feat(d3): implement waveform-audio

[github-actions]

Implementation: waveform-audio - javascript/d3

Implements the javascript/d3 version of waveform-audio.

File: plots/waveform-audio/implementations/javascript/d3.js

Parent Issue: #4563

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🤖 impl-generate workflow

[claude]

AI Review - Attempt 1/3

Image Description

Light render (plot-light.png): Warm off-white background (#FAF8F1). Three distinct syllable sections rendered as a filled waveform area using the Imprint brand green (#009E73) at 0.72 opacity. The min/max envelope technique creates dense vertical oscillation bands that clearly show the harmonic structure and amplitude envelope (attack → sustain → release) of each syllable. A thin horizontal zero reference line divides the positive and negative halves. Y-axis gridlines appear at −1, −0.5, 0, 0.5, 1 in subtle grey. Title "waveform-audio · javascript · d3 · anyplot.ai" in dark ink at the top; "Time (s)" label at the bottom; "Amplitude" rotated on the left. All text is dark on the warm-cream background and clearly readable.

Dark render (plot-dark.png): Warm near-black background (#1A1A17). The data fill color is identical to the light render — the same Imprint brand green (#009E73) waveform. Only chrome flips: title, axis labels, and tick labels render in light near-white ink. The waveform pops visually against the dark surface. Zero reference line and gridlines remain subtle. All text reads clearly as light-on-dark with no dark-on-dark failures observed. The brand green (#009E73) is fully visible against the near-black background.

Both paragraphs are required. A review that only describes one render is invalid.

Score: 88/100

Category	Score	Max
Visual Quality	29	30
Design Excellence	11	20
Spec Compliance	15	15
Data Quality	15	15
Code Quality	9	10
Library Mastery	9	10
Total	88	100

Visual Quality (29/30)

• VQ-01: Text Legibility (7/8) — Title 28px, axis labels 20px, tick labels 16px — all clearly readable in both themes. Minor deduction: axis labels ("Time (s)", "Amplitude") are slightly large relative to the tick labels, but within proportional bounds.
• VQ-02: No Overlap (6/6) — No text overlaps with data, axes, or other labels.
• VQ-03: Element Visibility (6/6) — Min/max envelope rendering handles the 13,600-sample density correctly; semi-transparent fill at 0.72 opacity reveals waveform structure without visual noise.
• VQ-04: Color Accessibility (2/2) — Single series in Imprint brand green; adequate contrast on both surfaces; CVD-safe.
• VQ-05: Layout & Canvas (4/4) — Canvas gate passed; good margins (top 80, right 50, bottom 90, left 100); no overflow; title spans ~70% of width.
• VQ-06: Axis Labels & Title (2/2) — "Time (s)" and "Amplitude" are descriptive with correct units; title follows the mandated {spec-id} · {language} · {library} · anyplot.ai format.
• VQ-07: Palette Compliance (2/2) — First (and only) series uses t.palette[0] (#009E73); light background is #FAF8F1; dark background is #1A1A17; all chrome tokens (ink, inkSoft, grid) flip correctly between themes.

Design Excellence (11/20)

• DE-01: Aesthetic Sophistication (5/8) — Above default: harmonic synthesis (fundamental + 3 harmonics) produces a realistic speech-like waveform; min/max envelope rendering is an intentional DSP-informed design choice; the semi-transparent fill with matching thin stroke adds visual depth. Does not reach maximum because only one visual layer is used and there are no annotations or callouts.
• DE-02: Visual Refinement (3/6) — Above default: only left and bottom domain lines drawn (no top/right spines); y-axis-only gridlines at stroke-width 0.5; generous whitespace; zero reference line uses inkSoft at stroke-width 1 for correct visual hierarchy.
• DE-03: Data Storytelling (3/6) — Above default: the three-syllable structure with trapezoidal amplitude envelopes creates a clear visual narrative of a voiced speech phrase. Gaps between syllables function as natural visual pauses. Focal point is clear. Could be strengthened with optional syllable annotations, but spec does not require them.

Spec Compliance (15/15)

• SC-01: Plot Type (5/5) — Correct: filled area waveform rendered via d3.area(), symmetric around zero.
• SC-02: Required Features (4/4) — Semi-transparent fill ✓; horizontal zero reference line ✓; min/max envelope rendering for dense data ✓; x-axis time in seconds ✓; y-axis normalized amplitude −1 to +1 ✓.
• SC-03: Data Mapping (3/3) — X: time in seconds (0–1.7 s); Y: amplitude domain [−1.05, 1.05] covering the full ±1 range; all data visible.
• SC-04: Title & Legend (3/3) — Title is "waveform-audio · javascript · d3 · anyplot.ai" exactly; no legend (single series, correct omission).

Data Quality (15/15)

• DQ-01: Feature Coverage (6/6) — Demonstrates all key aspects: voiced syllable envelope (attack/sustain/release), harmonic richness (4 partials per syllable), inter-syllable silence gaps, min/max envelope rendering for the dense waveform.
• DQ-02: Realistic Context (5/5) — Synthetic vocal phrase with 3 syllables at F0 130–155 Hz is a realistic and entirely neutral domain example; plausible sample rate (8 kHz), duration (1.7 s), and sample count (13,600).
• DQ-03: Appropriate Scale (4/4) — Amplitude normalized to ±1 per spec; 1.7 s at 8 kHz = 13,600 samples (within spec's 5,000–50,000 range); syllable timing and F0 values are phonetically plausible.

Code Quality (9/10)

• CQ-01: KISS Structure (2/3) — Mild deduction: two helper functions (envAt, signalAt) are defined. They are justified by the per-sample harmonic synthesis complexity, but they exceed the flat-code ideal.
• CQ-02: Reproducibility (2/2) — Fully deterministic: uses only Math.sin/Math.PI with fixed parameters; no RNG.
• CQ-03: Clean Imports (2/2) — No imports; correctly uses window.d3, window.ANYPLOT_TOKENS, window.ANYPLOT_SIZE globals.
• CQ-04: Code Elegance (2/2) — No fake interactivity; Float32Array for raw samples is idiomatic DSP practice; d3.area() used correctly; .datum() vs .data() used correctly for single-path rendering.
• CQ-05: Output & API (1/1) — D3 harness emits both plot-{theme}.png and plot-{theme}.html; no bare plot.png.

Library Mastery (9/10)

• LM-01: Idiomatic Usage (5/5) — Correct use of: d3.area() with .x(), .y0(), .y1(); .datum() for single-path binding; .selectAll().data().join() for gridlines; d3.axisBottom() / d3.axisLeft() with .tickValues() and .tickFormat(); D3 linear scales; unified axis styling loop.
• LM-02: Distinctive Features (4/5) — d3.area() generator with min/max envelope is quintessentially D3; .datum() for single-path data binding is a D3-specific idiom; selection-based axis styling via .selectAll("text") and .select(".domain"). Not a full 5 because no more advanced D3 capabilities are leveraged (e.g. d3.line() with custom curves, D3 zoom, or D3 brush).

Score Caps Applied

• None

Strengths

• Perfect spec compliance: all required waveform features implemented (filled area, semi-transparent fill, zero reference line, min/max envelope rendering, normalized y-axis, time x-axis)
• Sophisticated signal synthesis: 4-harmonic vocal synthesis with per-syllable attack/sustain/release envelopes produces a genuinely realistic-looking audio waveform
• Correct D3 idioms throughout: d3.area() with datum binding, selection-based axis styling, explicit tick values
• Both themes adapt correctly — Imprint palette data color is identical between renders; only chrome tokens flip

Weaknesses

• Helper functions (envAt, signalAt) add mild structural complexity beyond flat code; the signal computation could be inlined at the cost of readability
• Design excellence ceiling limited by single-color, single-layer approach — no annotations marking syllable boundaries or labeling the attack/sustain/release phases (spec does not require these, but they would elevate storytelling)

Issues Found

1. CQ-01 MINOR: Two named helper functions (envAt, signalAt) defined — justified by signal complexity but technically exceeds the flat-code preference.
   • Fix (optional): inline the envelope calculation into the Float32Array loop to eliminate function overhead.
2. DE-01/DE-03 ROOM: No syllable annotations or visual callouts; the three-section structure is visible but unlabeled.
   • Fix (optional): add small text labels above each syllable envelope peak to guide the reader — would raise DE-01 and DE-03 meaningfully.

AI Feedback for Next Attempt

Implementation is strong and spec-complete. To raise the score: (1) optionally add lightweight syllable boundary labels or peak markers to improve data storytelling (DE-03); (2) consider inlining the helper functions into the main data-generation loop for a flatter code structure (CQ-01). Current implementation is clean, idiomatic, and visually correct in both themes.

Verdict: APPROVED

[github-actions]

🔧 Repair Attempt 1/4

Applied fixes based on AI review feedback.

Status: Repair completed, re-triggering review...

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🤖 impl-repair

[claude]

AI Review - Attempt 2/3

Image Description

Light render (plot-light.png): Warm off-white background (#FAF8F1) correctly set via the harness pageBg token. Title "waveform-audio · javascript · d3 · anyplot.ai" renders in dark ink at the top, clearly visible. Three waveform segments are displayed in brand green (#009E73) as a filled min/max envelope area (fill-opacity 0.72), with smooth CatmullRom envelope outline curves overlaid in the same green at full opacity. Syllable annotations "Syl. 1 · 130 Hz", "Syl. 2 · 155 Hz", "Syl. 3 · 145 Hz" appear above the chart area; dashed vertical markers separate the syllables. X-axis label "Time (s)", Y-axis label "Amplitude", and tick labels are all clearly readable. Horizontal gridlines at -1, -0.5, 0, 0.5, 1 are subtle. Zero reference line is a thin inkSoft horizontal rule. All text is readable against the light background — PASS.

Dark render (plot-dark.png): Warm near-black background (#1A1A17) is correct. Title, axis labels, tick labels, and syllable annotations all render in light-colored text (inkSoft token), clearly readable against the dark surface. No dark-on-dark failures observed anywhere. Data colors — brand green filled waveform and envelope curves — are identical to the light render as required. The green reads well on the dark surface. All text is readable against the dark background — PASS.

Both paragraphs are required. A review that only describes one render is invalid.

Score: 88/100

Category	Score	Max
Visual Quality	29	30
Design Excellence	12	20
Spec Compliance	15	15
Data Quality	15	15
Code Quality	10	10
Library Mastery	7	10
Total	88	100

Visual Quality (29/30)

• VQ-01: Text Legibility (7/8) — All font sizes explicitly set. Title 28px, axis labels 20px, tick labels 16px. Readable in both themes. Slight deduction: syllable annotations at 14px CSS (28 source px) are slightly below style-guide target for this canvas size.
• VQ-02: No Overlap (6/6) — No overlapping text or data elements in either render.
• VQ-03: Element Visibility (6/6) — Waveform fill, envelope curves, zero reference line, and gridlines all clearly visible. Alpha-blending (0.72) is appropriate for dense waveform data.
• VQ-04: Color Accessibility (2/2) — Single series, no CVD risk. Brand green provides adequate contrast on both surfaces.
• VQ-05: Layout & Canvas (4/4) — Canvas gate passed. Generous margins. Nothing cut off. Good canvas utilization.
• VQ-06: Axis Labels & Title (2/2) — "Time (s)" with unit, "Amplitude" descriptive. Title format correct.
• VQ-07: Palette Compliance (2/2) — t.palette[0] (#009E73) for data; t.ink, t.inkSoft, t.grid for chrome. Both backgrounds correct.

Design Excellence (12/20)

• DE-01: Aesthetic Sophistication (5/8) — Clearly above defaults: 4-harmonic vocal synthesis, envelope overlay curves, syllable segmentation with frequency labels, semi-transparent fill. However, single color throughout with no secondary visual layer or multi-dimensional design differentiation.
• DE-02: Visual Refinement (3/6) — Only bottom and left axes created (no top/right spines). Subtle gridlines at stroke-width 0.5. Clean axis color via tokens. Above default but not exceptional — axis domain lines still present.
• DE-03: Data Storytelling (4/6) — Three-syllable speech structure with frequency labels creates a clear scientific narrative. Envelope curves guide the eye through amplitude modulation. Viewer immediately understands this is a 3-syllable utterance.

Spec Compliance (15/15)

• SC-01: Plot Type (5/5) — Correct waveform visualization with min/max envelope rendering.
• SC-02: Required Features (4/4) — Filled area, semi-transparent fill, zero reference line, time X-axis, amplitude Y-axis (−1 to +1), min/max envelope, synthetic audio data — all present.
• SC-03: Data Mapping (3/3) — Time on X, normalized amplitude on Y. All data visible.
• SC-04: Title & Legend (3/3) — "waveform-audio · javascript · d3 · anyplot.ai" correct. Single series, no legend required.

Data Quality (15/15)

• DQ-01: Feature Coverage (6/6) — Shows all waveform aspects: filled area, positive/negative amplitude, envelope modulation, silence gaps, syllable dynamics.
• DQ-02: Realistic Context (5/5) — 3-syllable speech signal is a real, neutral scientific scenario. Fundamental frequencies 130–155 Hz are within the human speech range.
• DQ-03: Appropriate Scale (4/4) — Amplitude normalized to ±1, timing realistic (1.7 s), frequencies scientifically plausible.

Code Quality (10/10)

• CQ-01: KISS Structure (3/3) — Linear procedural code: data → SVG mount → scales → gridlines → waveform → envelope → axes → labels → title.
• CQ-02: Reproducibility (2/2) — Fully deterministic — fixed SYLS parameters, no RNG.
• CQ-03: Clean Imports (2/2) — No explicit imports; d3 is a global as required.
• CQ-04: Code Elegance (2/2) — Clean, appropriate complexity. No over-engineering or fake UI.
• CQ-05: Output & API (1/1) — Harness handles plot-{theme}.png + plot-{theme}.html. Current D3 v7 API throughout.

Library Mastery (7/10)

• LM-01: Idiomatic Usage (4/5) — d3.area() with y0/y1 for waveform fill, d3.line() with CatmullRom curve, .datum() binding for paths, d3.axisBottom/Left, .join() — all idiomatic D3 patterns.
• LM-02: Distinctive Features (3/5) — d3.area() y0/y1 for filled waveform is distinctively D3. d3.curveCatmullRom.alpha(0.5) is a D3-specific curve interpolation. Min/max envelope feeding into area() is a D3-idiomatic pattern for dense signal visualization.

Score Caps Applied

• None

Strengths

• Sophisticated 4-harmonic vocal synthesis produces a scientifically realistic speech signal with three syllables at distinct frequencies (130/155/145 Hz) and trapezoidal amplitude envelopes
• Min/max envelope downsampling per pixel column correctly avoids waveform aliasing on dense data, exactly as specified
• Envelope overlay curves (d3.curveCatmullRom.alpha(0.5)) add a visually informative layer showing amplitude modulation — a creative addition beyond the baseline spec
• Syllable onset dashed vertical markers and mid-label annotations with frequency values make the chart self-documenting for a speech-analysis audience
• Full palette and theme compliance: t.palette[0] (#009E73) for data, t.ink/t.inkSoft/t.grid for chrome, warm backgrounds correct in both renders
• Fully deterministic code — no RNG, fixed SYLS parameters — guarantees reproducible output across runs

Weaknesses

• Syllable annotation labels at 14px CSS (28 source px after 2× Playwright scale) are noticeably smaller than tick labels (16px) — increase to at least 16px for better mobile readability
• Single brand-green throughout with no secondary visual layer — envelope curves could use slightly different stroke styling (dashed or different opacity) to create hierarchy between waveform fill and envelope outline
• Axis domain lines still present; suppressing .domain paths on both axes would yield a cleaner floating-axis look consistent with the style guide's spine-removal recommendation

Issues Found

1. VQ-01 MINOR: Syllable annotations at 14px CSS are slightly small for the canvas resolution — increase to 16px to match tick-label sizing.
   • Fix: Change .style("font-size", "14px") on syllable labels to "16px"
2. DE-02 MINOR: Axis domain lines give a slight box-frame feel — suppressing them would add visual refinement.
   • Fix: After axis creation, add xAxis.select(".domain").remove(); yAxis.select(".domain").remove() (or set attr("stroke", "none"))

AI Feedback for Next Attempt

Implementation is high quality and spec-complete. To push above 90: (1) increase syllable annotation font-size from 14px to 16px for proportional balance; (2) suppress axis .domain paths to achieve a clean floating-axis look; (3) consider differentiating the envelope overlay curve from the fill using a dashed stroke or slightly lighter opacity to create visual hierarchy between the two layers. The data generation is excellent — no changes needed there.

Verdict: APPROVED