The heavy hvcc compiler for Pure Data patches. Updated to python3 and additional generators

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Getting Started

Audio Input/Output

To receive audio input into your patch add an [adc~] object.

To send audio output add a [dac~] The number of channels can be configured by providing arguments to object. For example [dac~ 1 2 3] will generate three output channels. [adc~ 1] will make a single channel of audio input.

Note that top-level graphs (e.g. _main.pd) should not have any [inlet~] or [outlet~] objects. These are reserved only for abstractions.

NOTE: Currently if your main patch does not have at least an adc~ or dac~ configured signal rate objects will not be evaluated in the graph!

Exposing Parameters

Input Parameters

All (control) [receive] and [r] objects annotated with @hv_param will be exposed as input parameters in each framework. The name provided will propagate through to the plugin interface.

For example, [r gain @hv_param 0 1 0.5] will show up as "gain", with a minimum value of 0, a maximum value of 1, and a default value of 0.5. If a patch has multiple exposed receivers with the same name, they must all have the same minimum, maximum, and default values as well.

Receivers not annotated with @hv_param are still completely functional, they simply will not be exported to the framework interface.


Parameter Type

An optional parameter type can be set to which generator implementations can program custom features. The default type is float.

For example, [r toggle @hvparam 0 1 1 bool].

See the DPF docs for more information on how parameter types can be integrated into a generator.

Output Parameters

In the same manner as above, all (control) [send] and [s] objects annotated with @hv_param will be exposed as output parameters.

For example, [s envelope @hv_param].

Messages passed to these send objects can be forwarded on to other parts of the application. This is useful for creating audio-driven behaviours or extracting analysis information.

See the specific framework details for more information on output parameter support and integration details.

Exposing Events

All (control) [receive] and [r] objects annotated with @hv_event will be exposed as events in the Unity and Javascript targets only.


For example, [r bang @hv_event] will show up as a button called "bang" in the Unity Editor interface.


See the Unity docs for more information on exposing events and controlling them.


Some generators, like Daisy and DPF, enable support for extra configuration metadata.json file using the -m. It depends on the generator what is supported. See the DPF docs for more information on setting meta data for plugins.

Simple Daisy example that selects the desired board to build for:

    "daisy": {
        "board": "seed"


If there's an incompatibility within the patch, Heavy will generate an error message.



Heavy will also perform patch analysis to look for common mistakes and inconsitencies between Pd and heavy behaviour. The targets will still be generated correctly but it might be useful information for example when cleaning up the patch.


Reporting Issues

If you experience any problems or have some thoughts on how to improve heavy make sure to browse and contribute to our public issue tracker.

Tips and Tricks

Just because pd-vanilla can run your patch, does not mean it will behave exactly the same using Heavy. Extra care needs to be taken when dealing with control messages and certain PD object features.

Known Limitations

This list will be continuously epanded to document differences in object behavior between PD and Heavy.