mirror of
https://codeberg.org/uzu/strudel
synced 2026-07-13 14:26:58 -04:00
alex
91 lines
3.7 KiB
JavaScript
91 lines
3.7 KiB
JavaScript
/*
|
|
stateful.mjs - File of shame for stateful, impure and otherwise illegal pattern methods
|
|
Copyright (C) 2025 Strudel contributors - see <https://codeberg.org/uzu/strudel/src/branch/main/packages/core/index.mjs>
|
|
This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more details. You should have received a copy of the GNU Affero General Public License along with this program. If not, see <https://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
import { register, reify, Pattern } from './pattern.mjs';
|
|
|
|
let timelines = {};
|
|
|
|
export const reset_state = function () {
|
|
reset_timelines();
|
|
};
|
|
|
|
export const reset_timelines = function () {
|
|
timelines = {};
|
|
};
|
|
|
|
/***
|
|
* Allows you to switch a pattern between different 'timelines'. This is particularly useful when
|
|
* live coding, for example when you want to cue a pattern up to play from its start.
|
|
*
|
|
* Timelines are specified by number, so that if you had a pattern like
|
|
* `n("<0 1 2 3>").s("num").timeline(1)` playing, then changed the '1'
|
|
* to '2', it would always align '0' to the nearest cycle. You will likely want to trigger
|
|
* an evaluation a little bit before the cycle starts, to avoid missing events.
|
|
*
|
|
* After the first use, a timeline will continue with the same 'offset'. That is, if you change
|
|
* a pattern without changing its timeline number, it will stay on that timeline without resetting.
|
|
*
|
|
* Rather than incrementing a timeline to reset it, it's easier to negate it, e.g. by switching between `-2`
|
|
* and `2`. This is because when you negate a timeline it will always reset.
|
|
*
|
|
* You can also pattern the timeline if you want, to create strange resetting patterns.
|
|
* @param {number | Pattern} timeline The timeline that the pattern should play on.
|
|
* @example
|
|
* n("<0 1 2 3>(3,8)")
|
|
* .sound("num")
|
|
* // resets the timeline every two cycles, by negating the timeline.
|
|
* // in a lot of cases this will be edited by a human live coder
|
|
* // rather than patterned!
|
|
* .timeline("<2 -2>".slow(2))
|
|
*/
|
|
|
|
export const timeline = register(
|
|
'timeline',
|
|
function (tpat, pat) {
|
|
tpat = reify(tpat);
|
|
const f = function (state) {
|
|
// Is this called from the scheduler? (rather than from e.g. the visualiser)
|
|
const scheduler = !!state.controls.cyclist;
|
|
const timehaps = tpat.query(state);
|
|
const result = [];
|
|
for (const timehap of timehaps) {
|
|
const tlid = timehap.value;
|
|
let offset;
|
|
if (tlid === 0) {
|
|
offset = 0;
|
|
} else if (tlid in timelines) {
|
|
offset = timelines[tlid];
|
|
} else {
|
|
const timearc = timehap.wholeOrPart();
|
|
if (!scheduler || state.span.begin.lt(timearc.midpoint())) {
|
|
offset = timearc.begin;
|
|
} else {
|
|
// Sync to end of timearc if we first see it over halfway into its
|
|
// timespan. Allows 'cuing up' next timeline when live coding.
|
|
offset = timearc.end;
|
|
}
|
|
}
|
|
if (scheduler) {
|
|
// update state
|
|
timelines[tlid] = offset;
|
|
if (tlid !== 0) {
|
|
delete timelines[-tlid];
|
|
}
|
|
}
|
|
|
|
const pathaps = pat
|
|
.late(offset)
|
|
.query(state.setSpan(timehap.part))
|
|
.map((h) => h.setContext(h.combineContext(timehap)));
|
|
result.push(...pathaps);
|
|
}
|
|
return result;
|
|
};
|
|
return new Pattern(f, pat._steps);
|
|
},
|
|
false,
|
|
);
|