phpOMS/Math/Geometry/Shape/D2/Polygon.php
2022-11-09 22:55:39 +01:00

299 lines
7.8 KiB
PHP
Executable File

<?php
/**
* Karaka
*
* PHP Version 8.1
*
* @package phpOMS\Math\Geometry\Shape\D2
* @copyright Dennis Eichhorn
* @license OMS License 1.0
* @version 1.0.0
* @link https://karaka.app
*/
declare(strict_types=1);
namespace phpOMS\Math\Geometry\Shape\D2;
/**
* Polygon class.
*
* @package phpOMS\Math\Geometry\Shape\D2
* @license OMS License 1.0
* @link https://karaka.app
* @since 1.0.0
*/
final class Polygon implements D2ShapeInterface
{
/**
* Epsilon for float comparison.
*
* @var float
* @since 1.0.0
*/
public const EPSILON = 4.88e-04;
/**
* Coordinates.
*
* These coordinates define the polygon
*
* @var array<int, array{x:int|float, y:int|float}>
* @since 1.0.0
*/
private array $coord = [];
/**
* Constructor.
*
* @param array<int, array{x:int|float, y:int|float}> $coord 2 Dimensional coordinate array where the indices are x and y
*
* @example Polygon([['x' => 1, 'y' => 2], ['x' => ...], ...])
*
* @since 1.0.0
*/
public function __construct(array $coord)
{
$this->coord = $coord;
}
/**
* Point polygon relative position
*
* @param array{x:int|float, y:int|float} $point Point location
*
* @return int
*
* @since 1.0.0
*/
public function pointInPolygon(array $point) : int
{
$coord = $this->coord;
$coord[] = $this->coord[0];
return self::isPointInPolygon($point, $coord);
}
/**
* Point polygon relative position
*
* @param array{x:int|float, y:int|float} $point Point location
* @param array<int, array{x:int|float, y:int|float}> $polygon Polygon definition
*
* @return int -1 inside polygon 0 on vertice 1 outside
*
* @link http://erich.realtimerendering.com/ptinpoly/
* @since 1.0.0
*/
public static function isPointInPolygon(array $point, array $polygon) : int
{
$length = \count($polygon);
// Polygon has to start and end with same point
if ($polygon[0]['x'] !== $polygon[$length - 1]['x'] || $polygon[0]['y'] !== $polygon[$length - 1]['y']) {
$polygon[] = $polygon[0];
}
// On vertex?
if (self::isOnVertex($point, $polygon)) {
return 0;
}
// Inside or ontop?
$countIntersect = 0;
$polygonCount = \count($polygon);
for ($i = 1; $i < $polygonCount; ++$i) {
$vertex1 = $polygon[$i - 1];
$vertex2 = $polygon[$i];
if (\abs($vertex1['y'] - $vertex2['y']) < self::EPSILON
&& \abs($vertex1['y'] - $point['y']) < self::EPSILON
&& $point['x'] > \min($vertex1['x'], $vertex2['x'])
&& $point['x'] < \max($vertex1['x'], $vertex2['x'])
) {
return 0; // boundary
}
if ($point['y'] > \min($vertex1['y'], $vertex2['y'])
&& $point['y'] <= \max($vertex1['y'], $vertex2['y'])
&& $point['x'] <= \max($vertex1['x'], $vertex2['x'])
&& \abs($vertex1['y'] - $vertex2['y']) >= self::EPSILON
) {
$xinters = ($point['y'] - $vertex1['y']) * ($vertex2['x'] - $vertex1['x']) / ($vertex2['y'] - $vertex1['y']) + $vertex1['x'];
if (\abs($xinters - $point['x']) < self::EPSILON) {
return 0; // boundary
}
if (\abs($vertex1['x'] - $vertex2['x']) < self::EPSILON || $point['x'] < $xinters) {
++$countIntersect;
}
}
}
if ($countIntersect % 2 !== 0) {
return -1;
}
return 1;
}
/**
* Is point on vertex?
*
* @param array{x:int|float, y:int|float} $point Point location
* @param array<int, array{x:int|float, y:int|float}> $polygon Polygon definition
*
* @return bool
*
* @since 1.0.0
*/
private static function isOnVertex(array $point, array $polygon) : bool
{
foreach ($polygon as $vertex) {
if (\abs($point['x'] - $vertex['x']) < self::EPSILON && \abs($point['y'] - $vertex['y']) < self::EPSILON) {
return true;
}
}
return false;
}
/**
* Get interior angle sum
*
* @return int
*
* @since 1.0.0
*/
public function getInteriorAngleSum() : int
{
return (\count($this->coord) - 2) * 180;
}
/**
* Get exterior angle sum
*
* @return int
*
* @since 1.0.0
*/
public function getExteriorAngleSum() : int
{
return 360;
}
/**
* Get surface area
*
* @return float
*
* @since 1.0.0
*/
public function getSurface() : float
{
return \abs($this->getSignedSurface());
}
/**
* Get signed surface area
*
* @return float
*
* @since 1.0.0
*/
private function getSignedSurface() : float
{
$count = \count($this->coord);
$surface = 0;
for ($i = 0; $i < $count - 1; ++$i) {
$surface += $this->coord[$i]['x'] * $this->coord[$i + 1]['y'] - $this->coord[$i + 1]['x'] * $this->coord[$i]['y'];
}
$surface += $this->coord[$count - 1]['x'] * $this->coord[0]['y'] - $this->coord[0]['x'] * $this->coord[$count - 1]['y'];
$surface /= 2;
return $surface;
}
/**
* Get perimeter
*
* @return float
*
* @since 1.0.0
*/
public function getPerimeter() : float
{
$count = \count($this->coord);
$perimeter = \sqrt(($this->coord[0]['x'] - $this->coord[$count - 1]['x']) ** 2 + ($this->coord[0]['y'] - $this->coord[$count - 1]['y']) ** 2);
for ($i = 0; $i < $count - 1; ++$i) {
$perimeter += \sqrt(($this->coord[$i + 1]['x'] - $this->coord[$i]['x']) ** 2 + ($this->coord[$i + 1]['y'] - $this->coord[$i]['y']) ** 2);
}
return $perimeter;
}
/**
* Get barycenter
*
* @return array{x:int|float, y:int|float}
*
* @since 1.0.0
*/
public function getBarycenter() : array
{
$barycenter = ['x' => 0, 'y' => 0];
$count = \count($this->coord);
for ($i = 0; $i < $count - 1; ++$i) {
$mult = ($this->coord[$i]['x'] * $this->coord[$i + 1]['y'] - $this->coord[$i + 1]['x'] * $this->coord[$i]['y']);
$barycenter['x'] += ($this->coord[$i]['x'] + $this->coord[$i + 1]['x']) * $mult;
$barycenter['y'] += ($this->coord[$i]['y'] + $this->coord[$i + 1]['y']) * $mult;
}
$mult = ($this->coord[$count - 1]['x'] * $this->coord[0]['y'] - $this->coord[0]['x'] * $this->coord[$count - 1]['y']);
$barycenter['x'] += ($this->coord[$count - 1]['x'] + $this->coord[0]['x']) * $mult;
$barycenter['y'] += ($this->coord[$count - 1]['y'] + $this->coord[0]['y']) * $mult;
$surface = $this->getSignedSurface();
$barycenter['x'] = 1 / (6 * $surface) * $barycenter['x'];
$barycenter['y'] = 1 / (6 * $surface) * $barycenter['y'];
return $barycenter;
}
/**
* Get area by side length
*
* @param float $length Side length
* @param int $sides Number of sides
*
* @return float
*
* @since 1.0.0
*/
public static function getRegularAreaByLength(float $length, int $sides) : float
{
return $length ** 2 * $sides / (4 * \tan(\M_PI / $sides));
}
/**
* Get area by radius
*
* @param float $r Radius
* @param int $sides Number of sides
*
* @return float
*
* @since 1.0.0
*/
public static function getRegularAreaByRadius(float $r, int $sides) : float
{
return $r ** 2 * $sides * \tan(\M_PI / $sides);
}
}