--TEST-- Testing imageflip() of GD library --SKIPIF-- <?php if ( ! extension_loaded('gd') || !function_exists('imageflip')) die( 'skip GD not present; skipping test' ); ?> --FILE-- <?php $im = imagecreatetruecolor( 99, 99 ); imagesetpixel($im, 0, 0, 0xFF); imagesetpixel($im, 0, 98, 0x00FF00); imagesetpixel($im, 98, 0, 0xFF0000); imagesetpixel($im, 98, 98, 0x0000FF); imageflip($im, IMG_FLIP_HORIZONTAL); imageflip($im, IMG_FLIP_VERTICAL); imageflip($im, IMG_FLIP_BOTH); var_dump(dechex(imagecolorat($im, 0, 0))); var_dump(dechex(imagecolorat($im, 0, 98))); var_dump(dechex(imagecolorat($im, 98, 0))); var_dump(dechex(imagecolorat($im, 98, 98))); ?> --EXPECT-- string(2) "ff" string(4) "ff00" string(6) "ff0000" string(2) "ff"