How can a host ask a plugin to reset to its default state?

Developer VST 3 SDK
1

I am developing a host and would like to know how can a host ask a plugin to reset to its default state?

For some plugin, it’s possible to achieve that by setting all parameters to their default value

setParamNormalized(info.id, info.defaultNormalizedValue);
vst3Processor->setParameter(info.id, info.defaultNormalizedValue, 0);

but some plugins (example: Stochas), it does not work! I guess we have to use “component->setState(&state);” for these plugins but is there a way to do it without keeping a copy of the initial state (at first load)?

Aslo, is there a way to know when a plugin use only parameters and not state?

Thank you

2

In order to save a specific state of a plug-in you have to use getState… Do not use parameters…
You could use too the VST 3 Interfaces: IStreamAttributes Class Reference to inform the plug-in about the fact that it is a default preset (not implemented by a lot of plug-in) : see
[3.6.0] Preset Meta-Information - VST 3 Developer Portal