strudel-docker/packages/tone/pianoroll.mjs
2022-06-05 23:37:24 +02:00

91 lines
3.5 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 ({
from = -2,
to = 2,
overscan = 1,
inactive = '#C9E597',
active = '#FFCA28',
// background = '#2A3236',
background = 'transparent',
maxMidi,
minMidi,
timeframe: timeFrameProp,
} = {}) {
if (timeFrameProp) {
console.warn('timeframe is deprecated! use from/to instead');
from = 0;
to = timeFrameProp;
}
const ctx = getDrawContext();
const w = ctx.canvas.width;
const h = ctx.canvas.height;
let midiRange, height;
const autorange = minMidi === undefined || maxMidi === undefined;
if (autorange && (minMidi !== undefined || maxMidi !== undefined)) {
console.warn('pianoroll: minMidi and maxMidi must both be set to have an effect!');
}
if (!autorange) {
midiRange = maxMidi - minMidi + 1;
height = h / midiRange;
}
const timeframe = to - from;
const t2x = (t) => Math.round(((t - from) / timeframe) * w);
const playheadX = t2x(0);
this.draw(
(ctx, events, t) => {
ctx.fillStyle = background;
ctx.clearRect(0, 0, w, h);
ctx.fillRect(0, 0, w, h);
const inFrame = (event) => event.whole.begin >= 0 && event.whole.begin <= t + to && event.whole.end >= t + from;
events.filter(inFrame).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;
ctx.beginPath();
ctx.moveTo(playheadX, 0);
ctx.lineTo(playheadX, h);
ctx.stroke();
const x = t2x(event.whole.begin);
const width = Math.round(((event.whole.end - event.whole.begin) / timeframe) * w);
const y = Math.round(h - ((Number(event.value) - minMidi + 1) / 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);
});
},
{
from: from - overscan,
to: to + overscan,
onQuery: (events) => {
if (autorange) {
const getValue = (e) => Number(e.value);
const { min, max } = events.reduce(
({ min, max }, e) => {
const v = getValue(e);
return {
min: v < min ? v : min,
max: v > max ? v : max,
};
},
{ min: Infinity, max: -Infinity },
);
minMidi = min;
maxMidi = max;
midiRange = maxMidi - minMidi + 1;
height = h / midiRange;
}
},
},
);
return this;
};