function ToolkitGdTest::testGifTransparentImages

Tests for GIF images with transparency.

File

core/tests/Drupal/KernelTests/Core/Image/ToolkitGdTest.php, line 451

Class

ToolkitGdTest

Tests for the GD image toolkit.

Namespace

Code

public function testGifTransparentImages() : void {
  // Test loading an indexed GIF image with transparent color set.
  // Color at top-right pixel should be fully transparent.
  $file = 'image-test-transparent-indexed.gif';
  $image = $this->imageFactory
    ->get('core/tests/fixtures/files/' . $file);
  $gd_image = $image->getToolkit()
    ->getImage();
  $color_index = imagecolorat($gd_image, $image->getWidth() - 1, 0);
  $color = array_values(imagecolorsforindex($gd_image, $color_index));
  $this->assertEquals(static::ROTATE_TRANSPARENT, $color, "Image {$file} after load has full transparent color at corner 1.");
  // Test deliberately creating a GIF image with no transparent color set.
  // Color at top-right pixel should be fully transparent while in memory,
  // fully opaque after flushing image to file.
  $file = 'image-test-no-transparent-color-set.gif';
  $file_path = $this->directory . '/' . $file;
  // Create image.
  $image = $this->imageFactory
    ->get();
  $image->createNew(50, 20, 'gif', NULL);
  $gd_image = $image->getToolkit()
    ->getImage();
  $color_index = imagecolorat($gd_image, $image->getWidth() - 1, 0);
  $color = array_values(imagecolorsforindex($gd_image, $color_index));
  $this->assertEquals(static::ROTATE_TRANSPARENT, $color, "New GIF image with no transparent color set after creation has full transparent color at corner 1.");
  // Save image.
  $this->assertTrue($image->save($file_path), "New GIF image {$file} was saved.");
  // Reload image.
  $image_reloaded = $this->imageFactory
    ->get($file_path);
  $gd_image = $image_reloaded->getToolkit()
    ->getImage();
  $color_index = imagecolorat($gd_image, $image_reloaded->getWidth() - 1, 0);
  $color = array_values(imagecolorsforindex($gd_image, $color_index));
  // Check explicitly for alpha == 0 as the rest of the color has been
  // compressed and may have slight difference from full white.
  $this->assertEquals(0, $color[3], "New GIF image {$file} after reload has no transparent color at corner 1.");
  // Test loading an image whose transparent color index is out of range.
  // This image was generated by taking an initial image with a palette size
  // of 6 colors, and setting the transparent color index to 6 (one higher
  // than the largest allowed index), as follows:
  // @code
  // $image = imagecreatefromgif('core/tests/fixtures/files/image-test.gif');
  // imagecolortransparent($image, 6);
  // imagegif($image, 'core/tests/fixtures/files/image-test-transparent-out-of-range.gif');
  // @endcode
  // This allows us to test that an image with an out-of-range color index
  // can be loaded correctly.
  $file = 'image-test-transparent-out-of-range.gif';
  $image = $this->imageFactory
    ->get('core/tests/fixtures/files/' . $file);
  $this->assertTrue($image->isValid(), "Image '{$file}' after load should be valid, but it is not.");
  $this->assertTrue(imageistruecolor($image->getToolkit()
    ->getImage()), "Image '{$file}' after load should be a truecolor image, but it is not.");
}