Vexylicon Development

Expert guidance for developing Vexylicon, a Python package that transforms SVG icons with dual contours into glass-morphism designs with beveled edges and theme support.

What This Skill Does

Provides comprehensive development guidelines for the Vexylicon project, including:

Instructions

1. Understand Project Architecture

Before making any changes:

```

vexylicon/

├── core.py # VexyliconGenerator - main glass effect engine

├── cli.py # Fire-based CLI interface

├── utils/

│ ├── svg_processor.py # lxml-based SVG DOM manipulation (NO string operations)

│ ├── path_tools.py # Path interpolation algorithms

│ └── theme_loader.py # Pydantic-based theme validation

└── assets/

├── best_base.svg # Canonical base template with dual contours

└── themes/

└── default.json # Theme definitions

```

**Core Workflow:**

1. Input: `best_base.svg` (1200x1200 with dual contours) + optional payload SVG

2. Parse dual contours (outer and inner paths)

3. Generate N interpolated rings (default 24)

4. Apply opacity progression (quartic by default)

5. Add `mix-blend-mode: screen` for glass effect

6. Inject payload with clipPath masking

7. Output: Glass effect SVG with optional theme variants

2. Follow Development Principles

**Code Quality Requirements:**

**SVG Processing Rules (CRITICAL):**

3. Implement Key Algorithms Correctly

**Path Interpolation:**

**Opacity Progression Modes:**

**Theme System (needs completion):**

4. Address Current Issues

**Priority Tasks:**

1. Fix Theme System:

- Implement `_duplicate_gradients_for_themes()`

- Add proper CSS with media queries

- Test light/dark switching

2. Complete Gradio-lite Interface:

- Minimal dependencies (may need to vendor svgpathtools)

- Handle Pyodide limitations

- Focus on core features only

3. Improve Testing:

- Unit tests for all path_tools functions

- Integration tests for full pipeline

- Snapshot tests for SVG output

**Known Issues:**

5. Development Workflow

**Before Changes:**

1. Read existing code thoroughly

2. Check PLAN.md and TODO.md

3. Understand the dual-contour SVG format

**Making Changes:**

1. Work in small, testable increments

2. Update CHANGELOG.md after each feature

3. Keep TODO.md current

**After Changes:**

```bash

Format and lint

black src tests

ruff check --fix src tests

Run tests

pytest

Type check

mypy src

```

6. Technical Constraints

7. Error Handling

Examples

**Reading the codebase:**

```

User: "How does path interpolation work?"

Assistant: [Reads path_tools.py, explains the algorithm for interpolating between dual contours]

```

**Implementing a feature:**

```

User: "Fix the theme system to support light/dark modes"

Assistant: [Reads theme_loader.py and svg_processor.py, implements _duplicate_gradients_for_themes(), adds CSS media queries, updates tests]

```

**Code review:**

```

User: "Review this SVG processing code"

Assistant: [Checks for string manipulation instead of lxml, verifies namespace preservation, validates coordinate rounding]

```

Important Notes