public function Rectangle::rotate in Drupal 8

Same name and namespace in other branches

1. 9 core/lib/Drupal/Component/Utility/Rectangle.php \Drupal\Component\Utility\Rectangle::rotate()
2. 10 core/lib/Drupal/Component/Utility/Rectangle.php \Drupal\Component\Utility\Rectangle::rotate()

Rotates the rectangle.

Parameters

float $angle: Rotation angle.

Return value

$this

File

core/lib/Drupal/Component/Utility/Rectangle.php, line 83

Class

Rectangle

Rectangle rotation algebra class.

Namespace

Drupal\Component\Utility

Code

public function rotate($angle) {

  // PHP 5.5 GD bug: https://bugs.php.net/bug.php?id=65148: To prevent buggy
  // behavior on negative multiples of 30 degrees we convert any negative
  // angle to a positive one between 0 and 360 degrees.
  $angle -= floor($angle / 360) * 360;

  // For some rotations that are multiple of 30 degrees, we need to correct
  // an imprecision between GD that uses C floats internally, and PHP that
  // uses C doubles. Also, for rotations that are not multiple of 90 degrees,
  // we need to introduce a correction factor of 0.5 to match the GD
  // algorithm used in PHP 5.5 (and above) to calculate the width and height
  // of the rotated image.
  if ((int) $angle == $angle && $angle % 90 == 0) {
    $imprecision = 0;
    $correction = 0;
  }
  else {
    $imprecision = -1.0E-5;
    $correction = 0.5;
  }

  // Do the trigonometry, applying imprecision fixes where needed.
  $rad = deg2rad($angle);
  $cos = cos($rad);
  $sin = sin($rad);
  $a = $this->width * $cos;
  $b = $this->height * $sin + $correction;
  $c = $this->width * $sin;
  $d = $this->height * $cos + $correction;
  if ((int) $angle == $angle && in_array($angle, [
    60,
    150,
    300,
  ])) {
    $a = $this
      ->fixImprecision($a, $imprecision);
    $b = $this
      ->fixImprecision($b, $imprecision);
    $c = $this
      ->fixImprecision($c, $imprecision);
    $d = $this
      ->fixImprecision($d, $imprecision);
  }

  // This is how GD on PHP5.5 calculates the new dimensions.
  $this->boundingWidth = abs((int) $a) + abs((int) $b);
  $this->boundingHeight = abs((int) $c) + abs((int) $d);
  return $this;
}