Enginine JUCE Plugin

So with my VCVRack > KRTPluginA plugins doing over 15,000+ downloads, I thought I'd give JUCE a go. So this is generic code. (2026-05-22) VCVRack can load VST3 plugins. The embedding into VCVRack allows for upto 8 outputs. The 24 parameters minus two inputs for a pre-filter insert is quite nice for options.

So I've dumped KDevelop and started using Zed (with bear to make the compile_commands.json symlinked from the Builds/LinuxMakefile directory where bear -- make was run as a command). Yes, now all the strange errors are gone. (2026-05-26) KDevelop used to be good when it had the Kt toolkit.

TODO

• Basic Audio Pass Volume
• ParameterAttachment Mechanism (for visual updates on parameter change)
• Load/Save State Mechanism
• Look and Feel
• Audio Processing
• Filter Input
• Extra Outputs
• Polyphonic Setup
• Oscillator
• Envelope
• Modulation Routing
• Layout Using Own Grid Mehtod (27 GUI)
• Keyboard
• Simple Legacy MIDI In and Out (good for standalone MIDI)
• Parameter Preset Mechanism
• Python Utilities
• Parameter Skew Mechanism
• Background
• Zed/Bear Build
• Hopefully Some Cool Sounding Stuff
• Preset Filling

MIDI CC Assignments

Testing with Carla as the host restricts use of CCs 2 (dry/wet), 7 (mix volume) and 8 (balance). Also CC 6 (RPN/NRPN data entry) would be somewhat of a pain to use in many studio kinds of settings. Also reserving CC 6 for RPN/NRPN data entry, can allow for some hidden parameters to be accessed via CC.

The modulation wheel CC 1 is specially routed and not part of any preset information. This then leaves the rest of the 14 bit CCs for use as the 27 knob slots. In C++ this was expressed in the 9 across and 3 down grid layout like below for matching with the front panel layout. This is not totally MIDI specification but does place the simple 14 bit CCs in a convenient grid layout for the front panel, while avoiding enough standardized ones.

    // MIDI CC 14 bit controller numbers n and n+32
    // 2 - Carla Dry/Wet (breath)
    // 6 - NRPN, RPN Data Entry (reserved)
    // 7 - Carla Volume
    // 8 - Carla Balance
    // parameter to MIDI CC
    int cc[3][9] = {
        {  0,  3,  4,  5,  9, 10, 11, 12, 13 },
        { 14, 15, 16, 17, 18, 19, 20, 21, 22 },
        { 23, 24, 25, 26, 27, 28, 29, 30, 31 }
    };

Other auxilliary controls can have CC numbers assigned, and the tooltips will show the CC number. As a polysynth design, portomento is not supported, and therefore was the first for reassignment. Not being a member of the MIDI Association I guess has benefits of some non-compliance flexibility.

Notes on Bear Setup and Building

The JUCE (8.0.13) is in ~/JUCE and Enginine is in ~/Enginine. All paths are absolute. A bear.yml file is used to configure the bear tool so this should be so. Note bear version schema 4.1 is used.

After cloning the repository. Do cd Enginine and make clean. Then maybe sudo apt install bear (for the bear tool) and bear -- make (instead of make just this once). Run make user to change $HOME (hardcoded to me as /home/jacko) to /home/$USER (your home directory) within compile_commands.json (for syntax completion). It might work. (2026-06-03)

The following make targets are available:

• make build - build the code (default make)
• make clean - clean the build
• make run - run the executable standalone build
• make juce - renew binary resource information (assumes Projucer built and ../JUCE git repo)
• make user - change $HOME to /home/$USER for syntax completion (do you need bear?)

You need to make juce if you edit the .png or save an updated presets.xml as factory defaults.

Comercial Stuff

• Might not be in this repository (JUCE has reasonable terms)

I'd like to make some cash on this one. So I might do some kind of mix between open source with commercial terms. I'll think about it. (2026-06-02)

Thanks

Simon Jackson

Project Director