + x + ", " + y + ", " + z + ")";
    }

    /**
     * Returns the ID of the neighboring section by stepping in the specified
     * direction.
     * @param direction the direction
     * @return the neighbor's ID
     */
    public SectionId getNeighbor(AxisAlignedDirection direction) {
        return new SectionId(x + direction.getSignX(), y + direction.getSignY(), z + direction.getSignZ());
    }

}