publiclab/mapknitter-exporter

The GDAL/ImageMagick-based exporter system from MapKnitter

MapKnitterExporter

Add this gem with gem install mapknitter_exporter

Then, use it with:

require 'mapknitter_exporter'

# this should work:

MapKnitterExporter.generate_perspectival_distort(
  scale,
  1, # a unique id
  [
    { lat: 41.8403113680142, lon: -71.3983854668186 },
    { lat: 41.8397358653566, lon: -71.3916477577732 },
    { lat: 41.8351476451765, lon: -71.392699183707  },
    { lat: 41.8377535388085, lon: -71.3981708900974 }
  ],
  'test/fixtures/demo.png',
  image,
  height,
  width
)

Tests

To run tests, use ruby test/exporter_test.rb.

Tests require minitest which you can install with bundle install.