feuerwerk/tests/editor/wave-view.test.ts

/**
 * The Sound tab's view (#343): seconds across, zoomed about the pointer, and the stretch of the
 * file between two handles – how a drag moves it and what the asset then stores.
 */
import { describe, expect, it } from 'vitest';
import {
  clampWave,
  draggedSpan,
  edgeAt,
  fitWave,
  levelMarks,
  MAX_LEVEL,
  MIN_LEVEL,
  rulerLabel,
  rulerStep,
  secondsToX,
  spanOf,
  spanPeak,
  storedCut,
  wavePeaks,
  xToSeconds,
  zoomLevel,
  zoomWave,
} from '../../src/editor/sound/waveView';

describe('the height of the wave (#357)', () => {
  it('zooms between a quarter and sixteen times full scale', () => {
    expect(zoomLevel(1, 2)).toBe(2);
    expect(zoomLevel(1, 0.5)).toBe(0.5);
    expect(zoomLevel(0.3, 0.5)).toBe(MIN_LEVEL);
    expect(zoomLevel(12, 2)).toBe(MAX_LEVEL);
  });

  it('marks every 6 dB that lies inside the area and not too close to the middle', () => {
    // Level 1, full scale 100 px from the middle: 0 dB at 100, -6 at 50, -12 at 25, -18 at 12.6.
    const marks = levelMarks(1, 100, 110, 14);
    expect(marks.map((m) => m.db)).toEqual([0, -6, -12]);
    expect(marks[1]!.offset).toBeCloseTo(50.1, 1);
    // Zoomed out, -6 dB lies 12.5 px from the middle and is left out.
    expect(levelMarks(0.25, 100, 110, 14).map((m) => m.db)).toEqual([0]);
    // Zoomed in, 0 dB lies past the edge and the quiet ones show.
    const loud = levelMarks(16, 100, 110, 14).map((m) => m.db);
    expect(loud[0]).toBe(-24);
    expect(loud).not.toContain(0);
  });
});

describe('the wave view', () => {
  it('zooms about the pointer and fits the file with a margin either side', () => {
    const view = { panX: 10, pxPerSecond: 100 };
    const zoomed = zoomWave(view, 2, 210);
    expect(xToSeconds(zoomed, 210)).toBeCloseTo(xToSeconds(view, 210));
    expect(zoomed.pxPerSecond).toBe(200);
    const fitted = fitWave(4, 832, 16);
    expect(secondsToX(fitted, 0)).toBe(16);
    expect(secondsToX(fitted, 4)).toBe(816);
  });

  it('keeps either end of the file from going further in than half the width', () => {
    expect(clampWave({ panX: 900, pxPerSecond: 100 }, 20, 1000).panX).toBe(500);
    expect(clampWave({ panX: -1600, pxPerSecond: 100 }, 20, 1000).panX).toBe(-1500);
    expect(clampWave({ panX: -900, pxPerSecond: 100 }, 20, 1000).panX).toBe(-900);
    // Two seconds fit: they stay on screen.
    expect(clampWave({ panX: 20, pxPerSecond: 100 }, 2, 1000).panX).toBe(20);
    expect(clampWave({ panX: -50, pxPerSecond: 100 }, 2, 1000).panX).toBe(0);
  });

  it('labels the ruler in steps of 1, 2 or 5, with the decimals the step needs', () => {
    expect(rulerStep(100, 70)).toBe(1);
    expect(rulerStep(40, 70)).toBe(2);
    expect(rulerStep(1000, 70)).toBeCloseTo(0.1);
    expect(rulerStep(10, 70)).toBe(10);
    expect(rulerLabel(1.5, 0.5)).toBe('1.5s');
    expect(rulerLabel(2, 1)).toBe('2s');
    expect(rulerLabel(0.25, 0.05)).toBe('0.25s');
    expect(rulerLabel(75, 5)).toBe('1:15');
  });
});

describe('the cut span', () => {
  const view = { panX: 0, pxPerSecond: 100 };

  it('reads an end of 0 or past the file as its end', () => {
    expect(spanOf(0, 0, 3)).toEqual({ start: 0, end: 3 });
    expect(spanOf(1, 9, 3)).toEqual({ start: 1, end: 3 });
    expect(spanOf(2.5, 1, 3)).toEqual({ start: 1, end: 1 });
  });

  it('finds the handle in reach, the nearer one where both are', () => {
    const span = { start: 1, end: 2 };
    expect(edgeAt(view, span, 103)).toBe('start');
    expect(edgeAt(view, span, 197)).toBe('end');
    expect(edgeAt(view, span, 150)).toBeNull();
    expect(edgeAt(view, { start: 1, end: 1.04 }, 103)).toBe('end');
  });

  it('moves one edge, never past the other, or spans a new stretch inside the file', () => {
    const span = { start: 1, end: 2 };
    expect(draggedSpan(span, 'start', 1, 0.5, 3, 0.001)).toEqual({ start: 0.5, end: 2 });
    expect(draggedSpan(span, 'start', 1, 2.5, 3, 0.001)).toEqual({ start: 1.999, end: 2 });
    expect(draggedSpan(span, 'end', 2, 9, 3, 0.001)).toEqual({ start: 1, end: 3 });
    expect(draggedSpan(span, null, 2.5, 0.5, 3, 0.001)).toEqual({ start: 0.5, end: 2.5 });
    expect(draggedSpan(span, null, -1, 1, 3, 0.001)).toEqual({ start: 0, end: 1 });
  });

  it('stores the ends of the file as 0, everything else to the sample', () => {
    expect(storedCut({ start: 0, end: 3 }, 3, 48000)).toEqual({ start: 0, end: 0 });
    expect(storedCut({ start: 0.000001, end: 2.999999 }, 3, 48000)).toEqual({ start: 0, end: 0 });
    expect(storedCut({ start: 1.2345678, end: 2 }, 3, 48000)).toEqual({ start: 1.234563, end: 2 });
  });
});

describe('the wave peaks', () => {
  it('reads the lowest and highest sample of any stretch, over the blocks and the samples at its ends', () => {
    const left = new Float32Array(1000);
    const right = new Float32Array(1000);
    left[10] = 0.5;
    right[600] = -0.75;
    left[999] = 0.9;
    const peaks = wavePeaks([left, right]);
    expect(peaks.max).toHaveLength(4);
    expect(spanPeak([left, right], peaks, 0, 1000)).toEqual({ min: -0.75, max: Math.fround(0.9) });
    expect(spanPeak([left, right], peaks, 5, 20)).toEqual({ min: 0, max: 0.5 });
    expect(spanPeak([left, right], peaks, 11, 599)).toEqual({ min: 0, max: 0 });
    expect(spanPeak([left, right], peaks, 300.2, 300.4)).toEqual({ min: 0, max: 0 });
  });
});