Plugin uses GD extension with freetype enabled, but doesn't do required/optional in a environment.xml

[danowar2k]

Moodle provides the ability to do an environment.xml where you describe which PHP version or PHP extensions your plugin needs.

Moodle core requires the GD extension, but doesn't check apart from "is this extension present".

You use freetype only functions, e.g. imagettfbbox() and imagettftext(). Could you add an environment.xml with a "required" for GD and an "optional check" with a custom function checking if freetype is enabled?

It would help others to determine the requirements to use this plugin better.

[danowar2k]

Corresponding Moodle core issue (they use freetype, too): https://tracker.moodle.org/browse/MDL-58999