some lv2 GUI's fail to initialize

[CarloCattano]

Environment

• Linux xTx 5.19.1-3-MANJARO SMP PREEMPT_DYNAMIC Sat Aug 13 06:34:52 UTC 2022 x86_64 GNU/Linux
• Giada version: [0.23] compiled from source today

Opening some lv2 plugins on a track FX leads to the UI not opening and the regular generic UI doesnt show up. I will do more tests to tell exactly which plugins fail to do so.

Here is an example with zam plugins

[pluginManager::makePlugin] plugin instance with pid=LV2-ZamComp-3daa6d14-3daa6d14 created
[Plugin] plugin initialized and ready. MIDI input params: 8
[gdPluginWindowGUI] Opening editor
WARNING: this host does not send sample-rate information for LV2 UIs, using 44100 as fallback (this could be wrong)
X_CreatePixmap: BadValue (integer parameter out of range for operation) 0x0
X_CopyArea: BadDrawable (invalid Pixmap or Window parameter) 0x560c911
X_FreePixmap: BadPixmap (invalid Pixmap parameter) 0x560c911

Steps to reproduce the behavior:

1. Open giada
2. Create a sample channel
3. Add an FX lv2 like zamComp
4. No UI is displayed

Expected behavior GUI appears or a fallback generic UI should be created from the params

Additional context I know lv2 its pretty recent, just wanted to help see if we can get things going

[gvnnz]

Thanks @CarloCattano for the report & investigation. I recommend to test plug-ins also in the JUCE Plug-in Host app and see if they work there.

[CarloCattano]

They do pretty much. Tested in Carla and BespokeSynth, the latter with lv2 juce 7 implemented

[gvnnz]

Thanks. I added some fixes to the plug-in's UI initialization here: 15f0ab4c87f6ac59955f96872c941ea1885b03ae .

[CarloCattano]

Hm. Now they open but dont display anything. Is a step forwards tho

[gdPluginWindowGUI] Opening editor
X_CreatePixmap: BadValue (integer parameter out of range for operation) 0x0
X_CopyArea: BadDrawable (invalid Pixmap or Window parameter) 0x5a25249
X_FreePixmap: BadPixmap (invalid Pixmap parameter) 0x5a25249

[gvnnz]

Might be related: https://github.com/juce-framework/JUCE/issues/1123