Euclidean trigs

Euclidean trigs are an overlay on top of normal TRIG rows.

• Normal trig values still work as before.
• Euclidean only fires on steps where the base trig is OFF.
• If a step already has another trig status (mute/prob/mod/sus/etc), that status wins: Euclidean is the lowest-priority trig source.

How to add a Euclidean trig pattern

1. Select the sequencer you want (it must be in TRIG view).
2. Hold LC_8B, the lower-right modifier button on the LaunchControl XL (see LaunchControl modifier buttons), and press a step on the Launchpad grid.
3. The pressed step becomes the rotation start point: the first pulse of the Euclidean pattern lands on that step.
4. On first enable, density is auto-bumped from 0 to 1, so you immediately hear a single hit at the pressed step.

Repeated presses on the same row

• Same step pressed again (LC_8B + same step): Euclidean pattern for that row toggles off and the pattern is cleared.
• Different step pressed (LC_8B + different step): Euclidean stays enabled and the pattern re-rotates to start at the new step. Density and length are unchanged.

Row selection

The last row you press with LC_8B becomes the selected row for that sequencer. The fader controls (below) target whichever row is currently selected. Selected row is remembered per sequencer and per player, so the two of you can have different rows selected on the same sequencer. That same selection is what the LC arrow-key trig rotation acts on (see Reset and randomise).

Algorithm

The pattern is computed using the Bjorklund algorithm (Toussaint, 2005), which spreads the pulses across the pattern length as evenly as possible. The result is a maximally even rhythm: gaps between consecutive pulses differ by at most 1 step.

Examples at rotation 0:

Rotation shifts the pattern so the first pulse lands at the pressed step. For example, E(3,8) with rotation=2 gives 10100100: the base tresillo pattern shifted right by 2.

Fader controls (while player is in trig view)

The LC faders control Euclidean parameters for the currently selected row on the viewed sequencer. Faders only respond when the player is in trig view.

These are the last three of the eight faders, on whichever LaunchControl you are playing. Which of the two players’ selected row a move lands on is decided by the template the unit is on rather than by the unit itself, so if a fader appears to be editing the other player’s row, the template is the thing to check.

Notes:

• Length changes automatically clamp density and rotation into valid range.
• Every fader move recomputes the pattern, and the engine picks it up on the next clock tick.
• The rotation fader and the LC_8B step press are two ways at the same setting, so they always agree: press a new step and the fader position follows, move the fader and the highlighted step follows.

Display

When a Euclidean row is enabled, OFF steps where the Euclidean pattern fires are shown in magenta on the Launchpad:

The overlay only appears on unmuted rows where the base trig is OFF. Steps with any other status (ON, mute, mod chance, sustain, etc.) show their normal colour and are not affected by the Euclidean overlay.

Clear behaviour

SHIFT + MUTE row reset in trig view clears both:

• The base trig row (all steps set to OFF)
• The Euclidean overlay for that row (disabled + pattern zeroed)

Density, rotation, and length parameters are not cleared. They are preserved so re-enabling the row with LC_8B restores the same pattern shape.

Priority

Euclidean trigs have the lowest priority of all trig types. The full priority order (highest to lowest):

1. Manual trig statuses (ON, TRIGMUTE, MOD, INVMOD, SUS_START, SUS_HOLD, PERCENTAGE_CHANCE)
2. Euclidean overlay (fires only when the base trig is OFF)

This means you can place manual trigs on top of a Euclidean row and they take precedence: the Euclidean pattern fills in the gaps.