image-sdf

Command-line tool which takes a 4-channel RGBA image and generates a signed distance field. The bitmask is determined by pixels with alpha over 128 and any RGB channel over 128.

# install the tool
npm install image-sdf -g

# apply the effect on an image
# and pipe it to a new file
image-sdf atlas.png --spread 32 --downscale 2 > atlas-sdf.png

The code has been adpated from libgdx.

PRs welcome. This could be split into more modules (generating a bit mask, computing SDF, better image support, etc).

Usage

image-sdf input.png [opt]

Options:
  -o, --output     output file                                    
  -s, --spread     distance spread amount, default 1              
  -d, --downscale  amount to downscale the output, default 1      
  -c, --color      output color, accepts css strings, default #fff
  -h               Show help                                      

Examples:

image-sdf input.png -c "rgb(128,255,20)" -s 10 -o output.png
image-sdf input.png --spread 2 --downscale 2 > output.png
image-sdf input.png --color black -o build/output.png

The programmatic API may evolve into their own modules, i.e. for custom bitmasks.

License

MIT, see LICENSE.md for details.