Pencil Renderer

---
name: pencil-renderer
description: |
  Render DNA codes to Pencil .pen frames. Does ONE thing well.

  Input: DNA code + component type (hero, card, form, etc.)
  Output: .pen frame ID + screenshot

  Use when: design-exploration or other orchestrators need to render
  visual proposals using Pencil MCP backend.
effort: high
---

# Pencil Renderer

Translate aesthetic DNA codes into Pencil .pen frames via MCP.

## Interface

**Input:**
- DNA code: `[layout, color, typography, motion, density, background]`
- Component type: `hero | card | form | nav | footer | section | button | input`
- Optional: Name, dimensions, parent frame ID

**Output:**
- Frame ID in .pen file
- Screenshot of rendered frame

## Workflow

### 1. Ensure Document Ready

```javascript
// Check if editor open
mcp__pencil__get_editor_state({ include_schema: false })

// If no editor, open or create
mcp__pencil__open_document({ filePathOrTemplate: "new" })
```

### 2. Get Style Foundation

```javascript
// Get available style guide tags
mcp__pencil__get_style_guide_tags()

// Get style guide matching DNA mood
// Map DNA to relevant tags:
// - dark color → ["dark-mode", "moody"]
// - light color → ["light", "clean"]
// - spacious density → ["airy", "whitespace"]
// etc.
mcp__pencil__get_style_guide({ tags: [mapped_tags] })
```

### 3. Translate DNA to Pencil Properties

Reference: `references/dna-to-pencil.md`

DNA axis → Pencil property mapping is deterministic.
Example: `centered` layout → `alignItems: "center"`, symmetric padding

### 4. Execute Design Operations

Reference: `references/batch-design-patterns.md`

```javascript
mcp__pencil__batch_design({
  filePath: "<path>.pen",
  operations: `
    frame=I(document, {type: "frame", name: "Hero-Brutalist", ...properties})
    heading=I(frame, {type: "text", content: "Headline", ...typography})
    // ... additional operations
  `
})
```

### 5. Capture Result

```javascript
// Screenshot for visual verification
mcp__pencil__get_screenshot({ nodeId: "frameId" })
```

### 6. Return

```markdown
Frame ID: [id]
DNA: [layout, color, typography, motion, density, background]
```

Plus screenshot image.

## Component Templates

| Type | Structure |
|------|-----------|
| `hero` | Container + headline + subhead + CTA buttons |
| `card` | Container + image area + content + actions |
| `form` | Container + labels + inputs + submit |
| `nav` | Container + logo + links + actions |
| `footer` | Container + columns + links + legal |
| `section` | Container + heading + content grid |
| `button` | Frame + text + icon slot |
| `input` | Frame + label + field + validation |

## DNA Translation Quick Reference

| DNA Axis | Key Pencil Properties |
|----------|----------------------|
| Layout: centered | `alignItems: "center"`, equal padding |
| Layout: asymmetric | Offset positions, varied gaps |
| Layout: bento | Grid with varied spans |
| Color: dark | Dark fill, light foreground |
| Color: gradient | `fill: {type: "linear", stops: [...]}` |
| Typography: display-heavy | Large heading sizes, high contrast |
| Typography: minimal | Restrained scale, single family |
| Density: spacious | gap: 24-48, generous padding |
| Density: compact | gap: 8-16, tight padding |
| Background: solid | Single fill color |
| Background: textured | G() for patterns/images |

## Constraints

- **Single concern**: Render DNA → frame. No interview, no iteration.
- **Pencil MCP required**: Fails fast if unavailable
- **Deterministic mapping**: Same DNA always produces same structure
- **Composable**: Called by orchestrators, not users directly

## References

- `references/dna-to-pencil.md` — Complete axis mapping
- `references/batch-design-patterns.md` — Common operation sequences
- `aesthetic-system/references/dna-codes.md` — DNA axis definitions

## Integration

**Called by:**
- `design-exploration` orchestrator (when Pencil backend available)

**Composes:**
- `aesthetic-system` (for DNA interpretation)