Contao\CoreBundle\Test\Contao\GdImageTest::testCopyTo PHP Method

    public function testCopyTo()
    {
        $image = imagecreatetruecolor(100, 100);
        // Whole image black
        imagefill($image, 0, 0, imagecolorallocatealpha($image, 0, 0, 0, 0));
        $image = new GdImage($image);
        $target = GdImage::fromDimensions(100, 100);
        $image->copyTo($target, 10, 10, 80, 80);
        $this->assertEquals(['red' => 0, 'green' => 0, 'blue' => 0, 'alpha' => 0], imagecolorsforindex($target->getResource(), imagecolorat($target->getResource(), 50, 50)), 'Center should be black');
        $this->assertEquals(['red' => 0, 'green' => 0, 'blue' => 0, 'alpha' => 0], imagecolorsforindex($target->getResource(), imagecolorat($target->getResource(), 10, 10)), '10 pixel from left top should be black');
        $this->assertEquals(['red' => 0, 'green' => 0, 'blue' => 0, 'alpha' => 0], imagecolorsforindex($target->getResource(), imagecolorat($target->getResource(), 89, 89)), '10 pixel from right bottom should be black');
        $this->assertEquals(127, imagecolorsforindex($target->getResource(), imagecolorat($target->getResource(), 0, 0))['alpha'], 'Left top pixel should be transparent');
        $this->assertEquals(127, imagecolorsforindex($target->getResource(), imagecolorat($target->getResource(), 99, 99))['alpha'], 'Bottom right pixel should be transparent');
        $this->assertEquals(127, imagecolorsforindex($target->getResource(), imagecolorat($target->getResource(), 9, 9))['alpha'], '9 pixel from left top should be transparent');
        $this->assertEquals(127, imagecolorsforindex($target->getResource(), imagecolorat($target->getResource(), 90, 90))['alpha'], '9 pixel from bottom right should be transparent');
    }