strudel-docker/packages/tone/pianoroll.mjs
2022-04-28 14:38:41 +01:00

45 lines
2.1 KiB
JavaScript

/*
pianoroll.mjs - <short description TODO>
Copyright (C) 2022 Strudel contributors - see <https://github.com/tidalcycles/strudel/blob/main/packages/tone/pianoroll.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 { Pattern } from '@strudel.cycles/core';
Pattern.prototype.pianoroll = function ({
timeframe = 10,
inactive = '#C9E597',
active = '#FFCA28',
background = '#2A3236',
maxMidi = 90,
minMidi = 0,
} = {}) {
const w = window.innerWidth;
const h = window.innerHeight;
const midiRange = maxMidi - minMidi + 1;
const height = h / midiRange;
this.draw(
(ctx, events, t) => {
ctx.fillStyle = background;
ctx.clearRect(0, 0, w, h);
ctx.fillRect(0, 0, w, h);
events.forEach((event) => {
const isActive = event.whole.begin <= t && event.whole.end >= t;
ctx.fillStyle = event.context?.color || inactive;
ctx.strokeStyle = event.context?.color || active;
ctx.globalAlpha = event.context.velocity ?? 1;
const x = Math.round((event.whole.begin / timeframe) * w);
const width = Math.round(((event.whole.end - event.whole.begin) / timeframe) * w);
const y = Math.round(h - ((Number(event.value) - minMidi) / midiRange) * h);
const offset = (t / timeframe) * w;
const margin = 0;
const coords = [x - offset + margin + 1, y + 1, width - 2, height - 2];
isActive ? ctx.strokeRect(...coords) : ctx.fillRect(...coords);
});
},
timeframe,
2, // lookaheadCycles
);
return this;
};