https://github.com/Cerwym/keeperfx-devtools

NOTE : This extension is also published to marketplace (https://marketplace.visualstudio.com/items?itemName=PeterLockett.keeperfx-devtools)

Started out as a way to view the RAW file data so I could see what I was doing when adding overlay support to lenses.

Features🔗

DAT Sprite Viewer🔗

• View .dat files: Opens .dat files that have sprite data inside them and attempts to redner the display
• Game palette: Automatically loads the game pallete, but you can select another to see how a different palette affects the content

Raw Image Viewer🔗

• View .raw files: Opens 256×256 8-bit indexed .raw image files used by KeeperFX
• Game palette: Automatically loads data/palette.dat from your workspace to display images with correct colors
• Transparency support: Shows color index 0 as transparent with a checkerboard background
• Zoom controls: Fit, 100%, 200%, 400%, and 800% zoom levels
• Pixel-perfect rendering: Uses nearest-neighbor scaling to preserve sharp pixels

Requirements🔗

• A KeeperFX workspace containing data/palette.dat (768 bytes: 256 colors × RGB with 6-bit values)
• .raw files must be exactly 65536 bytes (256×256 pixels)

Usage🔗

1. Open a KeeperFX workspace in VS Code
2. Open any .raw file (e.g., config/mods/your-mod/data/overlay_test.raw)
3. The custom viewer will automatically open showing the image with the correct palette
4. Use the toolbar buttons to zoom in/out

How It Works🔗

1. Reads the 256×256 indexed pixel data from the .raw file
2. Loads the palette from data/palette.dat in your workspace
3. Converts 6-bit RGB palette values (0-63) to 8-bit (0-255) by multiplying by 4
4. Maps each pixel's color index to RGB using the palette
5. Renders transparency (color 0) with checkerboard background
6. Displays the result in a webview canvas with zoom controls

Known Limitations🔗

• Only supports 256×256 .raw files (the standard size for KeeperFX lens overlays and mists)
• Requires data/palette.dat in the workspace (falls back to grayscale if not found)
• Read-only viewer (no editing capabilities)

Double click VSIX