feuerwerk/tests/editor/piano-roll.test.ts

import { describe, expect, it } from 'vitest';
import type { PatternNote } from '../../src/core/music/pattern';
import {
  barLabelStep,
  clampTimePan,
  fitTime,
  timeLines,
  xToTick,
  zoomTime,
} from '../../src/editor/music/timeView';
import {
  clampShift,
  draggedLength,
  drawnNote,
  duplicateOffset,
  moveDelta,
  placedCopies,
  resized,
  shifted,
  withVelocity,
} from '../../src/editor/pattern/rollEdit';
import {
  centreRows,
  clampRows,
  noteAt,
  noteAtY,
  noteTop,
  notesWithin,
  type RollView,
  ROWS,
  velocityAtY,
  velocityBarAt,
  zoomRows,
} from '../../src/editor/pattern/rollView';

const note = (id: string, tick: number, length: number, n = 60, velocity = 0.8): PatternNote => ({
  id,
  tick,
  length,
  note: n,
  velocity,
});
/** 0.1 px per tick: a 1/16 is 12 px, a bar of 4/4 192. Rows of 10 px, C4 (60) at the top. */
const VIEW: RollView = { panX: 0, pxPerTick: 0.1, panY: -(127 - 60) * 10, rowHeight: 10 };
const COMMON = { beats: 4, unit: 4 };

describe('time view of the piano roll (#333)', () => {
  it('zooms about the pointer and never shows time before 0', () => {
    const zoomed = zoomTime({ panX: -100, pxPerTick: 0.1 }, 2, 300);
    expect(xToTick(zoomed, 300)).toBeCloseTo(4000);
    expect(clampTimePan({ panX: 40, pxPerTick: 0.1 }).panX).toBe(0);
    expect(fitTime(7680, 768)).toEqual({ panX: 0, pxPerTick: 0.1 });
  });

  it('draws bars, beats and the grid, each tick at its strongest, the grid only with room', () => {
    const lines = timeLines(VIEW, COMMON, 120, 200);
    expect(lines.filter((l) => l.level === 0).map((l) => l.tick)).toEqual([0, 1920]);
    expect(lines.filter((l) => l.level === 1).map((l) => l.tick)).toEqual([480, 960, 1440]);
    expect(lines.filter((l) => l.level === 2)).toHaveLength(12);
    // At a twentieth of that a 1/16 is 0.6 px: bars only.
    expect(timeLines({ panX: 0, pxPerTick: 0.005 }, COMMON, 120, 200).every((l) => l.level === 0)).toBe(true);
  });

  it('keeps the beats of 6/8 between the lines of a triplet grid', () => {
    const lines = timeLines({ panX: 0, pxPerTick: 0.1 }, { beats: 6, unit: 8 }, 160, 150);
    expect(lines.filter((l) => l.level === 1).map((l) => l.tick)).toEqual([240, 480, 720, 960, 1200]);
    expect(lines.filter((l) => l.level === 2).map((l) => l.tick)).toEqual([160, 320, 640, 800, 1120, 1280]);
  });

  it('numbers every bar while there is room, else every second, fourth …', () => {
    expect(barLabelStep({ panX: 0, pxPerTick: 0.1 }, COMMON)).toBe(1);
    expect(barLabelStep({ panX: 0, pxPerTick: 0.01 }, COMMON)).toBe(2);
    expect(barLabelStep({ panX: 0, pxPerTick: 0.004 }, COMMON)).toBe(8);
  });
});

describe('rows of the piano roll (#333)', () => {
  it('puts the highest note on top and finds the note under a point', () => {
    expect(noteTop(VIEW, 60)).toBe(0);
    expect(noteTop(VIEW, 59)).toBe(10);
    expect(noteAtY(VIEW, 5)).toBe(60);
    expect(noteAtY(VIEW, 15)).toBe(59);
    expect(noteAtY({ ...VIEW, panY: 0 }, -1)).toBeNull();
    expect(noteAtY({ ...VIEW, panY: 0 }, ROWS * 10)).toBeNull();
  });

  it('keeps the rows on screen and zooms them about the pointer', () => {
    expect(clampRows({ ...VIEW, panY: 50 }, 300).panY).toBe(0);
    expect(clampRows({ ...VIEW, panY: -5000 }, 300).panY).toBe(300 - ROWS * 10);
    const zoomed = zoomRows(VIEW, 2, 25);
    expect(zoomed.rowHeight).toBe(20);
    expect(noteAtY(zoomed, 25)).toBe(58);
    expect(zoomRows(VIEW, 100, 0).rowHeight).toBe(28);
  });

  it('centres the notes it is fitted to, lower rows where they do not fit', () => {
    const fitted = centreRows(60, 64, 200);
    expect(fitted.rowHeight).toBe(14);
    const view = { ...VIEW, ...fitted };
    expect(noteAtY(view, 100)).toBe(62);
    expect(centreRows(24, 48, 200).rowHeight).toBeCloseTo(200 / 27);
    expect(centreRows(0, 127, 200).rowHeight).toBe(6);
  });

  it('tells a note body from its right end, and takes the one drawn last', () => {
    const notes = [note('a', 0, 480), note('b', 240, 480)];
    expect(noteAt(VIEW, notes, { x: 10, y: 5 })).toEqual({ id: 'a', part: 'body' });
    expect(noteAt(VIEW, notes, { x: 30, y: 5 })).toEqual({ id: 'b', part: 'body' });
    expect(noteAt(VIEW, notes, { x: 70, y: 5 })).toEqual({ id: 'b', part: 'end' });
    expect(noteAt(VIEW, notes, { x: 10, y: 15 })).toBeNull();
    // A note of a tick is still 4 px to the pointer.
    expect(noteAt(VIEW, [note('c', 1000, 1)], { x: 102, y: 5 })?.id).toBe('c');
  });

  it('picks the notes a band touches', () => {
    const notes = [note('a', 0, 120, 60), note('b', 480, 120, 59), note('c', 960, 120, 55)];
    expect(notesWithin(VIEW, notes, { x: 5, y: 2 }, { x: 50, y: 18 })).toEqual(['a', 'b']);
    expect(notesWithin(VIEW, notes, { x: 50, y: 60 }, { x: 0, y: 0 })).toEqual(['a', 'b']);
  });

  it('finds the velocity bar under the pointer, a picked one first', () => {
    const notes = [note('a', 0, 120), note('b', 0, 120, 64), note('c', 480, 120)];
    expect(velocityBarAt(VIEW, notes, new Set(), 2)).toBe('b');
    expect(velocityBarAt(VIEW, notes, new Set(['a']), 2)).toBe('a');
    expect(velocityBarAt(VIEW, notes, new Set(), 30)).toBeNull();
    expect(velocityAtY(10, 10, 64)).toBe(1);
    expect(velocityAtY(42, 10, 64)).toBe(0.5);
    expect(velocityAtY(100, 10, 64)).toBe(0);
  });
});

describe('editing in the piano roll (#333)', () => {
  it('draws on the grid line before the pointer, or on the tick with Alt', () => {
    expect(drawnNote(250, 62, 120, false, 120, 0.8)).toMatchObject({
      tick: 240,
      length: 120,
      note: 62,
      velocity: 0.8,
    });
    expect(drawnNote(250.4, 62, 120, true, 960, 0.5)).toMatchObject({
      tick: 250,
      length: 960,
      velocity: 0.5,
    });
    expect(drawnNote(250, 62, 120, false, 120, 1).id).not.toBe(drawnNote(250, 62, 120, false, 120, 1).id);
  });

  it('moves the grabbed note onto the grid, the others along, never before 0 or off the keys', () => {
    const notes = [note('a', 240, 120, 60), note('b', 480, 120, 120), note('c', 0, 120, 30)];
    const picked = new Set(['a', 'b']);
    expect(moveDelta(notes, picked, notes[0]!, 370, 62, 120, false)).toEqual({ ticks: 120, notes: 2 });
    expect(moveDelta(notes, picked, notes[0]!, 370, 62, 120, true)).toEqual({ ticks: 130, notes: 2 });
    expect(moveDelta(notes, picked, notes[0]!, -500, 80, 120, false)).toEqual({ ticks: -240, notes: 7 });
    expect(clampShift(notes, new Set(['c']), -10, -40)).toEqual({ ticks: 0, notes: -30 });
    expect(shifted(notes, picked, 120, 2).map((n) => [n.tick, n.note])).toEqual([
      [360, 62],
      [600, 122],
      [0, 30],
    ]);
  });

  it('drags a length to the nearest grid line, never back to its own start', () => {
    const anchor = note('a', 240, 120);
    expect(draggedLength(anchor, 470, 120, false)).toBe(240);
    expect(draggedLength(anchor, 250, 120, false)).toBe(120);
    expect(draggedLength(note('o', 250, 60), 255, 120, false)).toBe(110);
    expect(draggedLength(anchor, 241.2, 120, true)).toBe(1);
    expect(resized([anchor, note('b', 0, 60)], new Set(['a', 'b']), -100).map((n) => n.length)).toEqual([
      20, 1,
    ]);
  });

  it('puts a duplicate right behind the picked notes, in whole grid steps', () => {
    const notes = [note('a', 0, 120), note('b', 240, 60), note('c', 960, 120)];
    expect(duplicateOffset(notes, new Set(['a', 'b']), 120)).toBe(360);
    expect(duplicateOffset(notes, new Set(['b']), 120)).toBe(120);
    expect(duplicateOffset(notes, new Set(), 120)).toBe(0);
  });

  it('pastes copies with ids of their own, the earliest at the start', () => {
    const copies = placedCopies([note('a', 480, 120, 60), note('b', 720, 60, 64)], 1920);
    expect(copies.map((n) => [n.tick, n.note])).toEqual([
      [1920, 60],
      [2160, 64],
    ]);
    expect(copies.map((n) => n.id)).not.toContain('a');
  });

  it('sets the grabbed velocity and moves the other picked ones by as much', () => {
    const notes = [note('a', 0, 120, 60, 0.5), note('b', 0, 120, 62, 0.9), note('c', 0, 120, 64, 0.2)];
    expect(withVelocity(notes, new Set(['a', 'b']), notes[0]!, 0.7).map((n) => n.velocity)).toEqual([
      0.7, 1, 0.2,
    ]);
    // Unpicked, the grabbed note goes alone.
    expect(withVelocity(notes, new Set(['b']), notes[0]!, 0.1).map((n) => n.velocity)).toEqual([
      0.1, 0.9, 0.2,
    ]);
  });
});