Nubs\Geometron\LineSegment

Complexity

Total Complexity

8

Size/Duplication

Total Lines	94
Duplicated Lines	0 %

Coupling/Cohesion

Components	1
Dependencies	1

Importance

Changes

0

7 Methods

Rating	Name	Duplication	Size	Complexity
A	__construct()	0	9	2
A	a()	0	4	1
A	b()	0	4	1
A	isDegenerate()	0	4	1
A	vector()	0	4	1
A	length()	0	4	1
A	center()	0	4	1

<?php
namespace Nubs\Geometron;

use Exception;

/**
 * This class represents an immutable line segment in euclidean geometry and its
 * associated operations.
 *
 * Instances of this class will not change state.  Any operations on the line
 * segment will return a new line segment with the new state.
 */
class LineSegment implements Finite
{
    /** @type \Nubs\Geometron\Point One endpoint of the line segment. */
    protected $_a;

    /** @type \Nubs\Geometron\Point One endpoint of the line segment. */
    protected $_b;

    /**
     * Initalize the line segment with its two endpoints.
     *
     * @api
     * @param \Nubs\Geometron\Point $a One endpoint of the line segment.
     * @param \Nubs\Geometron\Point $b One endpoint of the line segment.
     */
    public function __construct(Point $a, Point $b)
    {
        if (!$a->isSameSpace($b)) {
            throw new Exception('The two points must be in the same geometric space');
        }

        $this->_a = $a;
        $this->_b = $b;
    }

    /**
     * Get an endpoint of the line segment.
     *
     * @api
     * @return \Nubs\Geometron\Point One endpoint of the line segment.
     */
    public function a()
    {
        return $this->_a;
    }

    /**
     * Get an endpoint of the line segment.
     *
     * @api
     * @return \Nubs\Geometron\Point One endpoint of the line segment.
     */
    public function b()
    {
        return $this->_b;
    }

    /**
     * Determine whether this line segment is degenerate.
     *
     * A line segment is degenerate if its two points are the same.
     *
     * @api
     * @return bool True if the line segment is degenerate, false otherwise.
     */
    public function isDegenerate()
    {
        return $this->a()->isEqual($this->b());
    }

    /**
     * Calculates the vector between the two endpoints of the line segment.
     *
     * @api
     * @return \Nubs\Vectorix\Vector The vector from a() to b().
     */
    public function vector()
    {
        return $this->b()->vector()->subtract($this->a()->vector());
    }

    /**
     * Calculates the length of the line segment.
     *
     * @api
     * @return float The length of the line segment.
     */
    public function length()
    {
        return $this->vector()->length();
    }

    /**
     * The center of a line segment is the point halfway along the line.
     *
     * @api
     * @return \Nubs\Geometron\Point The center-point of the line segment.
     * @see \Nubs\Geometron\Finite::center()
     */
    public function center()
    {
        return new Point($this->a()->vector()->add($this->vector()->divideByScalar(2)));
    }
}