lila-gif
Webservice to render Gifs of chess positions and games, and stream them frame by frame.
| size | render time | frames | colors | width | height |
|---|---|---|---|---|---|
| 336 KiB | ~60 ms | 93 | 63 | 720 px | 840 px |
Usage
lila-gif
USAGE:
lila-gif [OPTIONS]
OPTIONS:
--bind <BIND> Listen on this address [default: 127.0.0.1:6175]
-h, --help Print help information
HTTP API
GET /image.gif
curl http://localhost:6175/image.gif?fen=4k3/6KP/8/8/8/8/7p/8 --output image.gif
| name | type | default | description |
|---|---|---|---|
| fen | ascii | starting position | FEN of the position. Board part is sufficient. |
| white | utf-8 | none | Name of the white player. Known chess titles are highlighted. Limited to 100 bytes. |
| black | utf-8 | none | Name of the black player. Known chess titles are highlighted. Limited to 100 bytes. |
| comment | utf-8 | https://github.com/lichess-org/lila-gif |
Comment to be added to GIF meta data. Limited to 255 bytes. |
| lastMove | ascii | none | Last move in UCI notation (like e2e4). |
| check | ascii | none | Square of king in check (like e1). |
| orientation | white |
Pass black to flip the board. |
POST /game.gif
{
"white": "Molinari", // optional
"black": "Bordais", // optional
"comment": "https://www.chessgames.com/perl/chessgame?gid=1251038", // optional
"orientation": "white", // default
"delay": 50, // default frame delay in centiseconds
"frames": [
// [...]
{
"fen": "r1bqkb1r/pp1ppppp/5n2/2p5/2P1P3/2Nn2P1/PP1PNP1P/R1BQKB1R w KQkq - 1 6",
"delay": 500, // optionally overwrite default delay
"lastMove": "b4d3", // optionally highlight last move
"check": "e1" // optionally highlight king
}
]
}GET /example.gif
curl http://localhost:6175/example.gif --output example.gif
Render an example game.
Technique
Instead of rendering vector graphics at runtime, all pieces are prerendered on every possible background. This allows preparing a minimal color palette ahead of time. (Pieces are not just black and white, but need other colors for anti-aliasing on the different background colors).
All thats left to do at runtime, is copying sprites and Gif encoding. More than 95% of the rendering time is spent in LZW compression.
For animated games, frames only contain the changed squares on transparent background. The example below is the last frame of the animation.
License
lila-gif is licensed under the GNU Affero General Public License, version 3 or any later version, at your option.
The generated images include text in Noto Sans (Apache License 2.0) and a piece set by Colin M.L. Burnett (GFDL or BSD or GPL).