VST3 Does Not Scale Correctly In Some Linux Hosts

[astriiddev]

Some Linux DAWs/hosts, such as Renoise, handle VST3 scaling differently, causing JUCE plugins to render cropped; especially on high DPI screens.

I was able to fix this issue by adding

void setScaleFactor(float newScale) override;

to PluginEditor.h

adding

void QDelayAudioProcessorEditor::setScaleFactor(float /* newScale */)
{
    juce::AudioProcessorEditor::setScaleFactor(audioProcessor.scale);
}

to PluginEditor.cpp while also removing any lines containing Desktop::getInstance().setGlobalScaleFactor(audioProcessor.scale); in that file

and changing QDelayAudioProcessor::setScale to

void QDelayAudioProcessor::setScale(float s)
{
    scale = s;
    saveSettings();
    
    if(auto* editor = dynamic_cast<QDelayAudioProcessorEditor*>(this->getActiveEditor()))
        editor->setScaleFactor(scale);
}

This allows the host to automatically call the scale upon loading the GUI and handle scaling changes while providing a consistent experience across various hosts and platforms.

[tiagolr]

Strange, I used to do just that and switched to setGlobalScaleFactor because I thought was the right way to do it and worked in any system, will investigate (again).