src/main/java/com/montecarlo/geometry/BoundingBox.java - master - shvidkuli/kkrjava

src/main/java/com/montecarlo/geometry/BoundingBox.java
97 строк3 KB
kroc400
first_commit
30 апр 2026, 22:44
30 апр 2026, 22:442347fdb
package com.montecarlo.geometry;

import java.util.Random;

/**
 * An axis-aligned bounding box (AABB) defined by its minimum and maximum x/y extents.
 *
 * <p>Used by Monte Carlo calculations to define the sampling region and by each shape
 * to expose its spatial extent.</p>
 */
public class BoundingBox {

    private final double minX;
    private final double minY;
    private final double maxX;
    private final double maxY;

    /**
     * Constructs a BoundingBox with the given corner coordinates.
     *
     * @param minX left boundary
     * @param minY bottom boundary
     * @param maxX right boundary
     * @param maxY top boundary
     * @throws IllegalArgumentException if minX &gt; maxX or minY &gt; maxY
     */
    public BoundingBox(double minX, double minY, double maxX, double maxY) {
        if (minX > maxX || minY > maxY) {
            throw new IllegalArgumentException(
                "Invalid bounding box: min must be <= max. Got ["
                + minX + "," + maxX + "] x [" + minY + "," + maxY + "]");
        }
        this.minX = minX;
        this.minY = minY;
        this.maxX = maxX;
        this.maxY = maxY;
    }

    /** @return left boundary */
    public double getMinX() { return minX; }

    /** @return bottom boundary */
    public double getMinY() { return minY; }

    /** @return right boundary */
    public double getMaxX() { return maxX; }

    /** @return top boundary */
    public double getMaxY() { return maxY; }

    /** @return width of the bounding box */
    public double getWidth() { return maxX - minX; }

    /** @return height of the bounding box */
    public double getHeight() { return maxY - minY; }

    /**
     * Returns the area of this bounding box.
     *
     * @return width * height
     */
    public double area() {
        return getWidth() * getHeight();
    }

    /**
     * Generates a uniformly distributed random {@link Point} inside this bounding box.
     *
     * @param random the random number generator to use
     * @return a random point uniformly distributed in [minX, maxX] × [minY, maxY]
     */
    public Point randomPoint(Random random) {
        double x = minX + random.nextDouble() * getWidth();
        double y = minY + random.nextDouble() * getHeight();
        return new Point(x, y);
    }

    /**
     * Returns the smallest bounding box that contains both this box and {@code other}.
     *
     * @param other another bounding box
     * @return merged bounding box
     */
    public BoundingBox merge(BoundingBox other) {
        return new BoundingBox(
            Math.min(this.minX, other.minX),
            Math.min(this.minY, other.minY),
            Math.max(this.maxX, other.maxX),
            Math.max(this.maxY, other.maxY)
        );
    }

    @Override
    public String toString() {
        return String.format("BoundingBox([%.4f, %.4f] x [%.4f, %.4f])", minX, maxX, minY, maxY);
    }
}