https://github.com/movableink/abaculus
https://github.com/movableink/abaculus
Last synced: 3 months ago
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- Host: GitHub
- URL: https://github.com/movableink/abaculus
- Owner: movableink
- Created: 2016-03-27T07:35:35.000Z (about 9 years ago)
- Default Branch: master
- Last Pushed: 2019-05-08T16:30:18.000Z (about 6 years ago)
- Last Synced: 2025-01-31T13:43:41.918Z (4 months ago)
- Language: JavaScript
- Size: 1.07 MB
- Stars: 0
- Watchers: 7
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
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README
## abaculus
a small block of stone, tile, glass, or other material used in the construction of a mosaic
or,
a library for creating static maps from tiles based on center or corner lng,lat coordinates.
Uses node-mapnik to stitch tiles together.
[](https://travis-ci.org/mapbox/abaculus)
[](https://ci.appveyor.com/project/Mapbox/abaculus)
Looking to create high res images of maps? Abaculus was written for use in [Mapbox Studio](http://github.com/mapbox/mapbox-studio) and you can use Mapbox Studio to create and export high resolution images -- see [https://www.mapbox.com/guides/print/](https://www.mapbox.com/guides/print/) for more information. You can even use [that utility from the command line](https://github.com/mapbox/mapbox-studio/issues/1024#issuecomment-63535433).
### usage
Usage and example formatting below, or see the [tests](https://github.com/mapbox/abaculus/blob/master/test/test.js#L158-L204) for a more robust example with a `getTile` function.
#### input:
`scale`: integer between 1-4 and sets resolution (`scale: 1` is 72dpi, `scale: 4`, is 288dpi)
`zoom`: zoom level
`[w, s, e, n]`: the bounding box for the west (lat val), south (lng val), east (lat val), north (lng val) for the desired area
`x`: longitude coordinate
`y`: latitude coordinate
`width` and `height`: desired pixel bounds for a map with a center coordinate. Will be multiplied by scale to maintain resolution.
`format` (optional): `png` or `jpeg`, default is `png`.
`quality` (optional): when used with `jpeg` format, accepts 1-100 and defaults to 80. when used with `png` format, accepts 2-256 (# of colors to reduce the image to) and defaults to none.
`getTile`: a function that returns a tile buffer (png or otherwise) and headers given `z`, `x`, `y`, and a callback, such as from [tilelive-vector](https://github.com/mapbox/tilelive-vector/blob/master/index.js#L119-L218) or this [test function](https://github.com/mapbox/abaculus/blob/master/test/test.js#L184-L204).
`limit` (optional): max width or height of generated image in pixels. Default is `19008`.
```javascript
// Calculate image bounds from W,S,E,N bounding box.
var params = {
zoom: {zoom},
scale: {scale}
bbox: [{w}, {s}, {e}, {n}],
format: {format},
quality: {quality},
getTile: function(z,x,y, callback){
// do something
return callback(null, buffer, headers);
},
limit: {limit}
};
```
or
```javascript
// Calculate image bounds from center lng,lat coordinates and
// pixel dimensions of final image (will be multipled by scale).
var params = {
zoom: {zoom},
scale: {scale}
center: {
x: {x},
y: {y},
w: {width},
h: {height}
},
format: {format},
quality: {quality},
getTile: function(z,x,y, callback){
// do something
return callback(null, buffer, headers);
},
limit: {limit}
};
```
#### usage:
``` javascript
abaculus(params, function(err, image, headers){
if (err) return err;
// do something with image
});
```
#### output:
an image of desired resolution for the selected area.