Visual Programming | Computer-Assisted Composition

Reactive visual programs in OM

The reactive mode in OM is an intermediate model for visual programming inheriting both from the off-line, demand-driven, computation paradigm of OpenMusic, and the reactive features of interactive/real-time systems. The objective is to integrate and control the interactions between CAC programs and their external context. In this model, visual programming components are capable of “listening” to the environment, or to other components of the programs, updating contents or triggering calculations accordingly, and propagating changes. This “dataflow-oriented” approach implies new semantic definitions, implementation and corresponding user interactions. It is based on the existing OM semantics and conservative with regard to this semantics, so that existing programs created in the environment remain valid in the reactive framework.

The OM reactive mode is available in OM >= 6.9.

How to Use It:


Receiving from external applications:

Reactivity can make particular sense for receiving data from external applications and updating/computing OM visual programs accordingly.

Note: if an error occurs in the the processing of an incoming event, the MIDI or OSC receive loop might stay stuck in a disabled state. In this case, you might need to turn off and on (R+R) the receive process.

Example: Collecting/processing incoming MIDI using MIDI-IN