@perry-rylance/midi-macros

A TypeScript library of macros designed to work with midi.

This library provides a set of convenience functions for generating arrays of MIDI events.

Macros

channel

Takes an array of events or a callback that generates events, everything wrapped within the call will be forced onto the specified channel.

repeat

Takes a count and an array of events or callback that generates events, returns the events repeated.

The count is interpreted in musical terms. Zero will return no events, one will return the same input, two will return the input twice.

parallel

Takes a two dimensional array of events, merges them together respecting the event deltas.

Useful for merging lines of music for example to make a counterpoint or clave into one track.

partition

Takes a duration in MIDI ticks, a number of parts and a generator function. The generator function receives the delta, and index.

Useful for making repeating sequences of messages.

interpolate

Takes a duration in MIDI ticks, a number of parts and a generator function. The generator function receives the delta, the normalized interpolant, and index.

The generator is called the same as partition but also receives the interpolant, which goes from zero to one over the macros duration.

ramp

The same as interpolate, but allows you to specify the from and to values, as opposed to the normalized interpolant.

Optionally takes an ease function, which defaults to linear interpolation.

cycle

The same as interpolate, but takes a wave period. The generator receives a delta, and a value. Optionally, a wave function can be passed in. This defaults to Math.sin.

This macro cycles over the duration with the specified period, the wave function receives a radian angle which completes one revolution every period ticks.

Examples

See the examples/generate.ts for usage examples.

If you want to hear them, you can run npm run examples,