| 1 | # node-fontnik
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| 2 |
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| 3 | [](https://nodei.co/npm/fontnik/)
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| 4 | [](https://travis-ci.org/mapbox/node-fontnik)
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| 5 | [](https://codecov.io/gh/mapbox/node-fontnik)
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| 6 |
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| 7 | A library that delivers a range of glyphs rendered as SDFs (signed distance fields) in a protocol buffer. We use these encoded glyphs as the basic blocks of font rendering in [Mapbox GL](https://github.com/mapbox/mapbox-gl-js). SDF encoding is superior to traditional fonts for our usecase in terms of scaling, rotation, and quickly deriving halos - WebGL doesn't have built-in font rendering, so the decision is between vectorization, which tends to be slow, and SDF generation.
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| 8 |
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| 9 | The approach this library takes is to parse and rasterize the font with Freetype (hence the C++ requirement), and then generate a distance field from that rasterized image.
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| 10 |
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| 11 | See also [TinySDF](https://github.com/mapbox/tiny-sdf), which is a faster but less precise approach to generating SDFs for fonts.
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| 12 |
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| 13 | ## [API](API.md)
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| 14 |
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| 15 | ## Installing
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| 16 |
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| 17 | By default, installs binaries. On these platforms no external dependencies are needed.
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| 18 |
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| 19 | - 64 bit OS X or 64 bit Linux
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| 20 | - Node.js v8-v14
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| 21 |
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| 22 | Just run:
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| 23 |
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| 24 | ```
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| 25 | npm install
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| 26 | ```
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| 27 |
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| 28 | However, other platforms will fall back to a source compile: see [building from source](#building-from-source) for details.
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| 29 |
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| 30 | ## Building from source
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| 31 |
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| 32 | ```
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| 33 | npm install --build-from-source
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| 34 | ```
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| 35 | Building from source should automatically install `boost`, `freetype` and `protozero` locally using [mason](https://github.com/mapbox/mason). These dependencies can be installed manually by running `./scripts/install_deps.sh`.
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| 36 |
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| 37 | ## Local testing
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| 38 |
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| 39 | Run tests with
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| 40 |
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| 41 | ```
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| 42 | npm test
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| 43 | ```
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| 44 |
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| 45 | If you make any changes to the C++ files in the `src/` directory, you'll need to recompile the node bindings (`fontnik.node`) before testing locally:
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| 46 |
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| 47 | ```
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| 48 | make
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| 49 | ```
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| 50 |
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| 51 | See the `Makefile` for additional tasks you can run, such as `make coverage`.
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| 52 |
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| 53 | ## Background reading
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| 54 | - [Drawing Text with Signed Distance Fields in Mapbox GL](https://www.mapbox.com/blog/text-signed-distance-fields/)
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| 55 | - [State of Text Rendering](http://behdad.org/text/)
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| 56 | - [Pango vs HarfBuzz](http://mces.blogspot.com/2009/11/pango-vs-harfbuzz.html)
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| 57 | - [An Introduction to Writing Systems & Unicode](http://rishida.net/docs/unicode-tutorial/)
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