#GestVM

#Introduction

GestVM implements a so-called "gesture synthesizer", sequenced and controlled via the Uxn Virtual machine.

A Gesture Synthesizer is an audio-rate control signal generator whose timing is managed by another audio-rate control signal generator, called a conductor.

Conceptually, a Gesture can be thought of as something between an automation curve and breakpoint line generator.

#Overview of System

An instance of an Uxn VM is created inside of sndkit, and a ROM is loaded. One more signal generators, called nodes, are then created, which can concurrently evaluate the Uxn VM with different starting memory positions. Each node implements a gesture synthesizer, whose state can be controlled via an Uxn virtual output device. For input, a node takes in a "conductor" signal, which is periodic rising ramp signal commonly referred as a phasor.

The synthesized gesture signal produced by nodes can then be used to modulate parameters in other sndkit nodes. A common parameter is the pitch of an oscillator.

#Compilation

To use GestVM, first compile and install sndkit. Sndkit can be found on github or sourcehut.

Running make will build the gestvm binary (the sndkit LIL interpreter with added gestvm words), as well as a modified version of the uxnasm utility used to assemble Uxn ROMs.

#Running Examples

Examples can be found in the "examples" folder. Running the script ./render.sh will compile the Uxn programs and then render sndkit program which loads the ROM and generates the WAV files.

Each example comes with a Uxn program (".tal" extension) and a sndkit patch (".lil" extension). From these a ROM file (".rom") and WAV audio file (".wav") are generated.

sequence is a program which produces a sequence that gets proportionally faster every time it repeats. It starts with eigth notes, then triplets, then sixteenths, etc. Eventually it will hit a limit and start slowing down again.

skew is a program which tests out a concept called temporal skewing, a process which allows tempo to be locally warped without adding or subtracting time overall. This example has a phrase which uses an exponential temporal skewing curve to perform an accelerando over 9 beats.

weight is a program which tests out a concept called temporal weight, a process which gives the notes themselves to warp global tempo. This program produces a lyrical melody that uses weight to programatically shape the phrasing.