Nesting AudioProcessor instances in a parent AudioProcessor from a static library

Audio Plugins
1

I need to link multiple AudioProcessor classes from a static library into a parent AudioProcessor, and it took me a while to figure out, so here is what I did, in case it saves someone else time, and/or to learn how I should have done it :slightly_smiling_face: :

I am building for iOS on a Mac using Xcode et al. It almost “just works” to link from the static library created by the “Shared Code” target of a plugin Xcode project, as generated by Projucer. However, the problem is that every plugin defines createPluginFilter() which returns an AudioProcessor*, and we only want one createPluginFilter() function defined in the one parent plugin. I thought about removing this function from the static library in a postbuildScript (maybe ar can do it), but right now my solution is as follows:

  1. Copy myPlugin.jucer to nestedPlugin.jucer
    [wart: must be done again after the main .jucer file changes]

  2. Edit nestedPlugin.jucer to change myPlugin to myNestedPlugin in the name fields and bundleIdentifier field. Also insert defines="STATIC_LIBRARY" in the <JUCERPROJECT...> tag. All of this is near the top of the .jucer file.

  3. In PluginProcessor.cpp, near the end, say something like:

#ifdef STATIC_LIBRARY
extern "C" AudioProcessor* JUCE_CALLTYPE createMyNestedPlugin()
#else
AudioProcessor* JUCE_CALLTYPE createPluginFilter()
#endif
{
    return new MyAudioProcessor();
}

Note that only the Shared Code target will compile with STATIC_LIBRARY defined, since otherwise the function createPluginFilter() is required for compilation.

The wart could be removed by supporting defines on a per-target basis.

Thanks for any better ideas!

Julius

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