This filter-set does not take any visible action on its own, but provides a service to other filter-sets. It calls
after every OpenGL call to detect OpenGL errors (it does not detect X errors).
Usually you will not need to explicitly load this filter-set; if you want to be informed of OpenGL errors, either use the
gldb-gui(1). However, you may occasionally see the message
An OpenGL error was detected but will be lost to the application.
This means that
bugle's internal error-checking code accidentally collected an error caused by one of your calls, and thus if your application later called
it would not be informed of the error. However, if you add the
filter-set, it will catch the error first and your application will be correctly informed of the error.
Because the error reporting semantics of OpenGL are not completely defined (in particular, an implementation may choose how many error flags it has), it is impossible to guarantee that this filter-set is completely transparent to the application. However, the first call to
always return an error, and in practice this is all that is necessary.