Delta Skin to RetroArch Overlay Converter

Convert Delta emulator touch controller skins (.deltaskin files) to RetroArch overlay .cfg files with PNG assets.

Web Version (Recommended)

Use the web converter directly in your browser - no installation required:

Open Web Converter (update URL after deploying)

Or run locally:

# Open index.html in your browser
open index.html

The web version runs entirely in your browser - your files never leave your device.

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Command Line Version

Requirements

• Python 3.8+
• Poppler (for PDF to PNG conversion)

macOS

brew install poppler

Linux

sudo apt install poppler-utils  # Debian/Ubuntu

Installation

git clone https://github.com/warmenhoven/skin2overlay.git
cd skin2overlay
python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt

Usage

# Activate virtual environment
source venv/bin/activate

# Convert a single skin
python convert.py /path/to/Standard.deltaskin -o output/

# Convert specific devices only
python convert.py skin.deltaskin -o output/ --devices iphone ipad

# Convert all skins in a directory
python convert.py ~/skins/*.deltaskin -o output/

# Adjust image scale (default: 3x for retina)
python convert.py skin.deltaskin -o output/ --scale 2

Output Structure

The converter generates one overlay per device, with portrait and landscape orientations in the same config file:

output/
├── SkinName_GameType_iphone/
│   ├── SkinName_GameType_iphone.cfg   # RetroArch overlay config
│   ├── portrait.png                    # Portrait orientation image
│   └── landscape.png                   # Landscape orientation image
├── SkinName_GameType_ipad/
│   └── ...
└── SkinName_GameType_tv/
    └── ...

Features

• Input Mapping: Converts Delta button inputs to RetroArch equivalents

  • Standard buttons (A, B, X, Y, L, R, Start, Select)
  • D-pad → dpad_area
  • Analog stick → analog_left
  • N64 C-buttons → right analog (r_x_minus, r_x_plus, r_y_minus, r_y_plus)
  • N64 Z button → L2

• Viewport Positioning: Converts gameScreenFrame to overlay_viewport

  • DS dual screens: Computes bounding box of both screens

• Extended Touch Edges: Converts to RetroArch reach_* parameters

• Rotation Support: Portrait/landscape as separate overlay indices with invisible rotation buttons

• PDF to PNG: Renders vector PDFs at 3x mappingSize (retina quality)

Supported Platforms

• NES
• SNES
• N64
• Game Boy / Game Boy Color
• Game Boy Advance
• Nintendo DS
• Sega Genesis

Limitations

• Screen filters (CIFilter) - No RetroArch equivalent
• DS touch input - Not directly convertible
• TV auto-detection - TV overlays are generated but must be manually selected

Input Format

The converter accepts:

• .deltaskin ZIP archives (standard distribution format)
• Expanded deltaskin directories (as found in Delta source code)

License

MIT