Darcyegb Diagram Pipeline Diagram Illustrator Render

Skill 4: diagram-illustrator-render

Pipeline Position: Skill 4 of 4 Upstream Dependencies: diagram-visual-encoding (Skill 2), diagram-graphic-design (Skill 3) Output: Adobe Illustrator file (.ai), rendered PNG (200% scale), optionally PDF for print Execution Context: AppleScript + ExtendScript via osascript on macOS

Input

This skill consumes two structured specifications:

From diagram-graphic-design (Skill 3)

A YAML design specification defining the visual system:

grid:
  artboard_width: 800
  artboard_height: 600
  base_unit: 8
  margins: {top: 24, right: 24, bottom: 24, left: 24}
  gutter: 16

type:
  primary_font: "Helvetica Neue"
  secondary_font: "Menlo"
  scale:
    display: {size: 48, weight: 700, tracking: -1, leading: 56}
    headline: {size: 28, weight: 600, tracking: 0, leading: 36}
    body: {size: 14, weight: 400, tracking: 0, leading: 22}
    caption: {size: 11, weight: 400, tracking: 0.5, leading: 16}

color:
  primary: [66, 133, 244]      # RGB
  surface: [248, 249, 250]
  text_primary: [32, 33, 36]
  text_secondary: [95, 99, 104]
  divider: [218, 220, 224]

elements:
  stroke:
    heavy: 3
    medium: 2
    light: 1
  corners: 4
  spacing:
    xs: 8
    sm: 12
    md: 16
    lg: 24
    xl: 32

composition: "two_column" | "single_flow" | "radial" | "matrix"

From diagram-visual-encoding (Skill 2)

A visual encoding plan defining what goes where:

composition_type: "two_column"
channels:
  position: "x_y_grid"
  size: "element_hierarchy"
  color: "category_mapped"

layout:
  left_column: {width_units: 4, contains: ["labels", "legend"]}
  right_column: {width_units: 4, contains: ["diagram", "data_viz"]}

spatial_plan:
  - id: "title"
    position: [0, 0]
    size: {units_w: 8, units_h: 2}
  - id: "content_area"
    position: [0, 2]
    size: {units_w: 8, units_h: 4}

The skill reads only what's needed: grid dimensions, type definitions, color values, element stroke/corner specs, composition type. It ignores design rationale and selection criteria.

Architecture

The skill executes in a precise AppleScript ↔ ExtendScript cycle. This sequence prevents stalls and ensures reliable file I/O.

Execution Loop

Write JSX to /sessions/vibrant-peaceful-allen/my_diagram.jsx
           ↓
cp JSX to /mnt/<user>/Desktop/my_diagram.jsx (sync to Mac)
           ↓
osascript: activate Illustrator + delay 1 + do javascript file
           ↓
Read exported PNG with Read tool
           ↓
Evaluate against spec (grid alignment, type hierarchy, color, composition)
           ↓
Fix issues in JSX (if needed)
           ↓
Re-execute (repeat until specification met)
           ↓
Final PNG + optional .ai file saved

JSX File Execution Pattern (Critical)

The correct pattern prevents -1700 "event not handled" errors and AppleScript stalls:

CORRECT:

set jsxPath to POSIX file "/mnt/<user>/Desktop/my_diagram.jsx"
do javascript file (jsxPath as text)

INCORRECT (causes -1700 error):

do javascript file "/mnt/<user>/Desktop/my_diagram.jsx"  -- ✗ Doesn't work

Why: POSIX file is required to create an AppleScript file object. The as text coercion converts that to the string path Illustrator's JavaScript handler expects. Other patterns skip the object step and fail.

Full AppleScript template:

tell application "Adobe Illustrator"
    activate
    delay 1
    set jsxPath to POSIX file "/mnt/<user>/Desktop/my_diagram.jsx"
    do javascript file (jsxPath as text)
end tell

Document Cleanup (Before Every Run)

Execute this in AppleScript before each JSX run to prevent MRAP errors from stale documents:

tell application "Adobe Illustrator"
    do javascript "while(app.documents.length>0){app.documents[0].close(SaveOptions.DONOTSAVECHANGES);}"
end tell

delay 2  -- Wait for cleanup to finish

Then proceed with the JSX execution pattern above. This closes all unsaved documents and prevents "Application is busy" errors.

File Paths and Sync

All work paths on the Linux session:

• JSX written to: /sessions/vibrant-peaceful-allen/my_diagram.jsx
• Synced to Mac: /mnt/<username>/Desktop/my_diagram.jsx
• PNG exported by Illustrator to: /mnt/<username>/Desktop/diagram_preview.png
• Read back via tool: /mnt/<username>/Desktop/diagram_preview.png

The /mnt mount point is the user's local Mac filesystem. This allows Illustrator (running on Mac) to access and export files visible to the Linux session.

Core Workflow

Phase 1: Translate Specification to Script Structure

Map the design spec YAML to JSX source code structure:

Grid → Artboard + Position Math

artboard_width: 800, artboard_height: 600, base_unit: 8
→ JSX artboard dimensions (800 × 600 pt)
→ all element positions = (grid_col × base_unit, grid_row × base_unit)
→ margins, gutters calculated as unit multiples (24pt = 3 units, etc.)

Type → Font Constants

headline: {size: 28, weight: 600}
→ JSX: var headline = {font: "Helvetica Neue", size: 28, weight: 600};
→ ApplyFont("Helvetica Neue", 28, 600) helper function

Color → RGB Helper

primary: [66, 133, 244]
→ JSX: var colors = {primary: [66, 133, 244], surface: [248, 249, 250]};
→ rgb(66, 133, 244) → return new RGBColor() with R:66, G:133, B:244

Elements → Stroke/Corner Specs

stroke.medium: 2, corners: 4
→ JSX: const strokeWeight = 2;
→ var cornerRadius = 4;
→ Use in rect().strokeWeight = strokeWeight

Composition Type → Drawing Function Order

composition: "two_column"
→ JSX: use two_column_layout() function from references/composition-implementations.md
→ executes left column shapes, then right column shapes (front-to-back)

Coordinate System Translation (Critical)

Illustrator Origin: Bottom-left corner of artboard. Y-axis increases upward. Grid Specification Origin: Top-left corner (conventional web/print origin). Y increases downward.

Conversion:

Design spec (top-left origin):
  "place title 24pt from top" = y: 24

Illustrator (bottom-left origin):
  artboard_height = 600
  illustrator_y = 600 - 24 = 576

rectangle(top, left, width, height) in JSX:
  - top param = Y coordinate of top edge (in Illustrator coords)
  - For design spec y=24 from top: top = 600 - 24 = 576
  - left param = X coordinate of left edge
  - width, height = dimensions

rectangle(576, 24, 400, 60) creates a rect with:
  - Top edge at Y=576 (24pt from top of 600pt artboard)
  - Left edge at X=24 (24pt from left)
  - 400pt wide, 60pt tall

Apply this conversion consistently to all y coordinates from the design spec.

Phase 2: Build the JSX Script

Structure the JSX in this order. This ensures correct z-order (back-to-front rendering):

1. Close Existing Documents & Create New

while(app.documents.length > 0) {
    app.documents[0].close(SaveOptions.DONOTSAVECHANGES);
}

var doc = app.documents.add(DocumentColorSpace.RGB, 800, 600);
doc.rulerUnits = Units.POINTS;

2. Define Helper Functions

function rgb(r, g, b) {
    var color = new RGBColor();
    color.red = r;
    color.green = g;
    color.blue = b;
    return color;
}

function rectangle(top, left, width, height, fillColor, strokeColor, strokeWeight) {
    var rect = doc.pathItems.rectangle(top, left, width, height);
    if (fillColor) {
        rect.filled = true;
        rect.fillColor = fillColor;
    }
    if (strokeColor) {
        rect.stroked = true;
        rect.strokeColor = strokeColor;
        rect.strokeWidth = strokeWeight || 1;
    }
    return rect;
}

function textFrame(text, x, y, width, height, fontSize, fontName, fontColor) {
    var txt = doc.textFrames.add();
    txt.contents = text;
    txt.left = x;
    txt.top = y;
    txt.width = width;
    txt.height = height;
    txt.textRange.characterAttributes.size = fontSize;
    txt.textRange.characterAttributes.textFont = app.fonts.getByName(fontName);
    txt.textRange.characterAttributes.fillColor = fontColor;
    return txt;
}

3. Define All Constants from Design Spec

var colors = {
    primary: rgb(66, 133, 244),
    surface: rgb(248, 249, 250),
    text_primary: rgb(32, 33, 36),
    divider: rgb(218, 220, 224)
};

var spacing = {xs: 8, sm: 12, md: 16, lg: 24, xl: 32};
var strokeWeights = {heavy: 3, medium: 2, light: 1};
var cornerRadius = 4;

var fonts = {
    primary: "Helvetica Neue",
    mono: "Menlo"
};

var typescale = {
    headline: {size: 28, weight: 600},
    body: {size: 14, weight: 400},
    caption: {size: 11, weight: 400}
};

4. Create Elements in Visual Layer Order (Back to Front)

// Layer 1: Page background (if needed)
rectangle(600, 0, 800, 600, colors.surface, null, 0);

// Layer 2: Structural elements (cards, regions, dividers)
rectangle(500, 24, 352, 400, rgb(255, 255, 255), colors.divider, 1);
// ... more cards, borders, grid lines

// Layer 3: Connectors and arrows (if needed)
// ... draw lines, curves, arrows

// Layer 4: Text frames LAST (renders on top)
textFrame("Title", 24, 76, 352, 56, 28, fonts.primary, colors.text_primary);
textFrame("Body text", 24, 100, 352, 200, 14, fonts.primary, colors.text_secondary);
// ... more text

Why back-to-front? Illustrator renders elements in the order they're added to the document. Text added last renders on top of shapes. Previous approaches (adding text first) caused text to render behind card backgrounds, making it invisible.

5. Auto-Size Artboard to Content (Optional)

doc.artboards[0].artboardRect = [0, doc.height - 600, 800, 0];

6. Export PNG at 200% Scale

var exportOptions = new ExportOptionsPNG24();
exportOptions.antiAliasing = true;
exportOptions.transparency = true;
exportOptions.horizontalScale = 200;
exportOptions.verticalScale = 200;

var exportFile = new File("/mnt/<username>/Desktop/diagram_preview.png");
doc.exportFile(exportFile, ExportType.PNG24, exportOptions);

alert("Exported: " + exportFile.fsName);

Phase 3: Execute and Evaluate

After running the JSX and reading the exported PNG:

Grid Alignment Checklist:

• Margins correct? (spec: 24pt on all sides)
• Gutters visible and correctly sized? (spec: 16pt)
• Elements align to base_unit grid (8pt)?
• Content contained within artboard bounds?

Type Hierarchy Checklist:

• Title/display larger and bolder than body? (visual contrast)
• Body text readable at preview size?
• Captions distinct from body (size, weight, or color)?
• Font family and weight match spec (e.g., "Helvetica Neue Bold" vs. "Menlo Regular")?

Color Checklist:

• Colors match spec RGB values (not off by ~5 points)?
• Contrast sufficient? (text on background passes WCAG AA: 4.5:1 for normal text)?
• Divider lines visible but subtle? (expected: light gray)

Composition Checklist:

• Layout matches visual encoding plan (two-column, grid, etc.)?
• Visual hierarchy (size, color, position) guides eye correctly?
• No overlapping elements?
• Spacing between elements consistent with spec?

Bounding Box Containment Checklist: Every element must fit inside its parent container. Check each container (column background, card, group rect) and verify every child stays within bounds:

• Text labels beside shapes: shape width + gap + label width ≤ container width. Estimate text width as charCount × fontSize × 0.55 for Helvetica.
• Child shapes inside cards: shape bottom edge (y + height for rects, cy + radius for circles) ≤ card bottom edge. Scale or reposition if not.
• Text overlapping adjacent shapes: ensure the text bounding box and shape bounding box don't intersect. Add a gap or shift one element.
• Arrow/arrowhead overshoot: arrowheads extend past the line end. Keep arrows clear of container edges by the arrowhead length.

This is the most common class of rendering bug. Run this check explicitly on every container before moving to the next evaluation step.

24-Rule Audit from Skill 3 (Sample) If applicable:

• Rule: "All headline text is bold" → Is all headline text visibly bold?
• Rule: "Background panels have 4pt corners" → Do corners appear rounded?
• Rule: "Dividers are 1pt stroke in color.divider" → Are they the right color and weight?

Common Evaluation Failures and Fixes

Phase 4: Iterate

The render-evaluate-fix loop typically takes 2–4 iterations to reach specification.

Per iteration: Fix 2–3 issues maximum to avoid cascading problems:

1. Iteration 1: Evaluate grid alignment + type readability. Fix position math and font sizes.
2. Iteration 2: Evaluate colors + composition. Adjust stroke weights and color assignments.
3. Iteration 3: Fine-tune spacing and text frame dimensions. Re-export.
4. Iteration 4 (if needed): Verify 24-rule audit. Final polish.

Each fix should change one or two values (e.g., font size and text frame height). Then re-run, re-evaluate. This prevents introducing new bugs.

Example iteration:

Iteration 1: "Body text too small"
Fix: Change typescale.body.size from 12 to 14
Re-run JSX, re-export PNG, check readability ✓

Iteration 2: "Title color doesn't match spec (too blue)"
Fix: Change colors.primary from rgb(66, 133, 244) to rgb(60, 130, 240)
Re-run, compare to spec... still not exact. Adjust to rgb(66, 133, 244) per YAML.
✓

Iteration 3: "Margins look too wide on left"
Fix: Check grid math. margins.left = 24, but text starting at x=40.
Change to x=24. Re-run. ✓

Specification now met.

Phase 5: Final Export

Once the diagram passes evaluation:

1. PNG for Digital Review

// Already exported at 200% during iteration.
// Copy to workspace folder:
cp /mnt/<username>/Desktop/diagram_preview.png /sessions/vibrant-peaceful-allen/diagram_final.png

2. Optional: Save .ai File

doc.save(new File("/mnt/<username>/Desktop/diagram.ai"));

3. Optional: Export PDF for Print

var pdfOptions = new PDFSaveOptions();
doc.saveAs(new File("/mnt/<username>/Desktop/diagram.pdf"), pdfOptions);

4. Clean Up and Copy to User

# Copy final files to session workspace
cp /mnt/<username>/Desktop/diagram.ai /sessions/vibrant-peaceful-allen/
cp /mnt/<username>/Desktop/diagram.pdf /sessions/vibrant-peaceful-allen/

Provide the user with the final PNG and link to the .ai file for future editing.

Working with Existing AI Files

If iterating on an existing diagram:

1. Open Existing File

var doc = app.open(new File("/path/to/existing.ai"));

2. Read Structure (Optional) Document structure is visible in the Illustrator UI. Script can query:

for (var i = 0; i < doc.pathItems.length; i++) {
    var item = doc.pathItems[i];
    // item.left, item.top, item.width, item.height, item.fillColor, etc.
}

3. Modify Elements Update existing elements without recreating the entire diagram:

doc.pathItems[0].left = 50;  // Move first shape
doc.textFrames[0].contents = "New text";  // Update text

4. Re-export After modifications, export PNG and evaluate as usual.

Refer to references/extendscript-api.md Section 4 for full details on document structure, querying elements, and batch operations.

References

API & Patterns:

• references/extendscript-api.md — Complete ExtendScript API for Illustrator. Sections 1-7 cover core objects, properties, methods. Section 8: coordinate system. Section 10: text formatting. Section 13: MRAP error handling and recovery.

Composition Implementations:

• references/composition-implementations.md — JSX code patterns for each composition type (two-column, single-flow, radial, matrix, network). Copy patterns directly into Phase 2 script build.

Design System Reference:

• Skill 3 output (diagram-graphic-design) — The YAML spec. Always available in context as the immediate upstream input.

Tone and Scope

This skill is implementation-focused, not creative:

• It executes design decisions made in Skills 2 and 3 faithfully.
• It does not question the composition, color palette, or type hierarchy. Those are upstream.
• It does translate specifications into JSX precisely, handle platform quirks (AppleScript, coordinate systems, MRAP errors), and verify output against spec.
• Its success metric: the exported PNG visually matches the design specification within acceptable tolerance.

Use this skill when you have a complete design specification and need the actual Illustrator file. Use Skill 3 (diagram-graphic-design) if you still need to decide colors, type scale, or layout. Use Skill 2 (diagram-visual-encoding) if you're unsure how to visually represent your data.

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