Specifies the shape to be used at the corners of paths (or other vector shapes) when they are stroked.
Background color
 
Stroke color
 
Fill color
 
Specifies the shape to be used at the corners of paths (or other vector shapes) when they are stroked.
Parameters
linejoinintLINEJOIN_ constant
function setStrokeLineJoin($strokeColor, $fillColor, $backgroundColor)
{
    $draw = new \ImagickDraw();
    $draw->setStrokeWidth(1);
    $draw->setStrokeColor($strokeColor);
    $draw->setFillColor($fillColor);

    $draw->setStrokeWidth(20);

    $offset = 220;

    $lineJoinStyle = [\Imagick::LINEJOIN_MITER, \Imagick::LINEJOIN_ROUND, \Imagick::LINEJOIN_BEVEL,];

    for ($x = 0; $x < count($lineJoinStyle); $x++) {
        $draw->setStrokeLineJoin($lineJoinStyle[$x]);
        $points = [['x' => 40 * 5, 'y' => 10 * 5 + $x * $offset], ['x' => 20 * 5, 'y' => 20 * 5 + $x * $offset], ['x' => 70 * 5, 'y' => 50 * 5 + $x * $offset], ['x' => 40 * 5, 'y' => 10 * 5 + $x * $offset],];

        $draw->polyline($points);
    }

    $image = new \Imagick();
    $image->newImage(500, 700, $backgroundColor);
    $image->setImageFormat("png");

    $image->drawImage($draw);

    header("Content-Type: image/png");
    echo $image->getImageBlob();
}